Adhesive composition, film-like adhesive and semiconductor package using same, and method for manufacturing semiconductor package

Abstract

Disclosed is an adhesive composition which contains at least an epoxy resin (A), an epoxy resin curing agent (B), and a polymer component (C). The adhesive composition has a storage elastic modulus after curing of 2,000 MPa or less and a loss tangent after curing of 0.03 or more, and when the compositions are bonded to each other after curing, the bonding strength is 5 MPa or more. [The storage modulus and loss tangent after curing are measured under the conditions of a measuring temperature range of 20-300°C, a heating rate of 5°C / min, and a frequency of 1 Hz, after thermally curing the adhesive composition at 180°C for one hour, thereby obtaining a film-like adhesive piece of 5 mm × 17 mm × 200 μm. At this time, a measured value at the bonding temperature described below is sampled.] (Bonding temperature: any temperature within the range from 25°C to 300°C inclusive)

Description

Adhesive composition, film-like adhesive and semiconductor package using the same, and method for manufacturing semiconductor package

[0001] The present invention relates to an adhesive composition, a film-like adhesive and a semiconductor package using the same, and a method for producing a semiconductor package.

[0002] As electronic devices become smaller, lighter, and more powerful, there is a demand for higher integration of semiconductor chips, etc. However, there is a limit to how much circuitry can be miniaturized, and in recent years, a method has been proposed for achieving higher integration by vertically stacking multiple substrates (wafers), semiconductor chips, etc. to create a multi-layered three-dimensional structure. A typical example is a semiconductor package in which each semiconductor chip is housed and mounted on a Si interposer or RDL interposer, and then stacked on a 2.XD package.

[0003] To achieve high integration of substrates and semiconductor chips within such semiconductor packages, bonding has traditionally been done via bumps, but in the future, a method of directly bonding Cu wiring together (direct bonding) will become necessary to shorten the connection wiring distance. For direct bonding connection methods, connection methods using resin hybrid methods or inorganic hybrid methods are being considered, but the inorganic hybrid method has concerns about foreign material control and cost, so the resin hybrid method is attracting attention.

[0004] As a direct bonding material for the so-called resin hybrid method, for example, a method is known in which a composition containing an amide acid cross-linked silane compound is applied to a wafer by spin coating, and then dried and cured to form an imide cross-linked siloxane, and then bonding is performed using the composition (e.g., Patent Documents 1 and 2).

[0005] Japanese Patent Application Publication No. 2021-182621 International Publication No. 2020 / 085183 Pamphlet

[0006] Direct bonding connection methods often suffer from the problem of insufficient adhesive strength after bonding. This is believed to be due to variations in the thickness of the bonding layer and voids that are introduced during bonding. The spin coating method described in prior art documents presumably suffers from the problem of thickness accuracy varying depending on factors such as rotation speed, material viscosity, and drying speed, making control difficult and resulting in uneven adhesive strength. Therefore, the present invention aims to provide a film-like adhesive and an adhesive composition thereof that enable void-free bonding of semiconductor wafers, enable control of thickness variations, and provide sufficient adhesive strength and bonding reliability. Another object of the present invention is to provide a semiconductor package using the film-like adhesive, as well as a method for manufacturing the semiconductor package.

[0007] The inventors have tested and verified numerous adhesives and adhesive compositions of this type. They collected and analyzed a large amount of data on test items, including parameters such as physical properties, chemical properties, and physicochemical properties. After diligently compiling and verifying the results, they discovered that the above-mentioned objectives can be achieved by making the film-like adhesive have a storage modulus of 2000 MPa or less and a loss tangent of 0.03 or more at the bonding temperature. Furthermore, they found that the film-like adhesive must achieve good bonding properties and a bonding strength of 5 MPa or more. Furthermore, they found that the above-mentioned objectives can be more accurately achieved, if necessary, by adjusting the epoxy equivalent of the epoxy resin within a suitable range or by adjusting the blending ratio of the liquid epoxy resin to the solid epoxy resin within a suitable range. The present invention was derived from these findings and has the following configuration.

[0008] (1) An adhesive composition containing at least an epoxy resin (A), an epoxy resin curing agent (B), and a polymer component (C), characterized in that, after curing, the adhesive composition has a storage modulus of 2000 MPa or less and a loss tangent of 0.03 or more under the following conditions, and when the composition is bonded to itself after curing, the adhesive composition has a bond strength of 5 MPa or more under the following conditions: [The storage modulus and loss tangent after curing are measured under the following conditions: a 5 mm x 17 mm x 200 μm film-like adhesive piece obtained by thermally curing the adhesive composition at 180°C for 1 hour, a temperature range of 20 to 300°C, a heating rate of 5°C / min, and a frequency of 1 Hz, and measurements are taken at the following bonding temperatures:] [Bonding temperature: a temperature of 25°C or higher and 300°C or lower] [The bond strength is the strength measured when two 1.0 μm-thick chips with film-like adhesive, obtained by thermally curing the adhesive composition at 180°C for 1 hour, are prepared, and the film-like adhesive on each chip is brought into contact with the other chip and bonded at the bonding temperature, and then peeled off at room temperature. (2) The adhesive composition according to (1), wherein the epoxy equivalent of the epoxy resin (A) used in the adhesive composition is 300 g / eq or more, and the content of the epoxy resin (A) is 20 mass% or more of the total amount of the epoxy resin (A), the epoxy resin curing agent (B), and the polymer component (C). (3) The adhesive composition according to (1), wherein the epoxy resin (A) is a blend of an epoxy resin that is liquid at room temperature and a solid epoxy resin, and the contents of the liquid epoxy resin and the solid epoxy resin are 100 to 250 mass parts and 15 to 90 mass parts, respectively, per 100 mass parts of the polymer component (C), and the mass ratio of the solid epoxy resin to the liquid epoxy resin is in the range of 1:10 to 6:10. (4) The adhesive composition according to (1), wherein the epoxy resin curing agent (B) is an imidazole-based curing agent. (5) The adhesive composition according to (1), wherein the bonding temperature is 25°C or higher and 200°C or lower. (6) A film-like adhesive obtained by heat-treating the adhesive composition according to any one of (1) to (5). (7) The film-like adhesive according to (6), having a thickness of 0.1 to 50 μm.(8) A method for manufacturing a semiconductor package, comprising: adhering and heat-curing the film-like adhesive described in (6) to a semiconductor wafer having at least one semiconductor circuit formed on its surface to provide an adhesive layer; bonding and stacking semiconductor wafers via the adhesive layer; and compressing the adhesive layer as is at room temperature or further heat-curing and compressing the adhesive layer to form a cured resin body, thereby forming a multilayer structure of semiconductor wafers. (9) A method for manufacturing a semiconductor package described in (8), including a step of exposing terminals from the adhesive layer and flattening the adhesive layer so that the surface of the adhesive layer is flush with the surface of the terminals. (10) A semiconductor package composed of semiconductor wafers bonded with the cured resin body of the film-like adhesive described in (6). (11) A film-like adhesive obtained by heat-treating an adhesive composition containing at least an epoxy resin (A), an epoxy resin curing agent (B), and a polymer component (C), wherein the film-like adhesive has a storage modulus of 2000 MPa or less and a loss tangent of 0.03 or more under the following conditions, and has a bond strength of 5 MPa or more under the following conditions when bonded. [The storage modulus and loss tangent are measured using a 5 mm x 17 mm x 200 μm film adhesive piece obtained by thermally curing the adhesive composition at 180°C for 1 hour, under conditions of a measurement temperature range of 20 to 300°C, a temperature rise rate of 5°C / min, and a frequency of 1 Hz. Measurement values ​​are sampled at the following bonding temperatures.] [Bonding temperature: any temperature between 25°C and 300°C.] [The bonding strength is the strength when two 1.0 μm thick chips with film adhesive are prepared, the film adhesives are brought into contact and bonded at the above bonding temperature, and then peeled off at room temperature.]

[0009] The adhesive composition or film-like adhesive of the present invention enables void-free bonding of semiconductor wafers, enables control of thickness variations, and provides sufficient adhesive strength and bonding reliability. Furthermore, semiconductor packages using the film-like adhesive of the present invention have high quality and excellent performance reliability. Furthermore, the manufacturing method of the present invention allows for the favorable production of semiconductor packages using the above-mentioned film-like adhesive.

[0010] FIG. 1 is a flowchart showing a manufacturing process of a film-like adhesive and a process for applying the same. FIG. 2 is a cross-sectional view schematically showing a manufacturing process of a semiconductor wafer according to one embodiment of the present invention. FIG. 3 is a cross-sectional view schematically showing a planarization process by polishing employed in the planarization process (d) of FIG. 1. FIG. 4 is a side view schematically showing a state in which two substrates with film-like adhesives are joined by abutting the film-like adhesives. FIG. 5 is a drawing-substitute photograph taken as a microscopic image from the side of the state in which film-like adhesives are bonded together. FIG. 6 is a side view schematically showing an apparatus for measuring die shear strength and the measurement format.

[0011] The adhesive composition of the present invention contains at least an epoxy resin (A), an epoxy resin curing agent (B), and a polymer component (C), and is characterized in that after curing, the adhesive composition has a storage modulus of 2000 MPa or less and a loss tangent of 0.03 or more, and when the composition is bonded to another composition after curing, the bonding strength is 5 MPa or more. The present invention will be described in detail below, focusing on preferred embodiments and examples, and referring to the drawings as necessary.

[0012] In the adhesive composition of the present invention, the storage modulus and loss tangent after curing are values ​​measured on a film-like adhesive piece measuring 5 mm x 17 mm x 200 μm. The measurement temperature (sampling temperature) is the bonding temperature. The bonding temperature is the temperature at which substrates, etc. are bonded via the film-like adhesive, and is preferably 25°C or higher and 300°C or lower, typically ranging from room temperature (25°C) to 200°C. The storage modulus (E') is 2000 MPa or lower, and under conditions where the bonding temperature is 25°C (excluding cases where a filler is not included), it is preferably 1800 MPa or lower, more preferably 1600 MPa or lower. The lower limit is not particularly limited, but a practical value is 1000 MPa or higher. Under conditions where the bonding temperature is 200°C or when a filler is not included, the storage modulus is preferably 200 MPa or lower, more preferably 150 MPa or lower, and particularly preferably 100 MPa or lower. The lower limit is not particularly limited, but is preferably 1 MPa or more, more preferably 2 MPa or more, and even more preferably 5 MPa or more.

[0013] The adhesive composition of the present invention, after curing, has a loss tangent of 0.03 or more, preferably 0.04 or more, and more preferably 0.05 or more. There is no particular upper limit, but a practical upper limit is 1.0 or less. The cured film-like adhesive refers to a film-like adhesive that has been treated under the conditions of heat treatment 2 or heat treatment 3 described below.

[0014] The adhesive composition of the present invention, when cured into a film-like adhesive, has the above-mentioned storage modulus and loss tangent, which not only provides good handleability but also reduces the occurrence of voids at the bonding interface, which are often contradictory, thereby exhibiting good bonding properties. Furthermore, the surface of a substrate may have irregularities such as terminals. There was a concern that a film-like adhesive would not be able to conform to the outer shape of the substrate. However, by setting the storage modulus E' and loss tangent tanδ within the above-mentioned preferred ranges when formed into a film, the adhesive exhibits just the right amount of conformability and viscosity to the substrate, suppressing the occurrence of voids even in the areas of protruding terminals. Here, the storage modulus primarily aims to achieve shape stability and flexibility, and the range within which these properties are not lost is specified. The loss tangent primarily reflects its relationship with viscosity, and if it is equal to or greater than a certain value, the adhesive exhibits the property of deforming and conforming to the irregularities of the substrate with a delay.

[0015] The adhesive composition of the present invention has a bond strength after curing of 5 MPa or more, preferably 10 MPa or more, more preferably 15 MPa or more, even more preferably 20 MPa or more, even more preferably 25 MPa or more, even more preferably 30 MPa or more, and even more preferably 35 MPa or more. The higher this bond strength, the stronger the bond to the semiconductor chip. The bond strength is the strength when a dummy chip with a cured film-like adhesive and another dummy chip with a cured film-like adhesive are bonded together at the adhesive surface at the bonding temperature and then peeled off at room temperature (25°C). There is no particular upper limit to the bond strength, but a practical upper limit is 100 MPa or less.

[0016] The bonding temperature can be defined as, for example, the temperature at which an adhesive composition is cured at 180°C for 1 hour to form a film-like adhesive, and substrates are bonded via this film-like adhesive. The specific temperature is not particularly limited, but is preferably 25°C to 300°C, and more preferably 25°C to 200°C. In a preferred embodiment of the present invention, it is sufficient that the predetermined conditions (E', tan δ, bond strength) are satisfied at any of the above bonding temperatures. It is preferable that the predetermined conditions are satisfied at at least either 300°C (preferably 200°C) or 25°C, more preferably at least 300°C (preferably 200°C), and even more preferably at 25°C. Room-temperature bonding is particularly preferred because it is less likely to cause misalignment.

[0017] Although samples for measuring each parameter may be prepared as appropriate, in the present invention, it is preferable to use samples heat-treated under the following conditions: When the bonding temperature is room temperature (25°C) and when measuring viscoelastic properties: Heat treatment 1 [130°C, 1.5 minutes] ＊１ , Heat treatment 2 [70 ° C, pressure 0.3 MPa] ＊１ 180°C 1 hour When the bonding temperature is 200°C: Heat treatment 1 [130°C 1.5 minutes] ＊１ , Heat treatment 2 [70 ° C, pressure 0.3 MPa] ＊１ 180℃ 1 hour, Heat treatment 3 200℃, 10N / 40N *２ , 10 seconds *1 [ ] can be omitted *2 10N for die shear strength measurement, 40N for bondability evaluation

[0018] (Epoxy Resin (A)) The adhesive composition of the present invention contains an epoxy resin (A), an epoxy resin curing agent (B), and a polymer component (C). Epoxy resins (A) are classified into those that are solid at room temperature (25°C) and those that are liquid. In the adhesive composition of the present invention, a blend of a solid epoxy resin and a liquid epoxy resin or a liquid epoxy resin alone is preferred, and a blend of a solid epoxy resin and a liquid epoxy resin is more preferred. If only a liquid epoxy resin is used, the tackiness may be too strong, making handling difficult. Furthermore, a blend of both makes it easier to achieve both appropriate conformability and morphological stability. Specific examples of epoxy resins include solid BisA type epoxy resins, liquid flexible epoxy resins, and liquid BisA type epoxy resins. Among these, a combination of a solid BisA type epoxy resin and a liquid flexible epoxy resin is preferred.

[0019] Whether an epoxy resin is liquid or solid can be determined by its viscosity at room temperature (25°C). Liquid epoxy resins preferably have a viscosity of 50 Pa·s or less, more preferably 40 Pa·s or less, and even more preferably 30 Pa·s or less. While there is no particular lower limit, a viscosity of 0.5 Pa·s or more is preferred, more preferably 0.8 Pa·s or more, and even more preferably 1.0 Pa·s or more is preferred. As for the upper limit, a liquid epoxy resin within this range is preferred in terms of having adequate fluidity, ease of processing, and ability to conform to the unevenness of a substrate when made into a film-like adhesive. On the other hand, a solid epoxy resin has a viscosity greater than 50 Pa·s. The viscosity was measured in accordance with JIS Z8803:2011, Section 8. Viscosity measurement was performed using a coaxial double-cylinder rotational viscometer. The measurement device used was a precision rotational viscometer RSX-CC (manufactured by Eiko Seiki Co., Ltd.).

[0020] The epoxy equivalent of the epoxy resin (A) is preferably 200 g / eq or more, more preferably 300 g / eq or more, and even more preferably 350 g / eq or more. There is no particular upper limit, but it is practical to set it to 1000 g / eq or less. When the epoxy equivalent of the epoxy resin (A) is within the above range, the film-like adhesive can obtain appropriate flexibility and good adhesion, and exhibit excellent performance in terms of bondability and die shear strength.

[0021] The molecular weight of the solid epoxy resin is not particularly limited, but is preferably 700 or more, more preferably 800 or more, and particularly preferably 900 or more. The upper limit is preferably 2000 or less, more preferably 1500 or less, and even more preferably 1200 or less. When the molecular weight of the solid epoxy resin is within this range, the film-like adhesive is easily able to maintain its shape and is not too hard, resulting in a film-like adhesive with moderate elasticity. The molecular weight of the liquid epoxy resin is not particularly limited, but is preferably greater than 400, more preferably 450 or more, and even more preferably 470 or more. There is no particular upper limit, but it is preferably 800 or less, more preferably 700 or less, and even more preferably 650 or less. Having the molecular weight of the liquid epoxy resin within the above range is preferable in that it achieves moderate flexibility in the film-like adhesive, especially when combined with a solid epoxy resin. The specifications of the epoxy resins used in the examples are listed in Table 1 below. Unless otherwise specified in this specification, the molecular weight is the value (weight average molecular weight) calculated in terms of polystyrene by GPC (gel permeation chromatography). The conditions are not particularly specified, but for example, tetrahydrofuran is used as the carrier during measurement, and two TSKgel GMHXL columns and one G2500HXL column (φ7.8 mm × 30 cm, manufactured by Tosoh) are used as columns. The following conditions can be used: flow rate 1 mL / min, column temperature 40 ° C., injection volume 0.2 mL. However, low molecular weight compounds that are difficult to measure by GPC may be identified using a mass spectrometer (MS).

[0022]

[0023] The softening point of the solid epoxy resin is not particularly limited, but is preferably 60°C or higher, more preferably 70°C or higher, and even more preferably 75°C or higher. The upper limit is preferably 100°C or lower, more preferably 90°C or lower, and even more preferably 85°C or lower. Having the softening point of the solid epoxy resin within the above range is preferable because the film adhesive does not flow or deform when blended with a liquid epoxy resin. The softening point of the liquid epoxy resin is preferably 40°C or lower, more preferably 35°C or lower, and even more preferably 30°C or lower. Having the softening point of the liquid epoxy resin within the above range is preferable because the film adhesive can achieve stability in shape and conformability to the substrate when blended with a solid epoxy resin. In this specification, the softening point refers to a value measured based on the softening point test (ring and ball method) method (measurement conditions: in accordance with JIS-K7234-1986).

[0024] An example of an epoxy resin that can be used in the present invention is shown below. However, the present invention is not limited to this example. n represents an integer, preferably 0 to 2. R represents a hydrogen atom or a methyl group.

[0025] In the adhesive composition of the present invention, the amount of epoxy resin (solid and liquid combined) is preferably 150 parts by mass or more, more preferably 175 parts by mass or more, and even more preferably 190 parts by mass or more, based on 100 parts by mass of the polymer component (C). The upper limit is preferably 250 parts by mass or less, more preferably 230 parts by mass or less, and even more preferably 210 parts by mass or less. Blending the epoxy resin within this range is preferable in that sufficient adhesive strength is maintained and dimensional stability is also achieved. The blending amount of epoxy resin (A) is preferably 20% by mass or more, more preferably 30% by mass or more, and even more preferably 40% by mass or more, based on the total amount of epoxy resin (A), epoxy resin curing agent (B), and polymer component (C). The upper limit is preferably 90% by mass or less, more preferably 80% by mass or less, and even more preferably 70% by mass or less. When a filler is contained, the amount of epoxy resin (A) is preferably 20% by mass or more, more preferably 25% by mass or more, and even more preferably 30% by mass or more, based on the total amount of the adhesive composition. The upper limit is preferably 60% by mass or less, more preferably 50% by mass or less, and even more preferably 40% by mass or less. When a filler is not contained, the amount is preferably 40% by mass or more, more preferably 50% by mass or more, and even more preferably 60% by mass or more, based on the total amount of the adhesive composition. The upper limit is preferably 80% by mass or less, more preferably 75% by mass or less, and even more preferably 70% by mass or less.

[0026] The adhesive composition of the present invention is preferably a blend of a liquid epoxy resin (particularly a liquid flexible epoxy resin, sometimes referred to as a stress-relieving epoxy resin) and a solid epoxy resin. When the epoxy resin (A) is a blend of an epoxy resin that is liquid at room temperature and a solid epoxy resin, the amount of the liquid epoxy resin blended is preferably 100 to 250 parts by mass, more preferably 115 to 200 parts by mass, and even more preferably 120 to 180 parts by mass, per 100 parts by mass of the polymer component (C). The content of the solid epoxy resin is preferably 15 to 90 parts by mass, more preferably 20 to 80 parts by mass, and even more preferably 25 to 70 parts by mass, per 100 parts by mass of the polymer component (C). The mass ratio of the solid epoxy resin to the liquid epoxy resin is preferably in the range of 0.5:10 to 9:10, more preferably 0.75:10 to 8:10, even more preferably 1:10 to 6:10, and even more preferably 1.5:10 to 4.5:10. The content of the stress-relaxing epoxy resin (liquid flexible epoxy resin) relative to the total resins (epoxy resin (A) and polymer component (C)) is preferably 20% by mass or more, more preferably 30% by mass or more, and even more preferably 40% by mass or more. The upper limit is preferably 70% by mass or less, more preferably 60% by mass or less, and even more preferably 50% by mass or less. Here, the liquid non-reactive epoxy resin is typically an epoxy resin that maintains a flexible skeleton at the dashed line, as shown in the structure below. Therefore, stress relaxation ability is imparted. Indirectly, it has the effect of lowering the storage modulus and increasing the loss tangent, which are important parameters in the present invention. This action makes it possible to control variations in thickness when the film-like adhesive is formed, and sufficient adhesive strength and bonding reliability can be obtained.

[0027] The blending ratio of the solid epoxy resin and the liquid epoxy resin within the above range is preferable in that the dimensional stability of the film-like adhesive is ensured, while the film-like adhesive has flexibility and can adhere to the unevenness of the substrate. The above range is also preferable in that the film-like adhesive has excellent adhesive properties. Furthermore, the moderate adhesive properties allow for easy handling during production.

[0028] The adhesive composition of this embodiment is premised on being formed into a film and applied to a substrate. The conditions for converting the adhesive composition into a film-like adhesive are not particularly limited. For example, the essential components are dissolved in a solvent to form a softened varnish or mixed varnish, which is then heated at a predetermined temperature for a predetermined time to evaporate the solvent, thereby obtaining a film-like adhesive (see FIG. 1 , heat treatment 1). In this embodiment, this film-forming process and the subsequent heat curing process (heat treatment 2) are employed. Through these processes, an adhesive layer with a uniform surface with minimal irregularities can be achieved, which is not possible with a liquid adhesive. Conversely, it is important to select the component composition of the adhesive composition that will form a suitable film in the film-forming process. The heat treatment process will be described in detail in the description of the manufacturing method below.

[0029] The epoxy resin (A) may be used alone or in combination of two or more. When two or more types are used, the total amount thereof falls within the above range.

[0030] (Epoxy Resin Curing Agent (B)) As the curing agent for epoxy resins, conventionally used ones can be used. Examples include amines (aliphatic amines, aromatic amines, modified amines), polyamide resins, tertiary and secondary amines, imidazoles, polymercaptan curing agents, liquid polymercaptan, polysulfide resins, acid anhydrides, etc. In the present invention, imidazoles are particularly preferred. Examples of imidazole-based curing agents include the following compounds. Of these, compound (e) is preferred. In the formula, R represents a hydrogen atom or an organic group.

[0031]

[0032] The amount of epoxy resin curing agent (B) to be added may be determined appropriately according to the amount of epoxy resin, but for example, it is preferably 0.5 to 10 parts by mass, more preferably 1 to 6 parts by mass, and particularly preferably 2 to 4 parts by mass, per 100 parts by mass of polymer component (C). Adding the epoxy resin curing agent (B) in the above range is preferable in that the epoxy resin reacts and crosslinks appropriately. One type of epoxy resin curing agent (B) may be used, or two or more types may be used. When two or more types are used, the total amount falls within the above range.

[0033] (Polymer Component (C)) The polymer component (C) is a component that forms the base skeleton when the adhesive composition of the present invention is made into a film-like adhesive. The content of the polymer component (C) is preferably 5 to 50 mass%, more preferably 10 to 45 mass%, and even more preferably 15 to 40 mass%, when the total of the epoxy resin (A), the epoxy resin curing agent (B), and the polymer component (C) is taken as 100 mass%. The polymer that constitutes the polymer component can be used without limitation, and examples thereof include BisA-type phenoxy resin, urethane resin, and acrylic resin. The molecular weight of the polymer component is not particularly limited, but examples include those with a molecular weight of 20,000 to 1,000,000, with compounds with a molecular weight of 35,000 to 800,000 being preferred, and compounds with a molecular weight of 50,000 to 600,000 being more preferred. By setting the molecular weight of the polymer component (C) to be equal to or greater than the above-mentioned lower limit, a stable form can be obtained when the film-like adhesive is made. By setting the molecular weight to the above upper limit or less, flexibility is obtained that allows the polymer to conform to the irregularities (terminals) on the surface of the substrate and exhibit suitable adhesiveness. The method for measuring the molecular weight is as described above. The polymer component (C) may be one type or two or more types. When two or more types are used, the total amount thereof falls within the above range.

[0034] (Filler) In the adhesive composition of the present invention, silica, talc, calcium carbonate, etc. can be incorporated as a filler if necessary, and among these, silica is preferably used as a filler. This can particularly increase the storage modulus, and when formed into a film-like adhesive, good morphological stability can be obtained. There are no particular restrictions on the amount of filler incorporated, but when the entire adhesive composition is taken as 100% by mass, it is preferably 15% by mass or more and 80% by mass or less, more preferably 20% by mass or more and 70% by mass or less, and even more preferably 25% by mass or more and 65% by mass or less. One type of filler or two or more types may be used. When two or more types are used, the total amount falls within the above range.

[0035] (Silane Coupling Agent) A silane coupling agent is a compound that bonds with a filler (e.g., silica) to achieve stability within the system. Therefore, the silane coupling agent should be selected taking into account the amount and type of filler to be added. Furthermore, since the adhesive composition of the present invention uses an epoxy resin, compatibility is also desirable in this respect. For these reasons, the silane coupling agent used in the adhesive composition of the present invention is preferably an epoxysilane-type silane coupling agent. Specifically, it is preferable to use a compound in which an epoxy group (oxirane group) is introduced at one or both ends of a polysiloxane. The amount of silane coupling agent is preferably 0.5 to 6 parts by mass, more preferably 0.8 to 4 parts by mass, and particularly preferably 1 to 3 parts by mass, per 100 parts by mass of the polymer component (C). This range of silane coupling agent is preferable because it does not affect other performances, keeps the silica filler particles within the system, and prevents uneven distribution or detachment of the silica. One or more silane coupling agents may be used. When two or more types are used, the total amount is within the above-mentioned range.

[0036] (Solvent) The solvent used in the adhesive composition of the present invention is not particularly limited as long as it can dissolve or disperse the above-mentioned components, namely, the epoxy resin (A), the epoxy resin curing agent (B), and the polymer component (C). Organic solvents are preferred, including alcohols, ketones (methyl ethyl ketone (MEK), acetone, etc.), cyclic or chain hydrocarbons (e.g., cyclohexane, etc.), aldehydes, and carbonates (dimethyl carbonate, etc.). The boiling point of the organic solvent is not particularly limited, but from the viewpoint of not evaporating at room temperature and evaporating suitably in the above-mentioned heat treatment 1, the boiling point is preferably 50°C or higher, more preferably 60°C or higher, and even more preferably 70°C or higher. The upper limit is preferably 120°C or lower, more preferably 110°C or lower, and even more preferably 100°C or lower. One or more solvents may be used.

[0037] (Film-like adhesive, method for manufacturing semiconductor package) The film-like adhesive of the present invention is obtained from an adhesive composition having the above-mentioned component composition. An example of the process for manufacturing the film-like adhesive and the process for forming the film-like adhesive into a bonded adhesive layer is shown in FIG. 1 . The method for forming the adhesive composition into a film-like adhesive is not particularly limited, but examples include preparing a varnish containing the necessary components or a mixed varnish containing a filler, and heating it for a certain period of time on a release film or the like. The heating temperature for this heat treatment 1 is preferably 80°C to 150°C, more preferably 90°C to 140°C, and even more preferably 100°C to 135°C. The heating time (residence time) is preferably 10 seconds to 30 minutes, more preferably 20 seconds to 20 minutes, and even more preferably 30 seconds to 15 minutes. If the adhesive composition is heated too much when forming the film-like adhesive, the subsequent adhesive properties of the film-like adhesive may be poor. On the other hand, if the heating is insufficient, the surface morphology may become unstable, resulting in problems with bonding properties and adhesive strength. The thickness of the film adhesive is preferably 0.1 μm or more, more preferably 0.5 μm or more, and even more preferably 0.75 μm or more, and the upper limit is preferably 50 μm or less, more preferably 40 μm or less, and even more preferably 30 μm or less.

[0038] A method for manufacturing a package including a semiconductor wafer (in this specification, "semiconductor wafer" is used to mean "semiconductor substrate") using the film-like adhesive of this embodiment can include, for example, the steps shown in Figures 2 and 3. First, a semiconductor wafer having at least one semiconductor circuit formed on its surface is prepared (step a). A film-like adhesive formed from an adhesive composition is prepared (step b). The heating temperature and time for shaping (heat treatment 1) at this time are as described above. The film-like adhesive of the present invention is thermocompression bonded to the surface of the prepared semiconductor wafer on which the semiconductor circuit is formed to provide an adhesive layer (step c). As conditions for thermocompression bonding, the temperature is preferably 50°C or higher and 100°C or lower, more preferably 60°C or higher and 90°C or lower, and even more preferably 65°C or higher and 80°C or lower. The pressure is preferably 0.05 MPa or higher and 2 MPa or lower, more preferably 0.1 MPa or higher and 1.5 MPa or lower, and even more preferably 0.2 MPa or higher and 1 MPa or lower. The pressure application time is preferably 10 seconds to 10 minutes, more preferably 30 seconds to 8 minutes, and even more preferably 1 minute to 6 minutes. This manufacturing method of the present embodiment then includes a heating step for heat treatment 2. The temperature in the heating step for heat treatment 2 is preferably 150°C to 210°C, more preferably 160°C to 200°C, and even more preferably 170°C to 190°C. The heating time is preferably 30 minutes to 90 minutes, more preferably 40 minutes to 80 minutes, and even more preferably 50 minutes to 70 minutes. Through the thermocompression bonding and heating steps, a resin cured product is obtained that is moderately cured to an excellent shape stability while maintaining the adhesiveness of the adhesive layer. After stabilizing the shape of the adhesive layer, the terminals are exposed from the adhesive layer (cured film-like adhesive 4x), and the surface of the adhesive layer and the surface of the terminal are flattened to a smooth, flush surface (steps d and d'). In the embodiment shown in Fig. 3, CMP (Chemical Mechanical Planarization) is used to polish the adhesive layer and terminals with a polishing pad 5 to form flat surfaces (flattened adhesive layer 4A, flattened surfaces of terminals 2A). After CMP is performed, the abrasive (slurry) used therein is washed away and removed. Note that, if an adhesive layer is formed that conforms to the irregularities of the terminals, etc., steps d and d' may be omitted.Next, two semiconductor wafers with adhesive layers are prepared, and the film-like adhesive layers are bonded together to form a multilayer structure (steps e and f). In Figure 2, bonded adhesive layers (cured resin) 4B and bonded terminals 2B are formed. The bonding temperature at this time is as described above, and is preferably room temperature (25°C) to 200°C, with room temperature (25°C) or 200°C being more preferred. When the bonding temperature is 200°C, this step becomes heat treatment 3. When the bonding temperature is room temperature, the previous heat treatment 2 step becomes the final heat treatment step before bonding. Through the above steps, a semiconductor package can be obtained, consisting of semiconductor wafers bonded together with the cured resin film-like adhesive.

[0039] When the joining step is a heat treatment step, the temperature is preferably 160° C. or higher and 240° C. or lower, more preferably 170° C. or higher and 230° C. or lower, and even more preferably 175° C. or higher and 220° C. or lower. The pressure-bonding force is not particularly limited, but is preferably 2 N or higher and 80 N or lower, more preferably 4 N or higher and 60 N or lower, and even more preferably 6 N or higher and 50 N or lower. The heating time is not particularly limited, but is preferably 1 second or higher and 60 seconds or lower, more preferably 5 seconds or higher and 50 seconds or lower, and even more preferably 7 seconds or higher and 30 seconds or lower.

[0040] The present invention will be described in more detail below based on examples and comparative examples, but the present invention is not limited to the following examples. In particular, all of the embodiments shown in Figures 1 to 6 are merely examples of embodiments of the present invention, and the present invention is by no means limited to those shown. In each example and comparative example, the storage modulus, loss modulus, loss tangent tan δ evaluation at the bonding temperature, bondability evaluation, and die shear strength evaluation were performed by the methods shown below.

[0041] Measurement Example 1 Storage Modulus, Loss Modulus, and Loss Tangent (tanδ) at Bonding Temperature Using each adhesive composition obtained in each Example and Comparative Example, a single-layer film measuring 300 mm in length, 200 mm in width, and 200 μm in thickness was obtained by forming a film-like adhesive on a release film using a multi-coater. This sample was cured at 180°C for 1 hour, and the cured film-like adhesive was cut into a size of 5 mm x 17 mm (200 μm thick). The release film was removed, and measurements were performed using a dynamic viscoelasticity measuring device (product name: Rheogel-E4000F, manufactured by UBM Co., Ltd.) under conditions of a measurement temperature range of 20 to 300°C, a heating rate of 5°C / min, and a frequency of 1 Hz (tensile mode), to measure the storage modulus and loss modulus at each temperature. The storage modulus and loss modulus at the bonding temperature were read. The loss tangent tanδ was calculated by the following formula (1) (based on JIS K7244 (formerly K7198:1991)): Loss tangent tanδ = loss modulus ÷ storage modulus (1)

[0042] (Measurement Example 2) <Bondability Evaluation> The film-like adhesive with release film obtained in each Example and Comparative Example was first adhered to one side of a dummy silicon wafer (8 inch size, thickness 365 μm) using a manual laminator (trade name: FM-114, manufactured by Technovision Co., Ltd.) at a temperature of 70°C and a pressure of 0.3 MPa. After peeling the release film from the film-like adhesive, the wafer was cured at 180°C for 1 hour in a heating oven. After this heat treatment, a dicing tape (trade name: K-13, manufactured by Furukawa Electric Co., Ltd.) and a dicing frame (trade name: DTF2-8-1H001, manufactured by DISCO Corporation) were adhered to the side of the cured film-like adhesive opposite the dummy silicon wafer using a manual laminator (trade name: FM-114, manufactured by Technovision Co., Ltd.) at room temperature and a pressure of 0.3 MPa. Next, using a dicing machine (trade name: DFD-6340, manufactured by DISCO) equipped with a two-axis dicing blade (Z1: NBC-ZH2050 (27HEDD), manufactured by DISCO / Z2: NBC-ZH127F-SE (BC), manufactured by DISCO), dicing was performed from the dummy silicon wafer side to a size of 10 mm x 10 mm, and a dummy chip with a cured film-like adhesive (adhesive thickness of 1.0 μm) was obtained. Using the same processing method, using the film-like adhesive with release film obtained in each example and comparative example, dicing was performed from the dummy silicon wafer side to a size of 12 mm x 12 mm, and a dummy chip with a cured film-like adhesive (adhesive thickness of 1.0 μm) was obtained. Next, using a flip chip bonder (product name: TFC Z100C, manufactured by Shibaura Mechatronics Co., Ltd.), a 10 mm x 10 mm dummy chip (test substrate) 12 ( FIG. 4 ) with the cured film-like adhesive was picked up from the dicing tape and mounted on a 12 mm x 12 mm dummy chip (test substrate) 13 with the cured film-like adhesive placed on a stage so that the film-like adhesive bonded together. The mounting conditions were as follows: When the temperature of the collet 11 was raised to 200°C, the temperature of the stage 14 was also raised to 150°C.Collet 11 temperature: room temperature (25°C) or 200°C Stage 14 temperature: room temperature (25°C) or 150°C Bonding pressure: 40 N Bonding time: 10 seconds The bonded dummy chips were observed for the presence or absence of voids at the interface between the cured film-like adhesive at room temperature (25°C) using an ultrasonic flaw detector (SAT) (FS300III, manufactured by Hitachi Power Solutions), and bondability was evaluated based on the following evaluation criteria. In this test, an evaluation rank of "A" is the pass level. Evaluation criteria AA: No voids were observed in any of the 100 mounted dummy chips. A: No voids were observed in any of the 24 mounted dummy chips. B: Voids were observed in one to three dummy chips out of the 24 mounted dummy chips. C: Voids were observed in four or more dummy chips out of the 24 mounted dummy chips. The cross-sectional image of the bonded interface of one example is shown in Figure 5 under a microscope. It can be seen that the interface between the two film-like adhesives has disappeared, resulting in a highly bonded state. No voids are observed.

[0043] (Measurement Example 3) <Evaluation of Die Shear Strength> The film-like adhesive with release film obtained in each Example and Comparative Example was first adhered to one side of a dummy silicon wafer (8 inch size, thickness 365 μm) using a manual laminator (trade name: FM-114, manufactured by Technovision Co., Ltd.) at a temperature of 70°C and a pressure of 0.3 MPa. After the release film was peeled from the film-like adhesive, the wafer was cured at 180°C for 1 hour in a heating oven. A dicing tape (trade name: K-13, manufactured by Furukawa Electric Co., Ltd.) and a dicing frame (trade name: DTF2-8-1H001, manufactured by DISCO Corporation) were adhered to the side of the cured film-like adhesive opposite the dummy silicon wafer using a manual laminator (trade name: FM-114, manufactured by Technovision Co., Ltd.) at room temperature and a pressure of 0.3 MPa. Next, a dicing machine (trade name: DFD-6340, manufactured by DISCO) equipped with a two-axis dicing blade (Z1: NBC-ZH2050 (27HEDD), manufactured by DISCO / Z2: NBC-ZH127F-SE (BC), manufactured by DISCO) was used to dicing to a size of 2 mm x 2 mm (adhesive layer thickness is 1.0 μm) from the dummy silicon wafer side, and subjected to a heat treatment at 180 ° C. for 1 hour to obtain a dummy chip with a cured film-like adhesive. Using the same processing method, using the film-like adhesive with release film obtained in each example and comparative example, dicing was performed from the dummy silicon wafer side to a size of 12 mm x 12 mm (adhesive layer thickness is 1.0 μm), and subjected to a heat treatment at 180 ° C. for 1 hour to obtain a dummy chip with a cured film-like adhesive. Next, using a flip chip bonder (product name: TFC Z100C, manufactured by Shibaura Mechatronics Co., Ltd.), a 2 mm x 2 mm dummy chip 12 with the film-like adhesive (see Figure 4, however, this dummy chip is narrower than shown) was picked up from the dicing tape and mounted on a 12 mm x 12 mm dummy chip 13 with the film-like adhesive placed on a stage so that the film-like adhesive bonded to each other. The mounting conditions were as follows: When the collet 11 was heated to 200°C, the stage was also heated to 150°C.Collet 11 temperature: room temperature (25° C.) or 200° C. Stage 14 temperature: room temperature (25° C.) or 150° C. Bonding pressure: 10 N Bonding time: 10 seconds.

[0044] The die shear strength of the bonded dummy chips with film-like adhesive at room temperature (25°C) was measured using a bond tester (product name: 4000 Universal Bond Tester, manufactured by Dage Corporation). Specifically, as shown in FIG. 6, a 2 mm x 2 mm dummy chip 12 bonded to a 12 mm x 12 mm dummy chip 13 was used. The 2 mm x 2 mm dummy chip 12 was pressed from the side with a specified shearing jig 15 from a height of 10 μm from the surface of the adherend at a shear rate of 0.5 mm / sec, applying a load, and the strength at break was measured at room temperature (25°C). The average value of eight tests was calculated as the die shear strength. Die shear strength evaluation was performed based on the following evaluation criteria. In this test, an evaluation rank of "A" is the pass level (in accordance with MIL-STD-883 Method No. 2019). The die shear strength corresponds to the bonding strength according to the present invention. AAA: Average die shear strength is 40 MPa or more. AA: Average die shear strength is less than 40 MPa and 20 MPa or more. A: Average die shear strength is less than 20 MPa and 10 MPa or more. B: Average die shear strength is less than 10 MPa and 5 MPa or more. C: Average die shear strength is less than 5 MPa.

[0045] Example 1 First, 60 parts by mass of bisphenol A type epoxy resin (trade name: YD-012, weight average molecular weight: 1000, softening point: 81°C, solid, epoxy equivalent: 655, manufactured by Nippon Steel Chemical & Material Co., Ltd.), 140 parts by mass of flexible epoxy resin (trade name: YX-7105, weight average molecular weight: 600, softening point: 25°C or less, liquid, epoxy equivalent: 487, manufactured by Mitsubishi Chemical Corporation), 100 parts by mass of bisphenol A type phenoxy resin (trade name: YP-50, mass average molecular weight: 70000, Tg: 84°C, manufactured by Nippon Chemical Epoxy Manufacturing Co., Ltd.), and 67 parts by mass of MEK were heated and stirred in a 1000 ml separable flask at a temperature of 110°C for 2 hours to obtain a resin varnish. Next, 367 parts by mass of this resin varnish was transferred to an 800 ml planetary mixer, and 240 parts by mass of silica filler (trade name: SO-C1, average particle size (d50): 0.3 μm, manufactured by Admatechs Co., Ltd.) was added, followed by 2.5 parts by mass of an imidazole-type curing agent (trade name: 2PHZ-PW, manufactured by Shikoku Kasei Co., Ltd.) and 3.0 parts by mass of a silane coupling agent (trade name: S-510, manufactured by JNC Corporation). The mixture was stirred and mixed at room temperature for 1 hour, and then degassed under vacuum to obtain a mixed varnish (adhesive composition). Next, the resulting mixed varnish was applied to a 38 μm thick release-treated PET film (release film) using a multi-coater (head: knife coater, model: MPC-400L, manufactured by Matsuoka Machine Works, Ltd.) at a processing temperature of 130°C (drying oven 1.5 m) and a linear speed of 1.0 m / min (residence time 1.5 min), resulting in a two-layer laminate film (film-like adhesive with release film) with a width of 200 mm, a length of 10 m, and a thickness of 1 μm, in which an adhesive layer was formed on the release film. The bonding temperature (collet temperature) for bondability evaluation and die shear evaluation was 200°C. The sampling temperature for viscoelastic properties was also the same as the bonding temperature (200°C).

[0046] Example 2 An adhesive composition and a film-like adhesive were obtained in the same manner as in Example 1, except that 30 parts by mass of a Bis phenol A type epoxy resin (trade name: YD-012, weight average molecular weight: 1000, softening point: 81°C, solid, epoxy equivalent: 655, manufactured by Nippon Steel Chemical & Material Co., Ltd.) and 170 parts by mass of a flexible epoxy resin (trade name: YX-7105, weight average molecular weight: 600, softening point: 25°C or less, liquid, epoxy equivalent: 487, manufactured by Mitsubishi Chemical Corporation) were used. The bonding temperature (collet temperature) for bondability evaluation and die shear evaluation was 200°C. The sampling temperature for viscoelastic properties was also the same as the bonding temperature (200°C).

[0047] Example 3 An adhesive composition and a film-like adhesive were obtained in the same manner as in Example 1, except that 0 parts by mass of a Bis phenol A type epoxy resin (trade name: YD-012, weight average molecular weight: 1000, softening point: 81°C, solid, epoxy equivalent: 655, manufactured by Nippon Steel Chemical & Material Co., Ltd.) and 200 parts by mass of a flexible epoxy resin (trade name: YX-7105, weight average molecular weight: 600, softening point: 25°C or less, liquid, epoxy equivalent: 487, manufactured by Mitsubishi Chemical Corporation) were used. The bonding temperature (collet temperature) for bondability evaluation and die shear evaluation was 200°C. The sampling temperature for viscoelastic properties was also the same as the bonding temperature (200°C).

[0048] Example 4 An adhesive composition and a film-like adhesive were obtained in the same manner as in Example 1, except that 400 parts by mass (of which 100 parts by mass of urethane resin) of a urethane resin solution (product name: Dynaleo VA-9310MF, weight average molecular weight: 110,000, Tg: 27°C, room temperature elastic modulus: 289 MPa, solvent: MEK / IPA mixed solvent, manufactured by Toyochem Co., Ltd.) was used instead of the phenoxy resin. The bonding temperature (collet temperature) for the bondability evaluation and die shear evaluation was 200°C. The sampling temperature for viscoelastic properties was also the same as the above bonding temperature (200°C).

[0049] Example 5 An adhesive composition and a film-like adhesive were obtained in the same manner as in Example 4, except that the collet temperature during bondability evaluation and die shear evaluation, and the sampling temperature for viscoelastic properties were 25°C.

[0050] Example 6 An adhesive composition and a film-like adhesive were obtained in the same manner as in Example 1, except that 140 parts by mass of AER9000 (weight average molecular weight: 500, softening point: 25°C or less, liquid, epoxy equivalent: 375, manufactured by Asahi Kasei Corporation) was used instead of YX-7105 as the flexible epoxy resin. The bonding temperature (collet temperature) for the bondability evaluation and die shear evaluation was 200°C. The sampling temperature for the viscoelastic properties was also the same as the bonding temperature (200°C).

[0051] Example 7 An adhesive composition and a film-like adhesive were obtained in the same manner as in Example 6, except that the collet temperature during bondability evaluation and die shear evaluation, and the sampling temperature for viscoelastic properties were 25°C.

[0052] Example 8 An adhesive composition and a film-like adhesive were obtained in the same manner as in Example 1, except that 400 parts by mass (of which 100 parts by mass of acrylic polymer) of an acrylic polymer solution (product name: S-2060, mass average molecular weight: 500,000, Tg: -23°C, elastic modulus at room temperature (25°C): 50 MPa, solids content 25% (organic solvent: toluene), manufactured by Toa Gosei Co., Ltd.) was used instead of the phenoxy resin. The bonding temperature (collet temperature) for the bondability evaluation and die shear evaluation was 200°C. The sampling temperature for viscoelastic properties was also the same as the bonding temperature (200°C).

[0053] Example 9 An adhesive composition and a film-like adhesive were obtained in the same manner as in Example 5, except that silica filler (trade name: SO-C1, average particle size (d50): 0.3 μm, manufactured by Admatechs Co., Ltd.) and silane coupling agent (trade name: S-510, manufactured by JNC Corporation) were not used. The collet temperature during bondability evaluation and die shear evaluation, and the sampling temperature for viscoelastic properties were 25°C.

[0054] Example 10 An adhesive composition and a film-like adhesive were obtained in the same manner as in Example 9, except that 140 parts by mass of AER9000 (weight average molecular weight: 500, softening point: 25°C or less, liquid, epoxy equivalent: 375, manufactured by Asahi Kasei Corporation) was used instead of YX-7105 as the flexible epoxy resin. The collet temperature during bondability evaluation and die shear evaluation, and the sampling temperature for viscoelastic properties were 25°C.

[0055] Comparative Example 1 An adhesive composition and a film-like adhesive were obtained in the same manner as in Example 1, except that 140 parts by mass of a bisphenol A type epoxy resin (trade name: YD-128, weight average molecular weight: 400, softening point: 25°C or less, liquid, epoxy equivalent: 190, manufactured by Shin-Nichika Epoxy Manufacturing Co., Ltd.) and 840 parts by mass of a silica filler (trade name: SO-C1, average particle size (d50): 0.3 μm, manufactured by Admatechs Co., Ltd.) were used instead of YX-7105. The bonding temperature (collet temperature) for bondability evaluation and die shear evaluation was 200°C. The sampling temperature for viscoelastic properties was also the same as the above bonding temperature (200°C).

[0056] (Comparative Example 2) An adhesive composition and a film-like adhesive were obtained in the same manner as in Comparative Example 1, except that 240 parts by mass of silica filler (product name: SO-C1, average particle size (d50): 0.3 μm, manufactured by Admatechs Co., Ltd.) was used. The bonding temperature (collet temperature) for the bondability evaluation and die shear evaluation was 200°C. The sampling temperature for the viscoelastic properties was also the same as the bonding temperature (200°C).

[0057] (Comparative Example 3) An adhesive composition and a film-like adhesive were obtained in the same manner as in Comparative Example 1, except that silica filler (product name: SO-C1, average particle size (d50): 0.3 μm, manufactured by Admatechs Co., Ltd.) was not used. The bonding temperature (collet temperature) for the bondability evaluation and die shear evaluation was 200°C. The sampling temperature for the viscoelastic properties was also the same as the bonding temperature (200°C).

[0058] Comparative Example 4 An adhesive composition and a film-like adhesive were obtained in the same manner as in Example 1, except that 150 parts by mass of a Bis phenol A type epoxy resin (trade name: YD-012, weight average molecular weight: 1000, softening point: 81°C, solid, epoxy equivalent: 655, manufactured by Nippon Steel Chemical & Material Co., Ltd.) and 50 parts by mass of a flexible epoxy resin (trade name: YX-7105, weight average molecular weight: 600, softening point: 25°C or less, liquid, epoxy equivalent: 487, manufactured by Mitsubishi Chemical Corporation) were used. The collet temperature during bondability evaluation and die shear evaluation, and the sampling temperature for viscoelastic properties were 25°C.

[0059]

[0060] (Discussion) The adhesive compositions of the Examples all used epoxy resins with an epoxy equivalent of 300 g / eq or more, and when formed into films, they satisfied the following properties: a storage modulus of 2000 MPa or less at the bonding temperature (25°C, 200°C) and a loss tangent of 0.03 or more at the bonding temperature. As a result, good results were obtained in the bondability evaluation and die shear strength (A, AA, AAA). In contrast, the adhesive compositions of Comparative Examples 1 to 3 had epoxy resins with epoxy equivalents of 189 and well below 300, and did not satisfy the film storage modulus of 2000 MPa or less and a loss tangent of 0.03 or more. As a result, the bondability evaluation and die shear strength were insufficient (B, C).

[0061] Examples 4 and 5, and Examples 6 and 7 each have the same composition, but the storage modulus and loss tangent values ​​of the present invention were satisfied whether the bonding temperature was 200°C or 25°C, and good performance was exhibited both at low bonding temperatures and when heated.

[0062] The adhesive compositions in the examples are blends of solid epoxy resin and liquid epoxy resin. Example 3 is an example using only liquid epoxy resin, but it shows good results in both bonding evaluation and die shear. However, as mentioned above, using only liquid epoxy resin results in excessive tackiness and poor handleability.

[0063] Various polymers can be used to form the adhesive composition, including BisA phenoxy resin, urethane resin, and acrylic resin, but Example 8, which used acrylic resin, received a result of A in the bonding evaluation and die shear strength, making it inferior to the others. From this perspective, phenoxy resin and urethane resin are preferred as polymers that form the skeleton of the matrix.

[0064] Furthermore, the adhesive compositions of the Examples are formulated with a richer proportion of liquid epoxy resin than solid epoxy resin, except for Example 3. When this is reversed and the solid epoxy resin is made rich, the adhesive compositions are inferior in bondability evaluation and die shear strength, as in Comparative Example 4.

[0065] REFERENCE SIGNS LIST 1 Silicon substrate 2 Copper terminal 2A Planarized copper terminal 2B Bonded copper terminal 4 Film adhesive 4A Planarized film adhesive 4B Bonded film adhesive 4x Hardened film adhesive 5 Polishing pad 11 Collet 12, 13 Test substrate 14 Stage 15 Shearing jig

Claims

1. An adhesive composition containing at least an epoxy resin (A), an epoxy resin curing agent (B), and a polymer component (C), characterized in that the adhesive composition has a storage modulus of 2000 MPa or less and a loss tangent of 0.03 or more under the following conditions after curing, and when the compositions are bonded together after curing, the bonding strength under the following conditions is 5 MPa or more. [The storage modulus and loss tangent after curing are measured under the conditions of a measurement temperature range of 20 to 300°C, a heating rate of 5°C / min, and a frequency of 1 Hz, using a film-like adhesive piece of 5 mm x 17 mm x 200 μm obtained by thermally curing the adhesive composition at 180°C for 1 hour. At this time, the measured values ​​at the following bonding temperatures are sampled.] [Bonding temperature: any temperature of 25°C or more and 300°C or less] [The bonding strength is the strength when two chips with a film-like adhesive having a thickness of 1.0 μm, which are obtained by heating the adhesive composition at 180°C for 1 hour and thermally curing it, are provided, and the film-like adhesives of both chips are brought into contact and bonded at the above bonding temperature, and then peeled off at room temperature. ] 2. The adhesive composition according to claim 1, characterized in that the epoxy equivalent of the epoxy resin (A) used in the adhesive composition is 300 g / eq or more, and the content of the epoxy resin (A) is 20 mass% or more of the total amount of the epoxy resin (A), the epoxy resin hardener (B), and the polymer component (C).

3. An adhesive composition according to claim 1, wherein the epoxy resin (A) is a blend of an epoxy resin that is liquid at room temperature and a solid epoxy resin, the contents of the liquid epoxy resin are 100 to 250 parts by mass and the solid epoxy resin are 15 to 90 parts by mass per 100 parts by mass of polymer component (C), and the mass ratio of the solid epoxy resin to the liquid epoxy resin is in the range of 1:10 to 6:

10.

4. The adhesive composition according to claim 1, wherein the epoxy resin curing agent (B) is an imidazole-based curing agent.

5. The adhesive composition according to claim 1, wherein the bonding temperature is 25°C or higher and 200°C or lower.

6. A film-like adhesive obtained by heat-treating the adhesive composition according to any one of claims 1 to 5.

7. The film adhesive according to claim 6, which has a thickness of 0.1 to 50 μm.

8. A method for manufacturing a semiconductor package, comprising: adhering and heat-curing the film-like adhesive described in claim 6 to a semiconductor wafer having at least one semiconductor circuit formed on its surface to provide an adhesive layer; bonding and stacking semiconductor wafers via the adhesive layer; and bonding the adhesive layer as is at room temperature or by further heat-curing and pressing the adhesive layer with a resin cured body to form a multi-layered semiconductor wafer.

9. The method for manufacturing a semiconductor package according to claim 8, further comprising the step of exposing the terminals from the adhesive layer and flattening the surface of the adhesive layer so that it is flush with the surface of the terminals.

10. A semiconductor package comprising semiconductor wafers bonded together with the resin cured product of the film-like adhesive according to claim 6.

11. A film-like adhesive obtained by heat-treating an adhesive composition containing an epoxy resin (A), an epoxy resin curing agent (B), and a polymer component (C), the film-like adhesive having a storage modulus of 2000 MPa or less and a loss tangent of 0.03 or more under the following conditions, and a bonding strength of 5 MPa or more under the following conditions when bonded. [The storage modulus and loss tangent are measured using a film-like adhesive piece measuring 5 mm x 17 mm x 200 μm, under conditions of a measurement temperature range of 20 to 300° C., a heating rate of 5° C. / min, and a frequency of 1 Hz. At this time, the measured values ​​at the bonding temperature described below are sampled.] [Bonding temperature: any temperature between 25° C. and 300° C.] [The bonding strength is the strength when two chips with a film-like adhesive having a thickness of 1.0 μm are provided, the film-like adhesives on both chips are brought into contact with each other and bonded at the above bonding temperature, and then peeled off at room temperature.]

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