Adhesive tape, laminated body, and manufacturing method for semiconductor device

Abstract

To provide an adhesive tape enabling reduction of variations in semiconductor device processing.SOLUTION: An adhesive tape includes a first adhesive layer, a second adhesive layer, and an intermediate layer disposed between the first adhesive layer and the second adhesive layer. The intermediate layer contains at least one selected from the group consisting of an inorganic oxide, an inorganic nitride, an inorganic oxynitride, a metal, and a siloxane compound. The intermediate layer has a thickness of 5 nm or more and 3 μm or less.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a method for manufacturing an adhesive tape, a laminate, and a semiconductor device.

Background Art

[0002] An adhesive tape is used, for example, for temporarily fixing members and parts in the manufacturing process of semiconductor devices.

[0003] For example, a semiconductor chip is manufactured by polishing the back surface of a semiconductor wafer with a polishing machine to reduce the thickness of the semiconductor wafer to about 30 to 600 μm, then forming electrodes and the like on the back surface, and dicing to form chips. Here, when performing the back grinding process, an adhesive tape is attached to the surface of the semiconductor wafer, or a support is attached via the adhesive tape, thereby preventing damage to the semiconductor wafer and facilitating processing such as polishing.

[0004] In addition, a semiconductor package may be manufactured through a process of resin-sealing two or more semiconductor chips supported by an adhesive tape and then grinding the back surface of the obtained sealed body to a predetermined thickness.

[0005] The adhesive tape used in such a process is required to have a high adhesive strength sufficient to firmly fix adherends such as semiconductor wafers and semiconductor chips during processing, and to be peelable without adhesive residue after processing.

[0006] As such an adhesive tape, for example, Patent Document 1 discloses an adhesive tape having a base material and two adhesive layers disposed on both sides thereof. Specifically, an adhesive tape including a transparent PET film with a thickness of 100 μm as the base material and two adhesive layers containing a photocurable acrylic adhesive is disclosed. And it is described that by irradiating the adhesive tape with light, the adhesive strength can be reduced and it can be easily peeled off.

Prior Art Documents

Patent Documents

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-231871 [Summary of the Invention] [Problems to be Solved by the Invention]

[0008] However, when back-grinding a semiconductor wafer or a sealing body using the above-described adhesive tape, variations may occur in the processing. As a result, thickness variations may occur within the plane of the semiconductor wafer, or thickness variations may occur between two or more semiconductor chips.

[0009] An object of the present invention is to provide an adhesive tape, a laminate, and a method for manufacturing a semiconductor device that can reduce variations in the processing of semiconductor devices. [Means for Solving the Problems]

[0010] [1] An adhesive tape having a first adhesive layer, a second adhesive layer, and an intermediate layer disposed between the first adhesive layer and the second adhesive layer, wherein the intermediate layer contains at least one selected from the group consisting of inorganic oxides, inorganic nitrides, inorganic oxynitrides, metals, and siloxane compounds, and the thickness of the intermediate layer is 5 nm or more and 3 μm or less. [2] The adhesive tape according to [1], wherein when two or more semiconductor chips having a size of 1 cm × 1 cm × height 50 μm are disposed on the first adhesive layer, the variation in the height of the semiconductor chips from the surface of the adhesive tape opposite to the surface on which the two or more semiconductor chips are disposed is less than 5 μm. [3] The adhesive tape according to [1] or [2], wherein the light transmittance of the intermediate layer for light having a wavelength of 355 nm is 60% or more. [4] The adhesive tape according to any one of [1] to [3], wherein the first adhesive layer contains a radiation-curable adhesive. [5] A laminate including the adhesive tape according to any one of [1] to [4] and a semiconductor device disposed on the first adhesive layer of the adhesive tape. [6] The semiconductor device is the laminate according to [5], which is two or more semiconductor chips. [7] A method for manufacturing a semiconductor device, comprising the steps of bonding the second adhesive layer of the adhesive tape according to any one of [1] to [4] to the support, bonding the first adhesive layer to the semiconductor device, processing the semiconductor device, and peeling between the first adhesive layer and the processed semiconductor device or between the second adhesive layer and the support. [8] The first adhesive layer contains a radiation-curable adhesive. In the peeling step, radiation is irradiated to the first adhesive layer through the second adhesive layer to cure the radiation-curable adhesive, thereby peeling the first adhesive layer from the processed semiconductor device. The method for manufacturing a semiconductor device according to [7]. [Advantages of the Invention]

[0011] According to the present invention, it is possible to provide an adhesive tape, a laminate, and a method for manufacturing a semiconductor device that can reduce variations in the processing of semiconductor devices. [Brief Description of the Drawings]

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

[0013] Hereinafter, the adhesive tape according to an embodiment of the present invention and a method for manufacturing a semiconductor device using the same will be described in detail. In this specification, the description of "~" means a numerical range including the lower limit and the upper limit which are endpoints, unless otherwise specified. In an embodiment of the present invention, the amount of each component means the total amount of a plurality of substances when there are a plurality of substances corresponding to each component, unless otherwise specified.

[0014] 1. Adhesive tape The adhesive tape according to an embodiment of the present invention has a first adhesive layer, a second adhesive layer, and an intermediate layer disposed therebetween.

[0015] As described above, when back grinding a semiconductor wafer or a sealing body using a conventional adhesive tape, variations may occur in the processing.

[0016] Also, in back grinding and subsequent electrode formation processes and the like, the process temperature becomes high. However, since conventional adhesive tapes have low heat resistance, voids are likely to occur at the interface between the adhesive tape and the wafer in a high-temperature process, and the adhesive tape is likely to peel off or wrinkle from the semiconductor wafer. When peeling or wrinkling occurs, the semiconductor wafer or the sealing body cannot be stably supported and fixed, so variations in the processing of semiconductor devices are more likely to occur.

[0017] The inventors of the present invention have found that variations in the processing of semiconductor devices are caused by variations in the thickness of the adhesive tape, and that the variations in the thickness of the adhesive tape are mainly caused by variations in the thickness of the intermediate layer. And it has been found that by making the thickness of the intermediate layer thinner than a predetermined value, variations in the thickness of the intermediate layer can be reduced, and thereby variations in the processing of semiconductor devices can be reduced.

[0018] In addition, the inventors of the present invention have found that by including one or more selected from the group consisting of inorganic oxides, inorganic nitrides, inorganic oxynitrides, metals, and siloxane compounds in the intermediate layer, not only can the barrier property be maintained even when the thickness of the intermediate layer is reduced, but also the heat resistance can be enhanced. As a result, while suppressing the movement of low-molecular-weight components between the first adhesive layer and the second adhesive layer via the intermediate layer, it is possible to suppress deformation of the adhesive tape even in a high-temperature process, and it has been found that variations in the processing of semiconductor devices can be reduced.

[0019] That is, in the present embodiment, the intermediate layer includes one or more selected from the group consisting of inorganic oxides, inorganic nitrides, inorganic oxynitrides, metals, and siloxane compounds. And the thickness of the intermediate layer is adjusted to be a predetermined value or less (specifically, 5 nm to 3 μm). Hereinafter, each layer will be specifically described.

[0020] 1-1. Intermediate layer The intermediate layer is disposed between the first adhesive layer and the second adhesive layer and has a function of blocking the movement of low-molecular-weight components and the like between them. Also, in a high-temperature process, it is desirable for the intermediate layer to stably support and fix an adherend such as a semiconductor device.

[0021] From these viewpoints, the intermediate layer includes one or more selected from the group consisting of inorganic oxides, inorganic nitrides, inorganic oxynitrides, metals, and siloxane compounds as described above.

[0022] Examples of the inorganic oxide include silicon oxide, aluminum oxide, magnesium oxide, titanium oxide, tin oxide, indium oxide alloy, calcium oxide, silver oxide, manganese oxide, platinum oxide, etc. Examples of the inorganic nitride include silicon nitride, aluminum nitride, titanium nitride, etc. Examples of the inorganic oxynitride include silicon oxynitride, etc. Examples of the metal include aluminum, silver, copper, tin, nickel, titanium, silicon, etc. Examples of the inorganic include diamond-like carbon, graphene, etc.

[0023] The siloxane compound is a compound having an Si-O bond. Examples of the siloxane compound include polysiloxanes having one or more functional groups selected from an epoxy group, an amino group, a hydroxy group, a mercapto group, a carboxy group, a (meth)acryloyl group, an isocyanate group, a vinyl group, an alkyl group, and a phenyl group. Examples of the polysiloxane include cured products of alkoxysilane and / or its partial condensate.

[0024] The alkoxysilane can be exemplified by a compound represented by the following formula (1), for example. [Chemical formula]

[0025] In formula (1), x represents an integer of 0 to 2. R1 represents a lower alkyl group, an allyl group, or an aryl group which may have a functional group selected from the group consisting of an epoxy group, an amino group, a (meth)acryloyl group, an isocyanate group, and a mercapto group. A plurality of R1s may be the same or different. R2 represents a hydrogen atom or a lower alkyl group. The lower alkyl group means a linear or branched alkyl group having 6 or less carbon atoms.

[0026] In the alkoxysilane represented by formula (1), Examples of the case where x = 0 include tetraalkoxysilanes such as tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetraisopropoxysilane, and tetrabutoxysilane; Examples for the case of x = 1 include trialkoxysilanes such as methyltrimethoxysilane, methyltriethoxysilane, methyltripropoxysilane, methyltributoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, isopropyltrimethoxysilane, isopropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, 3,4-epoxycyclohexylethyltrimethoxysilane, 3,4-epoxycyclohexylethyltriethoxysilane; Examples for the case of x = 2 include dialkoxysilanes such as dimethyldimethoxysilane, dimethyldiethoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, γ-glycidoxysikopropylmethyldimethoxysilane, γ-mercaptopropylmethyldimethoxysilane. Note that as the alkoxysilane, tetraalkoxysilanes and / or trialkoxysilanes are preferred. These alkoxysilanes can be used alone or in combination of two or more.

[0027] The partial condensate of alkoxysilane is a partial condensation in which one or more kinds of alkoxysilanes are hydrolyzed by at least two molecules or more. The degree of condensation of the condensate of alkoxysilane is not particularly limited, but from the viewpoint of good handleability, a condensate containing an average of 2 to 8 Si atoms per molecule of the condensate of alkoxysilane is preferred. The structure of the condensate is not particularly limited, and may be either a linear structure or a branched structure, and there may be a bond via an oxygen atom between branched chains or between a branched chain and a main chain.

[0028] Among them, from the viewpoint that high barrier properties can be easily obtained even when the thickness of the intermediate layer is reduced, metals, inorganic substances, and siloxane compounds are preferable. From the viewpoint of making it easier to further enhance light transmittance and making it easier to photocure the pressure-sensitive adhesives constituting the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer, siloxane compounds are more preferable.

[0029] The content of one or more components selected from the group consisting of inorganic oxides, inorganic nitrides, inorganic oxynitrides, metals, and siloxane compounds in the intermediate layer can be 90% by mass or more with respect to the intermediate layer.

[0030] In this embodiment, the thickness of the intermediate layer is set to 5 nm to 3 μm. By setting the thickness of the intermediate layer to 3 μm or less, the variation in the thickness of the intermediate layer can be reduced. Therefore, the variation in the thickness of the entire adhesive tape can also be reduced, and the variation in the processing of the semiconductor device can be reduced. Further, by setting the thickness of the intermediate layer to 5 nm or more, the barrier properties can be enhanced, and the movement of low molecular weight components and the like between the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer can be suppressed. From the same viewpoint, it is preferable that the thickness of the intermediate layer is 10 to 500 nm, and more preferably 30 to 150 nm. The thickness of the intermediate layer may be measured by observing the cross section of the adhesive tape with an electron microscope, or may be measured with a film thickness measuring device using the spectroscopic interference method. For example, when the intermediate layer contains a siloxane compound, it can be measured with a non-contact film thickness measuring device using the spectroscopic interference method (for example, Optical Nano Gauge C13027 manufactured by Hamamatsu Photonics K.K.).

[0031] The surface resistivity of the intermediate layer is not particularly limited, but is preferably 10 -10 Ω / sq or less, and more preferably 10 -9 Ω / sq or less. When the surface resistivity of the intermediate layer is 10 -10 Ω / sq or less, the risk of circuit breakdown due to static electricity can be suppressed. The surface resistivity of the intermediate layer can be measured with a surface resistance meter ST-4 manufactured by SIMCO.

[0032] The intermediate layer may or may not have light transmissivity. For example, when irradiating light through the intermediate layer to cure the adhesive in the first adhesive layer or the second adhesive layer by light, the intermediate layer preferably has light transmissivity.

[0033] The light transmittance of the intermediate layer for light with a wavelength of 355 nm is preferably, for example, 60% or more, and more preferably 80% or more. When the light transmittance of the intermediate layer is 60% or more, it is possible to facilitate the photocuring of the adhesive contained in the first adhesive layer or the second adhesive layer through the intermediate layer. The light transmittance of the intermediate layer can be measured by an optical transmittance measuring instrument (DST-2501 manufactured by Toa System Create Co., Ltd.).

[0034] The light transmittance of the intermediate layer can be adjusted by the material of the intermediate layer. For example, by using a siloxane compound as the material of the intermediate layer, the light transmittance can be further increased.

[0035] The heat shrinkage rate of the intermediate layer is preferably, for example, 0.3% or less, more preferably 0.2% or less, and even more preferably 0.1% or less. When the heat shrinkage rate of the intermediate layer is 0.3% or less, the shape stability when heat is applied when made into an adhesive tape can be enhanced. The heat shrinkage rate of the intermediate layer can be evaluated as the ratio of the shrinkage amount due to heating to the dimension before heating after heating in an oven at 200 °C for 10 minutes and then cooling to room temperature. Specifically, it can be calculated from the following formula. Heat shrinkage rate of the intermediate layer (%) = [(Dimension before heating - Dimension after heating) / Dimension before heating] × 100

[0036] The heat shrinkage rate of the intermediate layer can be adjusted by the material of the intermediate layer. For example, by selecting a material that is less likely to cause thermal expansion due to heat (such as inorganic oxides, inorganic nitrides, inorganic oxynitrides, metals, and siloxane compounds), the heat shrinkage rate can be made lower.

[0037] The intermediate layer may be one layer or two or more layers. When there are two or more intermediate layers, the combination of the materials of the intermediate layers may be the same or different.

[0038] The intermediate layer can be produced by any method. For example, the intermediate layer can be formed by a dry coating method, a wet coating method, or a lamination method. Examples of the dry coating method include a vacuum evaporation method, an oxidation reaction evaporation method, a sputtering method, a plasma chemical vapor deposition method, etc. Examples of the wet coating method include a die coating method, a gravure coating method, etc. Examples of the lamination method include a method of laminating a metal foil or the like. Among these, the lamination method is preferable. Specifically, it can be formed by forming the intermediate layer on a release film by the gravure coating method and then laminating the intermediate layer on the adhesive layer and peeling off the release film for transfer.

[0039] 1-2. First Adhesive Layer The first adhesive layer is disposed on one surface of the intermediate layer. For example, when an adhesive tape is used in the manufacture of a semiconductor device, the first adhesive layer is preferably located on the side where the semiconductor device is disposed. The adhesive contained in the first adhesive layer may be an adhesive whose adhesive force decreases by applying light or heat, or a pressure-sensitive adhesive. In the present embodiment, the adhesive contained in the first adhesive layer is preferably an adhesive whose adhesive force decreases by applying light or heat.

[0040] The adhesive whose adhesive force decreases by applying light or heat may be a radiation-curable adhesive or a heat-expandable adhesive.

[0041] 1-2-1. Radiation-Curable Adhesive The radiation-curable adhesive is an adhesive that cures by irradiation with, for example, an electron beam, ultraviolet rays, α-rays, β-rays, γ-rays, or X-rays, and is preferably an adhesive that cures by ultraviolet irradiation (photo-curable adhesive).

[0042] The radiation-curable adhesive contains at least a base polymer as an adhesive base. The radiation-curable adhesive may further contain a radiation-polymerizable monomer component or oligomer component having a functional group such as a radiation-polymerizable carbon-carbon double bond, if necessary, or may further contain a thermal crosslinking agent, a photopolymerization initiator, or the like.

[0043] (Base polymer) The base polymer can be an acrylic polymer. The acrylic polymer contains a structural unit derived from a (meth)acrylic acid ester. In the present specification, (meth)acrylic means acrylic and / or methacrylic.

[0044] Examples of the (meth)acrylic acid ester include hydrocarbon group-containing (meth)acrylic acid esters such as (meth)acrylic acid alkyl esters, (meth)acrylic acid cycloalkyl esters, and (meth)acrylic acid aryl esters. Examples of the (meth)acrylic acid alkyl ester 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, tridecyl ester, tetradecyl ester, hexadecyl ester, octadecyl ester, and eicosyl ester of (meth)acrylic acid. Examples of the (meth)acrylic acid cycloalkyl ester include cyclopentyl ester and cyclohexyl ester of (meth)acrylic acid. Examples of the (meth)acrylic acid aryl ester include phenyl (meth)acrylate and benzyl (meth)acrylate. The monomer constituting the acrylic polymer may contain one type of (meth)acrylic acid ester or may contain two or more types of (meth)acrylic acid esters.

[0045] The content of the structural unit derived from the (meth)acrylic acid ester is preferably 40% by mass or more, more preferably 60% by mass or more, based on all the structural units of the acrylic polymer.

[0046] The acrylic polymer may further contain structural units derived from one or more other monomers copolymerizable with the (meth)acrylic acid ester, if necessary.

[0047] Examples of the other monomers include functional group-containing monomers such as carboxy group-containing monomers, acid anhydride monomers, hydroxy group-containing monomers, glycidyl group-containing monomers, sulfonic acid group-containing monomers, phosphoric acid group-containing monomers, acrylamide, and acrylonitrile. By further containing structural units derived from these functional group-containing monomers in the acrylic polymer, the cohesive force and heat resistance can be enhanced. Examples of the 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 the acid anhydride monomers include maleic anhydride and itaconic anhydride. Examples of the hydroxy 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-hydroxydodecyl (meth)acrylate, and (4-hydroxymethylcyclohexyl)methyl (meth)acrylate. Examples of the glycidyl group-containing monomers include glycidyl (meth)acrylate and methyl glycidyl (meth)acrylate. Examples of the sulfonic acid group-containing monomers include styrene sulfonic acid, allyl sulfonic acid, 2-(meth)acrylamide-2-methylpropane sulfonic acid, (meth)acrylamide propane sulfonic acid, sulfopropyl (meth)acrylate, and (meth)acryloyloxy naphthalene sulfonic acid. Examples of the phosphoric acid group-containing monomers include 2-hydroxyethyl acryloyl phosphate.

[0048] Examples of other monomers also include polyfunctional monomers copolymerizable with (meth)acrylic acid esters. By further including structural units derived from polyfunctional monomers in the acrylic polymer, radiation-polymerizable groups can be introduced into the polymer backbone, thereby imparting crosslinkability. As a result, the crosslink density increases, making it easier to cause a decrease in the adhesive force during peeling and enhancing the cohesive force. A crosslinked structure can be formed. Examples of 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, epoxy (meth)acrylate (i.e., polyglycidyl (meth)acrylate), polyester (meth)acrylate, and urethane (meth)acrylate.

[0049] When the acrylic polymer contains structural units derived from other monomers, the content of the structural units derived from other monomers may preferably be 1% by mass or more and 40% by mass or less, more preferably 5% by mass or more and 20% by mass or less, based on all the structural units of the acrylic polymer.

[0050] Also, the acrylic base polymer may have functional groups such as radiation-polymerizable carbon-carbon double bonds in the polymer side chains, in the polymer main chain, or at the polymer main chain terminals. A radiation-curable pressure-sensitive adhesive containing such a base polymer has radical polymerizability even without containing the monomer components and oligomer components described later.

[0051] As a method for introducing a radiation-polymerizable carbon-carbon double bond into an acrylic polymer, for example, after copolymerizing a raw material monomer containing a monomer having a predetermined functional group (first functional group) to obtain an acrylic polymer, a compound having a predetermined functional group (second functional group) capable of reacting and bonding with the first functional group and a radiation-polymerizable carbon-carbon double bond is subjected to a condensation reaction or an addition reaction with the acrylic polymer while maintaining the radiation polymerizability of the carbon-carbon double bond.

[0052] Examples of the combination 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 preferable. Further, since it is technically difficult to produce a polymer having a highly reactive isocyanate group, in terms of ease of production or availability of the acrylic polymer, it is more preferable that the first functional group on the acrylic polymer side is a hydroxy group and the second functional group is an isocyanate group. Examples of the isocyanate compound having both a radiation-polymerizable carbon-carbon double bond and an isocyanate group as the second functional group include methacryloyl isocyanate, 2-methacryloyloxyethyl isocyanate (MOI), and m-isopropenyl-α,α-dimethylbenzyl isocyanate.

[0053] The number average molecular weight of the acrylic polymer is preferably 100,000 or more, more preferably 200,000 to 3,000,000. The number average molecular weight can be measured by the GPC method in terms of polystyrene conversion.

[0054] (Monomer component, oligomer component) The radiation-polymerizable monomer component and oligomer component are preferably bifunctional or higher-functional monomers and oligomers having two or more radiation-polymerizable groups from the viewpoint of facilitating the formation of a crosslinked structure by irradiation with radiation.

[0055] Examples of the radiation-polymerizable monomer component include trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol monohydroxy penta(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and 1,4-butanediol di(meth)acrylate.

[0056] Examples of the radiation-polymerizable oligomer component include oligomers such as urethane-based, polyether-based, polyester-based, polycarbonate-based, and polybutadiene-based oligomers. The molecular weight of the oligomer component can be, for example, about 100 to 30,000.

[0057] The total content of the radiation-polymerizable monomer component and oligomer component in the radiation-curable pressure-sensitive adhesive is not particularly limited, but from the viewpoint of easily reducing the adhesive strength of the first adhesive layer by irradiation with radiation, it is preferably, for example, 0.5 to 150 parts by mass, more preferably 1 to 100 parts by mass, and even more preferably 3 to 10 parts by mass with respect to 100 parts by mass of the base polymer.

[0058] (Thermal crosslinking agent) The radiation-curable pressure-sensitive adhesive preferably further contains a thermal crosslinking agent. The thermal crosslinking agent mainly reacts with functional groups (such as carboxy groups, hydroxy groups, epoxy groups, amide groups, etc.) possessed by the base polymer to form a crosslinked structure. The thermal crosslinking agent can crosslink the base polymer, for example, when the radiation-curable pressure-sensitive adhesive is applied and then dried by heating to form the first adhesive layer. Thereby, it becomes easier to adjust the cohesive force and the like of the first adhesive layer.

[0059] The heat crosslinking agent may be any crosslinking agent that reacts with the functional groups of the base polymer. Examples of such heat crosslinking agents include polyisocyanate-based crosslinking agents, epoxy-based crosslinking agents, polyol-based crosslinking agents (such as polyphenol-based compounds), aziridine-based crosslinking agents, and melamine-based crosslinking agents. The content of the heat crosslinking agent is preferably 6 parts by mass or less, more preferably 0.1 to 5 parts by mass, based on 100 parts by mass of the base polymer, for example.

[0060] (Photoinitiator) The radiation curable pressure-sensitive adhesive preferably further contains a photoinitiator. The photoinitiator mainly reacts with acrylic polymers, monomer components, and oligomer components having radiation polymerizable groups to form a crosslinked structure. For example, when the first adhesive layer is irradiated with ultraviolet rays or the like, the photoinitiator can make it easier to crosslink the base polymer, monomer components, etc., and can further reduce the adhesive force.

[0061] Examples of photoinitiators 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, acylphosphine oxides, and acylphosphonates. Examples of α-ketol compounds include 4-(2-hydroxyethoxy)phenyl(2-hydroxy-2-propyl)ketone, α-hydroxy-α,α'-dimethylacetophenone, 2-methyl-2-hydroxypropiophenone, and 1-hydroxycyclohexyl phenyl ketone. Examples of acetophenone compounds include methoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-dimethoxy-1,2-diphenylethane-1-one, 2,2-diethoxyacetophenone, and 2-methyl-1-[4-(methylthio)-phenyl]-2-morpholinopropan-1. Examples of benzoin ether compounds include benzoin ethyl ether, benzoin isopropyl ether, and anisoin methyl ether. Examples of the ketal compounds include benzyldimethyl ketal. Examples of the aromatic sulfonyl chloride compounds include 2-naphthalenesulfonyl chloride. Examples of the photoactive oxime compounds include 1-phenyl-1,2-propanedione-2-(O-ethoxycarbonyl) oxime. Examples of the benzophenone compounds include benzophenone, benzoylbenzoic acid, and 3,3'-dimethyl-4-methoxybenzophenone. Examples of the thioxanthone compounds include thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-dichlorothioxanthone, 2,4-diethylthioxanthone, and 2,4-diisopropylthioxanthone.

[0062] The content of the photopolymerization initiator in the radiation-curable pressure-sensitive adhesive is, for example, 0.05 to 20 parts by mass with respect to 100 parts by mass of the base polymer.

[0063] (Other additives) The radiation-curable pressure-sensitive adhesive may further contain a photosensitizer, a tackifier, an antioxidant, a colorant, etc., as long as the effects of the present invention are not impaired.

[0064] The photosensitizer may be benzophenone or the like.

[0065] The colorant may be a pigment or a dye. Further, the colorant may be a compound that is colored by radiation irradiation. Examples of such a compound include leuco dyes.

[0066] The radiation-curable pressure-sensitive adhesive may be an addition-type radiation-curable pressure-sensitive adhesive containing a base polymer such as an acrylic polymer and a radiation-polymerizable monomer component or oligomer component having a functional group such as a radiation-polymerizable carbon-carbon double bond; or an inherent-type radiation-curable pressure-sensitive adhesive containing a base polymer having a functional group such as a radiation-polymerizable carbon-carbon double bond in the polymer side chain, in the polymer main chain, or at the polymer main chain terminal.

[0067] 1-2-2. Heat-expandable adhesive The heat-expandable adhesive contains, for example, at least an adhesive base and a component that foams or expands upon heating. When the heat-expandable adhesive layer is heated sufficiently, the foaming or expandable component expands, creating an uneven shape on its surface (adhesive surface). When the heat-expandable adhesive layer is heated in a state where the adhesive surface is adhered to a predetermined adherend, the adhesive layer expands, creating an uneven shape on its adhesive surface and reducing the total adhesion area to the adherend, thereby decreasing the adhesive force to the adherend.

[0068] As the adhesive base, an acrylic polymer, a rubber-based adhesive, or a silicone-based adhesive as described above can be used.

[0069] Examples of the component that foams or expands upon heating include a foaming agent and thermally expandable microspheres.

[0070] Examples of the foaming agent include various inorganic and organic foaming agents. Examples of the inorganic foaming agent include ammonium carbonate, ammonium bicarbonate, sodium bicarbonate, ammonium nitrite, sodium borohydride, and azides. Examples of the organic foaming agent include chlorofluorocarbons such as trichloromonofluoromethane and dichloromonofluoromethane, azo compounds such as azobisisobutyronitrile, azodicarbonamide, and barium azodicarboxylate, hydrazine compounds such as paratoluenesulfonyl hydrazide, diphenyl sulfone-3,3'-disulfonyl hydrazide, 4,4'-oxybis(benzenesulfonyl hydrazide), and allyl bis(sulfonyl hydrazide), semicarbazide compounds such as ρ-toluenesulfonyl semicarbazide and 4,4'-oxybis(benzenesulfonyl semicarbazide), triazole compounds such as 5-morpholyl-1,2,3,4-thiatriazole, and N-nitroso compounds such as N,N'-dinitrosopentamethylenetetramine and N,N'-dimethyl-N,N'-dinitrosoterephthalamide.

[0071] Examples of the thermally expandable microspheres include microspheres having a structure in which a substance that easily gasifies and expands by heating is encapsulated inside a shell. Examples of the substance that easily gasifies and expands by heating include isobutane, propane, and pentane. Thermally expandable microspheres can be produced by encapsulating a substance that easily gasifies and expands by heating in a shell-forming substance by a coacervation method, an interfacial polymerization method, or the like. As the shell-forming substance, a substance exhibiting thermal fusibility or a substance that can be ruptured by the action of thermal expansion of the encapsulated substance can be used. Examples of such substances include vinylidene chloride-acrylonitrile copolymer, polyvinyl alcohol, polyvinyl butyral, polymethyl methacrylate, polyacrylonitrile, polyvinylidene chloride, and polysulfone.

[0072] The heat-expandable adhesive may further contain a heat crosslinking agent and other additives similar to the above-described radiation-curable adhesive as long as the effects of the present invention are not impaired.

[0073] 1-2-3. Physical properties The thickness of the first adhesive layer is not particularly limited, but is preferably, for example, 1 to 100 μm. Among them, when the first adhesive layer contains a radiation-curable adhesive, the thickness of the first adhesive layer is preferably, for example, 2 to 50 μm.

[0074] 1-3. The second adhesive layer The second adhesive layer is disposed on the other surface of the intermediate layer. For example, when an adhesive tape is used in the manufacture of a semiconductor device, the second adhesive layer is preferably located on the side where the support is disposed.

[0075] The adhesive contained in the second adhesive layer may be an adhesive whose adhesive force decreases by applying light or heat, or a pressure-sensitive adhesive. That is, the adhesive contained in the second adhesive layer may be a radiation-curable adhesive, a heat-expandable curable adhesive, or a pressure-sensitive adhesive.

[0076] The radiation-curable adhesive and heat-expandable curable adhesive may be the same as the radiation-curable adhesive and heat-expandable curable adhesive used for the first adhesive layer, respectively. The key is to adjust the composition and physical properties according to the usage method of the adhesive tape. For example, when a high adhesive force and high peelability like those of the first adhesive layer are not required for the second adhesive layer, it may be one that can maintain a certain level of adhesive force. On the contrary, the second adhesive layer may have higher peelability than the first adhesive layer.

[0077] For example, a radiation-curable adhesive (additive radiation-curable adhesive) containing a base polymer such as an acrylic polymer and a radiation-polymerizable monomer component or oligomer component having a functional group such as a radiation-polymerizable carbon-carbon double bond may be used. Also, a radiation-curable adhesive (intrinsic radiation-curable adhesive) containing a base polymer having a functional group such as a radiation-polymerizable carbon-carbon double bond in the polymer side chain, in the polymer main chain, or at the polymer main chain terminal may be used. Further, these may be used in combination. Regarding the degree of reduction in adhesive force due to radiation irradiation, it can be adjusted, for example, by the content of a functional group such as a radiation-polymerizable carbon-carbon double bond, the content of the above-mentioned monomer component and oligomer component, the type and content of the photoinitiator, etc.

[0078] The type and amount of the low molecular weight components contained in the radiation-curable adhesive of the second adhesive layer may be different from those of the radiation-curable adhesive of the first adhesive layer. For example, the content of the low molecular weight components contained in the radiation-curable adhesive of the second adhesive layer may be less or more than the content of the low molecular weight components contained in the radiation-curable adhesive of the first adhesive layer. Also, the radiation-curable adhesive of the second adhesive layer may not contain a photosensitizer, while the radiation-curable adhesive of the first adhesive layer may contain a photosensitizer.

[0079] As the pressure-sensitive adhesive, the above-mentioned acrylic polymer, rubber-based adhesive, or silicone-based adhesive as the main adhesive can be used.

[0080] The adhesive contained in the second adhesive layer may further contain the same other additives as the adhesive contained in the first adhesive layer.

[0081] The thickness of the second adhesive layer is not particularly limited and may be the same as or different from the thickness of the first adhesive layer. For example, in order to adhere to a support with a flat surface, the second adhesive layer can be made thinner than the first adhesive layer. The thickness of the second adhesive layer is preferably, for example, 0.1 to 30 μm, and more preferably 0.1 to 10 μm.

[0082] 1-4. Other Layers The adhesive tape may further contain other layers other than the intermediate layer, the first adhesive layer, and the second adhesive layer described above.

[0083] 1-5. Physical Properties of the Adhesive Tape When two or more semiconductor chips are arranged on the first adhesive layer, it is preferable that the variation in the height of the semiconductor chips is less than 5 μm.

[0084] The variation in the chip height can be measured by the following procedure. 1) First, cut the adhesive tape into a size of 10 cm × 10 cm. Then, attach the second adhesive layer of the adhesive tape to a glass substrate. 2) Next, place five semiconductor chips with a size of 1 cm × 1 cm × a height of 50 μm on the first adhesive layer of the adhesive tape. Specifically, place the semiconductor chips at the center and four corners of the first adhesive layer, respectively, and press and fix them with a force of 2 N. 3) Then, measure the total thickness of the glass substrate, the adhesive tape, and the semiconductor chips with a height measuring instrument (for example, a contact type height measuring instrument such as Mitutoyo Litematic VL-50A-S). Subtract the thickness of the glass substrate measured in advance from the measured value to measure the height of the semiconductor chips on the adhesive tape (the height of the semiconductor chips from the surface of the adhesive tape opposite to the surface where the semiconductor chips are arranged). Make three samples, and take the difference between the maximum value and the minimum value among the measurement results of 5 points × 3 samples = 15 points for each sample as the "variation in the height of the semiconductor chips".

[0085] As described above, the variation in the height of the semiconductor chip can be adjusted by the thickness of the intermediate layer. The smaller the thickness of the intermediate layer, the more likely the variation in the height of the semiconductor chip is to be smaller.

[0086] 1-6. Method for manufacturing an adhesive tape The above adhesive tape can be manufactured by any method. For example, a first adhesive layer may be formed on one surface of the intermediate layer, and a second adhesive layer may be formed on the other surface to manufacture the adhesive tape. Also, a first adhesive layer formed on a separator and a second adhesive layer formed on a separator may be prepared respectively, and the first adhesive layer with the separator is bonded to one surface of the intermediate layer, and the second adhesive layer with the separator is bonded to the other surface of the intermediate layer to manufacture the adhesive tape. Each adhesive layer can be formed by applying an adhesive and then drying it by heating.

[0087] 2. Method for manufacturing a semiconductor device The method for manufacturing a semiconductor device according to the present embodiment includes a step of disposing a semiconductor device on a support via an adhesive tape, a step of processing the semiconductor device, and a step of peeling between the first adhesive layer and the processed semiconductor device or between the second adhesive layer and the support.

[0088] The semiconductor device can be a semiconductor wafer, a semiconductor chip, and a semiconductor device in which a plurality of chips are molded. The semiconductor wafer has a substrate containing at least one semiconductor material selected from the group consisting of, for example, silicon, silicon carbide, gallium nitride, gallium oxide, and sapphire. A predetermined circuit may be formed on the surface of the substrate. The semiconductor chip can be an electric circuit element using the substrate.

[0089] The process of processing the semiconductor device is not particularly limited, and for example, it may be a process of grinding and thinning the back surface of the semiconductor wafer, or a process of forming an electrode on the back surface of the semiconductor wafer. Further, the process of processing the semiconductor device may be a process of resin-sealing one or two or more semiconductor chips, or a process of grinding and thinning the back surface of the obtained sealed body. In the following embodiments, as an example of the process of processing the semiconductor device, an example will be described in which after resin-sealing two or more semiconductor chips, the back surface of the obtained sealed body is ground and thinned.

[0090] Figs. 1A to 1G are schematic partial enlarged cross-sectional views showing a method of manufacturing a semiconductor device according to an embodiment of the present invention. Fig. 2 shows a partial enlarged cross-sectional view of Fig. 1A.

[0091] As shown in Figs. 1A to 1G, the method of manufacturing a semiconductor device according to the present embodiment includes: 1) a step of disposing two or more semiconductor chips 30 on a support 20 via an adhesive tape 10 (see Fig. 1A); 2) a step of resin-sealing two or more semiconductor chips 30 to obtain a sealed body 40 (see Fig. 1B); 3) a step of grinding the back surface of the sealed body 40 (see Fig. 1C); 4) a step of peeling between the adhesive tape 10 and the support 20 (see Figs. 1D and 1E); and 5) a step of peeling between the adhesive tape 10 and two or more semiconductor chips 30 (see Figs. 1F and 1G). In the present embodiment, an example will be described in which the first adhesive layer 11 and the second adhesive layer 12 of the adhesive tape 10 contain radiation-curable adhesives having different light absorption wavelengths.

[0092] The step of 1) Two or more semiconductor chips 30 are disposed on the support 20 via the adhesive tape 10 (see Fig. 1A). In the present embodiment, the second adhesive layer 12 of the adhesive tape 10 is bonded to the support 20, and the first adhesive layer 11 is bonded to the semiconductor chip 30 (see Fig. 2). Thereby, a laminate including the adhesive tape 10, two or more semiconductor chips 30 disposed on the first adhesive layer 11, and the support 20 disposed on the second adhesive layer 12 is obtained.

[0093] The support 20 may be a substrate having rigidity, and for example, any of a resin substrate, a ceramic substrate, and a glass substrate may be used. Among these, when peeling by reducing the adhesive force of the first adhesive layer 11 and the second adhesive layer 12 by ultraviolet irradiation, the support is preferably a transparent support that transmits ultraviolet rays, and it is preferably a glass substrate or a transparent resin substrate such as acrylic, olefin, polycarbonate, vinyl chloride, ABS, PET, nylon, and urethane. Among them, from the viewpoints of high thickness accuracy and heat resistance (small difference in the linear expansion coefficient from the semiconductor device), a glass substrate or a ceramic substrate is preferable, and from the viewpoint of ultraviolet transmittance, a glass substrate is more preferable.

[0094] The thickness of the support 20 is not particularly limited as long as it can stably support and fix the semiconductor chip, but is preferably 500 μm to 3 mm, and more preferably 0.7 to 1 mm.

[0095] The semiconductor chip 30 may be arranged such that the circuit formation surface (front surface) faces the first adhesive layer 11 side, or may be arranged such that the surface opposite to the circuit formation surface (back surface) faces the first adhesive layer 11 side. In the present embodiment, the semiconductor chip 30 is arranged such that the circuit formation surface (front surface) faces the first adhesive layer 11 side.

[0096] The semiconductor chip 30 can be arranged by pressing. Note that the bonding of the first adhesive layer 11 and the semiconductor chip 30 and the bonding of the second adhesive layer 12 and the support 20 may be performed simultaneously or sequentially.

[0097] Step of 2) Next, with two or more semiconductor chips 30 fixed to the support 20 via the adhesive tape 10, a sealing material S is applied so as to fill the two or more semiconductor chips 30 to obtain a sealed body 40 (see FIG. 1B).

[0098] The encapsulant is not particularly limited and may be a curable composition. The curable composition may include, for example, a thermosetting resin and a curing agent. Examples of the thermosetting resin include epoxy resins. Examples of the curing agent include acid anhydrides, amine compounds, phenolic compounds, etc. The curable composition may further include an inorganic filler or the like as necessary.

[0099] After applying the encapsulant to fill two or more semiconductor chips 30, it is cured. The method of applying the encapsulant is not particularly limited and may be an inkjet method. Curing of the encapsulant can be performed by heating. The heating temperature of the encapsulant may be a temperature at which the thermosetting resin can be cured, for example, it can be 150 - 185°C.

[0100] Step of (3) Next, with the encapsulant 40 fixed to the support 20 via the adhesive tape 10, the back surface of the encapsulant 40 is ground (see Fig. 1C). Thereby, the encapsulant 40 is thinned to a thickness below a predetermined value.

[0101] Step of (4) Next, the adhesive tape 10 and the support 20 are peeled off (see Figs. 1D and 1E). In this embodiment, light close to the absorption wavelength of the radiation-curable adhesive of the second adhesive layer 12 is irradiated through the support 20 to cure the radiation-curable adhesive of the second adhesive layer 12. Thereby, the adhesive force of the second adhesive layer 12 is reduced and the support 20 is peeled off.

[0102] The radiation to be irradiated may be of a wavelength capable of curing the adhesives constituting the first adhesive layer 11 and the second adhesive layer 12 of the adhesive tape 10. For example, it may be light with a wavelength of 200 - 360 nm (preferably 355 nm). The irradiation energy may be such that it sufficiently reduces the adhesive force of the adhesive of the second adhesive layer 12.

[0103] Step of (5) Then, peel between the adhesive tape 10 and the sealing body 40 (see FIGS. 1F and 1G). In the present embodiment, by irradiating light close to the absorption wavelength of the radiation-curable adhesive of the first adhesive layer 11 through the second adhesive layer 12 and the intermediate layer 13, the radiation-curable adhesive of the first adhesive layer 11 is cured. Thereby, the adhesive force of the first adhesive layer 11 is reduced, and the adhesive tape 10 is peeled from the sealing body 40.

[0104] (Function) In the above embodiment, processing such as sealing and grinding of the semiconductor chip 30 is performed in a state of being fixed to the support 20 via the adhesive tape 10 (steps (2) and (3) above). Since the thickness of the intermediate layer 13 of the adhesive tape 10 is thin, the variation in the thickness of the entire adhesive tape 10 is small. Therefore, when two or more semiconductor chips 30 are arranged on the first adhesive layer 11 of the adhesive tape 10, the height variation between the semiconductor chips 30 can be reduced, and thus the processing variation between the semiconductor chips 30 can also be reduced. Further, in the process of resin sealing or back grinding, the process temperature becomes high. Since the intermediate layer of the adhesive tape 10 has high heat resistance, peeling and wrinkles from the semiconductor device can be suppressed even under such high temperatures, so that the processing variation of the semiconductor chip 30 can be reduced.

[0105] On the other hand, when peeling the adhesive tape 10, it can be easily peeled by irradiating light through the support 20 (step (4)) or irradiating light through the second adhesive layer 12 or the intermediate layer 13 of the adhesive tape 10 (step (5)). In the present embodiment, since the intermediate layer 13 particularly has light transmissivity, even when light is irradiated from the second adhesive layer 12 side, the light can reach the inside of the first adhesive layer 11 through the intermediate layer 13. Therefore, the adhesive force of the first adhesive layer 11 can be reduced, and the adhesive tape 10 can be easily peeled.

[0106] 3. Modification In the above-described embodiment, after separating the adhesive tape 10 from the support 20 (step (4)), the adhesive tape 10 is separated from the semiconductor chip 30 (step (5)). However, the present invention is not limited to this. For example, step (4) and step (5) may be performed simultaneously, or step (4) may be omitted. When step (4) is omitted, it is sufficient that the first adhesive layer 11 contains a photocurable adhesive, and the second adhesive layer 12 does not necessarily contain a photocurable adhesive. For example, it may contain a pressure-sensitive adhesive. Further, when the second adhesive layer 12 contains a photocurable adhesive, the photocurable adhesive of the second adhesive layer 12 may be one in which the decrease in adhesive force due to light irradiation is less (the adhesive force can be maintained) than the photocurable adhesive of the first adhesive layer 11.

[0107] In the above-described embodiment, the adhesives of the first adhesive layer 11 and the second adhesive layer 12 are photocured by light irradiation to reduce the adhesive force. However, the present invention is not limited to this, and a heat-expandable adhesive may be used, or mechanical peeling may be performed. When a heat-expandable adhesive is used, at the time of peeling, it is preferable to heat the laminate to such an extent that the foaming component can foam, instead of light irradiation. Further, the intermediate layer of the support or the adhesive tape may not have light transmissivity.

[0108] In the above-described embodiment, an example of processing two or more semiconductor chips 30 as a semiconductor device is shown. However, the present invention is not limited to this, and one semiconductor wafer 30 may be processed.

[0109] Figs. 3A to 3G are schematic diagrams showing a method for manufacturing a semiconductor device according to a modified example. The method for manufacturing a semiconductor device according to the modified example includes: 1) a step of disposing a semiconductor wafer 30 on a support 20 via an adhesive tape 10 (see Fig. 3A); 2) a step of grinding the back surface of the semiconductor wafer 30 (see Fig. 3B); 3) a step of forming an electrode 50 on the back surface of the semiconductor wafer 30 (see Fig. 3C); 4) a step of peeling between the adhesive tape 10 and the support 20 (see Figs. 3D and 3E); and 5) a step of peeling between the adhesive tape 10 and the semiconductor wafer 30 (see Figs. 3F and 3G). The method for manufacturing a semiconductor device according to the modified example is the same as the method for manufacturing a semiconductor device according to the above-described embodiment, except that the semiconductor wafer 30 is used as the semiconductor device and the processing contents are different.

[0110] In the step of 2), for example, the back surface of the semiconductor wafer 30 is ground until the thickness becomes 100 μm or less (see Fig. 3B). In the step of 3), electrodes or the like can be formed on the back surface of the semiconductor wafer 30 (see Fig. 3C).

[0111] In this way, processing such as back surface grinding and electrode formation of the semiconductor wafer 30 is performed in a state where the semiconductor wafer 30 is fixed to the support 20 via the adhesive tape 10 (steps 2) and 3) above). As described above, since the thickness of the intermediate layer 13 of the adhesive tape 10 is thin, the variation in the thickness of the entire adhesive tape 10 is also small. Therefore, when the semiconductor wafer 30 is disposed on the first adhesive layer 11 of the adhesive tape 10, the variation in the height within the plane of the semiconductor wafer 30 can be reduced. Therefore, the variation in processing within the plane of the semiconductor wafer 30 can also be reduced.

[0112] In the above-described embodiment, an example is shown in which a semiconductor device is disposed on the first adhesive layer 11 and a support 20 is disposed on the second adhesive layer 12. However, the present invention is not limited to this, and a semiconductor device may be disposed on the second adhesive layer 12 and a support 20 may be disposed on the first adhesive layer 11.

[0113] Further, in the above embodiment, in the step of 1), a laminate including the adhesive tape 10, two or more semiconductor chips 30 disposed on the first adhesive layer 11, and a support 20 disposed on the second adhesive layer 12 is obtained (see FIGS. 1A and 3A). Also, in the step of 5), a laminate having the adhesive tape 10 and two or more semiconductor chips 30 disposed on the first adhesive layer 11 is obtained (see FIGS. 1E and 3E). These laminates can be transported, stored, or used as structures in which semiconductor devices are temporarily fixed.

Example

[0114] Hereinafter, the present invention will be described with reference to examples. The scope of the present invention is not construed as being limited by the examples. FIGS. 4A and 4B are schematic diagrams showing a method for measuring the variation in the height of semiconductor chips.

[0115] 1. Materials 1-1. Preparation of a solution of an adhesive base (base polymer) 48.5 parts by mass of ethyl acrylate, 19.5 parts by mass of 2-ethylhexyl acrylate, 21.5 parts by mass of methyl acrylate, 10.5 parts by mass of glycidyl methacrylate, and 0.5 part by mass of benzoyl peroxide as a polymerization initiator were mixed, and the mixture was added dropwise at 80° C. over 5 hours while stirring in a nitrogen-substituted flask containing 39 parts by mass of toluene and 49 parts by mass of ethyl acetate, and further stirred for 5 hours to cause a reaction. After completion of the reaction, the mixture was cooled, and 74 parts by mass of xylene, 5.0 parts by mass of acrylic acid, 0.03 part by mass of phenothiazine, and 0.6 part by mass of tetradecyldimethylbenzylammonium chloride were added thereto, and the reaction was carried out at 85° C. for 32 hours while blowing air, to obtain a solution of an adhesive base containing an acrylic resin having a radical-polymerizable carbon-carbon double bond (weight average molecular weight: 250,000) (solid content: 39 wt%).

[0116] 1-2. Materials for the first adhesive layer · Adhesive 1 (photo-curable adhesive) To 100 parts by mass of the obtained solution of the pressure-sensitive adhesive main agent, 0.81 part by mass of dipentaerythritol penta and hexaacrylate (manufactured by Toagosei Co., Ltd., Aronix M400) as a monomer component (photo-crosslinking component), 0.52 part by mass of 2,2-dimethoxy-2-phenylacetophenone (manufactured by IGM Resins B.V.: Omnirad651) as a photoinitiator, 0.12 part by mass of a polyisocyanate prepolymer (Orestar P49-75s manufactured by Mitsui Chemicals, Inc.) as a thermal crosslinking agent, and 116.5 parts by mass of ethyl acetate were added to obtain Adhesive Material 1.

[0117] · Adhesive Material 1-2 (pressure-sensitive adhesive) To 100 parts by mass of the obtained solution of the pressure-sensitive adhesive main agent, 0.24 part by mass of a polyisocyanate prepolymer (manufactured by Mitsui Chemicals, Inc., Orestar P49-75s) as a thermal crosslinking agent and 95 parts by mass of ethyl acetate were added to obtain Adhesive Material 1-2.

[0118] 1-3. Material for the second pressure-sensitive adhesive layer · Adhesive Material 2 To 100 parts by mass of the obtained solution of the pressure-sensitive adhesive main agent, 4.41 parts by mass of dipentaerythritol penta and hexaacrylate (manufactured by Toagosei Co., Ltd., Aronix M400) as a monomer component (photo-crosslinking component), 2.63 parts by mass of 2,2-dimethoxy-2-phenylacetophenone (manufactured by IGM Resins B.V.: Omnirad651) as a photopolymerization initiator, 0.12 part by mass of a polyisocyanate prepolymer (Orestar P49-75s manufactured by Mitsui Chemicals, Inc.) as a thermal crosslinking agent, and 116.5 parts by mass of ethyl acetate were added to obtain Adhesive Material 2.

[0119] 1-4. Material for the intermediate layer · C-1 Corcoat N-103X manufactured by Corcoat Co., Ltd. · C-2 Copper foil (manufactured by Fukuda Metal Foil & Powder Co., Ltd., FUTF 5DAS-2, thickness 2 μm) · C-3 PET film (manufactured by Toray Industries, Inc., Lumirror S10, thickness 50 μm) · C-4 PEN film (manufactured by Toyobo Co., Ltd., Teonex Q51, thickness 50 μm)

[0120] (Thickness) For the intermediate layer C-1, as will be described later, Corkote N-103X (manufactured by Corkote Co., Ltd.) was coated on an OPP separator (manufactured by Oji Fine-Tex Corporation, AlphaN E-201M, thickness 50 μm) with a bar coater and dried at 100 °C for 10 minutes. The thickness of the obtained intermediate layer C-1 was measured with a film thickness measuring device: Optical Nano Gauge C13027 manufactured by Hamamatsu Photonics K.K.

[0121] (Light transmittance) The light transmittance of the intermediate layer was measured for light with a wavelength of 355 nm using an optical transmittance measuring device (DST-2501, manufactured by Toa System Create Co., Ltd.).

[0122] (Heat shrinkage rate) The intermediate layer was heated in an oven at 200 °C for 10 minutes and then cooled to room temperature. The dimensions before and after heating were measured, and the heat shrinkage rate (%) was calculated based on the following formula. Heat shrinkage rate of the intermediate layer (%) = [(Dimension before heating - Dimension after heating) / Dimension before heating] × 100

[0123] The physical properties of the intermediate layer are shown in Table 1.

Table 1

[0124] 2. Preparation of the adhesive tape 2-1. Preparation of each layer (Formation of the intermediate layer) As the intermediate layer, a siloxane-based resin (Corkote N-103X, manufactured by Corkote Co., Ltd.) was coated on an OPP separator (manufactured by Oji Fine-Tex Corporation, AlphaN E-201M, width 200 mm, length 300 mm, thickness 50 μm) with a bar coater and dried at 100 °C for 10 minutes to form an intermediate layer with a thickness of 50 nm.

[0125] (Formation of the first adhesive layer) Next, the adhesive 1 was coated on a PET separator (manufactured by Mitsui Chemicals Toagosei Co., Ltd., L41, width 200 mm, length 300 mm, thickness 38 μm) with a bar coater and dried at 100 °C for 10 minutes to form an adhesive layer 1 with a thickness of 5 μm as the first adhesive layer.

[0126] Also, the adhesive 1-2 was coated on a PET separator (manufactured by Mitsui Chemicals Toagosei Co., Ltd., L41, width 200 mm, width 200 mm, length 300 mm, thickness 38 μm) with a bar coater and dried at 100 °C for 10 minutes to form an adhesive layer 1-2 with a thickness of 5 μm as the first adhesive layer.

[0127] (Formation of the second adhesive layer) Next, the adhesive 2 was coated on a separator (manufactured by Mitsui Chemicals Toagosei Co., Ltd., T15, width 200 mm, length 300 mm, thickness 38 μm) with a bar coater and then dried at 100 °C for 10 minutes to form an adhesive layer 2 with a thickness of 5 μm as the second adhesive layer.

[0128] 2-2. Production of Adhesive Tape 1 The obtained intermediate layer was laminated with the adhesive layer 1, the OPP on the intermediate layer side was peeled off, then the adhesive layer 2 was laminated on the intermediate layer, and further treated at 50 °C for 3 days to obtain an adhesive tape in which a PET separator (L41) / adhesive layer 1 / intermediate layer (Kolkote N-103X) / adhesive layer 2 / PET separator (T15) were laminated in this order.

[0129] <Production of Adhesive Tapes 2 to 5> An adhesive tape with a separator was obtained in the same manner as Adhesive Tape 1 except that the intermediate layer and the first adhesive layer were changed as shown in Table 2.

[0130] 3. Evaluation The following evaluations were performed on the above-prepared adhesive tapes 1 to 5 with separators.

[0131] 3-1. Height Variation of Semiconductor Chips First, the above-prepared adhesive tape with a separator was cut into a size of 10 cm × 10 cm. Next, the separator (not shown) on the second adhesive layer 12 of the adhesive tape 10 was peeled off and attached to a glass substrate (not shown) of the same size. Next, after peeling off the separator (not shown) on the first adhesive layer 11 of the adhesive tape 10, five semiconductor chips 30 with a size of 1 cm × 1 cm × height 50 μm were arranged on the exposed first adhesive layer 11. Specifically, the semiconductor chips 30 were arranged at the center and four corners of the first adhesive layer 11 and pressed and fixed with a force of 2 N (see Fig. 4A). Then, the total thickness of the glass substrate (not shown), the adhesive tape 10, and the semiconductor chips 30 was measured with a Mitutoyo contact type height measuring instrument Litematic VL-50A-S. The thickness of the glass substrate (not shown) measured in advance was subtracted from the value obtained by the measurement to measure the height of the semiconductor chips 30 on the adhesive tape 10 (the height H of the semiconductor chips 30 from the surface of the adhesive tape 10 on the side opposite to the surface where the semiconductor chips 30 were arranged) (see Fig. 4B). This measurement was performed on 3 samples. And the difference between the maximum value and the minimum value among the measurement results of 5 points × 3 samples = 15 points was defined as the "variation in the height of the semiconductor chips".

[0132] 3-2. Adhesiveness 3-2-1. Adhesive force (First adhesive layer) The adhesive tape with the separator prepared above was cut into a size of 50 mm × 200 mm. The separator on the second adhesive layer of this adhesive tape was peeled off, and a peeling tape was bonded to this second adhesive layer. Then, the separator on the first adhesive layer was peeled off, attached to SUS304, and after 1 hour passed, ultraviolet rays were irradiated from the second adhesive layer side (light source: high-pressure mercury lamp, irradiation intensity: 12 mW / cm 2 , time: 1 minute). Specifically, a peeling test was performed using a tensile testing machine (for example, RTF manufactured by A&D Company, Limited), and the peeling adhesive force of the first adhesive layer with respect to SUS304 was measured. The test conditions were a peeling speed of 300 mm / min, a peeling angle of 180°, and a temperature of 25°C.

[0133] The adhesive strength of the first adhesive layer in Example 2 was measured by the following method. The adhesive tape with separator prepared above was cut into a size of 50 mm × 200 mm. The separator on the second adhesive layer of this adhesive tape was peeled off, and a peeling tape was attached to this second adhesive layer. Then, the separator on the first adhesive layer was peeled off, attached to SUS304, and left for 1 hour. Specifically, a peeling test was performed using a tensile testing machine (for example, RTF manufactured by A&D Company, Limited), and the peeling adhesive strength of the first adhesive layer with respect to SUS304 was measured. The test conditions were a peeling speed of 300 mm / min, a peeling angle of 180°, and a temperature of 25°C.

[0134] (Second adhesive layer) The adhesive tape with separator prepared above was cut into a size of 50 mm × 200 mm. The separator on the second adhesive layer of this adhesive tape was peeled off, attached to SUS304, and left for 1 hour. Then, the separator on the first adhesive layer side was peeled off, and a peeling tape was attached. Then, ultraviolet rays were irradiated (light source: high-pressure mercury lamp, irradiation intensity: 12 mW / cm 2 , time: 1 minute). And the adhesive strength was measured in the same manner as above.

[0135] 3-3. Shape stability after heat history The separator on the first adhesive layer of the adhesive tape with separator was peeled off and attached to a glass substrate. The obtained laminate was heated in an oven at 230°C for 30 minutes, and then the appearance after cooling to room temperature was evaluated.

[0136] The evaluation results of Adhesive Tapes 1 to 5 are shown in Table 2.

Table 2

[0137] As shown in Table 2, in the adhesive tapes 4 and 5 having an intermediate layer with a thickness greater than 3 μm, the variation in the height of the semiconductor chip was large. Also, peeling or wrinkles of the adhesive tape from the semiconductor wafer occurred after the thermal history, indicating poor shape stability and low heat resistance.

[0138] On the other hand, in the adhesive tapes 1 to 3, the variation in the height of the semiconductor chip was small. Also, it can be seen that the heat shrinkage rate of the intermediate layer was low, the shape stability after the thermal history was good, and the heat resistance was high. Further, in the adhesive tapes 1 and 2, by having barrier properties, there was no permeation of the additive, and the decrease in the adhesive force after light irradiation through the intermediate layer was good.

[0139] From these facts, it can be seen that by setting the thickness of the intermediate layer to 3 μm or less, the variation in the height of the semiconductor chip can be reduced. Also, it can be seen that by forming the intermediate layer of a metal, a siloxane compound, or the like, the heat resistance and barrier properties can be improved.

Industrial Applicability

[0140] According to the present invention, it is possible to provide an adhesive tape, a laminate, and a method for manufacturing a semiconductor device that can reduce the variation in the processing of semiconductor devices.

Explanation of Symbols

[0141] 10 Adhesive tape 11 First adhesive layer 12 Second adhesive layer 13 Intermediate layer 20 Support 30 Semiconductor chip, semiconductor wafer 40 Sealing body 50 Electrode

Claims

1. An adhesive tape having a first adhesive layer, a second adhesive layer, and an intermediate layer disposed between the first adhesive layer and the second adhesive layer, wherein the intermediate layer contains at least one selected from the group consisting of inorganic oxides, inorganic nitrides, inorganic oxynitrides, metals, and siloxane compounds, and the thickness of the intermediate layer is 5 nm or more and 3 μm or less, adhesive tape.

2. When two or more semiconductor chips having a size of 1 cm × 1 cm × a height of 50 μm are disposed on the first adhesive layer, the variation in the height of the semiconductor chips from the surface of the adhesive tape opposite to the surface on which the two or more semiconductor chips are disposed is less than 5 μm, The adhesive tape according to Claim 1.

3. The light transmittance of the intermediate layer for light having a wavelength of 355 nm is 60% or more, The adhesive tape according to Claim 1.

4. The first adhesive layer contains a radiation-curable adhesive, The adhesive tape according to Claim 1.

5. An adhesive tape according to any one of Claims 1 to 4, and a semiconductor device disposed on the first adhesive layer of the adhesive tape, comprising, a laminate.

6. The semiconductor device is two or more semiconductor chips, The laminate according to Claim 5.

7. A step of bonding the second adhesive layer of the adhesive tape according to any one of Claims 1 to 4 to a support, and bonding the first adhesive layer to a semiconductor device, a step of processing the semiconductor device, and a step of peeling between the first adhesive layer and the processed semiconductor device, or between the second adhesive layer and the support, comprising, a method for manufacturing a semiconductor device.

8. The first adhesive layer contains a radiation-curable adhesive, In the peeling step, radiation is irradiated to the first adhesive layer through the second adhesive layer to cure the radiation-curable adhesive, thereby peeling the first adhesive layer from the processed semiconductor device, The method for manufacturing a semiconductor device according to Claim 7.

Images