TWI657550B - Extensible sheet and method for manufacturing laminated wafer - Google Patents

Abstract

The present invention provides an extendable sheet capable of appropriately producing a laminated wafer including a most distal convex portion in a multi-projection workpiece, and a method of manufacturing a laminated wafer using the stretchable sheet.

In order to solve the above problems, an extendable sheet 10 comprising a heat-shrinkable substrate 1 and an adhesive layer 2 laminated on one main surface of the substrate 1 and a processing region 10a by a plan view are provided. The first region 11a having the outer circumference of the processing region 10a as the outer circumferential region and the second region having the processing region 10a as the center on the inner peripheral side of the first region 11a located in the annular region 12a is formed, and the processing region is formed on the first main surface of the main surface on the side of the adhesive layer 2 closer to the substrate 1 of the extendable sheet 10, and should be adhered to the substrate 21 in the thickness direction in use. A region on the member to be processed 20 including a plurality of convex portions 22; the first region 11a includes a surface 11pa formed by the first projection 11p as a projection from the base region 1 with respect to the second region 12a. .

Description

Extensible sheet and method for manufacturing laminated wafer

The present invention relates to an extendable sheet used for dividing a member to be processed such as a semiconductor wafer into small pieces, and a method of manufacturing a laminated wafer using the extendable sheet. Furthermore, in this specification, the term "sheet" is used to include the concept of the term "belt" and the concept of the term "film".

In recent years, there has been an increase in the density of packages, in which a silicon wafer is used instead of a substrate, and a Si through electrode (TSV, Through-Silicon Via) is used to laminate a wafer thereon. The technique of manufacturing a wafer in this manner is also referred to as a chip on wafer technique (for example, refer to Patent Document 1). The laminate manufactured by the COW technique has a state in which the wafer is protruded on the substrate, and the height of the protrusion is several hundred μm.

Advanced technical literature Patent literature

Patent Document 1: Japanese Laid-Open Patent Publication No. 2009-110995

In this way, the workpiece to be processed (in the present specification, such a workpiece is also referred to as a "multi-projection workpiece") is divided and manufactured in the thickness direction in the thickness direction by a laminate including a plurality of convex portions. Contains a plurality of convex When the laminated wafer of the sheet-like body of at least one of the portions is compared with the wet-cutting process such as blade dicing where there is a possibility that the processing liquid containing the solute enters between the plurality of wafers constituting the laminated wafer Dry dicing such as Stealth Dicing (registered trademark) is preferred.

Here, in the process of the invisible dicing (registered trademark), the processing sheet is applied to the processing sheet adhered to the workpiece, and the processing sheet is stretched by the tension of the peripheral portion from the center portion, thereby adhering to the processing sheet. The member to be processed of the sheet is also provided with a force that causes the peripheral portion to be separated from the central portion thereof, and a plurality of sheet-like bodies that are separated from each other are obtained. In the present specification, an extensible processing sheet for invisible cutting (registered trademark) processing or the like is referred to as an "extensible sheet".

In the case where the workpiece is a multi-projection workpiece, only the protrusion of the multi-projection workpiece is adhered to the extendable sheet, and based on the extension of the extendable sheet, the division line is sandwiched, and the arranged protrusions are separated from each other. Perform multi-projection division of the workpiece. For this reason, the convex portion located in the workpiece farthest from the center of the workpiece (also referred to as "the farthest convex portion" in the present specification) can not be protruded from the farthest position in the workpiece. Part of the farther yuan separates itself. Therefore, in a state in which the stretchable sheet is adhered to the convex portion, it is impossible to manufacture the laminated wafer including the most distal convex portion to an appropriate size, and it is necessary to set the most distal convex portion as a predetermined convex portion. The step of setting such a hypothetical farthest convex portion is itself wasteful, and it is expected to be improved from the viewpoint of effectively utilizing the processed member.

An object of the present invention is to provide an extendable sheet which can suitably produce a laminated wafer including a farthest convex portion in a multi-projection workpiece, and a method for producing a laminated wafer using the stretchable sheet.

In order to achieve the above-mentioned object, the inventors of the present invention have found that the following is known: in the state in which the stretchable sheet is adhered to the multi-projection workpiece, the stretchable sheet has a portion which is a part of the laminated wafer. The part to be adhered (in the present specification, the most distant residual portion) can be suitably fabricated into a laminated wafer containing the most distant convex portion, and the above portion is regarded as a farthest position of the workpiece than the multi-projected workpiece. The convex portion is farther away from the far part of the multi-projected workpiece center (of course not the convex portion).

Based on the above-described findings, the first invention provides an extendable sheet which is an extensible sheet comprising a heat-shrinkable substrate and an adhesive layer laminated on one main surface of the substrate; In the processing region, the first region of the annular region in which the outer periphery of the processing region is defined as a plane in plan view, and the inner peripheral side of the first region in the annular region include the processing region. Formed in a second region having a plane as a center, and the processing region is to be adhered to the first main surface of the main surface on the side of the adhesive layer closer to the substrate of the stretchable sheet. a region on a member to be processed including a plurality of convex portions in a thickness direction on the substrate; the first region includes a first protrusion as a protrusion from the substrate in a direction away from the substrate The surface formed by the part (Invention 1).

In the above invention (Invention 1), the member to be processed is divided into a plurality of sheet-like bodies by a process including a dividing step, and the dividing step is to continuously form a laser beam having transparency to the member to be processed. a step of dividing a member to be processed by a formation of the modified layer along a division line having a reduced strength; the plurality of sheets having a sheet divided into at least one of the plurality of protrusions A laminated wafer of the shape is preferred (Invention 2).

In the above invention (Invention 1 or 2), in use, the most distal residual portion of the workpiece is preferably adhered to the surface formed by the first projection, and the most distal residual portion is in plan view. The portion located farther than the convex portion located farthest from the center of the workpiece is the portion other than the portion of the laminated wafer (Invention 3).

In the above invention (Inventions 1 to 3), in the above-described workpiece, it is preferable that the plurality of convex portions are adhered to the second region in the workpiece (Invention 4).

In the above invention (Inventions 1 to 4), it is preferable that the first main surface of the extendable sheet includes a third region on an outer peripheral side of the processing region in a plan view, and the third region has The second region is a third projection region formed on the surface of the third projection portion of the projection protruding from the direction in which the substrate is separated from each other, and the third projection has heat shrinkability (Invention 5).

In the above inventions (Inventions 1 to 5), it is preferable that the substrate is the thickest member in the portion of the stretchable sheet corresponding to at least a part of the region of the third region (Invention 6).

In the above invention (Inventions 1 to 6), the laminate including the base material and the pressure-sensitive adhesive layer is adhered to a mirror mirror wafer, and the adhesion of the laminate is measured based on JIS Z0237:2000. It is preferably 1000 mN/25 mm or more and 20,000 mN/25 mm or less (Invention 7).

In the above invention (Inventions 1 to 7), it is preferable that the projection of the first region has a projection height of 200 μm or more in the second region (Invention 8).

In the above invention (Inventions 1 to 8), the above substrate comprises polyene A hydrocarbon film is preferred (Invention 9).

According to a second aspect of the invention, there is provided a method of manufacturing a laminated wafer in which a laminated wafer including at least one of the plurality of convex portions is formed on a substrate from a workpiece including a plurality of convex portions in a thickness direction, The method includes a dividing step, an adhering step, an expanding step and a picking step. The dividing step is to continuously irradiate the processed member with the laser beam to form a modified layer on the processed member, and the formation of the modified layer decreases along the strength. The step of dividing the predetermined line to divide the workpiece; the sticking step is to continuously form a modified layer on the processed member after irradiating the processed member with the laser beam, and the formation of the modified layer is reduced along the strength The workpiece to be processed in the step of dividing the predetermined line to be processed, and the annular frame disposed on the outer peripheral side of the workpiece in a plan view, and the extendable sheet described in the above invention (Inventions 1 to 9) are adhered a material in which the plane is regarded as a portion farther away from a convex portion located farthest from the center of the workpiece to be processed, and is the above a portion other than a portion of the layer wafer, that is, a portion of the most distant element, a surface formed by the first protrusion, and a state in which the second region is adhered to the plurality of convex portions of the workpiece And the expanding step of extending the stretchable sheet to divide the processed member into a plurality of sheet-like bodies, and the plurality of laminated wafers including at least one of the plurality of convex portions are spaced apart from each other a portion disposed on the extendable sheet and having a portion other than the convex portion of the workpiece to be adhered to the surface formed by the first projection is a state of being separated from the laminated wafer; and the picking step is The step of separating the laminated wafer from the extensible sheet.

In the above invention (Invention 10), the first protruding portion is as described above The ratio of the protrusion height in the second region to the protrusion height of the convex portion included in the workpiece to be processed is preferably 80% or more and 120% or less (Invention 11).

In the above invention (Invention 10 or 11), in the expanding step, the extending of the extendable sheet is performed by heating a part of the stretchable sheet corresponding to a part of the third region portion It is preferable that the step of abutting the portion of the annular member in the extending sheet to shrink the portion of the substrate is preferably prepared between the above-described picking steps after the end of the expanding step (Invention 12).

In the above invention (Inventions 10 to 12), the pressure-sensitive adhesive layer including the stretchable sheet contains an energy ray-curable material, and the energy ray-curable material is cured by irradiating the adhesive layer with an energy ray. It is preferable that the energy ray irradiation step of reducing the adhesion of the above-mentioned adhesive layer to the wafer is started between the above-described pickup steps after the completion of the expansion step (Invention 13).

By using the stretchable sheet according to the present invention, the manufacturing method relating to the present invention can be suitably carried out, and a laminated wafer containing the convex portion at the farthest position of the multi-projected workpiece can be suitably produced.

10‧‧‧Extensible sheet

1‧‧‧Substrate

2‧‧‧Adhesive layer

10A‧‧‧1st main face of extendable sheet 10

10a‧‧‧Processing area

11a‧‧‧1st area

11p‧‧‧1st protrusion

11pa‧‧‧1st convex surface

12a‧‧‧2nd area

13a‧‧‧3rd area

13p‧‧‧3rd protrusion

13b‧‧‧3rd convex area

13c‧‧‧Recoverable area

10L‧‧‧ load area

20‧‧‧Multiple artifacts

21‧‧‧Substrate

21R‧‧‧The farthest residual

21m‧‧‧modified layer

22‧‧‧ plural convex parts

22d‧‧‧The farthest convex

30‧‧‧Circular frame

40‧‧‧Multilayer wafer

40d‧‧‧The farthest layer of laminated wafer

50‧‧‧Extensible sheet

10‧‧‧1st main face

1A‧‧‧Multiple projecting

20‧‧‧ and ring frame

30‧‧‧Laminated structural structures

60‧‧‧ ring members

70‧‧‧Expanded laminate

Fig. 1 is a schematic cross-sectional view showing an example of an extendable sheet according to an embodiment of the present invention.

Fig. 2 is a schematic plan view showing an example of an extendable sheet according to an embodiment of the present invention.

Fig. 3 is a schematic plan view showing another example of the stretchable sheet according to an embodiment of the present invention.

Fig. 4 is a schematic cross-sectional view showing another example of the stretchable sheet according to the embodiment of the present invention.

Fig. 5 is a schematic cross-sectional view showing a laminated structure in which a stretchable sheet and a ring-shaped frame are adhered to the stretchable sheet shown in Fig. 1;

Fig. 6 is a schematic cross-sectional view showing a state in which an expansion step is performed on the laminated structure shown in Fig. 5;

Fig. 7 is a schematic cross-sectional view showing the expanded laminated body obtained from the laminated structure shown in Fig. 6.

FIG. 8 is a schematic cross-sectional view showing a state in which the laminated structure in which the workpiece and the annular frame are adhered to the stretchable sheet shown in FIGS. 3 and 4 are subjected to an expanding step.

Fig. 9 is a schematic cross-sectional view showing the expanded laminated body obtained from the laminated structure shown in Fig. 8.

In the following description, the "modified layer breaking type tensile division" means that a modified layer is continuously formed by irradiating a laser beam having transparency to a member to be processed, and the formation of the modified layer is lowered along the strength. The divided planned line divides the workpiece to be processed. As a method of producing a wafer based on the modified layer breaking type stretching, a stealth cutting (registered trademark) method such as Hamamatsu Photonics sings can be mentioned.

Hereinafter, embodiments of the present invention will be described.

1. Extendable sheet

Fig. 1 is a cross-sectional view schematically showing the structure of an example of an extendable sheet according to an embodiment of the present invention. The stretchable sheet 10 according to an embodiment of the present invention includes a heat-shrinkable base material 1 and an adhesive layer 2 laminated on one main surface of the base material 1.

(1) Substrate

The base material 1 of the stretchable sheet 10 of the present embodiment has heat shrinkability, and at the same time, as long as the stretchable sheet 10 is stretched in order to obtain a laminated wafer (in the present specification, the stretchable sheet 10 will be elongated) The step is also referred to as "expansion step". The constituent material is not particularly limited, and is usually composed of a film mainly composed of a resin-based material. As a specific example of the film, a polyolefin film containing a film having a polymer based on a constituent unit of an olefin can be exemplified. Specific examples of the polyolefin film include an ethylene-vinyl acetate copolymer film, an ethylene-(meth)acrylic copolymer film, and an ethylene-(meth)acrylate copolymer film; A polyethylene film such as a low density polyethylene (LDPE) film, a linear low density polyethylene (LLDPE) film, or a high density polyethylene (HDPE) film. Further, a polypropylene film, a polybutene film, a polybutadiene film, a polymethylpentene film, an ethylene-norbornene copolymer film, a norbornene resin film, or the like can also be used as a specific example of the polyolefin film. List. Further, a bridge film of the polyolefin film or a degeneration film such as an ionomer film may be used. The substrate 1 may be a film of the above-described composition, or may be a laminate film formed by combining the two or more types. In the present specification, "(meth)acrylic acid" means both acrylic acid and methacrylic acid. The same is true for other similar terms.

The film constituting the substrate 1 is preferably composed of a vinyl copolymer film from the viewpoint of heat shrinkability and suitability of the expansion step (not easily broken).

The substrate 1 may contain various additives such as a pigment, a flame retardant, a plasticizer, an antistatic agent, a lubricant, and a filler in the film containing the resin material as a main material. Examples of the pigment include titanium dioxide, carbon black, and the like. Further, examples of the filler include an organic material such as melamine resin, an inorganic material such as smog, and a metal material such as nickel particles. The content of these additives is not particularly limited.

When the energy ray is applied to the adhesive layer 2, when the ultraviolet ray is used as the energy ray, the substrate 1 is preferably permeable to ultraviolet rays. When the electron beam is used as the energy ray for irradiating the adhesive layer 2, the substrate 1 preferably has electron beam permeability.

Further, the surface of the substrate 1 facing the opposite side of the main surface of the adhesive layer 2 may be provided with various coating films as long as the desired function can be achieved.

The thickness of the substrate 1 is not particularly limited. The range is preferably 20 μm or more and 450 μm or less, more preferably 25 μm or more and 400 μm or less, and particularly preferably 50 μm or more and 350 μm or less.

In the present embodiment, the breaking elongation of the substrate 1 is preferably 100% or more as a value measured at 23 ° C and a relative humidity of 50%, and particularly preferably 200% or more and 1000% or less. Here, the breaking elongation is a stretching ratio of the length of the test piece with respect to the length of the test piece when the test piece is broken in the tensile test based on JIS K7161:1994 (ISO 527-1 1993). The base material 1 having a breaking elongation of 100% or more is not easily broken during the expansion step, and it is easy to separate the laminated wafer formed by dividing the multi-projection workpiece.

Further, the tensile stress at the 25% strain of the substrate 1 of the present embodiment is preferably 5 N/10 mm or more and 15 N/10 mm or less, and the maximum tensile stress is obtained. It is preferably 15 MPa or more and 50 MPa or less. Here, the tensile stress and the maximum tensile stress at 25% strain were measured by the test in accordance with JIS K7161:1994. If the tensile stress is less than 5 N/10 mm at 25% strain or the maximum tensile stress is less than 15 MPa, the stretchable sheet 10 is adhered to the multi-projection workpiece, and is fixed to a jig of a ring frame or the like due to the substrate. 1 When the hair is soft, there is a possibility that the slack occurs, and the slack is a cause of the transport failure. Further, when the tensile stress at 25% strain exceeds 15 N/10 mm, or the maximum tensile stress exceeds 50 MPa, problems such as peeling of the stretchable sheet 10 from a jig such as a ring frame are likely to occur during the expansion step. Further, the breaking elongation, the tensile stress at 25% strain, and the maximum tensile stress refer to values obtained by measuring the substrate 1 in the longitudinal direction of the raw material.

(2) Adhesive layer

The adhesive layer 2 of the stretchable sheet 10 of the present embodiment can be formed by various adhesive compositions previously known. As such an adhesive, there is no limitation, and an adhesive composition such as a rubber-based, acryl-based, enamel-resin or polyvinyl ether can be used. Further, an energy ray-curing type or a heat-foaming type or water-swellable type of adhesive composition can also be used.

The adhesive layer 2 included in the stretchable sheet 10 of the present embodiment may be composed of an energy ray-polymerizable adhesive composition containing a component which generates a polymerization reaction by irradiation with an energy ray. Examples of the energy ray used for the polymerization include electromagnetic waves such as X-rays and ultraviolet rays, and electron beams. Among these energy lines, ultraviolet rays having a low cost required for setting up the equipment and excellent workability are preferred.

Examples of the ultraviolet ray-polymerizable adhesive composition include an acrylic polymer (α) and an energy ray polymerizable compound described below. The substance (β) further contains an adhesive composition such as a bridging agent (γ) as necessary.

(2-1) Acrylic polymer (α)

An example of the adhesive composition for forming the pressure-sensitive adhesive layer 2 of the present embodiment contains an acrylic polymer (α). In the adhesive layer 2 formed of the adhesive composition, at least a part of the acrylic polymer (α) is contained as a bridging material, and a bridging reaction is carried out with a bridging agent (γ) to be described later.

As the acrylic polymer (α), a conventionally known acrylic polymer can be used. a weight average molecular weight (Mw) of the acrylic polymer (α), a coating liquid formed from the adhesive composition for forming the above-mentioned adhesive layer 2 or a composition obtained by adding a solvent thereto (in the present specification, The film forming property in the case of the coating of the "coating liquid for forming an adhesive layer" is preferably 10,000 or more and 2,000,000 or less, more preferably 100,000 or more and 1.5 million or less. Further, the glass transition temperature Tg of the acrylic polymer (α) is preferably from -70 ° C to 30 ° C, more preferably from -60 ° C to 20 ° C. The glass transition temperature can be calculated by the Fox formula.

The acrylic polymer (α) may be a single polymer formed of one type of acrylic monomer, or may be a copolymer of a plurality of acrylic monomers, or may be one or more acrylic monomers. A copolymer formed with a monomer other than the acrylic monomer. The specific type of the compound to be an acrylic monomer is not particularly limited, and specific examples thereof include (meth)acrylic acid, (meth)acrylic acid ester, and derivatives thereof (acrylonitrile or the like).

Further, specific examples of the (meth) acrylate include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, and butyl (meth)acrylate. Chained bone such as 2-ethylhexyl methacrylate (meth) acrylate; cyclohexyl (meth) acrylate, benzyl (meth) acrylate, isobornyl (meth) acrylate, dicyclopentyl (meth) acrylate, (meth) acrylate (meth)acrylate having a cyclic skeleton such as tetrahydrofurfuryl ester or quinone imine acrylate; 2-hydroxyethyl (meth)acrylate or 2-hydroxypropyl (meth)acrylate having a hydroxyl group (Meth) acrylate; (meth) acrylate having a reactive functional group other than a hydroxyl group such as glycidyl (meth)acrylate or N-methylaminoethyl (meth)acrylate. In addition, examples of the monomer other than the acrylic monomer include olefins such as ethylene and norbornene, vinyl acetate, and styrene. Further, when the acrylic monomer is an alkyl (meth)acrylate, the carbon number of the alkyl group is preferably in the range of 1 to 18.

When the adhesive composition for forming the adhesive layer 2 of the present embodiment contains a bridging agent (γ) capable of bridging the acrylic polymer (α), the acrylic polymer (α) has The type of the reactive functional group is not particularly limited, and may be appropriately determined depending on the type of the bridging agent (γ). For example, when the bridging agent (γ) is a polyisocyanate compound, the reactive functional group of the acrylic polymer (α) may, for example, be a hydroxyl group, a carboxyl group or an amine group. Among these, when the bridging agent (γ) is a polyisocyanate compound, a hydroxyl group having high reactivity with an isocyanate group is preferably used as the reactive functional group. The method of introducing a hydroxyl group into the acrylic polymer (α) as a reactive functional group is not particularly limited. As an example, the acrylic polymer (α) may contain a constituent unit of a hydroxy group having a hydroxyl group such as 2-hydroxyethyl (meth)acrylate in the skeleton.

When the acrylic polymer (α) has a reactive functional group, the content of the monomer having a reactive functional group to the total monomer in terms of a monomer forming the acrylic polymer (α) is 1% by mass or more and 20% by mass. % below Preferably, it is more preferably 2% by mass or more and 10% by mass or less.

(2-2) Energy ray polymerizable compound (β)

The energy ray polymerizable compound (β) which is an adhesive composition for forming the pressure-sensitive adhesive layer 2 of the present embodiment can be polymerized by irradiation with energy rays such as ultraviolet rays or electron beams as long as it has an energy ray polymerizable group. The specific configuration of the reaction is not particularly limited. By polymerizing the energy ray polymerizable compound (β), the adhesion of the adhesive layer 2 to the film for forming a protective film 4 can be lowered.

The type of the energy ray polymerizable group is not particularly limited. Specific examples thereof include functional groups such as an ethylenically unsaturated bond such as a vinyl group or a (meth) acrylonitrile group. When the adhesive composition contains a bridging agent (γ), the energy ray polymerizable group has an ethylenically unsaturated bond from the viewpoint of reducing the possibility of functional duplication at the portion where the bridging reaction (γ) undergoes bridging reaction. The functional group of the junction is preferred, and the (meth) acrylonitrile group is more preferable from the viewpoint of high reactivity when irradiating the energy ray.

The molecular weight of the energy ray polymerizable compound (β) is not particularly limited. When the molecular weight is excessively small, in the manufacturing process of the adhesive composition or the adhesive layer 2, the compound is volatilized, and the stability of the composition of the adhesive layer 2 is lowered. Therefore, the molecular weight of the energy ray polymerizable compound (β) is preferably 100 or more as the weight average molecular weight (Mw), more preferably 200 or more, and particularly preferably 300 or more.

The molecular weight of at least a part of the energy ray polymerizable compound (β) is preferably 4,000 or less as the weight average molecular weight (Mw). As such an energy ray polymerizable compound (β), a group consisting of a monofunctional monomer and a polyfunctional monomer selected from an energy ray polymerizable group, and an oligomer of the monomers can be exemplified. A compound consisting of two or more species.

The specific composition of the above compound is not particularly limited. Specific examples of the above compound include trimethylolpropane tri(meth)acrylate, tetramethylolmethanetetra(meth)acrylate, tris(meth)acrylic acid pentaerythritol ester, and five (A) Diisoprenyl alcohol monohydroxy ester, diisopentyl hexa(meth)acrylate, 1,4-butanediol di(meth)acrylate, di(meth)acrylic acid 1,6 - an alkyl (meth) acrylate having a chain skeleton such as hexanediol; dicyclopentadienyl dimethoxy bis(meth) acrylate or isobornyl (meth) acrylate; Alkyl (meth)acrylate having a cyclic skeleton; polyethylene glycol di(meth)acrylate, oligoester (meth)acrylate, urethane (meth)acrylate oligomer, epoxy An acrylate-based compound such as a modified (meth) acrylate or a polyether (meth) acrylate. Among these, the acrylate compound is preferred because it has high compatibility with the acrylic polymer (α).

The number of the energy ray polymerizable groups of the energy ray-polymerizable compound (β) in one molecule is not limited, but is preferably a plural number, more preferably 3 or more, and particularly preferably 5 or more.

The content of the energy ray polymerizable compound (β) contained in the adhesive composition of the pressure-sensitive adhesive layer 2 of the present embodiment is 50 parts by mass or more and 300 parts by mass for the acrylic polymer (α) 100 parts by mass. The following is preferable, and it is more preferably 75 mass parts or more and 150 mass parts or less. In the present specification, the "mass portion" indicating the content of each component means the amount of the solid matter. By setting the content of the energy ray polymerizable compound (β) in such a range, it is possible to sufficiently ensure the adhesion of the adhesive layer 2 to the multi-projected workpiece or the laminated wafer obtained by the energy ray irradiation, and the adhesion before the energy ray irradiation. Agent layer 2 pairs of multiple protrusion workpieces or points The difference in adhesion of the laminated wafer obtained by cutting it.

As another example of the energy ray polymerizable compound (β), an energy ray polymerizable compound (β)-based acrylic polymer has a constituent unit containing an energy ray polymerizable group in a main chain or a side chain. In this case, since the energy ray polymerizable compound (β) has a property as an acrylic polymer (α), the composition of the composition forming the adhesive layer 2 can be simplified, and the energy ray which is easily controlled in the adhesive layer 2 can be easily obtained. The existence density of the polymerizable group and the like.

The energy ray polymerizable compound (β) having the properties of the acrylic polymer (α) as described above can be prepared, for example, by the following method. Copolymerization comprising a constituent unit of a (meth) acrylate based on a functional group containing a hydroxyl group, a carboxyl group, an amine group, a substituted amine group, an epoxy group or the like and a constituent unit based on an alkyl (meth) acrylate The acrylic polymer is reacted with a compound having a functional group reactive with the functional group and an energy ray polymerizable group (for example, a group having an ethylenic double bond) in one molecule, and the acrylic polymer can be used. The upper addition energy line polymerizable group.

The energy rays for curing the energy ray polymerizable compound (β) include ionizing radiation, that is, X-rays, ultraviolet rays, electron beams, and the like. Among these, it is preferred that the irradiation device is relatively easy to introduce ultraviolet rays.

When ultraviolet rays are used as the ionizing radiation, it is sufficient to use near-ultraviolet rays including ultraviolet rays having a wavelength of about 200 to 380 nm from the viewpoint of easy handling. As the amount of ultraviolet light, in accordance with the thickness of the energy ray polymerizable compound (beta]), or of the kind of the adhesive agent layer 2 can be appropriately selected, generally 50 ~ 500mJ / cm ² or so, to 100 ~ 450mJ / cm ² preferably to 200 ~400mJ/cm ² is better. Further, the intensity of ultraviolet is generally 50 ~ 500mW / cm ^2, and at 100 ~ 450mW / cm ² preferably, to 200 ~ 400mW / cm ² is more preferred. The ultraviolet light source is not particularly limited, and for example, a high pressure mercury lamp, a metal halide lamp, a UV-LED, or the like can be used.

When an electron beam is used as the ionizing radiation, the acceleration voltage is preferably selected in accordance with the type of the energy ray polymerizable compound (β) or the thickness of the adhesive layer 2, and the acceleration voltage is usually preferably from 10 to 1000 kV. In addition, the irradiation line amount may be set in a range in which the energy ray polymerizable compound (β) is appropriately cured, and is usually selected in the range of 10 to 1000 krad. The electron source is not particularly limited, and for example, a Cockcroft-Walton type, a Van-de-Graaff type, a resonant transformer type, an insulated core transformer type or Various electron line accelerators such as linear type, Dynamitron type, and high frequency wave type.

(2-3) bridging agent (γ)

The adhesive composition for forming the adhesive layer 2 of the present embodiment may contain a bridging agent (γ) reactive with the acrylic polymer (α) as described above. At this time, the adhesive layer 2 of the present embodiment contains a bridge material obtained by bridging reaction of the acrylic polymer (α) and the bridging agent (γ).

Examples of the type of the bridging agent (γ) include a polyethylenimine compound such as an epoxy compound, an isocyanate compound, a metal chelate compound, or an aziridine compound, a melamine resin, a urea resin, and a dialdehyde. Classes, methylol polymers, metal alkoxides, metal salts, and the like. Among these, the bridging agent (γ) is preferably a polyisocyanate compound and/or a polyepoxide because of the ease of controlling the bridging reaction or the like.

Here, the polyisocyanate compound will be described in detail. A polyisocyanate compound is a compound having two or more isocyanate groups per molecule. Examples thereof include aromatic polyisocyanates such as tolyl diisocyanate, diphenylmethane diisocyanate, and xylyl diisocyanate; dicyclohexylmethane-4,4'-diisocyanate, dicycloheptane triisocyanate, and sub An alicyclic isocyanate compound such as cyclopentyl diisocyanate, cyclohexene diisocyanate, methyl cyclohexylene diisocyanate or hydrogenated xylylene diisocyanate; hexamethylene diisocyanate, trimethyl hexamethylene Isocyanate having a chain skeleton such as bis-isocyanate or lysine diisocyanate.

Further, a biuret or isocyanurate of these compounds or a compound thereof may be used, and a non-aromatic low molecular active hydrogen such as ethylene glycol, trimethylolpropane or castor oil may be contained. A denatured product such as an adduct of a reactant of a compound. The polyisocyanate compound may be used alone or in combination of plural kinds.

When the adhesive layer 2 of the present embodiment has a bridging material based on an acrylic polymer (α) and a bridging agent (γ), the adhesive can be controlled by adjusting the bridging density of the bridging material contained in the adhesive layer 2 The characteristics of the elastic modulus and the like are stored before the irradiation of the layer 2. The bridging density can be adjusted by changing the content of the bridging agent (γ) contained in the composition for forming the adhesive layer 2, and the like. Specifically, the amount of the bridging agent (γ) used in the adhesive composition for forming the adhesive layer 2 is 5 parts by mass or more for the mass portion of the acrylic polymer (α) 100, and the adhesive can be easily used. The storage modulus before the irradiation of the layer 2 is controlled to an appropriate range. From the viewpoint of improving the controllability, the content of the bridging agent (γ) is preferably 10 parts by mass or more, and particularly preferably 20 parts by mass or more, based on 100 parts by mass of the acrylic polymer (α). The upper limit of the content of the bridging agent (γ) is not particularly limited. However, when the content is too high, it is difficult to control the adhesion of the adhesive layer 2 to the range described later. The mass portion of the acrylic polymer (α) is preferably 50 parts by mass or less, more preferably 40 parts by mass or less.

When the adhesive composition for forming the adhesive layer 2 of the present embodiment contains the bridging agent (γ), it is preferred to contain an appropriate bridging promoter in accordance with the type of the bridging agent (γ). For example, when the bridging agent (γ) is a polyisocyanate compound, it is preferable that the adhesive composition for forming the adhesive layer 2 contains an organometallic compound-based bridging promoter such as an organic tin compound.

(2-4) Other ingredients

The adhesive composition for forming the adhesive layer 2 included in the stretchable sheet 10 of the present embodiment, together with the above components, may also contain an oligomeric polymer having an adhesive-imparting resin or a long-chain alkyl group. Various additives such as an oligomer component such as a material, a photopolymerization initiator, a coloring material such as a dye or a pigment, a flame retardant, a filler, and an antistatic agent.

The photopolymerization initiator may, for example, be a photoinitiator such as a benzoin compound, an acetophenone compound, a mercaptophosphine oxide compound, a titanocene compound, a thioxanthone compound or a peroxide compound, or an amine or an anthracene. A light sensitizer or the like, specifically, 1-hydroxycyclohexyl benzophenone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzyl diphenyl sulfide, tetramethyl thiuram monosulfide Benzene, isobutyl nitrile, dibenzyl, hydrazine, β-chloropurine, 2,4,6-trimethylbenzimidyldiphenylphosphine oxide, and the like. When ultraviolet rays are used as the energy ray, the irradiation time and the amount of irradiation can be reduced by blending the photopolymerization initiator.

(2-5) thickness

The thickness of the adhesive layer 2 included in the stretchable sheet 10 of the present embodiment is not particularly limited. Properly maintaining the adhesive layer 2 against the body (multiple The thickness of the adhesive layer 2 is preferably 1 μm or more, more preferably 2 μm or more, and 3 μm, from the viewpoint of adhesion of a workpiece, a laminated wafer formed by dividing a workpiece, and a jig for a ring-shaped frame. The above is especially good. Further, from the viewpoint of reducing the possibility of occurrence of wafer defects in the dicing step, the thickness of the adhesive layer 2 is preferably 80 μm or less, more preferably 50 μm or less, and particularly preferably 30 μm or less.

(2-6) Adhesion

The adhesiveness of the adhesive layer 2 included in the stretchable sheet 10 of the present embodiment is not particularly limited. In the fracture-stretching division of the modified layer, the laminate formed of the substrate 1 and the adhesive layer 2 is adhered to the 矽 mirror wafer from the viewpoint of stably holding the obtained wafer on the adhesive layer. The adhesion based on JIS Z0237:2000 measured on the (Silicon mirror wafer) (in the case of the adhesion of the energy-polymerized adhesive composition to the adhesive layer 2 for the purpose of low adhesion to the adhesive after being adhered to the object) The adhesion before the irradiation of the energy ray is preferably 1000 mN/25 mm or more and 20,000 mN/25 mm or less, and more preferably 1500 mN/25 mm or more and 15000 mN/25 mm or less.

(3) 1st main face 10A

As shown in FIG. 5, the member to be processed to which the stretchable sheet 10 according to the embodiment of the present invention is attached is a plurality of projections including the substrate 21 and the main surface of one of the substrates 21 which are protruded in the thickness direction. The portion 22 of the portion 22 is protruded from the workpiece 20. A modified layer 21m is formed in the substrate 21 along a predetermined dividing line. The convex portions 22 are located at the most distant position from the center of the multi-projection workpiece 20 in plan view, and are the most distal convex portions 22d. In the multi-projection workpiece 20, the plane is regarded as being located farther from the center of the multi-projection workpiece 20 than the farthest position convex portion 22d, and is divided into The portion other than the portion which becomes one of the laminated wafers 40 at the time of cutting is the farthest remaining portion 21r. As shown in FIG. 6 and the like, in the multilayer wafer 40 obtained by dividing the multi-projection workpiece 20, the laminated wafer including the farthest convex portion 22d is the farthestmost laminated wafer 40d.

The first main surface 10A located on the main surface of the stretchable sheet 10 which is closer to the adhesive layer 2 side than the substrate 1 includes a processing region 10a which is used in the stretchable sheet 10 At the time, the portion of the substrate 21 including the plurality of convex portions 22 in the thickness direction, that is, the region on the workpiece 20 to which the workpiece is to be processed, should be adhered. The shape of the processing region 10a is of course the same as the shape of the multi-projection workpiece 20. Generally, the sheet 10 can be stretched so that the peripheral portion is biased from the center of the center thereof, and the processing region 10a is located at almost the center of the first main surface 10A.

The processing region 10a is composed of a first region 11a and a second region 12a which will be described below.

(3-1) First area 11a

The first area 11a is regarded as a circular area in which the outer periphery of the processing area 10a is the outer periphery. The first region 11a includes a surface 11pa formed by the first projections 11p of the projections in the direction in which the base material 1 is separated from the second region 12a to be described later. In the present specification, the surface 11pa formed by the first projections 11p is referred to as a "first convex surface". As shown in FIGS. 1 and 2, the entire surface of the first region 11a may be constituted by the first convex surface 11pa. As shown in FIGS. 3 and 4, a part of the first region 11a may be constituted by the first convex surface 11pa. As a specific example of the case where the first region 11a is partially formed by the first convex surface 11pa in FIGS. 3 and 4, the first projection 11p has a plurality of small projections arranged on the circular ring. In the case where the surface including the apex thereof constitutes the first convex surface 11pa.

The first convex surface 11pa adheres to the most distal residual portion 21r when the stretchable sheet 10 is used.

(3-2) 2nd area 12a

As described above, the second region 12a is located on the inner peripheral side of the first region 11a that is annular in plan view, and includes the center of the processing region 10a in plan view. When the stretchable sheet 10 is used, the second region 12a is adhered to the plurality of convex portions 22 of the multi-projection workpiece 20.

Thus, when the processing region 10a is composed of the first region 11a and the second region 12a, when the stretchable sheet 10 is adhered to the multi-projection workpiece 20, the first portion is adhered to the most distal residual portion 21r. In the region 11a, the second region 12a is adhered to the most distal convex portion 22d. When the stretchable sheet 10 is stretched in this state, the substrate 21 and the most connected to the most distal convex portion 22d are joined with the separation of the first region 11a and the second region 12a adhered to the most distal convex portion 22d. An detachment force is applied between the distal residual portions 21r, and the farthest residual portion 21r can be separated from the farthestmost laminated wafer 40d.

(3-3) First protrusion 11p

The first region 11a includes a height that can maintain the state of adhering to the most distant residual portion 21r. In the adhered state, when the shearing force generated by the elongation of the stretchable sheet 10 is applied to the first projection 11p, as long as it can be The tension required to separate the farthest remaining portion 21r and the farthestmost laminated wafer 40d is given to the farthest remaining portion 21r, and the specific structure of the first protruding portion 11p is not limited.

From the viewpoint of more stably achieving the proper separation of the farthest remaining portion 21r and the farthestmost laminated wafer 40d, the first protruding portion 11p is considered. The reference projection height of the second region 12a is preferably 80% or more and 120% or less with respect to the ratio of the reference projection height of the substrate 21 of the most distal convex portion 22d. When the ratio is too low, the first region 11a cannot be appropriately adhered to the farthest remaining portion 21r, and in the expanding step, the possibility of peeling between the first region 11a and the farthest remaining portion 21r increases. On the other hand, if the ratio is too high, the second region 12a cannot be appropriately adhered to the distal convex portion 22d adjacent to the farthest residual portion 21r, and in the expanding step, the second region 12a and the farthest convex portion The possibility of peeling between 22d increased. Specific examples of the projection height based on the second region 12a of the first projections 11p include 200 μm or more, 300 μm or more, or 400 μm or more, and may be a projection of the first projection 11p based on the second region 12a. High specific examples are listed.

In the expansion step, the storage modulus of the first projection 11p at 23 ° C is preferably 0.01 MPa or more from the viewpoint of more stably and easily separating the distal-most residual portion 21 r from the distal-most convex portion 22 d. It is more preferably 0.1 MPa or more and 10000 MPa or less, and particularly preferably 1 MPa or more and 1000 MPa or less. When the storage modulus of the first projection 11p at 23 ° C is 0.01 MPa or more, the possibility that the stretchable sheet 10 is broken in the expansion step is reduced. When the storage modulus of the first projection 11p at 23 ° C is 10000 MPa or less, the adhesion of the stretchable sheet 10 to the multi-projection workpiece 20 can be improved.

The material constituting the first projection 11p is not particularly limited as long as it can maintain a predetermined projection height and is suitable for the peel strength of the most distal residual portion 21r. Further, "the peeling strength of the most distant residual portion 21r is suitable" means that no peeling occurs between the first region 11a and the farthest remaining portion 21r in the expanding step. In addition, it means that after the expansion step is over, the farthest disability can be The sheet-like body composed of the remaining portion 21r is appropriately peeled off from the stretchable sheet 10.

In order to adhere the first region 11a to the most distal residual portion 21r, the first convex surface 11pa preferably has adhesiveness. Specific examples of the first projection 11p having adhesiveness as the first projection surface 11pa include a laminate including a film (resin film) made of a resin material and an adhesive layer, and an adhesive layer. The laminate (each layer may be plural) and a structure composed of a self-adhesive resin.

Specific examples of the resin film of the laminate include ethylene copolymerization such as an ethylene-vinyl acetate copolymer film, an ethylene-(meth)acrylic copolymer film, and an ethylene-(meth)acrylate copolymer film. Film; polyethylene film of low density polyethylene (LDPE) film, linear low density polyethylene (LLDPE) film, high density polyethylene (HDPE) film, polypropylene film, polybutene film, polybutadiene a polyolefin film such as a film, a polymethylpentene film, an ethylene-norbornene copolymer film, or a norbornene resin film; a polyvinyl chloride film such as a polyvinyl chloride film or a vinyl chloride copolymer film; and a poly(ethylene terephthalate); A polyester film such as a glycol ester film or a polybutylene terephthalate film; a polyurethane film; a polyimide film; a polystyrene film; a polycarbonate film; a fluororesin film. Further, such a bridging film, a degradable film such as an ionomer film may also be used. Further, as the resin film, a cured product obtained by curing an energy ray-curable composition by an energy ray can also be used. The cured product is a film (urethane film) which is used as an intermediate layer in Japanese Patent No. 4841802 and which is formed by forming and curing a composition containing a urethane oligomer. The layer formed by hardening the energy ray hardenable composition by the energy ray may be a solventless type, and the drying step may be omitted. Therefore, when the resin film is a cast film, a thick film can be obtained without lowering the productivity, so that The height of the first protrusion 11p is increased.

The adhesive layer of the above laminated body can be formed by various known adhesive compositions. As such an adhesive composition, although not limited, an adhesive composition such as rubber, acrylic, hydrazine or polyether vinyl can be used. And an energy ray-curable adhesive composition as described above can be used. Further, a heat-foaming type or water-swellable type of adhesive composition can also be used.

Examples of the self-adhesive resin include an acrylic resin and a enamel resin having a film thickness, an ethylene-vinyl acetate copolymer, a urethane resin, and the like. As an acrylic resin which has self-adhesiveness, an acrylate copolymer is mentioned. The acrylate copolymer used for this purpose has a weight average molecular weight of 100,000 or more, preferably 100,000 to 1,500,000, and particularly preferably 150,000 to 1,000,000. The acrylate copolymer is composed of a (meth)acrylic acid, a (meth) acrylate monomer, or a constituent unit derived from a derivative thereof or the like. As the (meth) acrylate monomer, an alkyl (meth) acrylate having an alkyl group having 1 to 18 carbon atoms is used. Examples of the derivative of the (meth) acrylate monomer include dioxane such as dimethyl acrylamide, dimethyl methacrylamide, diethyl acrylamide, and diethyl methacrylamide. Base (meth) acrylamide. Among them, especially methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, butyl acrylate, butyl methacrylate, isobutyl acrylate, A Isobutyl acrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, dimethyl methacrylate It is better. In addition to these monomers, copolymerization of vinyl acetate, styrene, vinyl acetate or the like is also possible.

As an acrylate copolymer having a functional group, having 2-hydroxyethyl Hydroxy group-containing acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 2-hydroxybutyl acrylate, 2-hydroxybutyl methacrylate A carboxyl group-containing compound such as acrylate, acrylic acid or methacrylic acid is used as a constituent unit.

The acrylate copolymer is a polymer which is commonly used as an adhesive, and when it is large, it has a sticky feeling peculiar to the adhesive. Therefore, when it is used as a self-adhesive resin layer, partial bridging is carried out with a bridging agent to suppress a sticky feeling, and it is adjusted in order to obtain the storage modulus value mentioned above. Examples of the bridging agent include an organic polyvalent isocyanate compound, an organic polyvalent epoxy compound, and an organic polyimine compound. In general, if the amount of the bridging agent used is increased, the viscosity of the acrylate copolymer is lowered and the storage modulus is increased.

When the first protrusion 11p is formed in the structure made of a self-adhesive resin, the arithmetic mean roughness Ra of the surface is preferably 1 μm or less, and 0.7 μm or less. Preferably, it is particularly preferably 0.0001 μm or more and 0.2 μm or less.

(3-4) Third area 13a

The first main surface 10A of the extendable sheet 10 is composed of a processing region 10a and a third region 13a which is an outer peripheral side region of the processing region 10a in plan view.

Usually, the outer peripheral region of the third region 13a is adhered to the jig of the annular frame 30 or the like. Further, in the expanding step, the annular member 60 is pressed against the portion corresponding to the third region 13a of the extendable sheet 10 on the outer peripheral side of the annular frame 30, and the annular member 60 is pressed. The position corresponding to the vertical direction of the jig such as the annular frame 30 is changed (generally, the annular member 60 is collided on the surface opposite to the first main surface 10A of the extendable sheet 10). ). As a result, the portion of the extendable sheet 10 which is located on the inner peripheral side of the annular member 60 in plan view and the portion of the extendable sheet 10 to which the annular frame 30 is adhered are different in position in the vertical direction, and the extendable sheet The material 10 is elongated according to its positional difference.

At this time, the portion of the extendable sheet 10 that is in contact with the annular member 60, or a portion thereof, is particularly susceptible to mechanical load and becomes the most elongated portion. That is, the portion of the extendable sheet 10 corresponding to the third region 13a includes the most elongated portion in the expanding step.

As will be described later, from the viewpoint of improving maneuverability and the like, there is a case where heat shrinkage (restoration step) is performed on a portion corresponding to the third region 13a in the stretchable sheet 10. In order to properly perform heat shrinkage of the portion, the stretchable sheet 10 according to an embodiment of the present invention may have the following constitution.

(3-4-1) 3rd convex area 13b

The third region 13a may include a third protruding region 13b formed of a surface of the protruding portion third protruding portion 13p that protrudes from the base material 11 with respect to the second region 12a. The third protruding region 13b may be a part of the third region 13a, and may be all of the third region 13a as shown in FIGS. 1 and 2.

The relationship between the first protrusion 11p and the third protrusion 13p is not particularly limited. They may be composed of members that are different from each other or may be composed of the same members. Further, the first protrusions 11p and the third protrusions 13p may have continuous portions or may be discontinuous. In the extendable sheet 10 shown in Figs. 1 and 2, the first projection 11p and the third projection 13p are continuous.

The material and structure (especially the laminated structure) of the third protrusion 13p are not particularly limited. It is preferable that the third protrusion 13p has heat shrinkability to It is more preferable that the substrate 1 has the same heat shrinkability. When the third protrusion 13p has the same heat shrinkability as the substrate 1, when the stretchable sheet 10 is thermally shrunk by heating, the third protrusion 13p shrinks first or the substrate 1 shrinks first. In the third protruding region 3B, the possibility of hindering heat shrinkage of the substrate 1 is lowered.

The third protrusion 13p may also include a heat shrinkable material included in the substrate 1. In this case, the third projections 13p can be thermally contracted in the same manner as the base material 1, so that the amount of loosening of the extendable sheet 10 can be more stably reduced (adhering to the annular frame 30 in the extendable sheet 10) The lower side of the portion is the reference, and the distance between the bottom surface of the sheet 10 and the vertical direction of the sheet 10 can be extended.

Since the third projections 13p are not adhered to the workpiece (the multi-projection workpiece 20) in the normal use mode, the third projections 13b may not include adhesiveness. However, as described above, when the first projection 11p and the third projection 13p have a continuous portion, the third projection 13p and the third projection 13p may have the same material, and the third region 13a may not have the third region 13a. Adhesive. In this case, from the viewpoint of improving the shape stability of the stretchable sheet 10 after heat shrinkage, the first projections 11p and the third projections 13p preferably include a heat-shrinkable material included in the substrate 1.

(3-4-2) Easy recovery area 13c

The portion of the third region 13a corresponding to the stretchable sheet 10 of the region may also include the easily recoverable region 13c in which the substrate 1 is the thickest member. The easily recoverable region 13c may be a part of the third region 13a or may be all of the third region 13a. In the extendable sheet 10 shown in Figs. 3 and 4, the third region 13a is entirely composed of the easily recoverable region 13c. With such a configuration, the sheet 10 can be stretched and easily When the portion corresponding to the restoration region 13c is heated, the deformation of the stretchable sheet 10 is facilitated by thermally shrinking the substrate 1. The third region 13a may include both the third protruding region 13b and the easily recoverable region 13c. Further, the thickness ratio of the substrate occupied by the total thickness of the stretchable sheet 10 portion corresponding to the third region 13a is preferably 50% or more, more preferably 70% or more and 100% or less, and more preferably 90% or more. 100% or less is especially good. The thicker the thickness ratio of the substrate occupied by the total thickness of the stretchable sheet 10, the deformation of the stretchable sheet 10 is prevented from being prevented when the easily recoverable region 13c is heated by the presence of a member other than the substrate.

(4) peeling sheet

The first main surface 10A of the stretchable sheet 10 according to the embodiment of the present invention may be adhered to the peeling surface of the release sheet until use. The composition of the release sheet is arbitrary, and a release sheet in which the plastic film is peeled off with a release agent is exemplified. 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, an anthrone, a fluorine, a long-chain alkyl or the like can be used, but an anthrone having a low cost and a stable performance can be preferably used. The thickness of the release sheet is not particularly limited, but is usually about 20 μm or more and 250 μm or less.

(5) long body, retractable body

The stretchable sheet 10 according to an embodiment of the present invention may be in the form of a long-length body in which a plurality of the plurality of stretchable sheets are continuously arranged in the same direction. Specific examples of such a case include a long-length cloth roll state in which the base material 1 is cut before the cutting of the base material 1 and a plurality of stretchable sheets 10 in which the base material 1 has a base member 1 as a common member. The long ruler can also be taken up as a retractable body for storage and transportation. lose. The retractable body is unfolded at the time of use, and the substrate 1 is cut from a long-length cloth roll to manufacture the stretchable sheet 10.

The stretchable sheet 10 according to an embodiment of the present invention may be in the form of a long body with the laminate of the release sheet. Specific examples of such a case include a long ruler in which a plurality of stretchable sheets 10 are arranged along the long-length direction on a long-length release sheet. The long ruler can also be taken up as a retractable body for storage and transportation. The retractable body is unfolded at the time of use, and the stretchable sheet 10 is peeled off from the peeling sheet.

2. Method of manufacturing extendable sheet 10

The method of manufacturing the stretchable sheet 10 is not particularly limited. The cutting (including half cut) operation and the lamination operation (including the operation of forming the film member) can be performed for the predetermined material. Hereinafter, an example of a method of producing a laminate of the stretchable sheet 10 and the release sheet will be described.

First, a long-length cloth roll of the substrate 1 is prepared. Next, a coating film is obtained by coating the adhesive composition for forming the adhesive layer 2 on the main surface on the side of the long-length cloth roll. The coating method is not limited. The composition of the adhesive composition and the thickness of the adhesive layer 2 may be appropriately set. Specific examples thereof include known coating methods such as die coating, curtain coating, spray coating, slit coating, and blade coating. By laminating the coating film on the long-length cloth roll, a laminate of the long-length cloth roll and the adhesive layer 2 (hereinafter referred to as a "first laminate") can be obtained. The drying conditions are not particularly limited, and may be appropriately set depending on the composition of the adhesive composition and the thickness of the adhesive layer 2. Specific examples of the drying conditions include drying at a temperature of from 70 ° C to 130 ° C for about 20 seconds to 3 minutes.

Then, on the surface composed of the adhesive layer 2 of the first laminate The first protrusion 11p is formed. The method of forming the first protrusions 11p is not particularly limited. Specifically, for example, as described below. The liquid composition for forming the first projection 11p is prepared, and the liquid composition is applied onto a suitable support, and the obtained coating film is dried or cured to obtain a film-like member (resin film) that provides the first projection 11p. And adhesive layer). The member in which the film-shaped member is half-cut or the portion which is not required to be partially cut off is obtained, and a member which provides the first protrusion 11p of a desired shape can be obtained. The member for providing the first projection 11p is adhered to the surface of the first laminate body by the adhesive layer 2, and the support is removed to form the surface of the adhesive layer 2 of the first laminate. on. The member that provides the first projection 11p is a resin film, and the resin film may be a film obtained by extrusion molding or the like. When the member providing the first projection 11p is a laminate including a resin film and an adhesive layer, it is preferable to laminate the layers before trimming the respective elements.

As another specific example for forming the first protrusions 11p, it is also possible to use a dispenser, a spin coating, an inkjet, a screen printing or the like, a laminate molding method such as a 3D printer, or injection molding, etc., to form the first one. The liquid composition or the like of the projections 11p is printed, molded, or the like on the surface of the adhesive layer 2 of the first laminate, and the printed matter or the like is dried or cured to obtain the first projections 11p. In this case, the first projection 11p of a desired shape can be formed on the surface of the adhesive layer 2 of the first laminate without the trimming as described above. The first projection 11p is formed by a dispenser or the like, and is not formed on the surface formed by the adhesive layer 2, and may be formed directly on the substrate 1, for example.

The third protrusion 13p can be basically formed by the same method as the method of forming the first protrusion 11p. When the first projection 11p is manufactured by an operation including coating, the third projection 13p is in view of productivity. It is preferable to form the first protrusions 11p at the same time. Specifically, when the trimming is performed, the half-cut position is changed, and the amount of the unnecessary portion is reduced, whereby the third projection 13p continuous with the first projection 11p can be formed.

As a result, the first protrusions 11p and the like are formed on the first layered body, and the release sheet is adhered to the side of the first layered body on the side where the first protrusions 11p and the like are formed. The laminated body of the obtained first laminate and the release sheet was subjected to half-cutting from the side of the first laminate to remove unnecessary portions, thereby forming the substrate 1. By the above operation, the stretchable sheet 10 is obtained by sticking the stretchable sheet 10 to the peeling sheet so that the first main surface 10A and the peeling surface face each other.

3. Method of manufacturing laminated wafer 40

In the following, in order to form the modified layer, the multi-projection workpiece 20 is irradiated with laser light, and in the multi-projection workpiece 20 in a state in which the modified layer 21m is formed, according to the estimated dividing line in the substrate 21 of the multi-projecting workpiece 20, A method of manufacturing the laminated wafer 40 will be described using the extendable sheet 10.

(1) Adhesion step

The stretchable sheet 10 is adhered to the multi-projection workpiece 20 formed by the modified layer and the annular frame 30 arranged on the outer peripheral side of the multi-projection workpiece 20 in plan view. As a result, as shown in FIG. 5, the surface formed by the first projection 11p is adhered to the most distal residual portion 21r, and the second region 12a is adhered to the plurality of projections 22 of the multi-projection workpiece 20. status. In this way, the laminated structure 50 formed by laminating the multi-projection workpiece 20 and the annular frame 30 on the first main surface 1A of the extendable sheet 10 is obtained. Here, as described above, from the viewpoint of achieving a more stable separation between the most distant residual portion 21r and the farthest layer laminated wafer 40d, the first projection 11p is second at the end of the adhesion step. The ratio of the projection height of the region 12a to the reference is preferably 80% or more and 120% or less of the ratio of the projection height of the most distal convex portion 22d based on the substrate 21.

(2) Extension steps

Then, the laminated structure 50 extends the annular region in which the first main surface 10A of the sheet 10 is exposed in plan view, that is, the portion corresponding to a portion of the third region 13a, from the main opposite to the first main surface 10A. The ring member 60 is pressed on the side of the face. In the present specification, the portion where the annular member 60 of the stretchable sheet 10 is pressed and the region of the first main surface 1A corresponding thereto are referred to as "load region 10L".

Further, in order to achieve the contact portion of the annular member 60 with respect to the stretchable sheet 10, the distance in the vertical direction with respect to the lower side surface of the portion of the extendable sheet 10 adhered to the annular frame 30 is increased. The annular member 60 is moved in the vertical direction. As a result, the stretchable sheet 10 is given tension in a plane view from the central portion toward the outer peripheral portion.

The tension applied thereto is transmitted to the convex portion 22 of the multi-projection workpiece 20 through the adhesive layer 2, and is transmitted to the most distal residual portion 21r of the multi-projection workpiece 20 by the first projection portion 11p, and the workpiece 20 is multi-projected. Between the farthest position convex portion 22d and the farthest position residual portion 21r, a force is generated in a direction separating them. By this force, the breakage of the farthest convex portion 22d and the farthest residual portion 21r and their separation are generated. Further, by irradiating the laser light for forming the modified layer, although the farthest convex portion 22d and the farthest residual portion 21r have been broken, in this case, the force in the above-mentioned separation direction is the farthest. The position convex portion 22d and the farthest position residual portion 21r are separated from each other. Therefore, the farthestmost layered wafer 40d can be obtained in a state of being separated from the farthest position remaining portion 21r. Thus, on the extensible sheet 10, the majority of the laminated wafers 40 including the farthestmost layered wafer 40d are separated from each other. In the state of the arrangement, it is possible to obtain a laminated structure in which the annular frame 30 is adhered in the vicinity of the outer peripheral portion in a plan view (hereinafter referred to as "expanded laminated body 70").

(3) Picking step

In the pickup step, the laminated wafer 40 included in the expanded laminated body 70 is separated from the stretchable sheet 10.

(4) Recovery steps

As described above, the portion of the extendable sheet 10 corresponding to the load region 10L is relatively given the strongest external force, and for this portion, the stretchable sheet 10 is in the most stretched state. Therefore, the annular member 60 in contact with the expanded laminated body 70 is separated, and the extendable sheet 10 is placed in an unloaded state. As shown in FIGS. 7 and 9, the expanded sheet 10 included in the expanded laminated body 70 becomes loose. The portion of the extendible sheet 10 adhered to the annular frame 30 and the central portion of the extendable sheet 10 are spaced apart in the vertical direction. When the amount of looseness is too large, the bottom surface of the stretchable sheet 10 at the time of transportation or the vicinity thereof is likely to collide with foreign matter, and the laminated body 70 is reduced in workability when it is used.

Therefore, the restoration step of heating the portion corresponding to the load region 10L in the stretchable sheet 10 of the expanded laminated body 70 may be performed. By heating the portion, the substrate 1 of the stretchable sheet 10 is thermally shrunk, and the amount of looseness of the stretchable sheet 10 of the expanded laminate 70 can be reduced.

As shown in FIG. 7, when the load region 10L overlaps with the third convex region 13b, when the third projection 13p is made of a heat-shrinkable material, the portion corresponding to the load region 10L of the extendable sheet 10 is heated. The third protrusion 13p can be thermally contracted together with the substrate 1. When the third protrusion 13p includes the heat-shrinkable material included in the substrate 1, the substrate is bonded to the substrate. The same heat shrinkage 1 can more stably reduce the looseness of the stretchable sheet 10.

As shown in Fig. 9, when the load region 10L overlaps with the easily recoverable region 13c, the heat shrinkage characteristic of the portion corresponding to the easily recoverable region 13c in the stretchable sheet 10 is such that the influence of the thickest member substrate 1 in this portion is large. Therefore, due to the heat shrinkage of the substrate 1, the amount of looseness of the stretchable sheet 10 can be more stably lowered.

The conditions (specifically, temperature, time, etc.) at the time of heating the corresponding portion of the load region 10L of the stretchable sheet 10 are at least one of the members constituting the stretchable sheet 10 as long as the stretchable sheet 10 can be lowered due to heat shrinkage. There is no particular limitation on the amount of looseness. As a specific example of the heating conditions, the stretchable sheet 10 is kept at a temperature of about 50 ° C to 70 ° C for about 1 minute.

In the case where the restoration step is carried out, there is no particular limitation as long as the implementation time thereof is after the expansion step. It is preferred to perform the time before the start of the picking step, and then the expansion step is implemented to be better.

(5) Energy line irradiation step

In the case where the energy ray-curable material (for example, a material including the energy ray-polymerizable compound (β) is included as a specific example), the adhesive layer 2 having the stretchable sheet 10 is irradiated with energy rays. The step of curing the energy ray-curable material to reduce the adhesion of the adhesive layer 2 to the multi-projection workpiece 20, that is, the energy ray irradiation step, is usually performed before the start of the pickup step. There is no limitation on the relationship between the implementation time of the energy ray irradiation step and the implementation time of the restoration step.

The embodiment described above is for the purpose of facilitating the invention. The description of the present invention is not intended to limit the present invention. Therefore, each of the elements disclosed in the above embodiments includes all design changes and equivalents belonging to the technical scope of the present invention.

For example, the second region 12a of the stretchable sheet 10 on the first main surface 10A is constituted by a surface composed of the adhesive layer 2 in the above embodiment, but is not limited thereto. For example, the adhesive layer 2 may be laminated with another film-like member, and the second region 12a may be formed by a surface composed of the laminate. Specific examples of such a film-like member include a member which is laminated on the laminated wafer 40 and which is formed by directly or preferably being cured by heating and energy ray irradiation as a protective film of the laminated wafer 40, and the laminated wafer 40 is laminated. A member used as an adhesive layer for adhering to other members (hereinafter referred to as "curable film or the like").

Further, the adhesive layer 2 itself may be a curable film or the like. At this time, in the pickup step, the laminated body of the laminated wafer 40 and the adhesive layer 2 such as a curable film is removed in the stretchable sheet 10.

Example

The present invention will be specifically described by the following examples, but the scope of the present invention is not limited by the examples and the like.

[Example 1]

(1) Production of extendable sheets

An ethylene methacrylic acid copolymer film having a thickness of 38 μm of an anthrone release-treated polyethylene terephthalate release film and two adhesive sheets having a thickness of 220 μm composed of an acrylic adhesive are prepared. The release film on the sheet was removed. The two layers are laminated in such a manner that the film surface of the adhesive sheet from which the release film is not removed is bonded to the surface of the adhesive sheet from which the release film is removed, thereby obtaining A member having a total thickness of 440 μm other than the release film. This member was subjected to shape processing by half-cutting and cutting of the unnecessary portion of the member from which the release film was removed. Thus, a member having a defect portion in a plane as a ring shape (outer diameter: 270 mm, inner diameter: 194 mm) was obtained as a member for providing a projection. Adhesive layer of an adhesive sheet (hereinafter referred to as "first adhesive sheet") composed of an ethylene methacrylic acid copolymer film having a substrate thickness of 80 μm and an acrylic adhesive having an adhesive layer thickness of 10 μm. On the main surface of the main surface, the member for providing the projection is bonded to the film surface of the projection member so as to face each other to obtain a laminate.

Thereafter, the entire cutting was performed to obtain an extendable sheet including the above-mentioned projections having an outer diameter of 270 mm in plan view.

The processing region of the stretchable sheet is a circular region having a diameter of 200 mm which is co-centered with the stretchable sheet as viewed in plan. Therefore, the first region is an annular region composed of the first convex region and having an outer diameter of 200 mm and an inner diameter of 194 mm. Further, the third region is an annular region composed of a third convex region and having an outer diameter of 270 mm and an inner diameter of 200 mm.

(2) Manufacturing of laminated wafers

In a circular main surface having a circular tantalum wafer having a plane viewing diameter of 200 mm, a circular area having a diameter of 180 mm which is common to both the planar view and the tantalum wafer is prepared to have a length and width of 5 mm × 5 mm and a height. The square column of 400 μm is a member to be processed in a state in which the distance between the plane and the closest square column is 5 mm, and the state is fixed in an ordered arrangement.

The substrate side and the opposite side of the stretchable sheet produced by the examples and the comparative examples were bonded using an adhesive tape apparatus ("RAD 2700 m/8" manufactured by LINTEC Co., Ltd.) On the main surface, the member to be processed and the annular frame (inner diameter 250 mm) subjected to the above-described step of forming the modified layer were adhered so as to become concentric circles.

For the tantalum wafer of the member to be processed, the substrate side of the stretchable sheet was irradiated with pulsed laser light having a wavelength of 1064 nm, and a modified layer was formed in the tantalum wafer along a projected dividing line of 20 mm × 20 mm.

For the stretchable sheet, the member to be processed, and the laminated structure formed by the annular frame, the separation expander ("DDS2300" manufactured by DISCO Corporation) was used to perform the heater expansion division according to the following conditions. The expansion step of the wafer. As a result, the member to be processed was divided, and a plurality of laminated wafers each having a sheet shape of 20 mm × 20 mm were formed on the stretchable sheet.

<Extended condition>

Temperature: 23 ° C

Pressure speed: 1mm/S

Pressure: 12mm

Maintenance time after pressure: 1 minute

A portion of the stretchable sheet which is placed in a plane between the member to be processed and the annular frame (a part of the third region) is heated by the above-described separating and expanding machine. Specifically, the warm air was sprayed from the air blowing ports at the two positions, and rotated at a speed of 1°/S for 180 seconds. The heating conditions are as follows. As a result, the portion is thermally contracted, and the amount of looseness of the stretchable sheet is reduced.

<Extended condition>

Temperature: 23 ° C

Pressure speed: 1mm/S

Pressure: 12mm

<recovery condition>

Warm air input temperature: 220 ° C

Air supply port ~ distance between extendable sheets: 20mm

Speed: 1°/S, 180 seconds heating

For the stretchable sheet subjected to the restoring step, a picking step of separately separating the plurality of laminated wafers from the stretchable sheet is carried out.

Thereby, a laminate wafer is produced using the stretchable sheet on the member to be processed.

[Example 2]

An adhesive sheet having a thickness of 330 μm (hereinafter referred to as a "second adhesive sheet") composed of a polyurethane film and an acrylic adhesive which are cured by an energy ray-curable composition, and an acrylic sheet in the second adhesive sheet. On the adhesive-like side surface, a laminate comprising a fluorene ketone peel-treated polyethylene terephthalate release film having a thickness of 38 μm on the release surface was adhered. The half-cut and the unnecessary portion of the second adhesive sheet are completely cut on the polyurethane film side of the laminate, and the shape is processed. Thereby, a member having a circular shape in plan view (outer diameter: 272 mm, inner diameter: 266 mm) was obtained on the release sheet as a member for providing the first projection. The member for providing the first projection and the laminate formed of the release sheet are provided on the surface (film surface) on the side of the first projection member, and are bonded to the first adhesive sheet used in the first embodiment and adhered to the same adhesive sheet. The main surface of the agent layer. The first adhesive sheet of the thus obtained laminated body was cut into a circular shape having an outer diameter of 270 mm in plan view. At this time, the two circles (the inner circumference side circle and the outer circumference side circle) in which the circle and the member providing the first protrusion portion are significantly protruded in plan view time are concentric circles. Thereby, an extendable sheet including the first projection portion having an outer diameter of 270 mm in plan view was obtained. Use the extendable sheet to Next, in the same manner as in the first embodiment, a laminated wafer was produced from the member to be processed.

[Comparative Example 1]

An ethylene methacrylic acid copolymer film as a substrate and an adhesive sheet having a thickness of 90 μm composed of an acrylic adhesive as an adhesive layer were cut as an extendable sheet having an outer diameter of 270 mm in plan view. Using the stretchable sheet, a laminate wafer was produced from the workpiece to be processed in the same manner as in the first embodiment.

[Test Example 1] <Observation of adhesion state>

The laminated structure of the stretchable sheet, the workpiece to be processed, and the annular frame obtained by the adhesion step was visually observed.

(View 1) Adhesion state of the first convex region of the most distant residual portion of the member to be processed

(View 2) Adhesion state of the second region of the convex portion of the member to be processed

For the observation results, the evaluation was performed according to the following criteria.

A: Moderate adhesion (good)

B: not moderately adhered (bad)

The evaluation results are shown in Table 1.

[Test Example 2] <Extensibility Evaluation>

The stretchable sheet after the expansion step was observed and evaluated according to the following criteria.

A: The stretchable sheet is moderately stretched (good)

B: The stretchable sheet is not moderately stretched (bad)

The evaluation results are shown in Table 1.

[Test Example 3] <Waferability Evaluation>

After the expansion step, the state of the member to be processed is divided and evaluated according to the following criteria.

A: The laminated wafer including the farthest convex portion is appropriately divided from the farthest residual portion (good)

B: The laminated wafer including the farthest convex portion is not appropriately divided from the farthest residual portion (defective)

The evaluation results are shown in Table 1.

[Test Example 4] <Heat shrinkage evaluation>

The stretchable sheet after the recovery step was observed and evaluated according to the following criteria.

A: The plurality of laminated sheets of the extensible sheet are sufficiently separated from each other while the stretchable sheet is sufficiently relaxed (good)

B: Although the adhesive sheet portion of the stretchable sheet is heat-shrinked, the third projection portion is not thermally shrunk, and as a result, the slack of the stretchable sheet is not sufficiently reduced (defective).

The evaluation results are shown in Table 1. Further, in Comparative Example 1, since the wafer splitting property was poor, the heat shrinkage property evaluation was not performed.

It can be seen from Table 1 that the embodiment satisfying the conditions of the present invention can be extended. Sheets can be said to be less prone to problems in both the expansion step and the recovery step.

Industrial availability

The stretchable sheet according to the present invention is suitably used for obtaining a sheet of a laminated wafer from a multi-projected workpiece such as a laminate produced by COW technology, and is suitably used as a dicing sheet, for example.

Claims (13)

An extendable sheet comprising an extensible sheet comprising a heat-shrinkable substrate and an adhesive layer laminated on a main surface of the substrate; wherein the processing region is to be viewed in a plan view The outer circumference of the processing region is formed as a first region of the outer circumferential region, and the inner region of the first region located in the annular region is formed by a second region including the processing region as a center. The processing region is disposed on the first main surface of the main surface on the side of the adhesive layer closer to the substrate of the stretchable sheet, and is bonded to the substrate in the thickness direction in use. a region of the member to be processed of the convex portion; the first region includes a surface formed by the first protrusion portion of the protrusion portion in the direction in which the substrate is separated from the second region. According to the stretchable sheet of the first aspect of the invention, the workpiece to be processed is divided into a plurality of sheet-like bodies by a process including a dividing step, and the dividing step is to irradiate the member to be processed. The laser beam continuously forms a modified layer, and the step of dividing the processed member by the formation of the modified layer along the dividing line of reduced strength; the plurality of sheets containing the plurality of sheets are divided into at least one of the plurality A laminated wafer of tabular bodies of convex portions. According to the stretchable sheet of the first aspect of the invention, in the use, the most distal residual portion of the workpiece is adhered to the surface formed by the first projection, and the most distal residual portion is The processing member is in a plan view and is located at a convex portion farthest from the center of the workpiece to be processed. The far portion is a portion other than the portion of the laminated wafer. According to the stretchable sheet of the first aspect of the invention, in the above-mentioned workpiece, the plurality of convex portions are adhered to the second region. According to the stretchable sheet of the first aspect of the invention, the first main surface of the extendable sheet includes a third region on the outer peripheral side of the processing region in a plan view, and the third region has The second region is a third projection region formed on the surface of the third projection portion of the projection protruding from the direction in which the substrate is spaced apart from each other, and the third projection has heat shrinkability. The stretchable sheet according to claim 1, wherein the base material is the thickest member in the portion of the stretchable sheet corresponding to at least a part of the third region. According to the stretchable sheet of the first aspect of the invention, the laminate including the substrate and the adhesive layer is adhered to a mirror mirror wafer, and the laminate is measured based on JIS Z0237:2000. The adhesion of the body is 1000mN/25mm or more and 20000mN/25mm or less. In the stretchable sheet according to the first aspect of the invention, the projection of the first region has a projection height of 200 μm or more as compared with the second region. The extensible sheet according to item 1, wherein the substrate comprises a polyolefin film. A method for producing a laminated wafer, which is a method for producing a laminated wafer of a sheet-like body including at least one of the plurality of convex portions from a member to be processed including a plurality of convex portions in a thickness direction on a substrate, The method includes a dividing step, an adhering step, an expanding step, and a picking step. The dividing step is: irradiating the processed member with the laser beam to continuously form the modified layer by the processed member, and the formation of the modified layer decreases along the strength The step of dividing the predetermined line to divide the workpiece; the sticking step is: forming a modified layer continuously by irradiating the processed member with the laser beam, and forming the modified layer along the strength The member to be processed which is the step of dividing the predetermined member by dividing the predetermined line, and the annular frame which is disposed on the outer peripheral side of the member to be processed in plan view, and adhered to any one of the first to ninth items of the patent application range The extendable sheet according to the above aspect, which is considered to be located at a position farther than a convex portion located farthest from the center of the workpiece to be processed in the above-mentioned workpiece, and which is one of the laminated wafers a portion other than the portion, that is, a portion farthest from the remaining portion, adheres to the surface formed by the first protrusion, and adheres to the plurality of convex portions of the member to be processed. a step of the state of the second region; the expanding step of extending the stretchable sheet, dividing the workpiece into a plurality of sheet-like bodies, and a plurality of sheets including at least one of the plurality of convex portions The laminated sheets of the body are disposed on the stretchable sheet, and the portion other than the convex portion of the workpiece to be adhered to the surface formed by the first projection is in a state of being separated from the laminated wafer. The step of picking up is a step of separating the laminated wafer from the stretchable sheet. According to the method of manufacturing a laminated wafer according to the above aspect of the invention, the protrusion height of the first protrusion based on the second region is a protrusion based on the substrate of the convex portion included in the workpiece. The ratio of height is 80% or more and 120% or less. The method for producing a laminated wafer according to claim 10, wherein the expanding step performs the stretchable sheet by abutting a ring-shaped member corresponding to a portion of the third region portion in the stretchable sheet. Extending, heating the portion of the extendable sheet that is abutted by the annular member, and shrinking the portion of the substrate, and completing the step of expanding after the step of expanding. The method for producing a laminated wafer according to claim 10, wherein the adhesive layer including the stretchable sheet contains an energy ray-curable material, and the energy ray is hardened by irradiating the adhesive layer with an energy ray. The energy material is hardened, and the energy ray irradiation step of lowering the adhesiveness of the adhesive layer to the wafer is started between the picking steps after the end of the expanding step.