Film-like adhesive, semiconductor processing sheet, and method for manufacturing semiconductor device

Abstract

The present invention provides a film-like adhesive that can be used to manufacture semiconductor devices that are not susceptible to corrosion during long-term storage, have a high elastic modulus after curing, and exhibit excellent storage stability; a semiconductor processing sheet provided with the film-like adhesive; and a method for manufacturing a semiconductor device using the semiconductor processing sheet. [Solution] A thermosetting film-like adhesive comprising a compound having a benzoxazine ring. Preferably, it further contains an epoxy resin (b1) comprising a polyfunctional epoxy compound having a cyclic or acyclic aliphatic skeleton, and more preferably contains a phenolic resin.

Description

[Technical Field]

[0001] The present invention relates to a film-like adhesive, a sheet for semiconductor processing, and a method for manufacturing a semiconductor device. [Background technology]

[0002] During the manufacturing of semiconductor devices, a semiconductor chip (sometimes referred to as a "semiconductor chip with film adhesive" in this specification) with a cut film-like adhesive attached to the side opposite to the side on which the circuit is formed (hereinafter sometimes abbreviated as the "circuit formation side") is die-bonded to a substrate equipped with conductors such as a lead frame using this film-like adhesive. In some cases, after stacking another semiconductor chip on the circuit formation side of the die-bonded semiconductor chip, wire bonding is performed to electrically connect the electrode portion of the circuit formation side of the semiconductor chip to a conductor on the substrate with a metal wire. Subsequently, the entire obtained semiconductor chip is covered with resin, and sealed by pressurizing and heating to form a semiconductor package.

[0003] A semiconductor chip with a film-like adhesive on its back surface is manufactured, for example, by dividing a semiconductor wafer with a film-like adhesive on its back surface and cutting the film-like adhesive as well. A widely used method for dividing a semiconductor wafer into semiconductor chips in this way is to dic the semiconductor wafer together with the film-like adhesive using a dicing blade. In this case, the film-like adhesive before cutting is laminated and integrated with a support sheet used to fix the semiconductor wafer during dicing, and is used as a dicing die bonding sheet. After dicing is complete, the semiconductor chips with the film-like adhesive are separated from the support sheet and picked up.

[0004] For example, Patent Document 1 discloses a method for manufacturing a semiconductor device, which includes the steps of: attaching a semiconductor wafer to the adhesive layer of an adhesive sheet consisting of a substrate and an adhesive layer formed peelably on the substrate; dicing the semiconductor wafer to form a semiconductor chip; picking up the semiconductor chip from the substrate with the adhesive layer fixed to the back surface of the semiconductor chip; and then placing the semiconductor chip on a die pad or on another semiconductor chip via the adhesive layer. Here, epoxy-based thermosetting resins such as bisphenol A type epoxy resin, o-cresol novolac type epoxy resin, and dicyclopentadiene skeleton-containing epoxy resin are used as the curable resin component of the adhesive layer (i.e., film-like adhesive). [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2012-169364 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] However, when semiconductor chips with film-like adhesives were fabricated using conventional film-like adhesives, and these film-like adhesive semiconductor chips were die-bonded to the conductor-forming surface of a substrate, and then sealed with resin to create a semiconductor package that was then stored for a long period of time, there was a risk of corrosion occurring on the conductor-forming surface of the substrate due to the chlorine components of the film-like adhesive. The elastic modulus after curing was sometimes insufficient. Furthermore, the storage stability of the film-like adhesive was sometimes compromised.

[0007] Therefore, the present invention aims to provide a film-like adhesive that can be used to produce semiconductor devices that are not susceptible to corrosion during long-term storage, have a high elastic modulus after curing, and exhibit excellent storage stability; a semiconductor processing sheet provided with the film-like adhesive; and a method for manufacturing a semiconductor device using the semiconductor processing sheet. [Means for solving the problem]

[0008] The present invention has the following aspects. [1] A thermosetting film adhesive, A film-like adhesive containing a compound having a benzoxazine ring. [2] The film-like adhesive according to [1] further comprises an epoxy resin (b1) containing a polyfunctional epoxy compound having a cyclic or acyclic aliphatic skeleton. [3] The film-like adhesive according to [2], wherein the epoxy resin (b1) is liquid at room temperature. [4] A film-like adhesive according to any one of [1] to [3], further comprising a phenolic resin. [5] A film-like adhesive according to any one of [1] to [4], further comprising a silica filler. [6] The film-like adhesive according to any one of [1] to [5], wherein the thickness of the film-like adhesive is 3 to 50 μm. [7] A cured product obtained by thermal curing a test laminate prepared by laminating one film-like adhesive or multiple film-like adhesives with a thickness of less than 200 μm by heating at 160°C for 1 hour, wherein a first test specimen with a thickness of 200 ± 20 μm and a width of 5 mm is held at two locations with a 20 mm gap between them, and the storage modulus E' of the first test specimen is measured while heating the first test specimen from 0°C to 350°C in tensile mode under the conditions of a frequency of 11 Hz, a heating rate of 3°C / min, and constant heating, and the storage modulus E' of the first test specimen when the temperature of the first test specimen is 23°C is 1.0 × 10⁻⁶ 3 A film-type adhesive described in any one of items [1] to [6], having a MPa of 1.5 MPa or higher. [8] The film-like adhesive according to any one of [1] to [7], wherein the chlorine content relative to the total mass of the film-like adhesive is less than 100 ppm. [9] A semiconductor processing sheet comprising a support sheet having a base material, on which a film-like adhesive described in any one of items [1] to [8] is provided.

[0009] A method for manufacturing a semiconductor device using a film-like adhesive described in any one of items [1] to [8], or a semiconductor processing sheet described in [9], A semiconductor wafer with a film-like adhesive is manufactured by attaching one side of the film-like adhesive, or the side of the film-like adhesive in the semiconductor processing sheet that is opposite to the side of the support sheet, to the back surface of a semiconductor wafer. When the semiconductor processing sheet is used, the semiconductor wafer is divided into semiconductor chips on the support sheet within the semiconductor processing sheet, and the film-like adhesive is cut to produce a semiconductor chip with film-like adhesive. When the film-like adhesive that does not constitute the semiconductor processing sheet is used, a dicing sheet is attached to the other side of the film-like adhesive in the semiconductor wafer with film-like adhesive, and then the semiconductor wafer is divided into semiconductor chips on the dicing sheet, and the film-like adhesive is cut to produce a semiconductor chip with film-like adhesive. The semiconductor chip with the film-like adhesive is picked up by separating it from the support sheet or dicing sheet. A method for manufacturing a semiconductor device, comprising die bonding the picked-up film-like adhesive semiconductor chip to the conductor-forming surface of a substrate having a conductor-forming surface using the film-like adhesive in the film-like adhesive semiconductor chip.

[11] The method for manufacturing a semiconductor device according to

[10] , further comprising the step of resin-encapsulating the entire semiconductor chip with a film-like adhesive that has been die-bonded onto the conductor-forming surface of a substrate. [Effects of the Invention]

[0010] The present invention provides a film-like adhesive that can be used to manufacture semiconductor devices that are not susceptible to corrosion during long-term storage, have a high elastic modulus after curing, and exhibit excellent storage stability; a semiconductor processing sheet provided with the film-like adhesive; and a method for manufacturing a semiconductor device using the semiconductor processing sheet. [Brief explanation of the drawing]

[0011] [Figure 1] This is a cross-sectional view schematically showing an example of a film-like adhesive according to an embodiment of the present invention. [Figure 2] This is a cross-sectional view schematically showing an example of a sheet for semiconductor processing using the film-like adhesive according to an embodiment of the present invention. [Figure 3] In the examples, this is a top view of the substrate used in the corrosion test.

Embodiments for Carrying Out the Invention

[0012] ◇Film-like Adhesive The film-like adhesive of the present invention is a thermosetting film-like adhesive and contains a compound having a benzoxazine ring. The compound having a benzoxazine ring is not limited as long as it is a compound in which the benzoxazine ring is opened by heat and undergoes a polymerization reaction. As the compound having a benzoxazine ring, a benzoxazine compound represented by the following formula (O) can be mentioned.

[0013]

Chemical Formula

[0014] R 1 , R 2 , R 3 and R 4 Examples of the organic groups of include a phenyl group which may have a substituent, a naphthyl group which may have a substituent, an alkyl group which may have a substituent, and the like.

[0015] The benzoxazine compound represented by the formula (O) is known to undergo a polymerization reaction by opening the benzoxazine ring by heat as follows.

[0016] [ka] [In the formula, R 1 R represents an organic group. 2 , R 3 and R 4 [where n represents a hydrogen atom or an organic group independently, and Δ represents a natural number, and Δ represents thermal energy.]

[0017] The benzoxazine compound represented by formula (O) may be the benzoxazine compound represented by formula (O)-1 or the benzoxazine compound represented by formula (O)-2.

[0018] [ka]

[0019] Conventional film-type adhesives have used epoxy thermosetting resins containing aromatic rings, such as bisphenol A type epoxy resin, o-cresol novolac type epoxy resin, and dicyclopentadiene skeleton-containing epoxy resin, as the curable resin component. However, many of these epoxy thermosetting resins contain chlorine as an impurity. On the other hand, the film-type adhesive of the present invention uses a compound having a benzoxazine ring as the curable component. Therefore, the film-type adhesive of the present invention can reduce the content of chlorine as an impurity, and by using the film-type adhesive of the present invention, it is possible to manufacture semiconductor devices that do not corrode during long-term storage, have a high elastic modulus after curing, and have excellent storage stability.

[0020] In the aforementioned film-like adhesive, the proportion of the compound having a benzoxazine ring to the total content of all components is preferably 5 to 80% by mass, more preferably 7 to 70% by mass, and even more preferably 9 to 60% by mass. Having the compound having a benzoxazine ring within this range makes it easier to adjust the above-mentioned effects.

[0021] The aforementioned film-like adhesive is preferably thermosetting and pressure-sensitive. A film-like adhesive having both thermosetting and pressure-sensitive properties can be applied to various substrates by lightly pressing it in its uncured state. Alternatively, the film-like adhesive may be applied to various substrates after being softened by heating. Upon curing, the film-like adhesive ultimately becomes a cured product with high impact resistance, and this cured product can maintain sufficient adhesive properties even under severe high temperature and high humidity conditions.

[0022] The film-like adhesive may consist of one layer (i.e., a single layer) or of two or more layers. When the film-like adhesive consists of multiple layers, these layers may be identical or different, and the combination of these layers is not particularly limited as long as it does not impair the effects of the present invention. Furthermore, if the film-like adhesive consists of multiple layers, at least one of the layers may be the film-like adhesive according to the above embodiment, and it is preferable that all layers be the film-like adhesive according to the above embodiment. In this specification, not only in the case of film-like adhesives, "multiple layers may be identical or different from one another" means "all layers may be identical, all layers may be different, or only some layers may be identical," and further, "multiple layers are different from one another" means "at least one of the constituent materials and thickness of each layer is different from the other."

[0023] The thickness of the film-like adhesive is not particularly limited, but is preferably 1 μm to 50 μm, and more preferably 3 μm to 50 μm. A film-like adhesive thickness greater than or equal to the lower limit provides higher adhesion to the adherend (i.e., semiconductor chip). Furthermore, a film-like adhesive thickness less than or equal to the upper limit allows for easier cutting by the expansion process described later. Here, "thickness of film adhesive" refers to the total thickness of the film adhesive. For example, the thickness of a multi-layered film adhesive refers to the total thickness of all the layers that make up the film adhesive. Methods for measuring the thickness of film adhesive include, for example, measuring the thickness at five arbitrary locations using a constant-pressure thickness gauge in accordance with JIS K7130, and calculating the average of the measured values.

[0024] The adhesive strength of the film-like adhesive to the semiconductor wafer before curing can be appropriately adjusted, for example, by adjusting the type and amount of components contained in the film-like adhesive. For example, the adhesive strength of the film-like adhesive can be easily adjusted by adjusting the molecular weight of the polymer component (a) described later, the ratio of each monomer component constituting the polymer component (a), the softening point of the components constituting the curable epoxy resin (b), and the content of each component contained in the film-like adhesive. However, these adjustment methods are just examples.

[0025] [Adhesive composition] A film-like adhesive can be formed from an adhesive composition containing constituent materials such as a compound having a benzoxazine ring and a solvent. For example, a film-like adhesive can be formed on the desired area by coating the adhesive composition onto the surface to be coated and drying it as needed. The ratio of components that do not vaporize at room temperature in the adhesive composition is usually the same as the ratio of such components in a film-like adhesive. In this specification, "room temperature" means a temperature that is not particularly cooled or heated, i.e., a normal temperature, such as 15 to 25°C.

[0026] The adhesive composition may be coated by known methods, such as using various coaters including air knife coaters, blade coaters, bar coaters, gravure coaters, comma coaters, roll coaters, roll knife coaters, curtain coaters, die coaters, knife coaters, screen coaters, Meyer bar coaters, and kiss coaters.

[0027] The drying conditions for the adhesive composition are not particularly limited, but if the adhesive composition contains a solvent as described later, it is preferable to heat dry it. For example, adhesive compositions containing a solvent are preferably dried at 70 to 130°C for 10 seconds to 5 minutes. The components of the film-type adhesive and adhesive composition will be described in detail below.

[0028] Preferred film-like adhesives and adhesive compositions include, for example, those containing a compound having a benzoxazine ring and a polymer component (a), those containing an epoxy resin (b1) containing a compound having a benzoxazine ring and a polyfunctional epoxy compound having a cyclic or acyclic aliphatic skeleton, those containing a compound having a benzoxazine ring and a phenol resin, those containing a compound having a benzoxazine ring, a polymer component (a), and a curable epoxy resin (b), and those containing a compound having a benzoxazine ring, a polymer component (a), a curable epoxy resin (b), and a silica filler. Each component will be described below.

[0029] (polymer component (a)) Polymer component (a) is a component that can be considered to have been formed by a polymerization reaction of polymerizable compounds, and it is a component that imparts film-forming properties and flexibility to the film-like adhesive, as well as improving adhesion (i.e., stickability) to the bonding target, such as semiconductor chips. Furthermore, polymer component (a) is a component that does not fall under the epoxy resin (b1) and thermosetting agent (b2) described later.

[0030] The polymer component (a) contained in the adhesive composition and the film-like adhesive may be one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0031] Examples of polymer component (a) include acrylic resin, polyester, urethane resin, acrylic urethane resin, silicone resin, rubber resin, phenoxy resin, thermosetting polyimide, etc., with acrylic resin being preferred.

[0032] Examples of the acrylic resin in polymer component (a) include known acrylic polymers.

[0033] The weight-average molecular weight (Mw) of the acrylic resin is preferably 10,000 to 2,000,000, and more preferably 100,000 to 1,500,000. Having the weight-average molecular weight of the acrylic resin within this range makes it easy to adjust the elongation at break of the film adhesive or laminate and the adhesive strength of the film adhesive to the above-mentioned range. On the other hand, if the weight-average molecular weight of the acrylic resin is above the lower limit, the shape stability (i.e., stability over time during storage) of the film-like adhesive is improved. Also, if the weight-average molecular weight of the acrylic resin is below the upper limit, the film-like adhesive can more easily conform to the uneven surface of the adherend, and the occurrence of voids and the like between the adherend and the film-like adhesive is further suppressed. In this specification, unless otherwise specified, "number-average molecular weight" and "weight-average molecular weight" are polystyrene-converted values ​​measured by gel permeation chromatography (GPC).

[0034] The glass transition temperature (Tg) of the acrylic resin is preferably -60 to 70°C, and more preferably -30 to 50°C. When the Tg of the acrylic resin is above the lower limit, the adhesive strength between the film-like adhesive and the support sheet described later is suppressed, making it easier to separate the semiconductor chip with the film-like adhesive from the support sheet during pickup. Furthermore, when the Tg of the acrylic resin is below the upper limit, the adhesive strength between the film-like adhesive and the semiconductor chip is improved. In this specification, "glass transition temperature" is expressed as the temperature at the inflection point of the DSC curve obtained by measuring the DSC curve of the sample using a differential scanning calorimeter.

[0035] Examples of acrylic resins include (meth)acrylic acid ester copolymers having constituent units derived from (meth)acrylic acid ester monomers. Examples of the (meth)acrylic acid esters constituting the acrylic resin include alkyl (meth)acrylates having 1 to 18 carbon atoms in the alkyl group, specifically methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate. Also, examples of (meth)acrylates having a cyclic skeleton include cyclohexyl (meth)acrylate, benzyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, and imide (meth)acrylate. Furthermore, examples of functional group-containing monomers include hydroxymethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, and 2-hydroxypropyl (meth)acrylate, which have hydroxyl groups; other examples include glycidyl (meth)acrylate, which have epoxy groups. Acrylic resins containing hydroxyl groups are preferred because they have good compatibility with the curable components described later. The above acrylic polymer may also be copolymerized with vinyl acetate, acrylonitrile, styrene, etc. However, from an environmental perspective, it is preferable that acrylonitrile is not substantially included.

[0036] In this specification, "(meth)acrylic acid" is a concept that encompasses both "acrylic acid" and "methacrylic acid." The same applies to terms similar to (meth)acrylic acid; for example, "(meth)acrylate" is a concept that encompasses both "acrylate" and "methacrylate," and "(meth)acryloyl group" is a concept that encompasses both "acryloyl group" and "methacryloyl group."

[0037] The acrylic resin may be obtained by copolymerizing one or more monomers selected from (meth)acrylic acid, itaconic acid, vinyl acetate, acrylonitrile, styrene, and N-methylolacrylamide, in addition to the (meth)acrylic acid ester mentioned above.

[0038] The monomers that make up the acrylic resin may be just one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0039] In addition to the hydroxyl groups mentioned above, the acrylic resin may also have functional groups that can bond to other compounds, such as vinyl groups, (meth)acryloyl groups, amino groups, carboxyl groups, and isocyanate groups. These functional groups, including the hydroxyl groups of the acrylic resin, may bond to other compounds via a crosslinking agent (f) described later, or they may bond directly to other compounds without the crosslinking agent (f). The bonding of the acrylic resin to other compounds via these functional groups tends to improve the reliability of packages obtained using film adhesives.

[0040] In the present invention, a thermoplastic resin other than acrylic resin (hereinafter sometimes simply referred to as "thermoplastic resin") may be used as polymer component (a) alone without using acrylic resin, or in combination with acrylic resin. By including the thermoplastic resin, it may become easier to separate the semiconductor chip with the film adhesive from the support sheet during pickup, and the film adhesive may conform more easily to the uneven surface of the adherend, thereby further suppressing the generation of voids and the like between the adherend and the film adhesive.

[0041] Examples of the thermoplastic resins include polyester, polyurethane, phenoxy resin, polybutene, polybutadiene, and polystyrene.

[0042] The thermoplastic resin contained in the adhesive composition and the film-like adhesive may be one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0043] In the adhesive composition, the ratio of the polymer component (a) content to the total content of all components other than the solvent (i.e., the polymer component (a) content of the film-like adhesive) is preferably 30% by mass or less, regardless of the type of polymer component (a), and may be, for example, 25% by mass or less, 20% by mass or less, 17% by mass or less, or 14% by mass or less. By keeping the ratio below the upper limit, it becomes easier to adjust the degree of the effect obtained by using components other than polymer component (a). On the other hand, the aforementioned ratio is preferably greater than 0% by mass, and is more preferably 6% by mass or more in that the effect obtained by using polymer component (a) is further enhanced.

[0044] The above-mentioned statement regarding the ratio of polymer component (a) content to the total mass of the film-like adhesive means that, in the adhesive composition, the ratio of polymer component (a) content to the total content of all components other than the solvent is preferably 30% by mass or less, regardless of the type of polymer component (a), for example, it may be 25% by mass or less, 20% by mass or less, 17% by mass or less, or 14% by mass or less, while the above ratio is preferably greater than 0% by mass and more preferably 6% by mass or more. This is based on the fact that, in the process of removing the solvent from a solvent-containing resin composition to form a resin film, the amount of components other than the solvent usually does not change, and the ratio of the contents of non-solvent components is the same in the resin composition and the resin film. Therefore, in this specification, not limited to the case of film-like adhesives, the content of non-solvent components will mainly refer to the content in the resin film obtained by removing the solvent from the resin composition.

[0045] (Curing epoxy resin (b)) The curable epoxy resin (b) contains epoxy resin (b1).

[0046] • Epoxy resin (b1) The epoxy resin (b1) includes polyfunctional epoxy compounds having a cyclic or acyclic aliphatic skeleton. Examples of polyfunctional epoxy compounds having a cyclic or acyclic aliphatic skeleton include butanetetracarboxylic acid tetra(3,4-epoxycyclohexylmethyl)-modified ε-caprolactone (Daicel Corporation's "Epolleed® GT401", epoxy equivalent 200-240 g / eq, molecular weight 788.94, liquid), 1,4-cyclohexanedimethanol diglycidyl ether (Showa Denko K.K.'s "Showfree® CDMDG", epoxy equivalent 136 g / eq, molecular weight 256.34, liquid), and 1,2-epoxy-4-(2-oxyranyl)cyclohexane adduct of 2,2-bis(hydroxymethyl)-1-butanol (Daicel Corporation's "EHPE3150", epoxy equivalent 170-190 g / eq, softening point: 70-90°C). Examples of polyfunctional epoxy compounds with an acyclic aliphatic skeleton and a molecular weight of 500 or more include epoxidized polybutadiene resin (JP-200, manufactured by Nippon Soda Co., Ltd., molecular weight 2000-2600, epoxy equivalent 210-240 g / eq).

[0047] While many epoxy thermosetting resins containing aromatic rings contain chlorine as an impurity, polyfunctional epoxy compounds having a cyclic or acyclic aliphatic skeleton can reduce the amount of chlorine as an impurity. Therefore, by using a film-like adhesive containing an epoxy resin (b1) containing a polyfunctional epoxy compound having a cyclic or acyclic aliphatic skeleton, the amount of chlorine as an impurity can be reduced, making it possible to manufacture semiconductor devices that are not susceptible to corrosion of the conductive surface of the substrate during long-term storage.

[0048] Since it is possible to manufacture semiconductor devices in which there is no risk of corrosion of the conductor-forming surface of the substrate during long-term storage, the chlorine content relative to the total mass of the film-like adhesive is preferably less than 100 ppm, more preferably 80 ppm or less, even more preferably 60 ppm or less, and particularly preferably 40 ppm or less.

[0049] By using a film-like adhesive containing an epoxy resin (b1) that includes a polyfunctional epoxy compound having a cyclic or acyclic aliphatic skeleton, the chlorine content relative to the total mass of the film-like adhesive can be kept low, making it possible to manufacture semiconductor devices that are not susceptible to corrosion during long-term storage and have excellent storage stability.

[0050] The epoxy resin (b1) may be liquid or solid at room temperature. Many solid alicyclic epoxy resins contain fluorine. Therefore, a alicyclic epoxy resin that is liquid at room temperature and does not contain fluorine is preferred.

[0051] As the epoxy resin (b1), an epoxy resin having unsaturated hydrocarbon groups may be used. Epoxy resins having unsaturated hydrocarbon groups have higher compatibility with acrylic resins than epoxy resins without unsaturated hydrocarbon groups. Therefore, including an epoxy resin having unsaturated hydrocarbon groups improves the reliability of packages obtained using film adhesives.

[0052] The epoxy resin (b1) contained in the adhesive composition and the film-like adhesive may be one type or two or more types, and if there are two or more types, the combination and ratio thereof can be arbitrarily selected.

[0053] In epoxy resin (b1), the molecular weight of the polyfunctional epoxy compound having a cyclic or acyclic aliphatic skeleton is preferably 500 or more, more preferably 600 or more, and even more preferably 700 or more. The epoxy resin (b1) may consist only of polyfunctional epoxy compounds with a molecular weight of 500 or more having a cyclic or acyclic aliphatic skeleton, or it may be a mixture of polyfunctional epoxy compounds with a molecular weight of 500 or more having a cyclic or acyclic aliphatic skeleton, and may have a molecular weight distribution. The number-average molecular weight of the epoxy resin (b1) is preferably 500 to 30,000, more preferably 600 to 10,000, and particularly preferably 700 to 3,000, from the viewpoint of the curability of the film-like adhesive and the strength and heat resistance of the film-like adhesive after curing.

[0054] The epoxy equivalent of epoxy resin (b1) is preferably 100 to 1000 g / eq, and more preferably 150 to 800 g / eq.

[0055] The epoxy resin (b1) may constitute the curable epoxy resin (b) on its own, or it may constitute the curable epoxy resin (b) together with the thermosetting agent (b2). A thermosetting film-like adhesive in which the curable epoxy resin (b) contains an epoxy resin (b1) and a thermosetting agent (b2) is particularly suitable for the manufacture of opaque semiconductor devices.

[0056] • Thermosetting agent (b2) The thermosetting agent (b2) functions as a curing agent for the epoxy resin (b1). Examples of the thermosetting agent (b2) include compounds having two or more functional groups capable of reacting with epoxy groups in one molecule. Examples of the functional groups include phenolic hydroxyl groups, alcoholic hydroxyl groups, amino groups, carboxyl groups, and groups in which an acid group has been converted to an anhydride. It is preferable that the functional group is a phenolic hydroxyl group, an amino group, or a group in which an acid group has been converted to an anhydride, and more preferably a phenolic hydroxyl group or an amino group.

[0057] Adhesive compositions and film-like adhesives preferably contain a phenolic resin. The phenolic resin functions as a curing agent for compounds having a benzoxazine ring and has the effect of lowering the curing reaction temperature of compounds having a benzoxazine ring. Furthermore, when the adhesive composition and film-like adhesive contain an epoxy resin (b1), the phenolic resin functions as a curing agent for the epoxy resin (b1).

[0058] Examples of phenolic curing agents having phenolic hydroxyl groups include polyfunctional phenolic resins, biphenols, novolac-type phenolic resins, dicyclopentadiene-type phenolic resins, and aralkyl-type phenolic resins. Examples of amine-based curing agents containing an amino group among the thermosetting agents (b2) include dicyandiamide (DICY).

[0059] The thermosetting agent (b2) may also have an unsaturated hydrocarbon group. Examples of thermosetting agents (b2) having unsaturated hydrocarbon groups include compounds in which some of the hydroxyl groups of a phenol resin are replaced with groups having unsaturated hydrocarbon groups, and compounds in which a group having an unsaturated hydrocarbon group is directly bonded to the aromatic ring of a phenol resin. The unsaturated hydrocarbon group in the thermosetting agent (b2) is the same as the unsaturated hydrocarbon group in the epoxy resin having the unsaturated hydrocarbon group described above.

[0060] In epoxy-based thermosetting resins using a thermal cationic polymerization initiator, residual acid may cause corrosion on the conductive surface of the substrate. Therefore, a curable epoxy resin (b) containing epoxy resin (b1) and thermosetting agent (b2) that does not generate acid is preferred. Since this concern is not present, it is preferable that the curable epoxy resin (b) contains a phenolic resin as the thermosetting agent (b2).

[0061] When a phenolic curing agent is used as the thermosetting agent (b2), it is preferable that the thermosetting agent (b2) has a high softening point or glass transition temperature, as this makes it easier to adjust the adhesive strength of the film-like adhesive to the range described above.

[0062] Among the thermosetting agents (b2), the number average molecular weight of the resin components, such as polyfunctional phenolic resins, novolac-type phenolic resins, dicyclopentadiene-type phenolic resins, and aralkyl-type phenolic resins, is preferably 300 to 30,000, more preferably 400 to 10,000, and particularly preferably 500 to 3,000. The molecular weight of the non-resin component of the thermosetting agent (b2), such as biphenol or dicyandiamide, is not particularly limited, but is preferably 60 to 500.

[0063] The thermosetting agent (b2) contained in the adhesive composition and the film-like adhesive may be one type or two or more types, and if there are two or more types, the combination and ratio thereof can be arbitrarily selected.

[0064] In the adhesive composition and the film-like adhesive, the content of the thermosetting agent (b2) is preferably 0.1 to 500 parts by mass, more preferably 1 to 200 parts by mass, and even more preferably 10 to 100 parts by mass, based on the content of 100 parts by mass of the epoxy resin (b1). When the content of the thermosetting agent (b2) is above the lower limit, the curing of the film-like adhesive proceeds more easily. Furthermore, when the content of the thermosetting agent (b2) is below the upper limit, the moisture absorption rate of the film-like adhesive is reduced, and the reliability of the package obtained using the film-like adhesive is further improved.

[0065] In the adhesive composition and the film-like adhesive, the content of the phenolic resin is preferably 0.1 to 200 parts by mass, more preferably 1 to 100 parts by mass, and even more preferably 10 to 40 parts by mass, based on 100 parts by mass of the compound having a benzoxazine ring. When the content of the thermosetting agent (b2) is above the lower limit, the curing of the film-like adhesive proceeds more easily at a lower reaction temperature. Furthermore, when the content of the thermosetting agent (b2) is below the upper limit, the moisture absorption rate of the film-like adhesive is reduced, and the reliability of the package obtained using the film-like adhesive is further improved.

[0066] In adhesive compositions and film-like adhesives, the content of curable epoxy resin (b) (i.e., the total content of epoxy resin (b1) and thermosetting agent (b2)) is preferably 15 to 300 parts by mass, more preferably 21 to 270 parts by mass, and particularly preferably 27 to 260 parts by mass, when the content of polymer component (a) is 100 parts by mass. For example, it may be any of 30 to 290 parts by mass, 60 to 280 parts by mass, 100 to 270 parts by mass, and 140 to 260 parts by mass. Having the content of curable epoxy resin (b) within such a range makes it easy to adjust the elongation at break of the film-like adhesive or laminate and the adhesive strength of the film-like adhesive to a suitable range.

[0067] In order to improve its various physical properties, the aforementioned film-like adhesive may also contain, if necessary, other components not falling under these categories, in addition to the compound having a benzoxazine ring, the polymer component (a), and the curable epoxy resin (b). Other preferred components contained in the aforementioned film-like adhesive include, for example, a curing accelerator (c), a filler (d), a coupling agent (e), a crosslinking agent (f), an energy ray curable resin (g), a photopolymerization initiator (h), and a general-purpose additive (i).

[0068] (Curing accelerator (c)) The curing accelerator (c) is an ingredient used to adjust the curing rate of the adhesive composition. Preferred curing accelerators (c) include, for example, tertiary amines such as triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, and tris(dimethylaminomethyl)phenol; imidazoles such as 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, and 2-phenyl-4-methyl-5-hydroxymethylimidazole (i.e., imidazoles in which one or more hydrogen atoms are substituted with groups other than hydrogen atoms); organophosphines such as tributylphosphine, diphenylphosphine, and triphenylphosphine (i.e., phosphines in which one or more hydrogen atoms are substituted with organic groups); and tetraphenylboron salts such as tetraphenylphosphonium tetraphenylborate and triphenylphosphine tetraphenylborate.

[0069] The curing accelerator (c) contained in the adhesive composition and the film-like adhesive may be one type or two or more types, and if there are two or more types, the combination and ratio thereof can be arbitrarily selected.

[0070] When a curing accelerator (c) is used, the content of the curing accelerator (c) in the adhesive composition and the film adhesive is preferably 0.01 to 10 parts by mass, and more preferably 0.1 to 5 parts by mass, when the content of the curable epoxy resin (b) is 100 parts by mass. When the content of the curing accelerator (c) is above the lower limit, the effect of using the curing accelerator (c) is more pronounced. Furthermore, when the content of the curing accelerator (c) is below the upper limit, for example, the effect of suppressing the migration and segregation of highly polar curing accelerators (c) to the adhesive interface side with the adherend in the film adhesive under high temperature and high humidity conditions is enhanced, and the reliability of packages obtained using semiconductor processing sheets is further improved.

[0071] (Filling material (d)) By including filler (d) in the film-type adhesive, the coefficient of thermal expansion can be easily adjusted, and by optimizing this coefficient of thermal expansion for the object to which the film-type adhesive is applied, the reliability of the package obtained using the film-type adhesive is further improved. In addition, by including filler (d) in the film-type adhesive, it is also possible to reduce the moisture absorption rate of the film-type adhesive after curing and improve its heat dissipation.

[0072] The filler (d) may be either an organic filler or an inorganic filler, but an inorganic filler is preferred. Preferred inorganic fillers include, for example, powders such as silica filler, alumina filler, talc, calcium carbonate, titanium white, red iron oxide, silicon carbide, and boron nitride; beads formed from these inorganic fillers in a spherical shape; surface-modified products of these inorganic fillers; single-crystal fibers of these inorganic fillers; and glass fibers. Among these, silica filler is more preferable because it can improve the elastic modulus after hardening.

[0073] The adhesive composition and the filler (d) contained in the film-like adhesive may consist of only one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0074] When using filler (d), the ratio of the filler (d) content to the total content of all components other than the solvent in the adhesive composition (i.e., the filler (d) content of the film adhesive) is preferably 5 to 80% by mass, more preferably 7 to 60% by mass, and even more preferably 9 to 40% by mass. Having the filler (d) content within this range makes it easier to adjust the coefficient of thermal expansion.

[0075] (Coupling agent (e)) The film-type adhesive exhibits improved adhesion and bonding to the substrate by containing a coupling agent (e). Furthermore, the inclusion of a coupling agent (e) in the film-type adhesive improves the water resistance of the cured product without compromising its heat resistance. The coupling agent (e) has a functional group that can react with inorganic or organic compounds.

[0076] The coupling agent (e) is preferably a compound having a functional group that can react with the functional groups of the polymer component (a), the curable epoxy resin (b), etc., and is more preferably a silane coupling agent. Preferred silane coupling agents include, for example, 3-glycidyloxypropyltrimethoxysilane (also known as 3-glycidoxypropyltrimethoxysilane; the same applies to other compounds hereafter), 3-glycidyloxypropylmethyldiethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-anilinopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, methyltrimethoxysilane, vinyltrimethoxysilane, imidazolesilane, oligomeric or polymeric organosiloxanes, and the like.

[0077] When a coupling agent (e) is used, the content of the coupling agent (e) in the adhesive composition and the film adhesive is preferably 0.03 to 20 parts by mass, more preferably 0.05 to 10 parts by mass, and particularly preferably 0.1 to 5 parts by mass, when the total content of polymer component (a) and curable epoxy resin (b) is 100 parts by mass. When the content of coupling agent (e) is above the lower limit, the effects of using coupling agent (e) are more pronounced, such as improved dispersibility of filler (d) in resin and improved adhesion of film adhesive to the adherend. Furthermore, when the content of coupling agent (e) is below the upper limit, outgassing is further suppressed.

[0078] (Crosslinking agent (f)) When a polymer component (a) is used that has functional groups such as vinyl groups, (meth)acryloyl groups, amino groups, hydroxyl groups, carboxyl groups, and isocyanate groups that can bond with other compounds, such as the acrylic resin mentioned above, the adhesive composition and the film-like adhesive may contain a crosslinking agent (f) for crosslinking the functional groups with other compounds. By crosslinking with the crosslinking agent (f), the initial adhesive strength and cohesive strength of the film-like adhesive can be adjusted.

[0079] If polymer component (a) has the functional group that can bond with other compounds, such as the acrylic resin described above, the crosslinking agent (f) crosslinks the functional group in polymer component (a) with the other compound. In this case, the initial adhesive strength and cohesive strength of the film-like adhesive can be adjusted.

[0080] Examples of crosslinking agents (f) include organic polyvalent isocyanate compounds, organic polyvalent imine compounds, metal chelate crosslinking agents (crosslinking agents having a metal chelate structure), and aziridine crosslinking agents (crosslinking agents having an aziridinyl group).

[0081] In adhesive compositions and film-like adhesives, the content of the crosslinking agent (f) is preferably 6 parts by mass or less, and more preferably 3 parts by mass or less, per 100 parts by mass of the polymer component (a). On the other hand, the content is 0 parts by mass or more. Since the pickability of the adhesive-cured chip tends to increase as the amount of crosslinking agent (f) decreases, it is particularly preferable that the amount is 0 parts by mass, that is, that the film-like adhesive does not contain crosslinking agent (f).

[0082] (General-purpose additive (i)) The general-purpose additive (I) may be any known additive and can be arbitrarily selected depending on the purpose, and is not particularly limited, but preferred examples include plasticizers, antistatic agents, antioxidants, colorants (i.e., dyes or pigments), gettering agents, etc.

[0083] The general-purpose additive (i) contained in the adhesive composition and the film-like adhesive may be one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected. The content of the adhesive composition and the film-like adhesive is not particularly limited and may be appropriately selected depending on the purpose.

[0084] (solvent) The adhesive composition preferably further contains a solvent. Adhesive compositions containing a solvent have better handling properties. The solvent is not particularly limited, but preferred examples include hydrocarbons such as toluene and xylene; alcohols such as methanol, ethanol, 2-propanol, isobutyl alcohol (2-methylpropan-1-ol), and 1-butanol; esters such as ethyl acetate; ketones such as acetone and methyl ethyl ketone; ethers such as tetrahydrofuran; and amides such as dimethylformamide and N-methylpyrrolidone (i.e., compounds having an amide bond). The adhesive composition may contain only one solvent or two or more solvents, and if there are two or more solvents, their combination and ratio can be arbitrarily selected.

[0085] The solvent contained in the adhesive composition is preferably a ketone such as methyl ethyl ketone, as this allows for more uniform mixing of the components contained in the adhesive composition.

[0086] [Method for manufacturing adhesive composition] An adhesive composition is obtained by blending the various components that make it up. There are no particular restrictions on the order in which each component is added during formulation, and two or more components may be added simultaneously. When using a solvent, the solvent may be mixed with any of the other components to pre-dilute the mixture, or the solvent may be mixed with the other components without pre-diluting them.

[0087] The method of mixing each component during formulation is not particularly limited; it can be appropriately selected from known methods such as mixing by rotating a stirring bar or impeller, mixing using a mixer, or mixing by applying ultrasonic waves. The temperature and time during the addition and mixing of each component are not particularly limited as long as the components do not deteriorate, and can be adjusted as appropriate, but a temperature of 15 to 30°C is preferred.

[0088] Figure 1 is a schematic cross-sectional view showing an example of the film-like adhesive of this embodiment. Note that, for convenience in order to make the features of the present invention easier to understand, the figures used in the following description may show enlarged versions of key parts, and the dimensional ratios of each component may not be the same as in reality.

[0089] The film-like adhesive 13 shown herein has a first release film 151 on one side (sometimes referred to as the "first side" in this specification) 13a and a second release film 152 on the other side (sometimes referred to as the "second side" in this specification) 13b opposite to the first side 13a. Such a film-like adhesive 13 is suitable for storage, for example, in the form of a roll.

[0090] The film-like adhesive 13 can be formed using the adhesive composition described above.

[0091] The first release film 151 and the second release film 152 may both be known. The first release film 151 and the second release film 152 may be the same as each other, or they may be different from each other, for example, having different peeling forces required to peel them from the film-like adhesive 13. It is preferable that both the first release film 151 and the second release film 152 are release films constructed by forming a silicone-based release agent layer on one side of a polyethylene terephthalate film (by silicone treatment).

[0092] In the film-like adhesive 13 shown in Figure 1, one of the first release film 151 and the second release film 152 is removed, and the resulting exposed surface becomes the adhesive surface on the back of the semiconductor wafer (not shown). Then, the remaining other of the first release film 151 and the second release film 152 is removed, and the resulting exposed surface becomes the adhesive surface for the support sheet or dicing sheet described later.

[0093] ◇ Sheets for semiconductor processing A semiconductor processing sheet according to one embodiment of the present invention is provided with a film-like adhesive according to the above embodiment of the present invention on a support sheet having a substrate. The semiconductor processing sheet of this embodiment can be used by attaching it to the back surface of a semiconductor wafer with a film-like adhesive during the dicing of a semiconductor wafer. In other words, the support sheet in the semiconductor processing sheet can be used as a dicing sheet.

[0094] The semiconductor processing sheet of this embodiment may be the same as a conventional semiconductor processing sheet, except that it is equipped with the film-like adhesive of this embodiment described above.

[0095] By using the semiconductor processing sheet of this embodiment, it is possible to manufacture semiconductor devices that are not susceptible to corrosion during long-term storage, have a high elastic modulus after curing, and exhibit excellent storage stability.

[0096] <<Support Sheet>> Examples of the support sheet include those having a base material. Such a support sheet may be, for example, made of a base material (i.e., having only a base material), or it may have a base material and other layers other than the base material. Examples of the support sheet having other layers include those having an adhesive layer on the base material. In the semiconductor processing sheet of this embodiment, the film-like adhesive is provided on a support sheet. Therefore, for example, if the support sheet has an adhesive layer on a substrate, the film-like adhesive is provided on the adhesive layer, and if the support sheet is made of a substrate, the film-like adhesive is provided in direct contact with the substrate.

[0097] The support sheet may consist of one layer (i.e., a single layer) or of two or more layers. If the support sheet consists of multiple layers, these layers may be identical or different, and the combination of these layers is not particularly limited as long as it does not impair the effects of the present invention.

[0098] <Base material> The substrate may be in the form of a sheet or a film, and may be one of known types. Examples of constituent materials for the base material include various resins. Examples of the aforementioned resins include polyolefins such as low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), high-density polyethylene (HDPE), and polypropylene; ethylene-based copolymers such as ethylene-vinyl acetate copolymer and ethylene-(meth)acrylic acid copolymer (polymers obtained using ethylene as a monomer); vinyl chloride resins (resins obtained using vinyl chloride as a monomer); polyester; and polyimide. Examples of the aforementioned resins include crosslinked resins obtained by crosslinking one or more of the aforementioned resins exemplified so far; and modified resins such as ionomers using one or more of the aforementioned resins exemplified so far.

[0099] The resins that make up the base material may consist of only one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0100] The base material may consist of one layer (i.e., a single layer) or of two or more layers. If the base material consists of multiple layers, these layers may be identical or different, and the combination of these layers is not particularly limited as long as it does not impair the effects of the present invention. A single-layer substrate may have its surface stripped using a known method.

[0101] The thickness of the substrate can be appropriately selected depending on the purpose, but it is preferably 50 μm to 300 μm, and more preferably 70 μm to 150 μm. Here, "substrate thickness" refers to the total thickness of the substrate. For example, the thickness of a substrate consisting of multiple layers refers to the total thickness of all the layers that make up the substrate. Methods for measuring the substrate thickness include, for example, measuring the thickness at five arbitrary locations using a contact-type thickness gauge and calculating the average of the measured values.

[0102] The substrate may have its surface subjected to surface treatments such as sandblasting, solvent treatment to create unevenness, corona discharge treatment, electron beam irradiation treatment, plasma treatment, ozone / ultraviolet irradiation treatment, flame treatment, chromic acid treatment, or hot air treatment in order to improve adhesion with other layers, such as the adhesive layer described later, which are provided thereon. Furthermore, the substrate may have a surface that has been treated with a primer. Furthermore, the substrate may have an antistatic coating layer, a layer that prevents the substrate from adhering to other sheets or to an adsorption table when semiconductor processing sheets are stacked and stored together, and so on.

[0103] <Adhesive layer> The adhesive layer is in the form of a sheet or film and contains an adhesive. The adhesive layer may be of known origin. Examples of the adhesive include adhesive resins such as acrylic resin, urethane resin, rubber resin, silicone resin, epoxy resin, polyvinyl ether, and polycarbonate, with acrylic resin being preferred.

[0104] In this invention, the term "adhesive resin" is a concept that includes both resins that are adhesive and resins that exhibit bonding properties. For example, it includes not only resins that are inherently adhesive, but also resins that exhibit adhesiveness when used in combination with other components such as additives, and resins that exhibit bonding properties in the presence of triggers such as heat or water.

[0105] The adhesive layer may be either energy-ray curable or non-energy-ray curable, but non-energy-ray curable is preferred.

[0106] The adhesive strength of the adhesive layer to the semiconductor wafer can be adjusted as appropriate, for example, by adjusting the type and amount of components contained in the adhesive layer. For example, the adhesive strength of the adhesive layer can be easily adjusted by adjusting the combination of monomers constituting the adhesive resin, the ratio of the monomers, the amount of crosslinking agent added, the amount of filler, etc. However, these adjustment methods are just examples.

[0107] The adhesive layer may consist of one layer (i.e., a single layer) or of two or more layers. If the adhesive layer consists of multiple layers, these layers may be identical or different, and the combination of these layers is not particularly limited as long as it does not impair the effects of the present invention.

[0108] The thickness of the adhesive layer can be appropriately selected depending on the purpose, but is preferably 1 μm to 100 μm, more preferably 1 μm to 60 μm, and particularly preferably 1 μm to 30 μm. Here, "thickness of the adhesive layer" refers to the total thickness of the adhesive layer. For example, the thickness of an adhesive layer consisting of multiple layers refers to the total thickness of all the layers that make up the adhesive layer. Methods for measuring the thickness of the adhesive layer include, for example, measuring the thickness at five arbitrary locations using a contact-type thickness gauge and calculating the average of the measured values.

[0109] An adhesive layer can be formed using an adhesive composition containing an adhesive. For example, an adhesive layer can be formed on the desired area by applying the adhesive composition to the surface on which the adhesive layer is to be formed and drying it as needed. The ratio of components that do not vaporize at room temperature in the adhesive composition is usually the same as the ratio of those components in the adhesive layer.

[0110] The adhesive composition can be applied in the same manner as described above for the adhesive composition.

[0111] When the adhesive layer is energy ray curable, examples of energy ray curable adhesive compositions include: adhesive composition (I-1) containing a non-energy ray curable adhesive resin (I-1a) (hereinafter sometimes abbreviated as "adhesive resin (I-1a)") and an energy ray curable compound; adhesive composition (I-2) containing an energy ray curable adhesive resin (I-2a) (hereinafter sometimes abbreviated as "adhesive resin (I-2a)") in which an unsaturated group is introduced into the side chain of the adhesive resin (I-1a); and adhesive composition (I-3) containing the adhesive resin (I-2a) and an energy ray curable compound.

[0112] When the adhesive layer is non-energy ray curable, examples of non-energy ray curable adhesive compositions include adhesive compositions (I-4) containing the adhesive resin (I-1a).

[0113] Adhesive compositions such as (I-1) to (I-4) can be manufactured in the same manner as the adhesive compositions described above, except that the constituent components differ.

[0114] Next, examples of semiconductor processing sheets according to this embodiment will be described below, for each type of support sheet, with reference to the drawings.

[0115] Figure 2 is a schematic cross-sectional view showing a semiconductor processing sheet according to one embodiment of the present invention. In Figures 2 and subsequent figures, the same components as those shown in previously described figures are denoted by the same reference numerals as in those previously described figures, and their detailed descriptions are omitted.

[0116] The semiconductor processing sheet 101 shown herein comprises a support sheet 10, and a film-like adhesive 13 is provided on one surface (sometimes referred to as the "first surface" in this specification) 10a of the support sheet 10. The support sheet 10 consists only of a substrate 11, and the semiconductor processing sheet 101, in other words, has a structure in which the film-like adhesive 13 is laminated on one surface (sometimes referred to as the "first surface" in this specification) 11a of the substrate 11. Furthermore, the semiconductor processing sheet 101 is provided with a release film 15 on the film-like adhesive 13.

[0117] In the semiconductor processing sheet 101, a film-like adhesive 13 is laminated on the first surface 11a of the base material 11, a jig adhesive layer 16 is laminated on a part of the surface 13a of the film-like adhesive 13 opposite to the side with the base material 11 (sometimes referred to as the "first surface" in this specification), i.e., in the area near the periphery, and a release film 15 is laminated on the surface of the first surface 13a of the film-like adhesive 13 that does not have the jig adhesive layer 16 laminated on it, and on the surface 16a (top surface and side surface) of the jig adhesive layer 16 that does not come into contact with the film-like adhesive 13. Here, the first surface 11a of the base material 11 is also referred to as the first surface 10a of the support sheet 10.

[0118] The release film 15 is the same as the first release film 151 or the second release film 152 shown in Figure 1.

[0119] The adhesive layer 16 for the jig may be, for example, a single-layer structure containing adhesive components, or a multi-layer structure in which layers containing adhesive components are laminated on both sides of a core sheet.

[0120] The semiconductor processing sheet 101 is used after the release film 15 has been removed, with the back surface of a semiconductor wafer (not shown) attached to the first surface 13a of the film-like adhesive 13, and further, the upper surface of the surface 16a of the jig adhesive layer 16 is attached to a jig such as a ring frame.

[0121] The semiconductor processing sheets of this embodiment are not limited to those shown in Figure 2. For example, some components of these semiconductor processing sheets may be modified, deleted, or added without departing from the spirit of the present invention.

[0122] For example, in a sheet for semiconductor processing, a gap may be present between the release film and the layer in direct contact with the release film. Furthermore, in semiconductor processing sheets, the size and shape of each layer can be arbitrarily adjusted according to the purpose.

[0123] The aforementioned semiconductor processing sheet can be manufactured by sequentially stacking the above-mentioned layers in corresponding positional relationships. The method for forming each layer is as described above. For example, when laminating an adhesive layer or film-like adhesive onto a substrate, the adhesive composition or adhesive composition can be applied to a release film and dried as necessary to pre-form the adhesive layer or film-like adhesive on the release film. Then, the exposed side of this pre-formed adhesive layer or film-like adhesive, opposite to the side in contact with the release film, can be bonded to the surface of the substrate. In this case, it is preferable to apply the adhesive composition or adhesive composition to the release treatment surface of the release film. The release film can be removed as necessary after the formation of the laminated structure.

[0124] For example, when manufacturing a semiconductor processing sheet (i.e., a semiconductor processing sheet in which the support sheet is a laminate of the substrate and the adhesive layer) in which an adhesive layer is laminated on a substrate and a film-like adhesive is laminated on the adhesive layer, the adhesive layer is laminated on the substrate using the method described above, and separately, an adhesive composition is applied to a release film and dried as necessary to form a film-like adhesive on the release film. The exposed surface of this film-like adhesive is then bonded to the exposed surface of the adhesive layer already laminated on the substrate, thereby laminating the film-like adhesive onto the adhesive layer and obtaining a semiconductor processing sheet. Even when forming a film-like adhesive on a release film, it is preferable to apply the adhesive composition to the release surface of the release film, and the release film may be removed as necessary after the formation of the laminated structure.

[0125] Thus, since all layers other than the substrate that make up the semiconductor processing sheet can be pre-formed on a release film and laminated by bonding them to the surface of the target layer, the semiconductor processing sheet can be manufactured by appropriately selecting the layers to which this process is applied as needed.

[0126] In addition, semiconductor processing sheets are typically stored with all necessary layers, such as an adhesive layer for fixing them to jigs like dicing ring frames, already applied, and a release film attached to the outermost surface opposite the support sheet.

[0127] ◇Manufacturing method for semiconductor devices (Method of using film-type adhesive and semiconductor processing sheet) The aforementioned film-like adhesive and semiconductor processing sheet can be used to manufacture semiconductor chips with the film-like adhesive, and the resulting semiconductor chips with the film-like adhesive can be further used to manufacture semiconductor devices.

[0128] A method for manufacturing a semiconductor device according to one embodiment of the present invention is a method for manufacturing a semiconductor device using a film-like adhesive or a semiconductor processing sheet as described in claim 6, A semiconductor wafer with a film-like adhesive is manufactured by attaching one side of the film-like adhesive, or the side of the film-like adhesive in the semiconductor processing sheet that is opposite to the side of the support sheet, to the back surface of a semiconductor wafer. When the semiconductor processing sheet is used, the semiconductor wafer is divided into semiconductor chips on the support sheet within the semiconductor processing sheet, and the film-like adhesive is cut to produce a semiconductor chip with film-like adhesive. When the film-like adhesive that does not constitute the semiconductor processing sheet is used, a dicing sheet is attached to the other side of the film-like adhesive in the semiconductor wafer with film-like adhesive (the side opposite to the semiconductor wafer, the exposed side), and then the semiconductor wafer is divided into semiconductor chips on the dicing sheet, and the film-like adhesive is cut to produce a semiconductor chip with film-like adhesive. The semiconductor chip with the film-like adhesive is picked up by separating it from the support sheet or dicing sheet. The picked-up semiconductor chip with the film-like adhesive is die-bonded to the conductor-forming surface of a substrate having a conductor-forming surface using the film-like adhesive in the semiconductor chip.

[0129] The manufacturing method of this embodiment may be the same as the conventional method for manufacturing semiconductor chips with film adhesive, except that it uses the film adhesive or semiconductor processing sheet of this embodiment described above instead of the conventional film adhesive or semiconductor processing sheet.

[0130] In the above manufacturing method, the attachment of the film-like adhesive or semiconductor processing sheet to the wafer can be carried out by known methods, for example, at room temperature (e.g., room temperature) or under heated conditions.

[0131] In the above manufacturing method, both the splitting of the semiconductor wafer and the cutting of the film-like adhesive can be performed by known methods. For example, by employing techniques such as blade dicing, water dicing, laser dicing, and plasma dicing, the splitting of the semiconductor wafer and the cutting of the film-like adhesive can be performed continuously.

[0132] Even after die bonding, semiconductor devices can be manufactured using the same methods as conventional methods. For example, if necessary, one or more semiconductor chips can be stacked on top of the die-bonded semiconductor chip on the conductor-forming surface of a substrate, and then wire bonding can be performed. Next, a film-like adhesive can be heat-cured, and then the entire semiconductor chip with the film-like adhesive that has been die-bonded to the conductor-forming surface of the substrate can be resin-encapsulated. [Examples]

[0133] The present invention will be described in more detail below with reference to specific examples. However, the present invention is not limited in any way to the examples shown below.

[0134] The components used in the manufacture of the adhesive composition are listed below.

[0135] [Compounds containing a benzoxazine ring (O)] (O)-1: A benzoxazine compound represented by the following formula (O)-1 (manufactured by Shikoku Chemicals, Inc., benzoxazine Fa) (O)-2: A benzoxazine compound represented by the following formula (O)-2 (manufactured by Shikoku Chemicals, Inc., benzoxazine Pd).

[0136] [ka]

[0137] [Polymer component (a)] (a)-1: An acrylic resin obtained by copolymerizing butyl acrylate (hereinafter abbreviated as "BA") (10 parts by mass), methyl acrylate (hereinafter abbreviated as "MA") (70 parts by mass), glycidyl acrylate (hereinafter abbreviated as "GMA") (5 parts by mass), and 2-hydroxyethyl acrylate (hereinafter abbreviated as "HEA") (15 parts by mass) (weight average molecular weight 400,000, glass transition temperature -1°C).

[0138] [Epoxy resin (b1)] (b1)-1:4-functional alicyclic epoxy resin, butanetetracarboxylate tetra(3,4-epoxycyclohexylmethyl) modified ε-caprolactone (Daicel Corporation "Epolleed® GT401", epoxy equivalent 200-240 g / eq, molecular weight 788.94, liquid) (b1)-2: Two-functional alicyclic epoxy resin (1,4-cyclohexanedimethanol diglycidyl ether (Showa Denko Corporation's "Showfree® CDMDG", epoxy equivalent 136 g / eq, molecular weight 256.34, liquid) (b1)-3: Ultra-high heat-resistant epoxy resin (DIC Corporation's "EPICLON® HP-4710", epoxy equivalent 171 g / eq, softening point: 96°C, solid) (b1)-4: o-cresol novolac type epoxy resin (EOCN-104S manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent 213-223 g / eq, softening point 90-94°C, solid)

[0139] [Thermosetting agent (b2)] (b2)-1: Novolac-type phenolic resin (BRG556, manufactured by Showa Denko Corporation)

[0140] [Curing accelerator (c)] (c)-1:2-phenyl-4,5-dihydroxymethylimidazole (manufactured by Shikoku Chemicals Co., Ltd. as "Curesol (registered trademark) 2PHZ-PW")

[0141] [Filler (d)] (d)-1: Silica filler (YA050C-MKK manufactured by Admatex Co., Ltd., average particle size 50 nm, epoxy group modified product)

[0142] [Coupling agent (e)] (e)-1: Oligomer-type silane coupling agent having epoxy groups, methyl groups, and methoxy groups (Shin-Etsu Silicone Co., Ltd. "X-41-1056", epoxy equivalent 280 g / eq)

[0143] <Manufacturing of film-like adhesives and sheets for semiconductor processing> [Example 1] (Manufacturing of adhesive compositions) A compound (O)-1 having a benzoxazine ring, polymer component (a)-1, epoxy resin (b1)-1, thermosetting agent (b2)-1, filler (d)-1, and coupling agent (e)-1 were dissolved or dispersed in methyl ethyl ketone so that their content (parts by mass) was as shown in Table 1, and the mixture was stirred at 23°C to obtain an adhesive composition with a concentration of 50% by mass.

[0144] (Manufacturing of film-type adhesives) A release film (SP-PET381031, manufactured by Lintec Corporation) made of polyethylene terephthalate film (thickness 38 μm) had one side treated with silicone for release. The adhesive composition obtained above was applied to the treated surface of the release film, and the film was heated and dried at 100°C for 1 minute to form a 10 μm thick film-like adhesive. Next, the release-treated surface of the release film was separately attached to the exposed surface of the film-like adhesive to obtain a film-like adhesive laminate (I) in which the release film was attached to both sides of a 10 μm thick film-like adhesive. Similarly, a film-like adhesive with a thickness of 40 μm was formed, and a film-like adhesive laminate (II) was obtained in which the release film was attached to both sides of the 40 μm thick film-like adhesive.

[0145] (Manufacturing of semiconductor processing sheets) One release film was removed from the aforementioned film-like adhesive laminate (I), exposing one surface of the film-like adhesive. Then, the exposed surface of the film-like adhesive was bonded to a substrate (Funclear® LLD#80, manufactured by Gunze Corporation) to obtain a semiconductor processing sheet (I) in which the substrate, a 10 μm thick film-like adhesive, and a release film were laminated in this order. Similarly, a semiconductor processing sheet (II) was obtained from the film-like adhesive laminate (II), in which a substrate, a 40 μm thick film-like adhesive, and a release film were laminated in that order.

[0146] [Examples 2-4, Comparative Examples 1-3] A film-like adhesive and a sheet for semiconductor processing were manufactured using the same method as in Example 1, except that the components of the adhesive composition were as shown in Table 1.

[0147] <Evaluation of film-type adhesives> The following items were evaluated for the film-like adhesive obtained above.

[0148] [Evaluation of chlorine content] (Measurement of chlorine content) The release film was removed from the film-like adhesive laminate (I) prepared above, and 100 mg of the 10 μm thick film-like adhesive was collected. The collected film-like adhesive was placed on a magnetic boat and attached to an automatic sample combustion device (Nitto Seikou Analytech Co., Ltd., AQF-2100H). The film-like adhesive was burned for 10 minutes in a reaction tube inside the automatic sample combustion device set to 1000°C. The generated gas was absorbed into 10 mL of absorption solution prepared by the method described below to obtain a sample solution. Next, using an ion chromatograph (Thermo Fisher Scientific K.K., ICS2100), the ion species contained in the sample solution were separated under the ion chromatography measurement conditions described below, and the chloride ion peak was quantitatively analyzed and converted to chlorine content [ppm] relative to the total mass of the film-like adhesive.

[0149] (Method for preparing absorbent solution) 0.4 g of KH2PO4 (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was dissolved in ultrapure water to make 100 mL. Then, 1 mL of this solution and 150 mL of a 30 wt% H2O2 aqueous solution (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) were taken, and ultrapure water was added to make 500 mL, which was used as the absorption solution.

[0150] (Ion chromatography measurement conditions) Separation column: IonPac AS19 (Thermo Fisher Scientific Co., Ltd.) Guard column: IonPac AG19 (Thermo Fisher Scientific Co., Ltd.) Eluent: 5.0mmol / L KOH Flow rate: 1.0 mL / min Temperature: 30°C (column temperature) Detector: Electrical conductivity detector Injection volume: 25μL

[0151] The results of the chlorine content measurement are shown in Table 1. A indicates that the chlorine content relative to the total mass of the film-like adhesive is less than 100 ppm, and B indicates that it is 100 ppm or more.

[0152] [Corrosion Test] A substrate was prepared in which a Cu electrode was formed on a glass substrate measuring 30 mm x 30 mm x 0.5 mm. Figure 3 shows a schematic diagram of the substrate used in the corrosion test. On this glass substrate 30, comb-shaped electrodes 32 and 33 are formed with a wiring pattern shown in Figure 3, with a line width / space spacing (L / S) of 100 μm / 100 μm and an electrode thickness of 10 μm. Note that the dimensions and number of wiring patterns shown in Figure 3 differ from the actual dimensions.

[0153] The release film was removed from the semiconductor processing sheet (I) prepared as described above, and the exposed surface of the 10 μm thick film-like adhesive was laminated using a laminator (MCL-650, manufactured by M.C.K. Co., Ltd.) so that the area at position B (10 mm x 10 mm) on the side of the comb-shaped electrodes 32 and 33 of the glass substrate 30 was sufficiently covered. Next, the substrate was removed to obtain a substrate for corrosion testing.

[0154] Subsequently, the corrosion test substrate was placed in a constant temperature bath (conditions: 85°C, 85%RH) and accelerated for 168 hours. After acceleration, the film-like adhesive was removed from the corrosion test substrate, and the electrode portion of the side surface of the comb-shaped electrodes 32 and 33, in a 1.1 mm × 5.0 mm area as shown in Figure 3 (area M in the figure, i.e., the central part of the attachment position B), was observed with a digital microscope (Keyence Corporation, VHX-7000) to confirm the presence or absence of corrosion. The results of the corrosion evaluation are shown in Table 1. Cases where no corrosion was found are indicated as A, and cases where corrosion was found are indicated as B.

[0155] [Measurement of the storage modulus E'(23) of the first test specimen] Using the five film-like adhesive laminates (II) prepared above, a test laminate with a release film was fabricated by sequentially bonding the exposed surfaces of the 40 μm thick film-like adhesives together, while removing the release films, so that the MD directions were the same. This resulted in a laminate consisting of a release film, five film-like adhesives (total thickness 200 μm), and another release film, all layered in this order. By heating the test laminate with the release film at 160°C for 1 hour, all the film-like adhesive (test laminate) was heat-cured, and a cured test laminate with the release film was prepared.

[0156] The release films on both sides were removed from this cured test laminate, and then a first test piece measuring 5 mm in width, 30 mm in length, and approximately 200 μm in thickness was cut from the cured test laminate so that its long axis was in the MD direction.

[0157] Using a viscoelasticity measuring device (TA instruments "DMA Q800"), the storage modulus E' of the first test specimen was measured using the tensile method (tensile mode) under the following measurement conditions: chuck distance of 20 mm, frequency of 11 Hz, heating rate of 3 °C / min, and constant rate heating, in the temperature range from 0 °C to 350 °C while the first test specimen was being heated. Table 1 shows the storage modulus E'(23) of the first test specimen when the temperature of the first test specimen was 23 °C.

[0158] The storage modulus E'(23) of the first test specimen is 1.0 × 10⁻⁶. 3 Cases where the value is MPa or higher are indicated as A, and the storage modulus E'(23) of the first test specimen is 1.0 × 10⁻⁶. 3 Cases below MPa are indicated as B.

[0159] [Evaluation of long-term storage at room temperature] (Measurement of melt viscosity (T0) at 110°C) Using the 500 film-like adhesive laminates (II) prepared above, the release films were removed and the exposed surfaces of the 40 μm thick film-like adhesives were sequentially bonded together to create a test laminate with a release film, consisting of a release film, 500 film-like adhesives (total thickness 20 mm), and another release film, in that order. Next, the release film was removed from this test laminate to create a cylindrical test specimen of the film-like adhesive with a diameter of 10 mm and a height of 20 mm. The test specimen, immediately after preparation, was placed in the measurement area of ​​a capillary rheometer (Shimadzu Corporation "CFT-100D"), and while applying a force of 5.10 N (50 kgf) to the specimen, the specimen was heated from 50°C to 150°C at a heating rate of 10°C / min. Then, the test specimen was extruded through a hole with a diameter of 0.5 mm and a height of 1.0 mm provided in the die, and the melt viscosity (T0) [Pa·s] at 110°C was measured. The measurement results for the melt viscosity (T0) [Pa·s] at 110°C are shown in Table 1.

[0160] (Store at room temperature) The semiconductor processing sheet (II) was stored for three months at 23°C and 50% RH.

[0161] (Measurement of melt viscosity (T) at 110°C) After storage, the substrate and release film were removed from 500 semiconductor processing sheets (II) as described above, and cylindrical test specimens of the film-like adhesive with a diameter of 10 mm and a height of 20 mm were prepared. Similarly, the newly prepared test specimens were placed in the measurement area of ​​a capillary rheometer (Shimadzu Corporation "CFT-100D"), and while applying a force of 5.10 N (50 kgf) to the specimens, the specimens were heated from 50°C to 150°C at a heating rate of 10°C / min. The specimens were then extruded through a hole with a diameter of 0.5 mm and a height of 1.0 mm provided in the die, and the melt viscosity (T) [Pa·s] at 110°C was measured. The measurement results for the melt viscosity (T) [Pa·s] at 110°C are shown in Table 1.

[0162] (Evaluation of long-term storage at room temperature) The melt viscosity change rate [%] was calculated from the melt viscosity at 110°C (T0) and the melt viscosity at 110°C (T) using the following formula. The results of the melt viscosity change rate [%] are shown in Table 1. Change in melt viscosity [%] = (T - T0) / T0 × 100 T0: Melt viscosity of the initially prepared film-like adhesive at 110°C T: Melt viscosity of film-like adhesive at 110°C after standing for 3 months.

[0163] Cases where the melt viscosity change rate [%] is less than 50% are indicated as A, and cases where the melt viscosity change rate (%) is 50% or more are indicated as B.

[0164] [Table 1]

[0165] The film-like adhesives of Examples 1 to 4 contain compounds having a benzoxazine ring. As is clear from the above results, no corrosion was observed on the conductive surface of the substrate used for corrosion testing with the film-like adhesives of Examples 1 to 4, indicating good performance. The first test specimen after curing exhibited excellent storage modulus E'(23) and storage stability.

[0166] In contrast, the film-type adhesives in Comparative Examples 1-3 had a high chlorine content and poor corrosiveness. Furthermore, while the film-type adhesive of Comparative Example 1 exhibited excellent storage modulus E'(23) of the first test specimen after curing, it had problems with storage stability. The film-type adhesives of Comparative Examples 2 and 3 exhibited excellent storage stability, but the storage modulus E'(23) of the first test specimen after curing was insufficient. [Industrial applicability]

[0167] This invention is industrially very important because it can be suitably used in the manufacture of semiconductor devices. [Explanation of symbols]

[0168] 101...Semiconductor processing sheet, 10...Support sheet, 10a...First surface of support sheet, 11...Substrate, 11a...First surface of substrate, 13...Film-like adhesive, 13a...First surface of film-like adhesive, 13b...Second surface of film-like adhesive, 30...Glass substrate, 32,33...Electrodes, L...Line, S...Space, B...Application position of film-like adhesive, M...Corrosion test evaluation area

Claims

1. A thermosetting film-like adhesive, A film-like adhesive containing a compound having a benzoxazine ring.

2. Furthermore, the film-like adhesive according to claim 1, further comprising an epoxy resin (b1) containing a polyfunctional epoxy compound having a cyclic or acyclic aliphatic skeleton.

3. The film-like adhesive according to claim 2, wherein the epoxy resin (b1) is liquid at room temperature.

4. Furthermore, the film-like adhesive according to claim 1, further containing a phenolic resin.

5. Furthermore, the film-like adhesive according to claim 1 contains silica filler.

6. The film-like adhesive according to claim 1, wherein the thickness of the film-like adhesive is 3 to 50 μm.

7. A cured product is obtained by heat-curing a test laminate, which is made by laminating one film-like adhesive or multiple film-like adhesives with a thickness of less than 200 μm, by heating it at 160°C for 1 hour. A first test specimen, with a thickness of 200 ± 20 μm and a width of 5 mm, is held at two locations with a 20 mm gap between them. The storage modulus E' of the first test specimen is measured while heating the first test specimen from 0°C to 350°C in tensile mode under the conditions of a frequency of 11 Hz, a heating rate of 3°C / min, and constant heating. When the storage modulus E' of the first test specimen is measured at a temperature of 23°C, the storage modulus E'(23) of the first test specimen is 1.0 × 10⁻⁶. ３ The film-like adhesive according to claim 1, wherein the pressure is MPa or higher.

8. The film-like adhesive according to claim 1, wherein the chlorine content relative to the total mass of the film-like adhesive is less than 100 ppm.

9. A semiconductor processing sheet comprising a support sheet having a base material, on which the film-like adhesive described in claim 1 is provided.

10. A method for manufacturing a semiconductor device using the film-like adhesive described in claim 1, or the semiconductor processing sheet described in claim 9, A semiconductor wafer with a film-like adhesive is manufactured by attaching one side of the film-like adhesive, or the side of the film-like adhesive in the semiconductor processing sheet that is opposite to the side of the support sheet, to the back surface of a semiconductor wafer. When the semiconductor processing sheet is used, the semiconductor wafer is divided into semiconductor chips on the support sheet within the semiconductor processing sheet, and the film-like adhesive is cut to produce a semiconductor chip with film-like adhesive. When the film-like adhesive that does not constitute the semiconductor processing sheet is used, a dicing sheet is attached to the other side of the film-like adhesive in the semiconductor wafer with film-like adhesive, and then the semiconductor wafer is divided into semiconductor chips on the dicing sheet, and the film-like adhesive is cut to produce a semiconductor chip with film-like adhesive. The semiconductor chip with the film-like adhesive is picked up by separating it from the support sheet or dicing sheet. A method for manufacturing a semiconductor device, comprising die bonding the picked-up film-like adhesive semiconductor chip to the conductor-forming surface of a substrate having a conductor-forming surface using the film-like adhesive in the film-like adhesive semiconductor chip.

11. Furthermore, the method for manufacturing a semiconductor device according to claim 10, further comprising the step of resin-encapsulating the entire semiconductor chip with a film-like adhesive that has been die-bonded onto the conductor-forming surface of a substrate.

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