JP7539224B2 - Dicing tape with adhesive film - Google Patents

Description

The present invention relates to a dicing tape with an adhesive film that can be used in the manufacturing process of semiconductor devices.

In the manufacturing process of semiconductor devices, a dicing tape with an adhesive film may be used to obtain a semiconductor chip with an adhesive film of a size equivalent to the chip for die bonding, i.e., a semiconductor chip with an adhesive film. The dicing tape with an adhesive film has, for example, a dicing tape made of a base material and an adhesive layer, and an adhesive film releasably attached to the adhesive layer side. The adhesive film has a disk shape larger than the semiconductor wafer, which is the workpiece, and is concentrically attached to the adhesive layer side of the dicing tape, which has a disk shape larger than the adhesive film, for example. A SUS ring frame can be attached to the area around the adhesive film that is not covered by the adhesive film in the adhesive layer of the dicing tape. The ring frame is a member that, when attached to the dicing tape, mechanically contacts a transport mechanism such as a transport arm provided in various devices when transporting the workpiece.

As one method for obtaining semiconductor chips with adhesive film using a dicing tape with adhesive film, a method is known in which the dicing tape with adhesive film is expanded and the adhesive film is cut. In this method, a semiconductor wafer is first laminated on the adhesive film of the dicing tape with adhesive film, with a ring frame attached to the area around the adhesive film of the dicing tape pressure-sensitive adhesive layer. This semiconductor wafer is processed so that it can be cut together with the cutting of the adhesive film and separated into multiple semiconductor chips. Next, a specific expanding device is used to cut the adhesive film so that multiple adhesive film pieces, each of which is in close contact with a semiconductor chip, are generated from the adhesive film on the dicing tape, and the dicing tape of the dicing tape with adhesive film is expanded in the radial direction of the wafer (expanding process). In this expanding process, the adhesive film is also cut at the places on the semiconductor wafer that correspond to the adhesive film cutting places, and the semiconductor wafer is cut into multiple semiconductor chips on the dicing tape with adhesive film or on the dicing tape. Next, the dicing tape is expanded (separation expansion) to increase the distance between chips on the dicing tape with adhesive film, and then each semiconductor chip, together with the adhesive film of a size equivalent to the chip that is attached to it, is pushed up from the underside of the dicing tape by the pin member of the pick-up mechanism and picked up from the dicing tape (pick-up process). In this way, a semiconductor chip with an adhesive film is obtained. This semiconductor chip with adhesive film is then fixed to an adherend such as a mounting substrate by die bonding via the adhesive film. For example, technology related to dicing tape with adhesive film used in the above manner is described in, for example, the following Patent Documents 1 and 2.

JP 2007-2173 A JP 2010-177401 A

In the past, in dicing tapes with adhesive films, an adhesive layer having ultraviolet curing properties has been used as the dicing tape adhesive layer. In the semiconductor device manufacturing process in which such dicing tapes with adhesive films are used, an ultraviolet irradiation step is carried out prior to the above-mentioned pick-up step, in order to significantly reduce the adhesive strength of the adhesive layer by irradiating the dicing tape adhesive layer with ultraviolet light, which is attached to a large number of semiconductor chips with adhesive films.

Some expanding devices for carrying out the above-mentioned expanding process are equipped with UV lamps for irradiating ultraviolet light onto the adhesive layer of the dicing tape that has undergone the expanding process. The UV irradiation by the UV lamps equipped in the expanding device reduces the adhesive strength of the dicing tape adhesive layer over substantially the entire surface of the dicing tape adhesive layer, not only in the area where the adhesive layer is attached to the workpiece, but also in the area where the adhesive layer is attached to the ring frame. When a dicing tape with an adhesive film, in which the adhesive strength of the dicing tape adhesive layer attached to the ring frame has been reduced in this way, is subjected to a subsequent process with a workpiece on the adhesive film, for example, during the above-mentioned separation expansion in the pick-up process, the dicing tape or its adhesive layer may peel off from the ring frame.

The present invention was conceived in light of the above circumstances, and its purpose is to provide a dicing tape with an adhesive film that is suitable for ensuring ring frame retention even after exposure to ultraviolet light in an ultraviolet-curable dicing tape adhesive layer.

The dicing tape with adhesive film provided by the present invention comprises a dicing tape and an adhesive film. The dicing tape has a laminated structure including a substrate and an ultraviolet-curable adhesive layer. The adhesive film is releasably attached to the adhesive layer of the dicing tape. The dicing tape exhibits a peel adhesion of ^{0.03 to 0.2 N/20 mm against the SUS flat surface in a peel test under conditions of 23° C., a peel angle of 180°, and a peel speed of 300 mm/min after the adhesive layer is attached to the SUS flat surface and then irradiated with ultraviolet light of 200} mJ/cm 2. In the present invention, the ultraviolet light irradiation of the adhesive layer of the dicing tape refers to irradiation through the substrate of the dicing tape (irradiation from the substrate side). The dicing tape with adhesive film having such a configuration can be used in the process of obtaining a semiconductor chip with an adhesive film in the manufacture of a semiconductor device.

As described above, the dicing tape of this adhesive film-attached dicing tape exhibits a peel adhesion strength of ^0.03 to 0.2 N/20 mm against the SUS flat surface in a peel test under conditions of 23°C, a peel angle of 180°, and a peel speed of 300 mm/min, after the adhesive layer side of the dicing tape is attached to the SUS flat surface and the adhesive layer is then irradiated with ultraviolet light at 200 mJ/cm2. The configuration in which the peel adhesion strength is 0.03 N/20 mm or more is suitable for ensuring the ring frame retention strength required at the attachment point during the semiconductor device manufacturing process, even when a metal ring frame such as SUS is attached to the dicing tape of this adhesive film-attached dicing tape and the ring frame attachment point of the dicing tape adhesive layer is irradiated with ultraviolet light. This configuration is suitable for, for example, during separation expansion in the pick-up process as described above, so that the ring frame attachment portion of the dicing tape pressure-sensitive adhesive layer continues to adhere to the ring frame against the tensile force acting thereon (i.e., suitable for suppressing peeling of the dicing tape from the ring frame). Furthermore, a configuration in which the peel adhesion strength is 0.2 N/20 mm or less is suitable for peeling the dicing tape of the dicing tape with adhesive film from the ring frame without leaving any adhesive residue after the ring frame is attached to the dicing tape of the dicing tape with adhesive film and the ring frame attachment portion of the dicing tape pressure-sensitive adhesive layer is irradiated with ultraviolet light.

As described above, the dicing tape with adhesive film is suitable for ensuring ring frame retention in the ultraviolet-curable dicing tape adhesive layer even after exposure to ultraviolet light, and is also suitable for preventing adhesive residue from the adhesive layer when peeled off from the ring frame. From the viewpoint of ensuring ring frame retention as described above, the peel adhesive strength is preferably 0.05 N/20 mm or more, more preferably 0.1 N/20 mm or more. From the viewpoint of preventing adhesive residue as described above, the peel adhesive strength is preferably 0.18 N/20 mm or less, more preferably 0.15 N/20 mm or less.

The dicing tape with adhesive film has a peel adhesion strength between the adhesive film and the adhesive layer irradiated with 200 mJ/ ^cm2 ultraviolet light in a T-type peel test at 23°C and a peel speed of 300 mm/min, preferably 0.03 to 0.12 N/20 mm, more preferably 0.04 to 0.11 N/20 mm. Such a configuration is suitable for appropriately carrying out the pick-up process. The configuration in which the peel adhesion strength is 0.03 N/20 mm or more, preferably 0.04 N/20 mm or more, is suitable for suppressing peeling between the dicing tape or its adhesive layer and the adhesive film of the semiconductor chip with adhesive film, i.e., chip peeling, during the separation expansion before chip pick-up in the above-mentioned pick-up process. The configuration in which the peel adhesion strength is 0.12 N/20 mm or less, preferably 0.11 N/20 mm or less, is suitable for carrying out chip pick-up without causing cracks in the semiconductor chip in the above-mentioned pick-up process.

In this dicing tape with adhesive film, the surface free energy of the adhesive film side surface of the pressure-sensitive adhesive layer irradiated with 200 mJ/cm ² of ultraviolet light is preferably 16 mJ/m ² or more, more preferably 23 mJ/m ² or more, and more preferably 25 mJ/m ² or more. Such a configuration is suitable for ensuring the interfacial adhesive strength of the dicing tape pressure-sensitive adhesive layer after ultraviolet light irradiation to a metal ring frame such as SUS, and therefore is suitable for ensuring the above-mentioned ring frame holding strength.

The dicing tape adhesive layer of the dicing tape with adhesive film preferably contains a polymer containing a nitrogen-containing monomer as a constituent monomer. The nitrogen-containing monomer is preferably acryloylmorpholine. The content of the nitrogen-containing monomer as a constituent monomer in the polymer is preferably 1 to 40 mol%, more preferably 3 to 35 mol%. In the dicing tape with adhesive film, the content of 1 mol% or more, preferably 3 mol% or more, is suitable for achieving high polarity for the polymer in the dicing tape adhesive layer, and is therefore suitable for ensuring the ring frame retention force described above. In the dicing tape with adhesive film, the content of 40 mol% or less, preferably 35 mol% or less, is suitable for obtaining good peelability of the semiconductor chip with adhesive film from the dicing tape in the pick-up process described above.

1 is a plan view of a dicing tape with an adhesive film according to one embodiment of the present invention. 2 is a schematic cross-sectional view of the dicing tape with adhesive film shown in FIG. 1. 3 shows some steps in an example of a semiconductor device manufacturing method in which the dicing tape with adhesive film shown in FIGS. 1 and 2 is used. This represents a step subsequent to the step shown in FIG. This represents a step subsequent to the step shown in FIG. This represents a step subsequent to the step shown in FIG. This represents a step subsequent to the step shown in FIG. This represents a step subsequent to the step shown in FIG. This represents a step subsequent to the step shown in FIG. 3 illustrates some steps in another example of a semiconductor device manufacturing method in which the dicing tape with an adhesive film shown in FIGS. 1 and 2 is used. This shows a process following the process shown in FIG. 3 illustrates some steps in another example of a semiconductor device manufacturing method in which the dicing tape with an adhesive film shown in FIGS. 1 and 2 is used. This represents a step subsequent to the step shown in FIG.

Figures 1 and 2 show a dicing tape X with an adhesive film according to one embodiment of the present invention. Figure 1 is a plan view of the dicing tape X with an adhesive film, and Figure 2 is a schematic cross-sectional view of the dicing tape X with an adhesive film.

The dicing tape X with adhesive film has a laminated structure including a dicing tape 10 and an adhesive film 20. The dicing tape 10 has a laminated structure including a substrate 11 and an adhesive layer 12. The adhesive layer 12 has an adhesive surface 12a on the adhesive film 20 side. The adhesive film 20 is releasably attached to the adhesive layer 12 of the dicing tape 10 or its adhesive surface 12a. In this embodiment, the dicing tape 10 and the adhesive film 20 have a disk shape and are arranged concentrically as shown in FIG. 1. A ring frame made of, for example, SUS can be attached to the area around the adhesive film that is not covered by the adhesive film 20 in the adhesive layer 12 of the dicing tape 10. The ring frame is a member that mechanically contacts a transport mechanism such as a transport arm provided in various devices when transporting a workpiece when attached to the dicing tape 10. Such a dicing tape X with adhesive film can be used in the process of obtaining a semiconductor chip with an adhesive film in the manufacture of a semiconductor device.

The substrate 11 of the dicing tape 10 in the dicing tape X with adhesive film is an element that functions as a support in the dicing tape 10 or the dicing tape X with adhesive film. The substrate 11 is, for example, a plastic substrate that is UV-transmissive, and a plastic film can be suitably used as the plastic substrate. Examples of the constituent material of the plastic substrate include polyolefin, polyester, polyurethane, polycarbonate, polyether ether ketone, polyimide, polyetherimide, polyamide, wholly aromatic polyamide, polyvinyl chloride, polyvinylidene chloride, polyphenyl sulfide, aramid, fluororesin, cellulose-based resin, and silicone resin. Examples of polyolefin include low-density polyethylene, linear low-density polyethylene, medium-density polyethylene, high-density polyethylene, very low-density polyethylene, random copolymer polypropylene, block copolymer polypropylene, homopolypropylene, polybutene, polymethylpentene, ethylene-vinyl acetate copolymer, ionomer resin, ethylene-(meth)acrylic acid copolymer, ethylene-(meth)acrylic acid ester copolymer, ethylene-butene copolymer, and ethylene-hexene copolymer. Examples of polyesters include polyethylene terephthalate, polyethylene naphthalate, and polybutylene terephthalate. The substrate 11 may be made of one type of material, or may be made of two or more types of materials. The substrate 11 may have a single-layer structure or a multi-layer structure. In addition, when the substrate 11 is made of a plastic film, it may be a non-stretched film, a uniaxially stretched film, or a biaxially stretched film.

The surface of the substrate 11 facing the adhesive layer 12 may be subjected to a physical treatment, a chemical treatment, or a primer treatment to enhance adhesion to the adhesive layer 12. Examples of physical treatments include corona treatment, plasma treatment, sand mat processing, ozone exposure treatment, flame exposure treatment, high-voltage shock exposure treatment, and ionizing radiation treatment. Examples of chemical treatments include chromate treatment.

The thickness of the substrate 11 is preferably 40 μm or more, and more preferably 50 μm or more, from the viewpoint of ensuring the strength required for the substrate 11 to function as a support in the dicing tape 10 or the dicing tape X with an adhesive film. In addition, from the viewpoint of realizing appropriate flexibility in the dicing tape 10 or the dicing tape X with an adhesive film, the thickness of the substrate 11 is preferably 200 μm or less, and more preferably 180 μm or less.

The haze of the substrate 11 is preferably 50 to 98%. The haze of a substrate such as a plastic substrate can be measured, for example, using a haze measuring device (product name "HM-150", manufactured by Murakami Color Research Laboratory Co., Ltd.). When the substrate 11 has a haze of 50% or more, the position of the dicing tape X with adhesive film can be appropriately recognized by an optical sensor provided in the lamination device in the process of laminating the dicing tape X with adhesive film to a semiconductor wafer. When the substrate 11 has a haze of 98% or less, this is suitable for UV curing the adhesive layer 12 of the dicing tape 10 by irradiating the adhesive layer 12 with ultraviolet light through the substrate 11.

The adhesive layer 12 of the dicing tape 10 is an ultraviolet-curable adhesive layer whose adhesive strength decreases when exposed to ultraviolet light. Examples of adhesives for forming the ultraviolet-curable adhesive layer include additive-type ultraviolet-curable adhesives that contain a base polymer such as an acrylic polymer, which is an acrylic adhesive, and an ultraviolet-polymerizable monomer component or oligomer component that has a functional group such as an ultraviolet-polymerizable carbon-carbon double bond.

The acrylic polymer preferably contains the largest amount of monomer units derived from (meth)acrylic acid esters by mass. "(Meth)acrylic" means "acrylic" and/or "methacrylic". (Meth)acrylic acid esters for forming monomer units of acrylic polymers, i.e., (meth)acrylic acid esters that are constituent monomers of acrylic polymers, include, for example, (meth)acrylic acid alkyl esters, (meth)acrylic acid cycloalkyl esters, and (meth)acrylic acid aryl esters. Examples of (meth)acrylic acid alkyl esters include methyl ester, ethyl ester, propyl ester, isopropyl ester, butyl ester, isobutyl ester, s-butyl ester, t-butyl ester, pentyl ester, isopentyl ester, hexyl ester, heptyl ester, octyl ester, 2-ethylhexyl ester, isooctyl ester, nonyl ester, decyl ester, isodecyl ester, undecyl ester, dodecyl ester (i.e., lauryl ester), tridecyl ester, tetradecyl ester, hexadecyl ester, octadecyl ester, and eicosyl ester of (meth)acrylic acid. Examples of (meth)acrylic acid cycloalkyl esters include cyclopentyl ester and cyclohexyl ester of (meth)acrylic acid. Examples of (meth)acrylic acid aryl esters include phenyl (meth)acrylate and benzyl (meth)acrylate. As a constituent monomer of an acrylic polymer, one type of (meth)acrylic acid ester may be used, or two or more types of (meth)acrylic acid esters may be used. As the (meth)acrylic acid ester for the acrylic polymer, 2-ethylhexyl acrylate is preferably used. In order to adequately express basic properties such as adhesion due to the (meth)acrylic acid ester in the adhesive layer 12, the proportion of the (meth)acrylic acid ester in the total constituent monomers of the acrylic polymer is preferably 40% by mass or more, more preferably 60% by mass or more.

The above acrylic polymer may contain one or more monomer units derived from other monomers copolymerizable with (meth)acrylic acid esters, for example, from the viewpoint of improving the cohesive strength and heat resistance. Examples of other copolymerizable monomers for forming the monomer units of the acrylic polymer, that is, other copolymerizable monomers that are constituent monomers of the acrylic polymer, include, for example, carboxy group-containing monomers, acid anhydride monomers, hydroxy group-containing monomers, nitrogen-containing monomers, epoxy group-containing monomers, sulfonic acid group-containing monomers, and phosphoric acid group-containing monomers. Examples of carboxy group-containing monomers include acrylic acid, methacrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid. Examples of acid anhydride monomers include maleic anhydride and itaconic anhydride. Examples of hydroxyl group-containing monomers include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, 12-hydroxylauryl (meth)acrylate, and (4-hydroxymethylcyclohexyl)methyl (meth)acrylate. Examples of nitrogen-containing monomers include acryloylmorpholine, acrylamide, and acrylonitrile. Examples of epoxy group-containing monomers include glycidyl (meth)acrylate and methylglycidyl (meth)acrylate. Examples of sulfonic acid group-containing monomers include styrenesulfonic acid, allylsulfonic acid, 2-(meth)acrylamido-2-methylpropanesulfonic acid, (meth)acrylamidopropanesulfonic acid, and (meth)acryloyloxynaphthalenesulfonic acid. An example of a phosphate group-containing monomer is 2-hydroxyethyl acryloyl phosphate. As the copolymerizable monomer for the acrylic polymer, preferably, at least one selected from the group consisting of hydroxy group-containing monomers and nitrogen-containing monomers is used. As the copolymerizable monomer for the acrylic polymer, more preferably, at least one selected from the group consisting of 2-hydroxyethyl (meth)acrylate and acryloyl morpholine is used.

When the above acrylic polymer contains a monomer unit derived from a hydroxyl group-containing monomer, that is, when the acrylic polymer contains a hydroxyl group-containing monomer as a constituent monomer, the proportion of the hydroxyl group-containing monomer as a constituent monomer in the acrylic polymer is preferably 1 to 40 mol %, more preferably 10 to 30 mol %.

When the above acrylic polymer contains a monomer unit derived from a nitrogen-containing monomer, i.e., when the acrylic polymer contains a nitrogen-containing monomer as a constituent monomer, the proportion of the nitrogen-containing monomer as a constituent monomer in the acrylic polymer is preferably 1 to 40 mol %, more preferably 5 to 30 mol %.

The acrylic polymer may contain a monomer unit derived from a polyfunctional monomer that is copolymerizable with a monomer component such as a (meth)acrylic acid ester to form a crosslinked structure in the polymer backbone. Examples of such polyfunctional monomers include hexanediol di(meth)acrylate, (poly)ethylene glycol di(meth)acrylate, (poly)propylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, pentaerythritol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, polyglycidyl (meth)acrylate, polyester (meth)acrylate, and urethane (meth)acrylate. "(Meth)acrylate" means "acrylate" and/or "methacrylate". As a constituent monomer of the acrylic polymer, one type of polyfunctional monomer may be used, or two or more types of polyfunctional monomers may be used. In order to adequately express basic properties such as adhesion due to (meth)acrylic acid ester in the adhesive layer 12, the proportion of polyfunctional monomers in the total constituent monomers of the acrylic polymer is preferably 40 mol % or less, and preferably 30 mol % or less.

Acrylic polymers can be obtained by polymerizing the raw material monomers for forming them. Examples of polymerization methods include solution polymerization, emulsion polymerization, bulk polymerization, and suspension polymerization. From the viewpoint of high cleanliness in the semiconductor device manufacturing process in which the dicing tape 10 or the dicing tape X with adhesive film is used, it is preferable that the amount of low molecular weight substances in the adhesive layer 12 of the dicing tape 10 or the dicing tape X with adhesive film is small, and the weight average molecular weight of the acrylic polymer is preferably 100,000 or more, more preferably 200,000 to 3,000,000. The weight average molecular weight (Mw) of the acrylic polymer refers to the value measured by gel permeation chromatography (GPC) and converted into standard polystyrene.

The adhesive layer 12 or the adhesive for forming it may contain, for example, a crosslinking agent to increase the average molecular weight of the base polymer such as an acrylic polymer. Examples of crosslinking agents for forming a crosslinked structure by reacting with a base polymer such as an acrylic polymer include polyisocyanate compounds, epoxy compounds, polyol compounds, aziridine compounds, and melamine crosslinking agents as isocyanate crosslinking agents. The content of the crosslinking agent in the adhesive layer 12 or the adhesive composition for forming it is preferably 0.01 parts by mass or more, more preferably 0.03 parts by mass or more, and more preferably 0.05 parts by mass or more, per 100 parts by mass of the base polymer such as an acrylic polymer. The content is preferably 5 parts by mass or less, more preferably 4 parts by mass or less, and more preferably 3 parts by mass or less.

Examples of the ultraviolet-polymerizable monomer components for forming the ultraviolet-curable adhesive include urethane (meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol monohydroxypenta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and 1,4-butanediol di(meth)acrylate. Examples of the ultraviolet-polymerizable oligomer components for forming the ultraviolet-curable adhesive include various oligomers such as urethane-based, polyether-based, polyester-based, polycarbonate-based, and polybutadiene-based oligomers, and those with a molecular weight of about 100 to 30,000 are suitable. The total content of ultraviolet-polymerizable monomer components and oligomer components in the ultraviolet-curable adhesive is determined within a range that can appropriately reduce the adhesive strength of the adhesive layer 12 to be formed, and is preferably 5 to 500 parts by mass, and more preferably 40 to 150 parts by mass, per 100 parts by mass of a base polymer such as an acrylic polymer. In addition, as an additive-type ultraviolet-curable adhesive, for example, one disclosed in JP-A-60-196956 may be used.

Examples of UV-curable adhesives for the adhesive layer 12 include inherent UV-curable adhesives that contain a base polymer having a functional group such as a UV-polymerizable carbon-carbon double bond on the polymer side chain, in the polymer main chain, or at the end of the polymer main chain. Such inherent UV-curable adhesives are suitable for suppressing unintended changes over time in adhesive properties caused by the movement of low molecular weight components within the adhesive layer 12 being formed.

The base polymer contained in the intrinsic UV-curable adhesive is preferably one having an acrylic polymer as the basic skeleton. The above-mentioned acrylic polymers can be used as the acrylic polymer having such a basic skeleton. As a method for introducing a UV-polymerizable carbon-carbon double bond into an acrylic polymer, for example, a method is given in which raw material monomers including a monomer having a specific functional group (first functional group) are copolymerized to obtain an acrylic polymer, and then a compound having a specific functional group (second functional group) that can react with and bond to the first functional group and a UV-polymerizable carbon-carbon double bond is subjected to a condensation reaction or addition reaction with the acrylic polymer while maintaining the UV-polymerizability of the carbon-carbon double bond.

Examples of combinations of the first functional group and the second functional group include a carboxy group and an epoxy group, an epoxy group and a carboxy group, a carboxy group and an aziridyl group, an aziridyl group and a carboxy group, a hydroxy group and an isocyanate group, and an isocyanate group and a hydroxy group. Among these combinations, from the viewpoint of ease of reaction tracking, a combination of a hydroxy group and an isocyanate group, or a combination of an isocyanate group and a hydroxy group is preferred. In addition, since it is technically difficult to prepare a polymer having a highly reactive isocyanate group, from the viewpoint of ease of preparation or availability of an acrylic polymer, it is more preferred that the first functional group on the acrylic polymer side is a hydroxy group and the second functional group is an isocyanate group. In this case, examples of isocyanate compounds having both a UV-polymerizable carbon-carbon double bond and an isocyanate group as a second functional group, i.e., UV-polymerizable unsaturated functional group-containing isocyanate compounds, include methacryloyl isocyanate, 2-methacryloyloxyethyl isocyanate (MOI), and m-isopropenyl-α,α-dimethylbenzyl isocyanate.

The adhesive layer 12 preferably contains a photopolymerization initiator. Examples of the photopolymerization initiator include α-ketol compounds, acetophenone compounds, benzoin ether compounds, ketal compounds, aromatic sulfonyl chloride compounds, photoactive oxime compounds, benzophenone compounds, thioxanthone compounds, camphorquinone, halogenated ketones, acylphosphinoxides, and acylphosphonates. Examples of the α-ketol compounds include 4-(2-hydroxyethoxy)phenyl(2-hydroxy-2-propyl)ketone, α-hydroxy-α,α'-dimethylacetophenone, 2-methyl-2-hydroxypropiophenone, and 1-hydroxycyclohexylphenylketone. Examples of acetophenone compounds include methoxyacetophenone, 2,2-dimethoxy-1,2-diphenylethan-1-one, 2,2-diethoxyacetophenone, and 2-methyl-1-[4-(methylthio)-phenyl]-2-morpholinopropane-1. Examples of benzoin ether compounds include benzoin ethyl ether, benzoin isopropyl ether, and anisoin methyl ether. Examples of ketal compounds include benzyl dimethyl ketal. Examples of aromatic sulfonyl chloride compounds include 2-naphthalenesulfonyl chloride. Examples of photoactive oxime compounds include 1-phenyl-1,2-propanedione-2-(O-ethoxycarbonyl)oxime. Examples of benzophenone compounds include benzophenone, benzoylbenzoic acid, and 3,3'-dimethyl-4-methoxybenzophenone. Examples of thioxanthone compounds include thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-dichlorothioxanthone, 2,4-diethylthioxanthone, and 2,4-diisopropylthioxanthone. The content of the photopolymerization initiator in the adhesive layer 12 is, for example, 0.05 to 10 parts by mass per 100 parts by mass of the base polymer, such as an acrylic polymer.

The adhesive layer 12 or the adhesive for forming it may contain, in addition to the above-mentioned components, a cross-linking accelerator or cross-linking assistant (such as a photocross-linkable oligomer), a tackifier, an anti-aging agent, a filler, and a colorant such as a pigment or dye. The colorant may be a compound that becomes colored when exposed to radiation. An example of such a compound is a leuco dye.

The thickness of the adhesive layer 12 is preferably 1 to 50 μm, more preferably 2 to 30 μm, and more preferably 5 to 25 μm. This configuration is suitable, for example, for balancing the adhesive strength of the adhesive layer 12 to, for example, the adhesive film 20 before and after UV curing.

The dicing tape 10 having the above-mentioned configuration exhibits a peel adhesion of 0.03 to 0.2 N/ ²⁰ mm (peel adhesion to SUS) against the SUS plane in a peel test under conditions of 23° C., a peel angle of 180°, and a peel speed of 300 mm/min, after the adhesive layer 12 is attached to the SUS plane on the adhesive layer 12 side and then irradiated with ultraviolet light at 200 mJ/cm 2. The peel adhesion is preferably 0.05 N/20 mm or more, more preferably 0.1 N/20 mm or more. The peel adhesion is preferably 0.18 N/20 mm or less, more preferably 0.15 N/20 mm or less. Such peel adhesion can be measured, for example, using a tensile tester (product name "Autograph AGS-J", manufactured by Shimadzu Corporation). In addition, the peel adhesion of the dicing tape 10 can be adjusted, for example, by adjusting the composition (type and ratio) of the monomers that form the polymer in the adhesive layer 12, selecting the type of crosslinking agent used and adjusting the amount thereof, adjusting the weight average molecular weight of the polymer, selecting the type of tackifier used and adjusting the amount thereof, selecting the type of filler used and adjusting the amount thereof, selecting the type of crosslinking assistant used (e.g., photocrosslinkable oligomer) used and adjusting the amount thereof, selecting the type of photopolymerization initiator used and adjusting the amount thereof, and adjusting the amount of low molecular weight components and the amount of residual monomers in the adhesive layer 12.

The adhesive film 20 in the dicing tape X with adhesive film has a configuration capable of functioning as a die bonding adhesive exhibiting thermosetting properties. The adhesive film 20 may have a composition containing a thermosetting resin and a thermoplastic resin as resin components, or may have a composition containing a thermoplastic resin with a thermosetting functional group that can react with a curing agent to form a bond. Such an adhesive film 20 may have a single layer structure, or may have a multilayer structure in which adjacent layers have different compositions.

When the adhesive film 20 has a composition containing a thermosetting resin and a thermoplastic resin, examples of the thermosetting resin include epoxy resin, phenol resin, amino resin, unsaturated polyester resin, polyurethane resin, silicone resin, and thermosetting polyimide resin. The adhesive film 20 may contain one type of thermosetting resin, or may contain two or more types of thermosetting resin. Epoxy resin is preferred as the thermosetting resin in the adhesive film 20 because it tends to contain a small amount of ionic impurities that can cause corrosion of the semiconductor chip to be die-bonded. In addition, phenol resin is preferred as a curing agent for expressing thermosetting properties in epoxy resin.

Epoxy resins include, for example, bisphenol A type, bisphenol F type, bisphenol S type, brominated bisphenol A type, hydrogenated bisphenol A type, bisphenol AF type, biphenyl type, naphthalene type, fluorene type, phenol novolac type, orthocresol novolac type, trishydroxyphenylmethane type, tetraphenylolethane type, hydantoin type, trisglycidyl isocyanurate type, and glycidylamine type epoxy resins. Phenol novolac type epoxy resins, orthocresol novolac type epoxy resins, biphenyl type epoxy resins, trishydroxyphenylmethane type epoxy resins, and tetraphenylolethane type epoxy resins are preferred as epoxy resins in the adhesive film 20 because they are highly reactive with phenol resins as a curing agent and have excellent heat resistance.

Examples of phenolic resins that can act as a curing agent for epoxy resins include novolac-type phenolic resins, resol-type phenolic resins, and polyoxystyrenes such as polyparaoxystyrene. Examples of novolac-type phenolic resins include phenol novolac resins, phenol aralkyl resins, cresol novolac resins, tert-butylphenol novolac resins, and nonylphenol novolac resins. The adhesive film 20 may contain one type of phenolic resin as a curing agent for epoxy resins, or may contain two or more types of phenolic resins. Phenol novolac resins and phenol aralkyl resins tend to improve the connection reliability of the adhesive when used as a curing agent for epoxy resins as a die bonding adhesive, and are therefore preferred as curing agents for epoxy resins in the adhesive film 20.

When the adhesive film 20 contains an epoxy resin and a phenolic resin as its curing agent, the two resins are mixed in a ratio of preferably 0.5 to 2.0 equivalents, more preferably 0.8 to 1.2 equivalents of hydroxyl groups in the phenolic resin to 1 equivalent of epoxy groups in the epoxy resin. This configuration is preferable for allowing the curing reaction of the epoxy resin and phenolic resin to proceed sufficiently when the adhesive film 20 is cured.

The content of the thermosetting resin in the adhesive film 20 is preferably 5 to 60% by mass, and more preferably 10 to 50% by mass, from the viewpoint of allowing the adhesive film 20 to properly exhibit its function as a thermosetting adhesive.

The thermoplastic resin in the adhesive film 20 serves, for example, as a binder. When the adhesive film 20 has a composition containing a thermosetting resin and a thermoplastic resin, examples of the thermoplastic resin include acrylic resin, natural rubber, butyl rubber, isoprene rubber, chloroprene rubber, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-acrylic acid ester copolymer, polybutadiene resin, polycarbonate resin, thermoplastic polyimide resin, polyamide resin such as 6-nylon and 6,6-nylon, phenoxy resin, saturated polyester resin such as polyethylene terephthalate and polybutylene terephthalate, polyamideimide resin, and fluororesin. The adhesive film 20 may contain one type of thermoplastic resin or two or more types of thermoplastic resin. Acrylic resin is preferable as the thermoplastic resin in the adhesive film 20 because it has few ionic impurities and high heat resistance.

When the adhesive film 20 contains an acrylic resin as a thermoplastic resin, the acrylic resin preferably contains, by mass proportion, monomer units derived from (meth)acrylic acid ester.

(Meth)acrylic acid esters for forming monomer units of acrylic resin, i.e., (meth)acrylic acid esters that are constituent monomers of acrylic resin, include, for example, (meth)acrylic acid alkyl esters, (meth)acrylic acid cycloalkyl esters, and (meth)acrylic acid aryl esters. Examples of such (meth)acrylic acid esters include the (meth)acrylic acid alkyl esters described above as constituent monomers of the acrylic polymer for the adhesive layer 12. One type of (meth)acrylic acid ester may be used as the constituent monomer of the acrylic resin, or two or more types of (meth)acrylic acid esters may be used.

The acrylic resin may contain one or more monomer units derived from other monomers copolymerizable with the (meth)acrylic acid ester, for example, from the viewpoint of improving its cohesive strength or heat resistance. Examples of other copolymerizable monomers for forming the monomer units of the acrylic resin, i.e., other copolymerizable monomers that are constituent monomers of the acrylic resin, include, for example, carboxy group-containing monomers, acid anhydride monomers, hydroxy group-containing monomers, nitrogen-containing monomers, epoxy group-containing monomers, sulfonic acid group-containing monomers, and phosphoric acid group-containing monomers. Specific examples of these monomers include those mentioned above as the constituent monomers of the acrylic polymer for the pressure-sensitive adhesive layer 12.

When the adhesive film 20 has a composition containing a thermoplastic resin with a thermosetting functional group, the thermoplastic resin can be, for example, a thermosetting functional group-containing acrylic resin. The acrylic resin for forming the thermosetting functional group-containing acrylic resin preferably contains the most monomer units derived from (meth)acrylic acid esters in terms of mass ratio. As such (meth)acrylic acid esters, for example, the same (meth)acrylic acid esters as those described above as constituent monomers of the acrylic polymer for the adhesive layer 12 can be used. On the other hand, as thermosetting functional groups for forming the thermosetting functional group-containing acrylic resin, for example, glycidyl groups, carboxy groups, hydroxy groups, and isocyanate groups can be mentioned. Of these, glycidyl groups and carboxy groups can be preferably used. That is, as the thermosetting functional group-containing acrylic resin, glycidyl group-containing acrylic resins and carboxy group-containing acrylic resins can be preferably used. In addition, a curing agent that can react with the thermosetting functional group in the thermosetting functional group-containing acrylic resin is selected according to the type of the thermosetting functional group. When the thermosetting functional group of the thermosetting functional group-containing acrylic resin is a glycidyl group, the curing agent can be the same phenolic resin as described above as the curing agent for epoxy resins.

In order to achieve a certain degree of crosslinking in the adhesive film 20 before it is cured for die bonding, it is preferable to incorporate a polyfunctional compound that can react with the functional groups at the molecular chain ends of the resin components contained in the adhesive film 20 to form bonds as a crosslinking agent in the resin composition for forming the adhesive film. This configuration is suitable for improving the adhesive properties of the adhesive film 20 at high temperatures and for improving the heat resistance. Examples of such crosslinking agents include polyisocyanate compounds. Examples of polyisocyanate compounds include tolylene diisocyanate, diphenylmethane diisocyanate, p-phenylene diisocyanate, 1,5-naphthalene diisocyanate, and adducts of polyhydric alcohols and diisocyanates. The content of the crosslinking agent in the resin composition for forming the adhesive film is preferably 0.05 parts by mass or more per 100 parts by mass of the resin having the functional group capable of reacting with the crosslinking agent to form a bond, from the viewpoint of improving the cohesive strength of the adhesive film 20 to be formed, and is preferably 7 parts by mass or less from the viewpoint of improving the adhesive strength of the adhesive film 20 to be formed. In addition, as the crosslinking agent in the adhesive film 20, other polyfunctional compounds such as epoxy resins may be used in combination with the polyisocyanate compound.

The adhesive film 20 may contain a filler. Adding a filler to the adhesive film 20 is preferable in terms of adjusting the physical properties of the adhesive film 20, such as its elastic modulus, yield strength, and breaking elongation. Examples of the filler include inorganic fillers and organic fillers. The filler may have various shapes, such as spherical, acicular, and flake-like. The adhesive film 20 may contain one type of filler, or two or more types of fillers.

Examples of materials constituting the inorganic filler include aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, magnesium silicate, calcium oxide, magnesium oxide, aluminum oxide, aluminum nitride, aluminum borate whiskers, boron nitride, crystalline silica, and amorphous silica. Examples of materials constituting the inorganic filler include simple metals such as aluminum, gold, silver, copper, and nickel, as well as alloys, amorphous carbon, and graphite. When the adhesive film 20 contains an inorganic filler, the content of the inorganic filler is preferably 10% by mass or more, and more preferably 20% by mass or more. The content is preferably 50% by mass or less, and more preferably 45% by mass or less.

Examples of materials that can be used for the organic filler include polymethylmethacrylate (PMMA), polyimide, polyamideimide, polyetheretherketone, polyetherimide, and polyesterimide. When the adhesive film 20 contains an organic filler, the content of the organic filler is preferably 2% by mass or more, and more preferably 5% by mass or more. The content is preferably 20% by mass or less, and more preferably 15% by mass or less.

When the adhesive film 20 contains a filler, the average particle size of the filler is preferably 0.005 to 10 μm, more preferably 0.05 to 1 μm. A configuration in which the average particle size of the filler is 0.005 μm or more is suitable for realizing high wettability and adhesion to an adherend such as a semiconductor wafer in the adhesive film 20. A configuration in which the average particle size of the filler is 10 μm or less is suitable for obtaining a sufficient filler addition effect in the adhesive film 20 and ensuring heat resistance. The average particle size of the filler can be determined, for example, using a photometric particle size distribution meter (product name "LA-910", manufactured by Horiba, Ltd.).

The adhesive film 20 may contain a thermosetting catalyst. The incorporation of a thermosetting catalyst into the adhesive film 20 is preferable in order to sufficiently advance the curing reaction of the resin components when curing the adhesive film 20 and to increase the curing reaction rate. Examples of such thermosetting catalysts include imidazole-based compounds, triphenylphosphine-based compounds, amine-based compounds, and trihalogen borane-based compounds. Examples of the imidazole compounds include 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2,4-diamino- 6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-undecylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole, and 2-phenyl-4-methyl-5-hydroxymethylimidazole. Examples of triphenylphosphine compounds include triphenylphosphine, tri(butylphenyl)phosphine, tri(p-methylphenyl)phosphine, tri(nonylphenyl)phosphine, diphenyltolylphosphine, tetraphenylphosphonium bromide, methyltriphenylphosphonium bromide, methyltriphenylphosphonium chloride, methoxymethyltriphenylphosphonium chloride, and benzyltriphenylphosphonium chloride. Triphenylphosphine compounds also include compounds having both a triphenylphosphine structure and a triphenylborane structure. Examples of such compounds include tetraphenylphosphonium tetraphenylborate, tetraphenylphosphonium tetra-p-tolylborate, benzyltriphenylphosphonium tetraphenylborate, and triphenylphosphine triphenylborane. Examples of amine compounds include monoethanolamine trifluoroborate and dicyandiamide. Examples of trihalogen borane compounds include trichloroborane. The adhesive film 20 may contain one type of thermosetting catalyst, or two or more types of thermosetting catalysts.

The adhesive film 20 may contain one or more other components as needed. Examples of such other components include a flame retardant, a silane coupling agent, and an ion trapping agent.

The thickness of the adhesive film 20 is preferably 3 μm or more, more preferably 7 μm or more. The thickness of the adhesive film 20 is preferably 150 μm or less, more preferably 140 μm or less.

The dicing tape X with adhesive film having the above-mentioned configuration preferably has a peel adhesion strength of 0.03 to 0.12 N/20 mm, more preferably 0.04 to 0.11 N/ ²⁰ mm, between the adhesive film 20 and the pressure-sensitive adhesive layer 12 irradiated with 200 mJ/cm2 ultraviolet light, as measured in a T-peel test at 23°C and a peel speed of 300 mm/min. The T-peel test can be performed using, for example, a tensile tester (product name "Autograph AGS-J", manufactured by Shimadzu Corporation). The peel adhesion strength can be adjusted by adjusting the composition of the pressure-sensitive adhesive layer 12 or the composition of the adhesive film 20. For example, with respect to the adhesive layer 12, the peel adhesion in the T-peel test can be adjusted by adjusting the composition (type and ratio) of the monomer for forming the polymer contained therein, the selection of the type of crosslinking agent used and the adjustment of the amount, the adjustment of the weight average molecular weight of the polymer, the selection of the type of tackifier used and the adjustment of the amount, the selection of the type of filler used and the adjustment of the amount, the selection of the type of crosslinking assistant (e.g., photocrosslinkable oligomer) used and the adjustment of the amount, the selection of the type of photopolymerization initiator used and the adjustment of the amount, as well as the adjustment of the amount of low molecular weight components and the amount of residual monomers in the adhesive layer 12. For example, with respect to the adhesive film 20, the peel adhesion in the T-peel test can be adjusted by selecting the type of resin component contained therein and the adjustment of the amount, and the selection of the type of filler used and the adjustment of the amount.

In addition, in the dicing tape X with adhesive film, the surface free energy of the adhesive surface 12a (surface on the adhesive film 20 side) of the pressure-sensitive adhesive layer 12 irradiated with ultraviolet light at 200 mJ/cm ² is preferably 16 mJ/m ² or more, more preferably 23 mJ/m ² or more, and more preferably 25 mJ/m ² or more. The surface free energy of the adhesive surface 12a of the pressure-sensitive adhesive layer 12 can be adjusted by adjusting the composition of various monomers for forming a base polymer such as an acrylic polymer in the pressure-sensitive adhesive layer 12. In this embodiment, the surface free energy is defined as the value γs (=γsd ₊ γsh) obtained by adding γsd (dispersion force component of surface free energy) and γsh (hydrogen bond force component of surface free energy) obtained according to the method described in Journal of Applied Polymer Science, vol.13, _pp.1741-1747 ( ₁₉₆₉ ) using the contact angles θw, θi measured by a contact angle meter for each droplet of water ( ^H2O ) and methylene iodide ( ^CH2I2 ) in contact with the target surface for which the surface free energy is to be identified under conditions of 20°C ^{and 65} % relative humidity. The method of deriving the surface free energy γs is specifically described later in the Examples.

The above-described dicing tape X with adhesive film can be manufactured, for example, as follows.

The dicing tape 10 of the dicing tape X with adhesive film can be prepared by providing an adhesive layer 12 on a prepared substrate 11. For example, the resin substrate 11 can be prepared by a film-forming method such as a calendar film-forming method, a casting method in an organic solvent, an inflation extrusion method in a closed system, a T-die extrusion method, a co-extrusion method, or a dry lamination method. The film or substrate 11 after film formation is subjected to a predetermined surface treatment as necessary. In forming the adhesive layer 12, for example, after preparing an adhesive composition for forming the adhesive layer, the composition is first applied onto the substrate 11 or a predetermined separator to form an adhesive composition layer. Examples of the application method of the adhesive composition include roll coating, screen coating, and gravure coating. Next, the adhesive composition layer is dried by heating as necessary, and a crosslinking reaction is caused as necessary. The heating temperature is, for example, 80 to 150°C, and the heating time is, for example, 0.5 to 5 minutes. When the adhesive layer 12 is formed on a separator, the adhesive layer 12 with the separator is attached to the substrate 11, and then the separator is peeled off. This produces the above-mentioned dicing tape 10 having a laminated structure of the substrate 11 and the adhesive layer 12.

In preparing the adhesive film 20 of the dicing tape X with adhesive film, first, an adhesive composition for forming the adhesive film 20 is prepared, and then the composition is applied onto a predetermined separator to form an adhesive composition layer. Examples of the separator include polyethylene terephthalate (PET) film, polyethylene film, polypropylene film, and plastic films and papers whose surfaces are coated with a release agent such as a fluorine-based release agent or a long-chain alkyl acrylate-based release agent. Examples of the application method of the adhesive composition include roll coating, screen coating, and gravure coating. Next, the adhesive composition layer is dried by heating as necessary, and a crosslinking reaction is caused as necessary. The heating temperature is, for example, 70 to 160°C, and the heating time is, for example, 1 to 5 minutes. In this manner, the above-mentioned adhesive film 20 can be prepared in a form accompanied by a separator.

In producing the dicing tape X with adhesive film, the adhesive film 20 with the separator is then punched into a disk shape of a specified diameter, and the adhesive film 20 is then pressed and bonded to the pressure-sensitive adhesive layer 12 side of the dicing tape 10. The bonding temperature is, for example, 30 to 50°C, and preferably 35 to 45°C. The bonding pressure (linear pressure) is, for example, 0.1 to 20 kgf/cm, and preferably 1 to 10 kgf/cm. Next, the dicing tape 10 bonded to the adhesive film 20 in this manner is punched into a disk shape of a specified diameter so that the center of the dicing tape 10 and the center of the adhesive film 20 coincide.

In this manner, the dicing tape X with adhesive film can be produced. The dicing tape X with adhesive film may have a separator (not shown) on the adhesive film 20 side, covering at least the adhesive film 20. The separator is an element for protecting the adhesive film 20 and the pressure-sensitive adhesive layer 12 from exposure, and is peeled off from the film when the dicing tape X with adhesive film is used.

Figures 3 to 9 show an example of a semiconductor device manufacturing method in which the above-described adhesive film-attached dicing tape X is used.

In this semiconductor device manufacturing method, first, as shown in Figures 3(a) and 3(b), a modified region 30a is formed in a semiconductor wafer W. The semiconductor wafer W has a first surface Wa and a second surface Wb. Various semiconductor elements (not shown) are already fabricated on the first surface Wa of the semiconductor wafer W, and wiring structures and the like (not shown) necessary for the semiconductor elements are already formed on the first surface Wa. In this process, a wafer processing tape T1 having an adhesive surface T1a is bonded to the first surface Wa of the semiconductor wafer W, and then, with the semiconductor wafer W held on the wafer processing tape T1, a laser beam focused on the inside of the wafer is irradiated on the semiconductor wafer W along its planned division line from the side opposite to the wafer processing tape T1, and a modified region 30a is formed in the semiconductor wafer W due to ablation caused by multiphoton absorption. The modified region 30a is a weakened region for separating the semiconductor wafer W into semiconductor chip units. A method for forming modified regions 30a on planned division lines in a semiconductor wafer by irradiating the wafer with laser light is described in detail, for example, in Japanese Patent Application Laid-Open No. 2002-192370. In this embodiment, the laser light irradiation conditions are appropriately adjusted, for example, within the following ranges:
<Laser light irradiation conditions>
(A) Laser light Laser source Semiconductor laser pumped Nd:YAG laser Wavelength 1064 nm
Laser light spot cross-sectional area: 3.14× ^{10-8 cm2}
Oscillation type: Q-switched pulse Repetition frequency: 100 kHz or less Pulse width: 1 μs or less Output: 1 mJ or less Laser light quality: TEM00
Polarization characteristics: Linearly polarized (B) Condenser lens Magnification: 100x or less NA 0.55
(C) Transmittance to the laser light wavelength: 100% or less (C) Movement speed of the mounting table on which the semiconductor substrate is placed: 280 mm/sec or less

Next, while the semiconductor wafer W is held on the wafer processing tape T1, the semiconductor wafer W is thinned by grinding from the second surface Wb until it reaches a predetermined thickness, thereby forming a semiconductor wafer 30A that can be diced into a plurality of semiconductor chips 31, as shown in FIG. 3(c) (wafer thinning process). The grinding can be performed using a grinding device equipped with a grinding wheel.

Next, as shown in FIG. 4(a), the semiconductor wafer 30A held by the wafer processing tape T1 is bonded to the adhesive film 20 side of the adhesive film-attached dicing tape X. After this, as shown in FIG. 4(b), the wafer processing tape T1 is peeled off from the semiconductor wafer 30A.

Next, a ring frame 41 made of, for example, SUS is attached to the adhesive layer 12 around the adhesive film 20 in the dicing tape X with adhesive film, and then, as shown in FIG. 5(a), the dicing tape X with adhesive film and the semiconductor wafer 30A are fixed to the holder 42 of the expansion device via the ring frame 41.

Next, a first expansion step (cool expansion step) under a predetermined low-temperature condition is performed as shown in FIG. 5(b), in which the semiconductor wafer 30A is divided into a plurality of semiconductor chips 31, and the adhesive film 20 of the dicing tape X with adhesive film is cut into small pieces of adhesive film 21 to obtain the semiconductor chips 31 with adhesive film. In this step, a hollow cylindrical push-up member 43 provided in the expansion device is raised while abutting against the dicing tape 10 on the lower side of the dicing tape X with adhesive film in the figure, and the dicing tape 10 of the dicing tape X with adhesive film attached to the semiconductor wafer 30A is expanded so as to be stretched in two-dimensional directions including the radial direction and circumferential direction of the semiconductor wafer 30A. This expansion is performed under conditions in which a tensile stress of, for example, 15 to 32 MPa is generated in the dicing tape 10. The temperature conditions in the cool expansion process are, for example, 0°C or lower, preferably -20 to -5°C, more preferably -15 to -5°C, more preferably -15°C. The expansion speed in the cool expansion process (the speed at which the push-up member 43 rises) is, for example, 1 to 400 mm/sec. The expansion amount in the cool expansion process is, for example, 3 to 16 mm. These conditions regarding expansion in the cool expansion process are also the same in the cool expansion process described below.

By such a cool expanding process, the adhesive film 20 of the dicing tape X with adhesive film is cut into small pieces of adhesive film 21 to obtain semiconductor chips 31 with adhesive film. Specifically, in this process, cracks are formed in the weak modified area 30a of the semiconductor wafer 30A, and the semiconductor wafer 30A is divided into individual semiconductor chips 31. At the same time, in this process, in the adhesive film 20 that is in contact with the adhesive layer 12 of the dicing tape 10 to be expanded, deformation is suppressed in each area where each semiconductor chip 31 of the semiconductor wafer 30A is in contact, while in the area facing the crack formation area of the wafer, tensile stress generated in the dicing tape 10 acts without such deformation suppression action. As a result, the adhesive film 20 is cut at the area facing the crack formation area between the semiconductor chips 31. After this process, as shown in FIG. 5(c), the push-up member 43 is lowered and the expanded state of the dicing tape 10 is released.

Next, the second expansion process (room temperature expansion process) is performed as shown in Figures 6(a) and 6(b), and the distance between the semiconductor chips 31 with adhesive film is expanded. In this process, the table 44 equipped in the expansion device is raised, and the dicing tape 10 of the dicing tape X with adhesive film is expanded. The table 44 is capable of vacuum-adsorbing the workpiece by applying negative pressure to the workpiece on the table surface. The temperature condition in the second expansion process is, for example, 10°C or higher, and preferably 15 to 30°C. The expansion speed in the second expansion process (the speed at which the table 44 rises) is, for example, 0.1 to 10 mm/sec. The expansion amount in the second expansion process is, for example, 3 to 16 mm. In this process, the dicing tape 10 is expanded by raising the table 44 (thereby widening the distance between the semiconductor chips 31 with adhesive film), and then the table 44 vacuum-adsorbs the dicing tape 10. Then, while maintaining the suction by the table 44, the table 44 is lowered with the workpiece as shown in FIG. 6(c). In this embodiment, in this state, the periphery of the semiconductor wafer 30A (the portion outside the semiconductor chip 31 holding area) of the dicing tape X with adhesive film is heated and shrunk (heat shrink process). After that, the vacuum suction state by the table 44 is released. Through the heat shrink process, the dicing tape X with adhesive film is in a state in which a predetermined degree of tension can act on the wafer bonding area that was stretched and relaxed in the first expansion process and the second expansion process described above, and the separation distance between the semiconductor chips 31 is fixed even after the vacuum suction state is released.

7, the adhesive layer 12 is irradiated with ultraviolet light to promote ultraviolet curing and reduce its adhesive strength (ultraviolet light irradiation step). Specifically, for example, a high-pressure mercury lamp is used to irradiate the entire adhesive layer 12 with ultraviolet light R from the substrate 11 side of the dicing tape 10. The cumulative amount of irradiation is, for example, 50 to 500 mJ/ ^cm2 , and preferably 100 to 300 mJ/ ^cm2 .

In this semiconductor device manufacturing method, next, a cleaning process is performed as necessary to clean the semiconductor chip 31 side of the dicing tape X with adhesive film using a cleaning liquid such as water, and then a pick-up process is performed using a dicing bonding device equipped with both a pick-up mechanism and an expand mechanism.

Specifically, as shown in FIG. 8(a), first, the dicing tape X with adhesive film or the dicing tape 10 with multiple semiconductor chips 31 is fixed to the holder 45 of the die bonding device via the ring frame 41, and the hollow cylindrical push-up member 46 of the device is raised up while abutting against the dicing tape 10 on the lower side of the dicing tape 10 in the figure. This causes the dicing tape 10 to expand so that it is stretched in two-dimensional directions including the radial and circumferential directions (pre-pickup expansion).

Next, as shown in FIG. 8(b), the semiconductor chip 31 with the adhesive film is picked up from the dicing tape 10. For example, for the semiconductor chip 31 with the adhesive film to be picked up, the pin members 47 of the pick-up mechanism are raised on the lower side of the dicing tape 10 in the figure, pushed up through the dicing tape 10, and then sucked and held by the suction jig 48. In this pick-up, the pushing-up speed of the pin members 47 is, for example, 1 to 100 mm/sec, and the pushing-up amount of the pin members 47 is, for example, 50 to 3000 μm.

Next, as shown in FIG. 9(a), the picked-up semiconductor chip 31 with adhesive film is temporarily attached to a predetermined adherend 51 via the adhesive film 21. Examples of the adherend 51 include a lead frame, a TAB (Tape Automated Bonding) film, and a wiring board.

Next, as shown in FIG. 9(b), the electrode pads (not shown) of the semiconductor chip 31 and the terminals (not shown) of the adherend 51 are electrically connected via bonding wires 52 (wire bonding process). The electrode pads of the semiconductor chip 31 and the terminals of the adherend 51 are connected to the bonding wires 52 by ultrasonic welding accompanied by heating, so as not to thermally harden the adhesive film 21. The bonding wires 52 may be, for example, gold wires, aluminum wires, or copper wires. The wire heating temperature in wire bonding is, for example, 80 to 250°C. The heating time is from a few seconds to a few minutes.

9(c), the semiconductor chip 31 is sealed with a sealing resin 53 for protecting the semiconductor chip 31 and the bonding wires 52 on the adherend 51 (sealing process). In this process, the adhesive film 21 is thermally cured. In this process, the sealing resin 53 is formed, for example, by a transfer molding technique using a metal mold. The sealing resin 53 can be made of, for example, an epoxy resin. In this process, the heating temperature for forming the sealing resin 53 is, for example, 165 to 185°C, and the heating time is, for example, 60 seconds to several minutes. If the curing of the sealing resin 53 does not progress sufficiently in this process (sealing process), a post-curing process is performed after this process to completely cure the sealing resin 53. Even if the adhesive film 21 is not completely thermally cured in the sealing process, the adhesive film 21 can be completely thermally cured together with the sealing resin 53 in the post-curing process. In the post-curing process, the heating temperature is, for example, 165 to 185°C, and the heating time is, for example, 0.5 to 8 hours.

In this manner, a semiconductor device can be manufactured.

In this semiconductor device manufacturing method, instead of the above-described configuration in which the semiconductor wafer 30A is bonded to the dicing tape X with the adhesive film, the semiconductor wafer 30B produced as follows may be bonded to the dicing tape X with the adhesive film.

In the manufacture of the semiconductor wafer 30B, first, as shown in FIG. 10(a) and FIG. 10(b), a dividing groove 30b is formed in the semiconductor wafer W (dividing groove forming process). The semiconductor wafer W has a first surface Wa and a second surface Wb. Various semiconductor elements (not shown) are already fabricated on the first surface Wa of the semiconductor wafer W, and wiring structures (not shown) necessary for the semiconductor elements are already formed on the first surface Wa. In this process, after a wafer processing tape T2 having an adhesive surface T2a is attached to the second surface Wb of the semiconductor wafer W, a dividing groove 30b of a predetermined depth is formed on the first surface Wa of the semiconductor wafer W using a rotating blade of a dicing device or the like while the semiconductor wafer W is held by the wafer processing tape T2. The dividing groove 30b is a gap for separating the semiconductor wafer W into semiconductor chip units (the dividing groove 30b is shown in the drawings as a schematic thick line).

Next, as shown in FIG. 10(c), the wafer processing tape T3 having the adhesive surface T3a is bonded to the first surface Wa of the semiconductor wafer W, and the wafer processing tape T2 is peeled off from the semiconductor wafer W.

10(d), the semiconductor wafer W is held on the wafer processing tape T3, and is then thinned by grinding from the second surface Wb until it reaches a predetermined thickness (wafer thinning process). In this embodiment, this wafer thinning process forms a semiconductor wafer 30B that can be diced into a plurality of semiconductor chips 31. Specifically, the semiconductor wafer 30B has a portion (connecting portion) that connects the portions of the wafer that will be diced into a plurality of semiconductor chips 31 on the second surface Wb side. The thickness of the connecting portion in the semiconductor wafer 30B, that is, the distance between the second surface Wb of the semiconductor wafer 30B and the tip of the dividing groove 30b on the second surface Wb side, is, for example, 1 to 30 μm. The semiconductor wafer 30B thus produced may be attached to a dicing tape X with an adhesive film instead of the semiconductor wafer 30A, and the processes described above with reference to FIGS. 5 to 9 may then be carried out.

11(a) and 11(b) specifically show the first expanding process (cool expanding process) performed after the semiconductor wafer 30B is bonded to the dicing tape X with adhesive film. In this process, a hollow cylindrical push-up member 43 provided in the expanding device is raised in contact with the dicing tape 10 at the lower side of the dicing tape X with adhesive film in the figure, and the dicing tape 10 of the dicing tape X with adhesive film bonded to the semiconductor wafer 30B is expanded so as to be stretched in two-dimensional directions including the radial and circumferential directions of the semiconductor wafer 30B. This cool expanding process causes the semiconductor wafer 30B to be broken at thin and easily cracked parts, resulting in individualization into semiconductor chips 31. At the same time, in this process, deformation is suppressed in the areas where the semiconductor chips 31 are in contact with the adhesive film 20 that is in contact with the adhesive layer 12 of the expanded dicing tape 10, while the tensile stress generated in the dicing tape 10 acts on the areas facing the dividing grooves between the semiconductor chips 31 without such deformation suppression. As a result, the areas of the adhesive film 20 facing the dividing grooves between the semiconductor chips 31 are broken. The semiconductor chips 31 with the adhesive film thus obtained are subjected to the pickup process described above with reference to FIG. 8, and then are subjected to the mounting process in the semiconductor device manufacturing process.

In the present semiconductor device manufacturing method, instead of the wafer thinning step described above with reference to FIG. 10(d), a wafer thinning step shown in FIG. 12 may be performed. After the process described above with reference to FIG. 10(c), in the wafer thinning step shown in FIG. 12, the semiconductor wafer W is held on the wafer processing tape T3, and the wafer is thinned by grinding from the second surface Wb until it reaches a predetermined thickness, and a semiconductor wafer divided body 30C including a plurality of semiconductor chips 31 and held on the wafer processing tape T3 is formed. In this step, a method (first method) in which the wafer is ground until the dividing groove 30b itself is exposed on the second surface Wb side may be adopted, or a method (second method) in which the wafer is ground from the second surface Wb side to before it reaches the dividing groove 30b, and then a crack is generated between the dividing groove 30b and the second surface Wb by the action of the pressing force from the rotating grindstone to the wafer to form the semiconductor wafer divided body 30C may be adopted. Depending on the method used, the depth from the first surface Wa of the dividing groove 30b formed as described above with reference to Figures 10(a) and 10(b) is appropriately determined. In Figure 12, the dividing groove 30b that has been subjected to the first method or the dividing groove 30b that has been subjected to the second method and the cracks connected thereto are shown in bold lines. The semiconductor wafer divided body 30C thus produced may be attached to a dicing tape X with an adhesive film instead of the semiconductor wafer 30A or semiconductor wafer 30B, and the steps described above with reference to Figures 5 to 9 may be carried out.

13(a) and 13(b) specifically show the first expanding step (cool expanding step) performed after the semiconductor wafer divided body 30C is bonded to the dicing tape X with adhesive film. In this step, a hollow cylindrical push-up member 43 provided in the expanding device is raised while abutting against the dicing tape 10 on the lower side of the dicing tape X with adhesive film in the figure, and the dicing tape 10 of the dicing tape X with adhesive film bonded to the semiconductor wafer divided body 30C is expanded so as to be stretched in two-dimensional directions including the radial and circumferential directions of the semiconductor wafer divided body 30C. By this cool expansion process, in the adhesive film 20 that is in contact with the adhesive layer 12 of the expanded dicing tape 10, deformation is suppressed in each region where each semiconductor chip 31 of the semiconductor wafer division body 30C is in contact, while the tensile stress generated in the dicing tape 10 acts on the portion facing the dividing groove 30b between the semiconductor chips 31 without such deformation suppression effect. As a result, the portion of the adhesive film 20 facing the dividing groove 30b between the semiconductor chips 31 is broken. The semiconductor chip 31 with the adhesive film obtained in this way is subjected to the pickup process described above with reference to FIG. 8, and then is subjected to the mounting process in the semiconductor device manufacturing process.

As described above, the dicing tape 10 of the dicing tape X with adhesive film exhibits a peel adhesion force (first peel adhesion force) of 0.03 to 0.2 N/ ²⁰ mm against the SUS flat surface in a peel test under conditions of 23° C., a peel angle of 180°, and a peel speed of 300 mm/min after the adhesive layer 12 is attached to the SUS flat surface and then irradiated with ultraviolet light at 200 mJ/cm 2 on the adhesive layer 12. The configuration in which the first peel adhesion force is 0.03 N/20 mm or more is suitable for ensuring the ring frame holding force required at the attachment portion in the semiconductor device manufacturing process, even when a metal ring frame such as SUS is attached to the dicing tape 10 of the dicing tape X with adhesive film and the ring frame attachment portion of the adhesive layer 12 is irradiated with ultraviolet light. This configuration is suitable for allowing the ring frame affixed portion of the adhesive layer 12 to continue to adhere to the ring frame 41 against the tensile force acting thereon when the dicing tape 10 is expanded before the pick-up step as described above (i.e., suitable for suppressing peeling of the dicing tape 10 from the ring frame 41). Furthermore, a configuration in which the first peel adhesion strength is 0.2 N/20 mm or less is suitable for peeling the dicing tape 10 of the dicing tape X with adhesive film from the ring frame 41 without leaving any glue residue after the ring frame affixed portion of the adhesive layer 12 is irradiated with ultraviolet light in a state in which the ring frame 41 is attached to the dicing tape 10 of the dicing tape X with adhesive film.

As described above, the dicing tape X with adhesive film is suitable for ensuring the ring frame holding power of the ultraviolet-curable adhesive layer 12 even after it has been irradiated with ultraviolet light, and is also suitable for preventing adhesive residue of the adhesive layer 12 when peeled off from the ring frame. From the viewpoint of ensuring the ring frame holding power as described above, the first peel adhesive strength is preferably 0.05 N/20 mm or more, and more preferably 0.1 N/20 mm or more. From the viewpoint of preventing adhesive residue as described above, the first peel adhesive strength is preferably 0.18 N/20 mm or less, and more preferably 0.15 N/20 mm or less.

As described above, the dicing tape X with adhesive film has a peel adhesion (second peel adhesion) between the adhesive film 20 and the adhesive layer 12 irradiated with 200 mJ/cm ² ultraviolet light in a T-type peel test under conditions of 23° C. and a peel speed of 300 mm/min, which is preferably 0.03 to 0.12 N/20 mm, more preferably 0.04 to 0.11 N/20 mm. Such a configuration is suitable for appropriately carrying out the above-mentioned pick-up step. A configuration in which the second peel adhesion is 0.03 N/20 mm or more, preferably 0.04 N/20 mm or more, is suitable for suppressing peeling between the dicing tape 10 or its adhesive layer 12 and the adhesive film 20 of the semiconductor chip 31 with adhesive film, i.e., chip peeling, when performing separation expansion before chip pick-up in the above-mentioned pick-up step. The second peel adhesion strength being 0.12 N/20 mm or less, preferably 0.11 N/20 mm or less, is suitable for picking up the chip without causing cracks or the like in the semiconductor chip 31 in the above-mentioned pick-up step.

As described above, in the dicing tape X with adhesive film, the surface free energy of the adhesive surface 12a (surface on the side of the adhesive film 20) of the adhesive layer 12 irradiated with ultraviolet light at 200 mJ/cm ² is preferably 16 mJ/m ² or more, more preferably 23 mJ/m ² or more, and more preferably 25 mJ/m ² or more. Such a configuration is suitable for ensuring the interfacial adhesive strength of the adhesive layer 12 after ultraviolet light irradiation with a metal ring frame such as SUS, and therefore is suitable for ensuring the above-mentioned ring frame holding strength.

When the adhesive layer 12 in the dicing tape X with adhesive film contains a polymer containing a nitrogen-containing monomer as a constituent monomer, the content of the nitrogen-containing monomer as a constituent monomer in the polymer is, as described above, preferably 1 to 40 mol%, more preferably 3 to 35 mol%. In the dicing tape X with adhesive film, a configuration in which the content is 1 mol% or more, preferably 3 mol% or more, is suitable for achieving high polarity for the polymer in the adhesive layer 12, and therefore is suitable for ensuring the above-mentioned ring frame holding force. In the dicing tape X with adhesive film, a configuration in which the content is 40 mol% or less, preferably 35 mol% or less, is suitable for obtaining good peelability of the semiconductor chip 31 with adhesive film from the dicing tape 10 in the above-mentioned pick-up process.

Example 1
<Preparation of dicing tape>
In a reaction vessel equipped with a cooling tube, a nitrogen inlet tube, a thermometer, and a stirrer, a mixture containing 99 mol parts of 2-ethylhexyl acrylate (2EHA), 21 mol parts of 2-hydroxyethyl acrylate (HEA), benzoyl peroxide as a polymerization initiator, and toluene as a polymerization solvent was stirred under a nitrogen atmosphere at 60° C. for 10 hours (polymerization reaction). In this mixture, the content of benzoyl peroxide was 0.4 parts by mass relative to 100 parts by mass of the monomer components, and the content of toluene was 80 parts by mass relative to 100 parts by mass of the monomer components. This polymerization reaction resulted in a polymer solution containing an acrylic polymer P _1. Next, 16 mol parts of 2-methacryloyloxyethyl isocyanate (MOI) was added to the solution containing the acrylic polymer P ₁ , and the mixture was stirred under an air atmosphere at 50° C. for 60 hours (addition reaction). As a result, a polymer solution containing an acrylic polymer P ₂ having a methacryloyl group in the side chain was obtained. Next, _0.05 parts by mass of a crosslinking agent (trade name "Coronate L", a polyisocyanate compound, manufactured by Tosoh Corporation) and 2 parts by mass of a first photopolymerization initiator (trade name "Irgacure 127", manufactured by BASF) were added to the polymer solution relative to 100 parts by mass of the acrylic polymer P 2 and mixed to obtain an adhesive composition. Next, the adhesive composition was applied using an applicator onto the silicone release-treated surface of a PET separator having a surface that had been subjected to silicone release treatment to form an adhesive composition layer. Next, this composition layer was heated and dried at 120°C for 2 minutes to form an adhesive layer having a thickness of 10 μm on the PET separator. Next, a laminator was used to attach a substrate made of ethylene-vinyl acetate copolymer (EVA) (trade name "RB0103", thickness 125 μm, manufactured by Kurabo Industries Co., Ltd.) to the exposed surface of this adhesive layer at room temperature. The haze of this substrate measured using a haze measuring device (product name "HM-150", manufactured by Murakami Color Research Laboratory Co., Ltd.) under an environment of 23°C and 50% RH is 90%. In this manner, a dicing tape of Example 1 including a substrate and an adhesive layer was produced. The composition of the adhesive layer of the dicing tape in Example 1 and each of the following Examples and Comparative Examples is shown in Table 1 (in Table 1, the molar ratio between the monomers is shown for the constituent monomers of the acrylic polymer, and the mass ratio to 100 parts by mass of the crosslinking agent and photopolymerization initiator is shown for the crosslinking agent and photopolymerization initiator. The proportion (mol%) of the nitrogen-containing monomer in the acrylic polymer is also shown in Table 1).

Preparation of adhesive film
45 parts by mass of acrylic resin, 15 parts by mass of phenolic resin (product name "MEH-7800", solid at 23°C, manufactured by Meiwa Kasei Co., Ltd.), and 40 parts by mass of inorganic filler (product name "SO-E2", spherical silica, manufactured by Admatechs Co., Ltd.) were added to methyl ethyl ketone and mixed to obtain an adhesive composition with a solid content concentration of 20% by mass. The acrylic resin is a copolymer of ethyl acrylate, butyl acrylate, and acrylonitrile, and has a weight average molecular weight of 1.2 million and a glass transition temperature of 20°C. Next, an adhesive composition was applied to the silicone release-treated surface of a PET separator having a surface treated with silicone release treatment using an applicator to form an adhesive composition layer. Next, this composition layer was heated and dried at 130°C for 2 minutes, and an adhesive film of Example 1 with a thickness of 10 μm was produced on the PET separator.

<Preparation of dicing tape with adhesive film>
The above-mentioned adhesive film of Example 1 with a PET separator was punched into a disk shape with a diameter of 330 mm. Next, after peeling off the PET separator from the above-mentioned dicing tape, the adhesive layer exposed in the dicing tape and the adhesive film with the PET separator were laminated using a roll laminator. In this lamination, the lamination speed was 10 mm/min, the temperature condition was 23°C, and the pressure condition was 0.15 MPa. Next, the dicing tape thus laminated with the adhesive film was punched into a disk shape with a diameter of 370 mm so that the center of the dicing tape and the center of the adhesive film were aligned. In this manner, a dicing tape with an adhesive film of Example 1 having a laminated structure including a dicing tape and an adhesive film was produced.

[Examples 2 and 3]
The dicing tapes with adhesive films of Examples 2 and 3 were prepared in the same manner as the dicing tape with adhesive film of Example 1, except that the amount of crosslinking agent (product name "Coronate L") used in forming the dicing tape adhesive layer was changed from 0.05 parts by mass to 0.5 parts by mass (Example 2) or 3 parts by mass (Example 3).

Example 4
The dicing tape with adhesive film of Example 4 was prepared in the same manner as the dicing tape with adhesive film of Example 1, except that in forming the dicing tape adhesive layer, the amount of crosslinking agent (product name "Coronate L") was changed from 0.05 parts by mass to 1.5 parts by mass, and 2 parts by mass of a second photopolymerization initiator (product name "Irgacure 184", manufactured by BASF) was used instead of 2 parts by mass of a first photopolymerization initiator (product name "Irgacure 127"), and 2 parts by mass of a second photopolymerization initiator was used.

Example 5
<Preparation of dicing tape>
In a reaction vessel equipped with a cooling tube, a nitrogen introduction tube, a thermometer, and a stirrer, a mixture containing 100 mol parts of 2-ethylhexyl acrylate (2EHA), 32 mol parts of 2-hydroxyethyl acrylate (HEA), 25 mol parts of acryloylmorpholine (ACMO), benzoyl peroxide as a polymerization initiator, and toluene as a polymerization solvent was stirred under a nitrogen atmosphere at 60° C. for 10 hours (polymerization reaction). In this mixture, the content of benzoyl peroxide was 0.4 parts by mass relative to 100 parts by mass of the monomer components, and the content of toluene was 80 parts by mass relative to 100 parts by mass of the monomer components. This polymerization reaction resulted in a polymer solution containing an acrylic polymer P _3. Next, 26 mol parts of 2-methacryloyloxyethyl isocyanate (MOI) was added to the solution containing the acrylic polymer P ₃ , and the mixture was stirred under an air atmosphere at 50° C. for 60 hours (addition reaction). This resulted in a polymer solution containing an acrylic polymer P ₄ having a methacryloyl group in the side chain. Next, 1.5 parts by mass of a crosslinking agent (trade name "Coronate L", a polyisocyanate compound, manufactured by Tosoh Corporation) and 2 parts _by mass of a first photopolymerization initiator (trade name "Irgacure 127", manufactured by BASF Corporation) were added to the polymer solution relative to 100 parts by mass of the acrylic polymer P 4 and mixed to obtain an adhesive composition. Next, the adhesive composition was applied to the silicone release-treated surface of a PET separator having a surface treated with silicone release treatment using an applicator to form an adhesive composition layer. Next, this composition layer was heated and dried at 120°C for 2 minutes to form an adhesive layer having a thickness of 10 μm on the PET separator. Next, a laminator was used to attach an EVA substrate (trade name "RB0103", thickness 125 μm, manufactured by Kurashiki Boseki Co., Ltd.) to the exposed surface of this adhesive layer at room temperature. In this manner, a dicing tape of Example 5 including a substrate and a pressure-sensitive adhesive layer was produced.

Then, the dicing tape with adhesive film of Example 5 was produced in the same manner as the dicing tape with adhesive film of Example 1, except that the dicing tape of Example 5 was used instead of the dicing tape of Example 1.

[Examples 6 and 7]
In the synthesis of the acrylic polymer for the dicing tape adhesive layer, the amount of 2EHA was changed from 100 mol parts to 75 mol parts, the amount of HEA was changed from 32 mol parts to 22 mol parts, and the amount of ACMO was changed from 25 mol parts to 9 mol parts (Example 6) or 24 mol parts (Example 7). The adhesive film-attached dicing tapes of Examples 6 and 7 were prepared in the same manner as the adhesive film-attached dicing tape of Example 5, except that:

Comparative Example 1
A dicing tape with an adhesive film of Comparative Example 1 was prepared in the same manner as the dicing tape with an adhesive film of Example 1, except that in the synthesis of the acrylic polymer for the dicing tape adhesive layer, 100 parts by mole of lauryl acrylate (LA) was used instead of 99 parts by mole of 2EHA, and the amount of HEA was changed to 20 parts by mole instead of 21 parts by mole.

<Peel adhesion to SUS>
The peel adhesion strength of the dicing tape in each adhesive film-attached dicing tape of Examples 1 to 7 and Comparative Example 1 against a SUS flat surface was examined as follows. First, a test piece with a width of 20 mm and a length of 100 mm was cut out from each dicing tape of Examples 1 to 7 and Comparative Example 1. Next, the adhesive layer side of the test piece was attached to a SUS plate (made of SUS403) by a pressure bonding operation in which a 2 kg roller was moved back and forth once, and then this laminate was left at room temperature for 30 minutes. Next, ultraviolet rays were irradiated onto the adhesive layer from the substrate side of the test piece. In the ultraviolet irradiation, a high-pressure mercury lamp was used, and the irradiation cumulative light amount was set to 200 mJ/cm ^2. Next, a tensile tester (trade name "Autograph AGS-J", manufactured by Shimadzu Corporation) was used to perform a tensile test of the test piece against the SUS plate. In the tensile test, the measurement temperature or peel temperature was set to 23°C, the tensile angle or peel angle was set to 180°, and the peel speed was set to 300 mm/min. The average peel strength during the peeling process excluding the first 20 mm and the last 20 mm was taken as the peel adhesion strength F ₁ (N/20 mm).

<T-type peel test>
For each adhesive film-attached dicing tape of Examples 1 to 7 and Comparative Example 1, the peel adhesion between the dicing tape pressure-sensitive adhesive layer and the adhesive film after ultraviolet irradiation was examined. First, ultraviolet light was irradiated onto the dicing tape pressure-sensitive adhesive layer of the dicing tape with the adhesive film through the dicing tape substrate. Specifically, ultraviolet light was irradiated onto the pressure-sensitive adhesive layer from the substrate side of the dicing tape using a high-pressure mercury lamp. The cumulative irradiation light amount was 200 mJ/cm ^2. Next, a backing tape (product name "BT-315", manufactured by Nitto Denko Corporation) was attached to the adhesive film side of the dicing tape with the adhesive film, and a test piece with a size of 50 mm wide x 120 mm long was cut out from the dicing tape with the adhesive film and the backing tape. Then, a T-type peel test was performed on the test piece using a tensile tester (product name "Autograph AGS-J", manufactured by Shimadzu Corporation), and the peel adhesion force F ₂ (N/20 mm) was measured. In this measurement, the temperature condition was 23° C. and the peel speed was 300 mm/min. The results are shown in Table 1.

<Surface free energy>
For each adhesive film-attached dicing tape of Examples 1 to 7 and Comparative Example 1, the surface free energy of the adhesive film-side surface of the adhesive layer after ultraviolet irradiation was determined. Specifically, first, ultraviolet light was irradiated from the dicing tape base material side to the dicing tape adhesive layer of the dicing tape with the adhesive film. For ultraviolet irradiation, a high-pressure mercury lamp was used, and the accumulated amount of irradiation was set to 200 mJ/cm ^2. Next, the adhesive film was peeled off from the dicing tape or its adhesive layer to expose the surface to be identified for surface free energy (the adhesive film-side surface of the adhesive layer). Next, under conditions of 20°C and 65% relative humidity, the contact angle was measured using a contact angle meter for each droplet of water (H ₂ O) and methylene iodide (CH ₂ I ₂ ) in contact with the surface to be identified for surface free energy. Next, using the measured values of the water contact angle θw and the methylene iodide contact angle θi, γs ^d (dispersion force component of surface free energy) and ^γsh (hydrogen bond force component of surface free energy) were calculated according to the method described in Journal of Applied Polymer Science, vol.13, p1741-1747 (1969). The value γs (= γs ^d + ^γsh ) obtained by adding γs ^d and ^γsh was regarded as the surface free energy of the target surface. Surface Free Energy Identification γs ^d and ^γsh for each target surface are obtained as solutions to the simultaneous equations with two unknowns shown in the following formulas (1) and (2). In formulas (1) and (2), γw is the surface free energy of water, γw ^d is the dispersion force component of the surface free energy of water, γw ^h is the hydrogen bond force component of the surface free energy of water, γi is the surface free energy of methyl iodide, γi ^d is the dispersion force component of the surface free energy of methyl iodide, and γi ^h is the hydrogen bond force component of the surface free energy of methyl iodide, and the known literature values of γw = 72.8 mJ/m ² , γw ^d = 21.8 mJ/m ² , γw ^h = 51.0 mJ/m ² , γi = 50.8 mJ/m ² , γi ^d = 48.5 mJ/m ² , and γi ^h = 2.3 mJ/m ² were used. The surface free energy γs (mJ/m ² ) of the adhesive film side surface of the pressure-sensitive adhesive layer after ultraviolet irradiation thus obtained is shown in Table 1.

<Ring frame retention and pick-up ability>
Using each of the dicing tapes with adhesive films of Examples 1 to 7 and Comparative Example 1, the following lamination step, cool expansion step, room temperature expansion step, and pick-up step were carried out.

In the lamination process, the semiconductor wafer divisions held on the wafer processing tape (product name "ELP UB-3083D", manufactured by Nitto Denko Corporation) were laminated to the adhesive film side of the dicing tape with adhesive film, and then the wafer processing tape was peeled off from the semiconductor wafer divisions. The semiconductor wafer divisions were formed and produced as follows. First, a Si mirror wafer (diameter 300 mm, thickness 780 μm, manufactured by Tokyo Kako Co., Ltd.) held together with a SUS ring frame on the wafer processing tape (product name "V12S-R2", manufactured by Nitto Denko Corporation) was used to form division grooves (width 20 to 25 μm, depth 50 μm) for dicing from one side with the rotating blade of a dicing device (product name "DFD6361", manufactured by Disco Corporation). Next, a wafer processing tape (product name "ELP UB-3083D", manufactured by Nitto Denko Corporation) was attached to the surface on which the dividing grooves were formed, and the wafer processing tape (product name "V12S-R2") was then peeled off from the Si mirror wafer. After this, the other surface of the Si mirror wafer (the surface on which the dividing grooves were not formed) was ground to thin the wafer down to a thickness of 20 μm. In this way, a semiconductor wafer divided body (held by the wafer processing tape) was formed. This semiconductor wafer divided body contained multiple semiconductor chips (6 mm x 12 mm).

The cool expansion process was carried out using a die separator (product name "Die Separator DDS2300", manufactured by Disco Corporation) in its cool expansion unit. Specifically, after the dicing tape adhesive layer around the adhesive film in the above-mentioned dicing tape with adhesive film with semiconductor wafer divisions on the adhesive film was attached to a ring frame, the dicing tape with adhesive film was set in the device, and the dicing tape of the dicing tape with adhesive film with semiconductor wafer divisions was expanded in its radial direction in the cool expansion unit of the device. In this expansion process, the temperature was -15°C, the expansion speed was 100 mm/sec, and the expansion amount was 7 mm. This process caused the adhesive film of the dicing tape with adhesive film to be cut into individual semiconductor chips, resulting in multiple semiconductor chips with adhesive film on the dicing tape.

The room temperature expansion process was carried out using a die separator device (product name "Die Separator DDS2300", manufactured by Disco Corporation) in its room temperature expansion unit. Specifically, the dicing tape with adhesive film, including the semiconductor wafer segments that had undergone the above-mentioned cool expansion process, was set in the device, and the dicing tape with adhesive film was expanded in its radial direction in the room temperature expansion unit of the device. In this expansion process, the temperature was 23°C, the expansion speed was 1 mm/sec, and the expansion amount was 5 mm.

The pick-up process was carried out using a die bonding device (product name "Die Bonder DB830Plus+", manufactured by Fasford Technology Co., Ltd.) equipped with both a pick-up mechanism and an expand mechanism. Specifically, first, the dicing tape with adhesive film or the dicing tape (with the ring frame attached to the dicing tape adhesive layer) that had undergone the above process was radially expanded by the expand mechanism of the device (expanded before pick-up). The expansion amount in this pre-pick-up expansion was 6 mm. After this expansion, the dicing tape with adhesive film together with the workpiece and the ring frame was left to stand for 3 hours. Then, regarding the ring frame retention of each dicing tape with adhesive film or the dicing tape adhesive layer, if the dicing tape adhesive layer did not peel off from the ring frame, it was evaluated as "good", and if peeling occurred, it was evaluated as "poor".

In the pick-up process, a die bonding device (product name "Die Bonder DB830Plus+", manufactured by Fasford Technology Co., Ltd.) was used to try to pick up the semiconductor chips with adhesive film on the dicing tape. This pick-up was a multi-stage pick-up in which the pin member was pushed up in three stages, with the amount of push-up by the pin member being 300 μm in the first stage, 300 μm in the second stage, and 300 μm in the third stage. The number of pick-up evaluations was 5. Regarding the pick-up ability of each dicing tape with adhesive film, if all five semiconductor chips with adhesive film could be picked up, it was evaluated as "good", and if not, it was evaluated as "poor". The dicing tape with adhesive film of Comparative Example 1 peeled off from the ring frame during the above-mentioned separation expansion, so pick-up evaluation could not be performed (not even one chip could be picked up).

X Dicing tape with adhesive film 10 Dicing tape 11 Substrate 12 Pressure-sensitive adhesive layer 20, 21 Adhesive film W, 30A, 30B Semiconductor wafer 30C Semiconductor wafer divided body 30a Modified region 30b Dividing groove 31 Semiconductor chip

Claims (7)

a dicing tape having a laminated structure including a substrate and an ultraviolet-curable adhesive layer;
an adhesive film releasably attached to the pressure-sensitive adhesive layer of the dicing tape;
The dicing tape is a dicing tape with an adhesive film, which, after being attached to a SUS flat surface with its adhesive layer side and then irradiating the adhesive layer with ultraviolet light at 200 mJ/ ^cm2 , exhibits a peel adhesion strength of 0.03 to 0.15 N/20 mm against the SUS flat surface in a peel test under conditions of 23°C, a peel angle of 180°, and a peel speed of 300 mm/min. 2. The dicing tape with adhesive film according to claim 1, wherein the peel adhesion between the adhesive film and the pressure-sensitive adhesive layer irradiated with 200 mJ/ ^cm2 ultraviolet light is 0.03 to 0.12 N/20 mm in a T-peel test under conditions of 23°C and a peel speed of 300 mm/min. 3. The dicing tape with adhesive film according to claim 1, wherein the surface of the pressure-sensitive adhesive layer on the adhesive film side irradiated with ultraviolet light at 200 mJ/ ^cm2 has a surface free energy of 16 mJ/ ^m2 or more. The dicing tape with adhesive film according to any one of claims 1 to 3, wherein the adhesive layer contains a polymer containing 1 to 40 mol % of a nitrogen-containing monomer as a constituent monomer. The dicing tape with adhesive film according to claim 4, wherein the nitrogen-containing monomer is acryloylmorpholine. The dicing tape with adhesive film according to claim 4 or 5, wherein the polymer is an acrylic polymer having a UV-polymerizable functional group. The dicing tape with adhesive film according to any one of claims 1 to 6, wherein the adhesive layer contains a polymer containing 10 to 30 mol% of a hydroxyl group-containing monomer as a constituent monomer.

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