Thermosetting adhesive composition, laminated film, and connection body and method for producing same

Abstract

Disclosed is a thermosetting adhesive composition. The thermosetting adhesive composition contains an epoxy resin, an elastomer, and a curing accelerator. The curing accelerator is a compound that generates a heterocyclic amine compound upon heating.

Description

Thermosetting adhesive composition, laminated film, and connection body, and method for producing the same

[0001] The present disclosure relates to a thermosetting adhesive composition, a laminated film, a connection body, and a method for producing the same.

[0002] Conventionally, semiconductor devices are manufactured through the following steps. First, a dicing process is performed with a semiconductor wafer attached to a dicing adhesive sheet, thereby dividing the semiconductor wafer into individual semiconductor chips. Then, a pickup process, a die bonding process, a wire bonding process, a molding process, and the like are performed. Patent Document 1 discloses an adhesive sheet (die bond dicing sheet) that has both the function of fixing a semiconductor wafer in a dicing process and the function of bonding a semiconductor chip to a substrate in a die bonding process. Patent Document 2 discloses an adhesive sheet that acts as a dicing tape in a dicing process, has excellent connection reliability in a process of bonding a semiconductor element to a support member, and retains sufficient fluidity after the heat history of wire bonding.

[0003] JP 2007-288170 A JP 2009-209345 A

[0004] In recent years, with the evolution of semiconductor modules for small devices such as smartphones, the manufacturing process for semiconductor modules has undergone significant changes. For example, processes that do not require dicing or die bonding are being commercialized. Accordingly, different performance is being demanded from thermosetting adhesive compositions used in the manufacturing process of semiconductor modules. In addition to this situation, the inventors, anticipating the use of materials with relatively low heat resistance in semiconductor modules, have been developing a thermosetting adhesive composition that undergoes sufficient curing reaction at low temperatures of 100°C or less. While improvements were made based on a conventional thermosetting adhesive composition with excellent low-temperature curing properties, the development goal of low-temperature curing was achieved, but the shear viscosity tended to increase over time. When the shear viscosity increases over time, the usable period after preparation is limited to about two weeks, so there is a demand for a longer usable period for thermosetting adhesive compositions.

[0005] A primary object of the present disclosure is to provide a thermosetting adhesive composition in which the curing reaction proceeds sufficiently under low temperature conditions and in which the increase in shear viscosity over time can be sufficiently suppressed.

[0006] In order to solve the above problems, the present inventors conducted research on thermosetting adhesive compositions and discovered that it is possible to suppress an increase in shear viscosity over time by adding a specific curing accelerator to a thermosetting adhesive composition, which led to the completion of the presently disclosed invention.

[0007] The present disclosure provides a thermosetting adhesive composition according to any one of [1] to [9], a laminate film according to

[10] , a method for producing a connection body according to any one of

[11] and

[12] , and a connection body according to any one of

[13] . [1] A thermosetting adhesive composition comprising an epoxy resin, an elastomer, and a curing accelerator, wherein the curing accelerator is a compound that generates a heterocyclic amine compound upon heating. [2] The thermosetting adhesive composition according to [1], wherein the heterocyclic amine compound is an aromatic heterocyclic amine compound. [3] The thermosetting adhesive composition according to [1], wherein the heterocyclic amine compound is a compound having a pyrazole ring or a compound having an imidazole ring. [4] The thermosetting adhesive composition according to any one of [1] to [3], wherein the curing accelerator is a compound that generates a heterocyclic amine compound by deprotecting a protecting group upon heating. [5] The thermosetting adhesive composition according to [4], wherein the protecting group is a substituted amide group. [6] The thermosetting adhesive composition according to any one of [1] to [5], which has a reaction rate of 50% or more after heating at 95°C for 3 hours. [7] The thermosetting adhesive composition according to any one of [1] to [6], which further contains an epoxy resin curing agent, wherein the epoxy resin curing agent is a phenolic resin. [8] The thermosetting adhesive composition according to any one of [1] to [7], which further contains an inorganic filler. [9] The thermosetting adhesive composition according to any one of [1] to [8], which has a shear viscosity at 95°C of 100 to 12,000 Pa s.

[10] A laminated film comprising a substrate film and an adhesive layer provided on a surface of the substrate film, the adhesive layer being composed of the thermosetting adhesive composition according to any one of [1] to [9].

[11] A method for producing a connection, comprising the steps of: (A) preparing a laminate including a first circuit member, a second circuit member, and an adhesive layer disposed between the first circuit member and the second circuit member; (B) heating the laminate at 90 to 110°C for 30 to 240 minutes; and (C) wire-bonding the first circuit member and the second circuit member, in this order; wherein the adhesive layer is formed from the thermosetting adhesive composition according to any one of [1] to [9].

[12] The method for producing a connection body according to

[11] , wherein the first circuit member is one selected from the group consisting of a printed circuit board and a semiconductor chip, and the second circuit member is a flexible printed circuit board.

[13] A connection body comprising a first circuit member, a second circuit member, and an adhesive layer disposed between the first circuit member and the second circuit member, the adhesive layer being composed of a cured product of the thermosetting adhesive composition according to any one of [1] to [9].

[0008] According to the present disclosure, there is provided a thermosetting adhesive composition that undergoes sufficient curing reaction under low-temperature conditions and that can sufficiently suppress an increase in shear viscosity over time. The present disclosure also provides an adhesive film having an adhesive layer made of such a thermosetting adhesive composition. The present disclosure also provides a connection structure using such a thermosetting adhesive composition and a method for producing the same.

[0009] FIG. 1 is a cross-sectional view schematically showing an embodiment of a laminate film according to the present disclosure. FIG. 2 is a cross-sectional view schematically showing a semiconductor module during a manufacturing process. FIG. 3 is a cross-sectional view schematically showing a semiconductor module during a manufacturing process. FIG. 4 is a perspective view schematically showing an example of a punched product according to the present disclosure. FIG. 5 is a cross-sectional view taken along line V-V shown in FIG. 4. FIG. 6 is a cross-sectional view schematically showing how an adhesive piece and a cover film covering the adhesive piece are picked up from a base film. FIG. 7 is a cross-sectional view schematically showing a semiconductor module during a manufacturing process.

[0010] The present embodiment will be described in detail below with reference to the drawings. However, the present disclosure is not limited to the following embodiments. In the following embodiments, the components (including steps, etc.) are not essential unless otherwise specified. The same or equivalent parts are given the same reference numerals, and duplicate explanations will be omitted. Furthermore, unless otherwise specified, positional relationships such as up, down, left, and right will be based on the positional relationships shown in the drawings. The sizes of the components in each figure are conceptual, and the relative size relationships between the components are not limited to those shown in each figure.

[0011] The same applies to the numerical values ​​and ranges in the present disclosure, and do not limit the present disclosure. In this specification, a numerical range indicated using "to" indicates a range that includes the numerical values ​​before and after "to" as the minimum and maximum values, respectively. In the numerical ranges described in stages in this specification, the upper limit or lower limit described in one numerical range may be replaced with the upper limit or lower limit of another numerical range described in stages. Furthermore, in the numerical ranges described in this specification, the upper limit or lower limit of that numerical range may be replaced with a value shown in the examples. Furthermore, the upper limit and lower limit values ​​described individually can be combined in any combination.

[0012] In this specification, the term "layer" includes not only a structure having a shape formed over the entire surface when observed in a plan view, but also a structure having a shape formed on a portion thereof. In this specification, the term "process" includes not only an independent process, but also a process that cannot be clearly distinguished from other processes as long as the intended effect of the process is achieved.

[0013] In this specification, "(meth)acrylate" means at least one of an acrylate and its corresponding methacrylate. The same applies to other similar expressions such as "(meth)acryloyl" and "(meth)acrylic acid." Furthermore, "(poly)" refers to both cases with and without the prefix "poly."

[0014] "A or B" means that either A or B is contained, or both are contained. Furthermore, unless otherwise specified, the materials exemplified below may be used alone or in combination of two or more. When a plurality of substances corresponding to each component are present in the composition, the content of each component in the composition means the total amount of the plurality of substances present in the composition, unless otherwise specified.

[0015] [Laminate Film] Figure 1 is a cross-sectional view schematically illustrating a laminate film according to this embodiment. The laminate film 10 shown in this figure comprises a substrate film 1, an adhesive layer 3, and a cover film 5, in this order. The laminate film 10 has a width of 300 to 500 mm and a total length of 10 to 400 m, for example, and is produced by being wound into a roll. The configuration of the laminate film 10 will be described below.

[0016] <Substrate Film> There are no particular limitations on the substrate film 1, as long as it can sufficiently withstand the tension applied in the manufacturing process of the adhesive layer 3 and the manufacturing process of the semiconductor module. The substrate film 1 is preferably transparent from the viewpoint of visibility of the adhesive layer 3 disposed thereon. Examples of the substrate film 1 include polyester-based films such as polyethylene terephthalate films; polyolefin-based films such as homocopolymers or copolymers, or mixtures thereof, of polytetrafluoroethylene films, polyethylene films, polypropylene films, polymethylpentene films, polyvinyl acetate films, poly-4-methylpentene-1, ethylene-vinyl acetate copolymers, and ethylene-ethyl acrylate copolymers; and plastic films such as polyvinyl chloride films and polyimide films. The substrate film 1 may have a single-layer structure or a multi-layer structure.

[0017] The thickness of the base film 1 may be appropriately selected within a range that does not impair workability, and may be, for example, 10 to 200 μm, 20 to 100 μm, or 25 to 80 μm. These thickness ranges are practically acceptable and economically effective.

[0018] In order to increase the adhesive strength of the adhesive layer 3 to the base film 1, the surface of the base film 1 may be subjected to a chemical or physical surface treatment such as corona treatment, chromic acid treatment, ozone exposure, flame exposure, high-voltage shock exposure, or ionizing radiation treatment. A film made of a fluororesin and having low surface energy can also be used as the base film 1. Examples of such films include A-63 (release treatment agent: modified silicone-based) manufactured by Toyobo Film Solutions Co., Ltd. and A-31 (release treatment agent: Pt-based silicone-based) manufactured by Toyobo Film Solutions Co., Ltd.

[0019] In order to prevent the adhesive strength of the adhesive layer 3 to the base film 1 from becoming excessively high, a release layer composed of a release agent such as a silicone-based release agent, a fluorine-based release agent, or a long-chain alkyl acrylate-based release agent may be formed on the surface of the base film 1.

[0020] The adhesion strength between the base film 1 and the adhesive layer 3 is, for example, 0.5 N / m or more. When this adhesion strength is 0.5 N / m or more, it is easy to prevent the adhesive layer 3 from accidentally peeling off from the base film 1 during the process of producing the laminate film 10. The adhesion strength between the adhesive layer 3 and the base film 1 means the 90° peel strength, and specifically means the peel strength measured when a 20 mm wide sample having the adhesive layer 3 formed on the base film 1 is prepared, and this adhesive layer is peeled off from the base film at an angle of 90° at a peel rate of 50 mm / min.

[0021] <Adhesive Layer> The adhesive layer 3 is used to bond circuit components together, and is suitably used, for example, to bond the leading end of a printed circuit board to an FPC board (flexible printed circuit board) or to bond a semiconductor chip to an FPC board. The module 50A (connected body) shown in FIG. 2 includes a semiconductor chip C, a printed circuit board 12 (first circuit member), an adhesive piece 3c, and an FPC board 15 (second circuit member). The adhesive piece 3c bonds the printed circuit board 12 to the leading end 15a of the FPC board 15. The adhesive piece 3c is composed of a cured product of the adhesive piece 3p (see FIG. 4). The adhesive piece 3p is formed by cutting the adhesive layer 3 shown in FIG. 1 into a predetermined shape by die-cutting. The adhesive layer 16 bonds the printed circuit board 12 to the semiconductor chip C. The adhesive layer 16 may have the same composition as the adhesive piece 3c, or a different composition.

[0022] The module 50B shown in Fig. 3 is obtained by performing wire bonding on the module 50A shown in Fig. 2. A wire W1 electrically connects the semiconductor chip C to the printed circuit board 12, and a wire W2 electrically connects the printed circuit board 12 to the FPC board 15. The semiconductor chip C is, for example, a sensor chip. The printed circuit board 12 processes signals from the semiconductor chip C. Signals from the printed circuit board 12 are transmitted to the tip portion 15a of the FPC board 15.

[0023] The adhesive piece 3p (adhesive layer) is made of a thermosetting adhesive composition (hereinafter, sometimes simply referred to as the "adhesive composition"). The adhesive composition contains an epoxy resin, an elastomer, and a curing accelerator. The curing accelerator is a compound that generates a heterocyclic amine compound when heated, and may be, for example, a compound that deprotects a protecting group when heated to generate a heterocyclic amine compound.

[0024] The shear viscosity (melt viscosity) of the adhesive composition at 95°C is 100 to 12,000 Pa·s, and may be 200 Pa·s or more, 300 Pa·s or more, 400 Pa·s or more, or 500 Pa·s or more, or 10,000 Pa·s or less, 8,000 Pa·s or less, 6,000 Pa·s or less, or 4,000 Pa·s or less. When the shear viscosity at 95°C is within the above range, even if the tip portion 15a of the FPC board 15 has irregularities, the adhesive composition tends to be able to be arranged without gaps between the tip portion 15a and the member to be bonded (printed circuit board 12).

[0025] The shear viscosity of an adhesive composition at 95°C can be measured, for example, by the following procedure. First, multiple film-like adhesives made from the adhesive composition are prepared, each 25 μm thick. Next, multiple film-like adhesives are laminated to a thickness of approximately 300 μm, and this laminate is punched out with a φ9 mm punch to prepare a measurement sample. An 8 mm diameter circular aluminum plate jig is installed in a dynamic viscoelasticity apparatus, and the measurement sample is set thereon. Next, measurements are performed while applying a 5% strain at 35°C and increasing the temperature to 100°C at a heating rate of 5°C / min, and the viscosity at 95°C is determined, thereby measuring the shear viscosity at 95°C. Note that during the measurement, the frequency is kept constant at 1 Hz, the initial load is maintained at 300 g, and the axial force is maintained at 100 g.

[0026] The following methods can be considered to adjust the shear viscosity at 95°C to a predetermined range, for example: Method 1: The amount of inorganic filler contained in the adhesive composition is made relatively small. Method 2: The amount of elastomer (e.g., acrylic rubber) contained in the adhesive composition is made relatively small. Method 3: The average particle size of the inorganic filler contained in the adhesive composition is made relatively large.

[0027] The adhesive composition may satisfy, for example, the following condition 1: Condition 1: After being heated at 95°C for 3 hours, the storage modulus at 95°C is 3 MPa or more.

[0028] An adhesive composition that satisfies condition 1 can be said to have excellent low-temperature curing properties. This has the advantage that components with relatively low heat resistance can be used as components of module 50B. To obtain an adhesive composition that satisfies condition 1, for example, it is possible to use an epoxy resin as an epoxy resin curing agent together with an epoxy resin. The reason that phenolic resin contributes to improving low-temperature curing properties is that the reactivity between phenolic resin and epoxy resin is higher than the reactivity between epoxy resins, and the use of phenolic resin makes it easier for the reaction to proceed.

[0029] By using an adhesive composition that satisfies condition 1, it is possible to reduce shaking of the adhesive piece 3c during the wire bonding process, making it easier to perform wire bonding. As described above, the storage modulus according to condition 1 may be 3 MPa or more, 5 MPa or more, or 7 MPa or more. The storage modulus according to condition 1 may be, for example, 50 MPa or less. The higher the storage modulus according to condition 1, the easier it tends to be to perform wire bonding.

[0030] The adhesive composition may, for example, satisfy the following condition 2: Condition 2: After being heated at 95°C for 3 hours, the storage modulus at 35°C is 700 MPa or less.

[0031] By using an adhesive composition that satisfies condition 2, the internal stress of the adhesive piece 3c is easily alleviated, and warping of the module 50B can be suppressed. As described above, the storage modulus according to condition 2 may be 700 MPa or less, or may be 650 MPa or less, 600 MPa or less, or 550 MPa or less. The storage modulus according to condition 2 may be, for example, 50 MPa or more, 100 MPa or more, or 150 MPa or more.

[0032] To obtain an adhesive composition that satisfies condition 2, the following methods can be considered, for example: Method 1: The amount of elastomer (e.g., acrylic rubber) contained in the adhesive composition is relatively large. Method 2: An elastomer with a relatively low glass transition temperature (Tg) is used. Method 3: An epoxy resin with a flexible skeleton is used.

[0033] According to the study by the present inventors, Methods 1 and 2 are more effective than Method 3. With regard to Method 1, the content of the elastomer, based on the total mass of the adhesive composition, is, for example, 20 to 40 mass%, or may be 22 to 38 mass%, or 25 to 35 mass%. With regard to Method 2, the Tg of the elastomer is, for example, -50 to 20°C.

[0034] The storage modulus at 95°C and 35°C can be measured, for example, by the following procedure. First, multiple film-like adhesives made from the adhesive composition are prepared, each 25 μm thick. Next, multiple film-like adhesives are laminated to a thickness of approximately 300 μm, and this is cut into a size of 4 mm wide x 33 mm, and heated at 95°C for 3 hours to prepare a measurement sample. The prepared measurement sample is placed in a dynamic viscoelasticity apparatus with a chuck distance of 20 mm, and a tensile load is applied, and measurement is performed under conditions of a frequency of 10 Hz and a heating rate of 3°C / min to measure the storage modulus at 95°C and 35°C.

[0035] It is preferable that the adhesive composition undergoes a curing reaction to some extent after heat treatment at 95°C for 3 hours. The extent to which the reaction has progressed can be quantified by differential scanning calorimetry. That is, the reaction rate calculated by the following formula from the calorific values ​​C1 and C2 determined from a DSC curve obtained by differential scanning calorimetry at a temperature rise rate of 10°C / min is, for example, 50% or more, and may also be 60% or more, or 70% or more. Reaction rate (%) = (C1 - C2) / C1 × 100

[0036] The calorific value C1 is the calorific value (unit: J / g) measured for the adhesive composition. The calorific value C2 is the calorific value (unit: J / g) measured for the resin composition after heating the adhesive composition at 95°C for 3 hours. The temperature range for differential scanning calorimetry is, for example, 30 to 300°C. The temperature range for determining the calorific values ​​C1 and C2 from the DSC curve obtained by measurement is 50 to 200°C. A reaction rate of 50% or more can suppress deterioration over time after the manufacturing process, and tends to result in excellent reliability.

[0037] The laminate film 10 can be produced, for example, as follows. First, a coating liquid is prepared by dissolving the adhesive composition that constitutes the adhesive layer 3 in a solvent such as an organic solvent to form a varnish. This coating liquid is then applied to the base film 1, and the solvent is then removed to form the adhesive layer 3. Coating methods include knife coating, roll coating, spray coating, gravure coating, bar coating, and curtain coating. Next, a cover film 5 is laminated to the surface of the adhesive layer 3 at room temperature (25°C) to 60°C. This allows the laminate film 10 to be obtained. Alternatively, the laminate film 10 can be obtained by forming the adhesive layer 3 on a wide base film, then laminating the cover film 5 to cover it, and then cutting (slitting) the laminate film 10 to a predetermined width.

[0038] <Punched Product> Figure 4 is a perspective view that schematically shows a punched product produced from laminate film 10. Figure 5 is a cross-sectional view taken along line V-V in Figure 4. The punched product 20 shown in Figures 4 and 5 comprises a strip-shaped base film 1 having a width of 100 mm or less, a plurality of adhesive pieces 3p arranged on the base film 1 in the longitudinal direction thereof (the direction of arrow X in Figure 4), and a cover film 5p that covers the upper surfaces 3f of the adhesive pieces 3p and has the same shape as the adhesive pieces 3p.

[0039] The adhesive piece 3p is suitably used for bonding a circuit member (semiconductor chip or printed circuit board) to the tip of the FPC board. The area of ​​the adhesive piece 3p in a plan view is, for example, 1 to 100 mm ２ and 3 to 50 mm ２ Or 5 to 40 mm ２ With the punched product 20, it is possible to sequentially pick up a plurality of adhesive pieces 3 p arranged in a line on the base film 1 (see FIG. 6 ), and then place each adhesive piece 3 p in a predetermined area on the circuit member, thereby efficiently bonding the circuit member and the FPC member.

[0040] The punched product 20 can be obtained, for example, through the following steps: (a) a step of preparing a laminated film 10. (b) a step of punching out the adhesive layer 3 and the cover film 5 in the laminated film 10 to obtain a plurality of adhesive pieces 3p arranged on the base film 1 in the longitudinal direction of the base film 1.

[0041] <Thermosetting Adhesive Composition (Adhesive Composition)> The adhesive composition constituting the adhesive layer 3 and the adhesive piece 3p will be described. As described above, the adhesive composition contains an epoxy resin, an elastomer, and a curing accelerator. The adhesive composition may further contain, for example, an epoxy resin curing agent, an inorganic filler, etc.

[0042] Epoxy Resins Examples of epoxy resins include bisphenol A epoxy resins, bisphenol F epoxy resins, bisphenol S epoxy resins, alicyclic epoxy resins, linear aliphatic epoxy resins, phenol novolac epoxy resins, cresol novolac epoxy resins, bisphenol A novolac epoxy resins, diglycidyl ethers of biphenols, diglycidyl ethers of naphthalenediols, diglycidyl ethers of phenols, diglycidyl ethers of alcohols, and difunctional epoxy resins such as alkyl-substituted, halide, and hydrogenated versions thereof, and novolac epoxy resins. Other commonly known epoxy resins, such as multifunctional epoxy resins and heterocycle-containing epoxy resins, may also be used. Note that components other than the epoxy resin may be contained as impurities to the extent that they do not impair the properties.

[0043] The epoxy resin may contain, for example, an epoxy resin that is solid at 25°C (hereinafter may be referred to as a "solid epoxy resin"). That is, the epoxy resin may be composed of a solid epoxy resin and an epoxy resin that is liquid at 25°C (hereinafter may be referred to as a "liquid epoxy resin"). When the epoxy resin contains a solid epoxy resin, it tends to be less sticky during film formation, to be able to prevent sticking to machines such as rolls, and to be able to prevent a decrease in workability when producing a laminated film.

[0044] Specific examples of solid epoxy resins include YDCN-700-10 (manufactured by Nippon Steel Chemical & Material Co., Ltd., cresol novolac type epoxy resin), N-500P-10 (manufactured by DIC Corporation, cresol novolac type epoxy resin), HP-4710 (manufactured by DIC Corporation, naphthalene type epoxy resin), and NC-7000L (manufactured by Nippon Kayaku Co., Ltd., naphthalene type epoxy resin).

[0045] Specific examples of liquid epoxy resins include YDF-8170C (bisphenol F type epoxy resin, manufactured by Nippon Steel Chemical & Material Co., Ltd.), EPICLON (registered trademark) series (EXA-830CRP, 830, 830-S, 835, etc.) (bisphenol F type epoxy resin, manufactured by DIC Corporation), and the like.

[0046] Epoxy Resin Curing Agent A commonly used known curing agent can be used as the epoxy resin curing agent. Examples of the epoxy resin curing agent include amines, polyamides, acid anhydrides, polysulfides, boron trifluoride, and phenolic resins. The epoxy resin curing agent may be, for example, a phenolic resin.

[0047] The phenolic resin is not particularly limited as long as it has a phenolic hydroxyl group in the molecule. Examples of the phenolic resin include novolak-type phenolic resins obtained by condensing or co-condensing phenols such as phenol, cresol, resorcinol, catechol, bisphenol A, bisphenol F, phenylphenol, and aminophenol and / or naphthols such as α-naphthol, β-naphthol, and dihydroxynaphthalene with a compound having an aldehyde group such as formaldehyde under an acidic catalyst, allylated bisphenol A, allylated bisphenol F, allylated naphthalenediol, phenol novolak, and phenol aralkyl resins, naphthol aralkyl resins, biphenyl aralkyl-type phenolic resins, and phenyl aralkyl-type phenolic resins synthesized from phenols such as phenol and / or naphthols with dimethoxyparaxylene or bis(methoxymethyl)biphenyl.

[0048] The total content of the epoxy resin and the epoxy resin curing agent (phenolic resin) is, for example, 35 to 70 mass %, or may be 40 to 65 mass %, or 45 to 60 mass %, based on the total amount of the adhesive composition. When the total content of the epoxy resin and the epoxy resin curing agent (phenolic resin) is within the above range, shrinkage due to thermal curing of the adhesive layer 3 can be suppressed, and excellent adhesion after thermal curing tends to be easily achieved.

[0049] The content of the epoxy resin is, for example, 10 to 40 mass %, or may be 15 to 35 mass %, or 20 to 30 mass %, based on the total amount of the adhesive composition. When the content of the epoxy resin is within the above range, sufficient thermosetting properties are obtained, and curing tends to proceed even at low temperatures.

[0050] The content of the solid epoxy resin relative to the total amount of epoxy resin is, for example, 10 to 30% by mass, or may be 12 to 28% by mass, or 15 to 25% by mass. When the content of the solid epoxy resin is within the above range, the film is not sticky during film formation, sticking to machines such as rolls can be suppressed, and a decrease in workability when producing a laminated film tends to be suppressed.

[0051] The content of the solid epoxy resin is, for example, 2 to 10 mass %, or may be 3 to 8 mass %, or 4 to 6 mass %, based on the total amount of the adhesive composition. When the content of the solid epoxy resin is within the above range, the adhesive composition tends to be non-sticky during film formation, preventing sticking to machines such as rolls, and preventing a decrease in workability when producing a laminated film.

[0052] Elastomer: The elastomer may be a thermoplastic resin, or a resin that is thermoplastic at least in an uncured state and forms a crosslinked structure after heating. The elastomer may be a (meth)acrylic copolymer having a reactive group (hereinafter, sometimes referred to as a "reactive group-containing (meth)acrylic copolymer") from the viewpoint of excellent shrinkage, heat resistance, and peelability.

[0053] When the adhesive composition contains a reactive group-containing (meth)acrylic copolymer as the elastomer, the adhesive composition may be in an embodiment that does not contain an epoxy resin, i.e., the adhesive composition may be in an embodiment that contains a reactive group-containing (meth)acrylic copolymer and a curing accelerator.

[0054] Examples of the (meth)acrylic copolymer include (meth)acrylic acid ester copolymers such as acrylic glass and acrylic rubber. The (meth)acrylic copolymer may be acrylic rubber. The acrylic rubber may be formed by copolymerizing an acrylic acid ester as a main component and a monomer selected from a (meth)acrylic acid ester and acrylonitrile.

[0055] Examples of (meth)acrylic acid esters include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, hexyl (meth)acrylate, cyclohexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, etc. Examples of (meth)acrylic acid ester copolymers include copolymers containing butyl acrylate and acrylonitrile as copolymerization components, and copolymers containing ethyl acrylate and acrylonitrile as copolymerization components.

[0056] The reactive group-containing (meth)acrylic copolymer may be a reactive group-containing (meth)acrylic copolymer containing a (meth)acrylic monomer having a reactive group as a copolymerization component. Such a reactive group-containing (meth)acrylic copolymer can be obtained by copolymerizing a monomer mixture containing the reactive group-containing (meth)acrylic monomer and the above-mentioned monomer.

[0057] From the viewpoint of improving heat resistance, examples of the reactive group include an epoxy group, a carboxyl group, a (meth)acryloyl group, a hydroxyl group, an episulfide group, etc. From the viewpoint of crosslinkability, the reactive group may be an epoxy group or a carboxyl group.

[0058] In this embodiment, the reactive group-containing (meth)acrylic copolymer may be an epoxy group-containing (meth)acrylic copolymer containing an epoxy group-containing (meth)acrylic monomer as a copolymerization component. In this case, examples of the epoxy group-containing (meth)acrylic monomer include glycidyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate glycidyl ether, and 3,4-epoxycyclohexylmethyl (meth)acrylate. From the viewpoint of heat resistance, the reactive group-containing (meth)acrylic monomer may be glycidyl (meth)acrylate.

[0059] The glass transition temperature (Tg) of the elastomer is, for example, -50 to 20°C, and may be -30 to 15°C. When the Tg of the elastomer is -50°C or higher, it is easy to prevent the adhesive layer 3 from becoming excessively soft, and excellent handleability and adhesiveness can be achieved. On the other hand, when the Tg of the elastomer is 0°C or lower, it is easy to ensure the flexibility of the adhesive layer 3, and excellent adhesive strength can be achieved. In addition, even if there are irregularities on the adherend surface, the adhesive layer 3 can easily follow the irregularities, and excellent adhesiveness can be achieved.

[0060] The Tg of an elastomer is the midpoint glass transition temperature obtained by differential scanning calorimetry (DSC). Specifically, the Tg of an elastomer is the midpoint glass transition temperature calculated by a method in accordance with JIS K7121:1987, measuring the change in calorific value under conditions of a temperature rise rate of 10°C / min and a measurement temperature of -80 to 80°C. Note that if the elastomer is a commercially available product, the value listed in the catalog or the like may be used.

[0061] The weight average molecular weight of the elastomer may be 100,000 to 2,000,000. When the weight average molecular weight is 100,000 or more, heat resistance is easily ensured. On the other hand, when the weight average molecular weight is 2,000,000 or less, deterioration in flow and adhesion is easily suppressed. The weight average molecular weight of the elastomer may be 400,000 to 1,500,000 or 500,000 to 1,200,000. The weight average molecular weight is a polystyrene-equivalent value obtained by gel permeation chromatography (GPC) using a calibration curve based on standard polystyrene.

[0062] The content of the elastomer is, for example, 20 to 40 mass %, or may be 22 to 38 mass %, or 25 to 35 mass %, based on the total amount of the adhesive composition. When the content of the elastomer is within the above range, shrinkage due to thermal curing of the adhesive layer 3 can be suppressed, and excellent adhesion after thermal curing tends to be easily achieved.

[0063] Curing accelerator The curing accelerator is a compound that generates a heterocyclic amine compound when heated. Examples of the curing accelerator include a compound that deprotects a protecting group when heated to generate a heterocyclic amine compound (hereinafter, sometimes referred to as a "first compound"), and an ionic compound that generates a heterocyclic amine compound when heated (hereinafter, sometimes referred to as a "second compound"). The first compound can be said to be a compound in which an amino group contained in the heterocycle of a heterocyclic amine compound is protected by a protecting group. Among these, the curing accelerator may be the first compound.

[0064] Adhesive compositions containing a first compound or a second compound as a curing accelerator generate a heterocyclic amine compound with curing-accelerating properties upon heating, thereby exhibiting thermosetting properties. Therefore, even if the adhesive composition is not used immediately after preparation but is stored for a certain period of time, the curing reaction of the epoxy resin is sufficiently inhibited. That is, the increase in shear viscosity of the adhesive composition over time is sufficiently inhibited, allowing the adhesive composition to remain usable for a relatively long period of time (e.g., more than two weeks) after preparation, thereby achieving a sufficiently long work life. In addition, the adhesive composition is also useful for achieving heat curing treatments at low temperatures below 100°C. That is, thermosetting resins with excellent low-temperature curing properties tend to undergo a curing reaction more easily when stored in a state mixed with a curing accelerator. However, since the above-mentioned curing accelerator exhibits its function by being deprotected by heating during use, the curing reaction of the epoxy resin is inhibited during storage. Such adhesive compositions can achieve both a long work life and low-temperature curing properties at a sufficiently high level.

[0065] Examples of heterocyclic amine compounds generated from compounds that generate heterocyclic amine compounds upon heating include compounds having a pyrrolidine ring, a piperidine ring, a piperazine ring, a morpholine ring, an oxazine ring, a quinuclidine ring, a pyrrole ring, a pyrazole ring, an imidazole ring, a pyridine ring, a pyridazine ring, a pyrimidine ring, a pyrazine ring, an oxazole ring, a thiazole ring, etc. In these rings, some of the hydrogen atoms directly bonded to the carbon atoms constituting the ring may be substituted with a substituent. The substituent is a group commonly used in the field of organic chemistry. Examples of the substituent include a halogen atom, a hydroxy group, an amino group, a sulfonic acid group, a nitro group, a cyano group, an alkyl group, an aryl group, an alkoxy group, a substituted amino group, etc. Among these, the heterocyclic amine compound may be, for example, an aromatic heterocyclic amine compound, and may be, for example, a compound having a pyrazole ring or a compound having an imidazole ring.

[0066] The protecting group in the first compound is a protecting group that protects an amino group contained in the heterocycle of the heterocyclic amine compound. The protecting group may be a group that is commonly used as a protecting group for an amino group in the field of organic chemistry. Examples of the protecting group include a tosyl group, a methoxymethyl group, a benzyloxymethyl group, an allyl group, a triisopropylsilyl group, a benzyl group, a methoxycarbonyl group, a p-methoxybenzyl group, and a p-methoxyphenyl group.

[0067] The protecting group in the first compound may, in one embodiment, be a substituted amide group. A substituted amide group is, for example, —C(O)N(R １ ) (R ２ ) represented by the group (R １ represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms in which some of the hydrogen atoms directly bonded to the carbon atom may be substituted with (meth)acryloyloxy groups, R ２ represents an alkyl group having 1 to 10 carbon atoms in which some of the hydrogen atoms directly bonded to the carbon atom may be substituted with (meth)acryloyloxy groups.

[0068] Examples of the alkyl group having 1 to 10 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an isopropyl group, and an isobutyl group.

[0069] Specific examples of the first compound include Karenz MOI-BP (trade name, manufactured by Resonac Corporation, 2-[(3,5-dimethylpyrazolyl)carbonylamino]ethyl methacrylate, "Karenz" is a registered trademark), Karenz AOI-BP (trade name, manufactured by Resonac Corporation, 2-[(3,5-dimethylpyrazolyl)carbonylamino]ethyl acrylate), and the like.

[0070] Examples of the second compound include pyrazonium salt compounds, imidazolium salt compounds, etc. A specific example of the second compound is EMZ-K (trade name, manufactured by Hokko Sangyo Co., Ltd., 2-ethyl-4-methylimidazolium tetraphenylborate, "EMZ-K" is a registered trademark).

[0071] The content of the curing accelerator is, for example, 0.1 to 20 mass %, or may be 1 to 18 mass %, or 3 to 15 mass %, based on the total amount of the adhesive composition. When the content of the curing accelerator is within the above range, the effects of the present disclosure tend to be easily and satisfactorily exhibited.

[0072] Inorganic Filler The inorganic filler can be selected depending on the desired function. Examples of inorganic fillers include metal (conductive) fillers such as silver powder, gold powder, and copper powder; and non-metal (insulating) fillers such as silica, alumina, boron nitride, titania, glass, iron oxide, and ceramic. The inorganic filler may be, for example, a silica filler.

[0073] The surface of the inorganic filler may have an organic group. By modifying the surface of the inorganic filler with an organic group, dispersibility in an organic solvent can be improved when preparing a varnish for forming the adhesive layer 3. In addition, shrinkage associated with thermal curing of the adhesive layer 3 can be suppressed, and the adhesive layer 3 tends to easily achieve both a high elastic modulus and excellent releasability. An inorganic filler having an organic group on its surface can be obtained, for example, by mixing a silane coupling agent represented by the following formula (B-1) with the inorganic filler and stirring at a temperature of 30°C or higher. Whether the surface of the inorganic filler has been modified with an organic group can be confirmed by ultraviolet-visible spectroscopy, infrared absorption spectroscopy, X-ray photoelectron spectroscopy, or the like.

[0074]

[0075] In formula (B-1), X represents an organic group selected from the group consisting of a phenyl group, a glycidoxy group, a (meth)acryloyloxy group, a mercapto group, an amino group, a vinyl group, an isocyanate group, and a methacryloxy group; s represents 0 or an integer of 1 to 10; R １１ , R １２ , and R １３ each independently represents an alkyl group having 1 to 10 carbon atoms.

[0076] The alkyl group having 1 to 10 carbon atoms may be the same as the alkyl group having 1 to 10 carbon atoms exemplified above for the substituted amide group.

[0077] From the viewpoint of availability, the alkyl group having 1 to 10 carbon atoms may be a group selected from the group consisting of a methyl group, an ethyl group, and a pentyl group. From the viewpoint of heat resistance, X may be a group selected from the group consisting of an amino group, a glycidoxy group, a mercapto group, and an isocyanate group, and may be a glycidoxy group or a mercapto group.

[0078] s may be an integer of 0 to 5, or may be an integer of 0 to 4, from the viewpoint of suppressing the fluidity of the film at high temperatures and improving the heat resistance.

[0079] The content of the inorganic filler is 1 to 25% by mass, based on the total amount of the adhesive composition. When the content of the inorganic filler is 25% by mass or less, based on the total amount of the adhesive composition, the adhesive strength with a resin member or the like tends to be sufficient. When the content of the inorganic filler is 1% by mass or more, based on the total amount of the adhesive composition, the adhesive strength of the adhesive composition tends to be prevented from becoming too high, which tends to prevent a decrease in workability. The content of the inorganic filler may be 2% by mass or more, 3% by mass or more, 5% by mass or more, or 7% by mass or more, based on the total amount of the adhesive composition, and may be 20% by mass or less, 15% by mass or less, 12% by mass or less, or 10% by mass or less.

[0080] The adhesive composition may further contain other components. Examples of the other components include coupling agents such as silane coupling agents, and organic fillers such as carbon, rubber-based fillers, silicone-based fine particles, polyamide fine particles, and polyimide fine particles. The content of the other components may be 0 to 30 mass % based on the total amount of the adhesive composition.

[0081] Organic Solvent The adhesive composition may be diluted with an organic solvent as needed, or may be used as an adhesive varnish. The organic solvent is not particularly limited, but can be determined taking into account the boiling point and volatility during film formation. Examples of organic solvents include relatively low-boiling point solvents such as methanol, ethanol, 2-methoxyethanol, 2-ethoxyethanol, 2-butoxyethanol, methyl ethyl ketone, acetone, methyl isobutyl ketone, toluene, and xylene; and relatively high-boiling point solvents such as dimethylacetamide, dimethylformamide, N-methyl-2-pyrrolidone, and cyclohexanone. Solvents with relatively low boiling points have the advantage that they do not easily promote film hardening during film formation. Solvents with relatively high boiling points have the advantage of improving film formability.

[0082] The thickness of the adhesive layer 3 may be appropriately selected within a range that does not impair workability, and may be, for example, 1 to 200 μm, 5 to 150 μm, or 10 to 150 μm. When the thickness of the adhesive layer 3 is 1 μm or more, sufficient adhesion is easily ensured, while when the thickness is 200 μm or less, the adhesive composition constituting the adhesive layer 3 tends to be easily prevented from spilling out from the base film 1 or the cover film 5.

[0083] <Cover Film> There are no particular restrictions on the cover film 5, as long as it can be easily peeled from the adhesive layer 3. Examples of the cover film 5 include polyester films such as polyethylene terephthalate film; polyolefin films such as homocopolymers or copolymers, or mixtures thereof, of polytetrafluoroethylene film, polyethylene film, polypropylene film, polymethylpentene film, polyvinyl acetate film, poly-4-methylpentene-1, ethylene-vinyl acetate copolymer, and ethylene-ethyl acrylate copolymer; and plastic films such as polyvinyl chloride film and polyimide film. The cover film 5 may have a single-layer structure or a multi-layer structure.

[0084] When the cover film 5 has a multilayer structure, it may be an adhesive film, specifically, an adhesive film for dicing (manufactured by Maxell, Ltd.). The adhesive film may have an adhesive layer and a base layer. In this case, the adhesive layer may be configured to be in contact with the adhesive layer 3. The adhesive layer may be a photocurable adhesive layer or a non-photocurable adhesive layer, and the base layer may be the above-mentioned plastic film or the like.

[0085] The adhesion strength between the adhesive layer 3 and the cover film 5 is, for example, 70 N / m or less, and may be 50 N / m or less, or 20 N / m or less. In particular, when the adhesive layer 3 is made of an adhesive composition, it is preferable that the adhesion strength of the cover film 5 to the adhesive layer 3 be within the above range after heat treatment at 75°C for 1 second. When this adhesion strength is 70 N / m or less, the adhesive layer 3 covered with the cover film 5 can be temporarily pressure-bonded to an adherend (e.g., a substrate) at 75°C for 0.5 seconds, and then the cover film 5 can be easily peeled from the semi-cured adhesive layer 3 with adhesive tape or the like. The adhesion strength of the cover film 5 to the adhesive layer 3 refers to the 90° peel strength, and specifically refers to the peel strength measured when a sample is prepared in which a cover film of the same width is placed on a 20 mm wide adhesive layer made of the same composition as the adhesive layer 3, and the cover film is peeled from the adhesive layer at a 90° angle at a peeling rate of 50 mm / min. When the cover film 5 is an adhesive film having a photocurable adhesive layer, the adhesive strength may be a value after light irradiation.

[0086] The thickness of the cover film 5 may be appropriately selected within a range that does not impair workability, and may be, for example, 10 to 200 μm, 10 to 180 μm, or 15 to 140 μm. These thickness ranges are practically acceptable and economically effective.

[0087] [Method of Manufacturing Connection Body (Semiconductor Module)] A method of manufacturing the module 50B (connection body) shown in FIG. 3 using the punched product 20 will be described. FIG. 6 is a cross-sectional view schematically showing how the adhesive piece 3p and the cover film 5p covering it are picked up from the base film 1. With a certain tension applied to the punched product 20, the surface of the punched product 20 facing the base film 1 is brought into contact with a wedge-shaped member 60, and the punched product 20 is moved in the direction of the arrow shown in FIG. 6. As a result, as shown in FIG. 6, the adhesive piece 3p and the front of the cover film 5p are raised above the base film 1. In this state, the adhesive piece 3p and the cover film 5p are picked up, for example, by a pickup device 65 having suction force.

[0088] Next, the adhesive piece 3p covered with the cover film 5p is placed on the surface 12a of the printed circuit board 12 (see FIG. 7). Thereafter, the adhesive piece 3p is pre-pressurized to the printed circuit board 12. Pre-pressurization can be performed, for example, at a temperature of 60 to 85°C and a pressure of 0.1 to 2 MPa for 0.1 to 10 seconds. The pre-pressurization semi-cures the adhesive piece 3p, thereby improving its adhesive strength to the surface 12a. Thereafter, the cover film 5p is peeled off from the adhesive piece 3p using adhesive tape or the like. This exposes the surface F1 of the adhesive piece 3p.

[0089] The bonding of the tip 15a of the FPC board 15 to the printed circuit board 12 includes a step of pressing the tip 15a against the adhesive piece 3p and then a step of curing the adhesive piece 3p by heating. That is, first, the tip 15a of the FPC board 15 is placed on the upper surface 3f of the adhesive piece 3p, and then the tip 15a is pressed against the adhesive piece 3p. This results in a laminate including the printed circuit board 12, the FPC board 15, and the adhesive piece 3p (step (A)). The pressing can be performed, for example, at a temperature of 60 to 85°C and a pressure of 0.1 to 3 MPa for 0.1 to 10 seconds.

[0090] Next, the adhesive pieces 3p are cured. The curing can be carried out, for example, at a temperature of 90 to 110°C for 30 to 240 minutes. As a result, the adhesive pieces 3p become adhesive pieces 3c composed of a cured product of the adhesive composition, and the module 50A shown in FIG. 2 is obtained (step (B)). Note that, from the viewpoint of the heat resistance of the components that make up the module 50A, the heating conditions in the above conditions 1 and 2 are set to 95°C for 3 hours. The relatively low temperature to which the module 50A is heated has the advantage of broadening the range of material options.

[0091] Wire bonding is performed on the module 50A (step (C)). This results in the module 50B shown in FIG. 3. The semiconductor module is then completed through processes such as protecting the wires W1 and W2 of the module 50B with a resin material and heating the adhesive piece 3c to promote a curing reaction. When manufacturing a connection body using this adhesive piece, steps (A), (B), and (C) can be performed in sequence.

[0092] Although the embodiments of the present disclosure have been described in detail above, the present disclosure is not limited to the above embodiments. For example, in the above embodiments, an example was given of a case where the adhesive piece 3p made of the adhesive composition was prepared in advance by die cutting, but the adhesive layer may also be formed by preparing a coating liquid containing the adhesive composition and coating this on the surface of the printed circuit board 12.

[0093] The present disclosure will be specifically described below using examples, but the present disclosure is not limited to these examples.

[0094] Examples 1 to 3 [Production of Laminated Film] <Material Preparation> The following materials were prepared to prepare the adhesive varnishes of the examples. (1) Epoxy Resin EXA-830CRP (trade name, manufactured by DIC Corporation, bisphenol F type epoxy resin, epoxy equivalent: 160 g / eq, liquid at 25°C) N-500P-10 (trade name, manufactured by DIC Corporation, cresol novolac type epoxy resin, epoxy equivalent: 204 g / eq, solid at 25°C) (2) Epoxy Resin Curing Agent MEH-7800-4S (trade name, manufactured by Meiwa Kasei Co., Ltd. (now UBE Corporation), xylylene type phenolic resin, hydroxyl group equivalent: 170 g / eq) (3) Elastomer SG-P3 Solvent Modified Product (trade name, manufactured by Nagase ChemteX Corporation, acrylic resin, weight average molecular weight: 800,000, Tg: 12°C) (4) Curing Accelerator Karenz MOI-BP (trade name, manufactured by Resonac Corporation, 2-[(3,5-dimethylpyrazolyl)carbonylamino]ethyl methacrylate, "Karenz" is a registered trademark) (5) Inorganic filler SC-2050-HLG (trade name, manufactured by Admatechs Corporation, surface-treated filler) (6) Solvent Cyclohexanone

[0095] An adhesive varnish was obtained by mixing the materials and solvent shown in Table 1 and vacuum degassing. This adhesive varnish was applied to a 38 μm thick surface-release-treated PET film as a base film. After a drying process, a 25 μm thick film adhesive (adhesive layer) was formed on one side of the PET film, and a dicing adhesive film (manufactured by Maxell, Ltd.) was attached to the surface of the film adhesive as a cover film, thereby obtaining laminate films of Examples 1 to 3, which comprised a base film, adhesive layer, and cover film. Multiple laminate films were prepared.

[0096] [Evaluation of Laminated Film] <Measurement of Reaction Rate> The reaction rate of the film adhesive was measured using the following method. Specifically, 10 mg of the film adhesive was weighed into an aluminum pan (manufactured by Epolead Services Co., Ltd.), an aluminum lid was placed on top, and the evaluation sample was sealed in the sample pan using a crimper. Using a differential scanning calorimeter (Thermo plus DSC8235E, manufactured by Rigaku Corporation), DSC was measured under a nitrogen atmosphere at a heating rate of 10°C / min over a measurement temperature range of 30 to 300°C. A partial area analysis method was used to analyze the calorific value. By instructing analysis in the temperature range of 50 to 200°C of the DSC curve, a baseline was specified for the analysis temperature range, and the total calorific value (unit: J / g) was calculated by integrating the peak area. This was designated the initial calorific value C1.

[0097] Next, the film-like adhesive (initial sample) was placed in an oven set to 95°C and heat-treated for 3 hours. Using the sample after heat treatment, the calorific value (unit: J / g) from 50 to 200°C was calculated using the same procedure as before heat treatment, as described above, and this was designated as the calorific value C2 after heat treatment. Using the two obtained values ​​of calorific value C1 and calorific value C2, the reaction rate was calculated using the following formula. The results are shown in Table 1. Reaction rate (%) = (C1 - C2) / C1 x 100

[0098] <Measurement of Shear Viscosity (Melt Viscosity)> The shear viscosity of the film adhesive (in a B-stage state before heating) at 95°C was measured using the following method. Specifically, multiple 25 μm thick film adhesives were laminated to a thickness of approximately 300 μm, and this laminate was punched out with a φ9 mm punch to prepare a sample. An 8 mm diameter circular aluminum plate was installed in an ARES dynamic viscoelasticity analyzer (manufactured by TA Instruments), and the sample was placed on the plate. The shear viscosity at 95°C was then measured while applying a 5% strain at 35°C and increasing the temperature to 100°C at a rate of 5°C / min. The frequency was kept constant at 1 Hz, the initial load was maintained at 300 g, and the axial force was maintained at 100 g. The results are shown in Table 1.

[0099] <Measurement of Storage Modulus> After the film adhesive was heated at 95°C for 3 hours, the storage modulus of the film adhesive was measured using the following method. Specifically, multiple 25 μm thick film adhesives were laminated to a thickness of approximately 300 μm, which was then cut into a size of 4 mm wide x 33 mm long and cured at 95°C for 3 hours to obtain a sample for measurement. The sample was placed in a dynamic viscoelasticity apparatus (product name: Rheogel E-4000, manufactured by UBM Corporation) with a chuck distance of 20 mm, and a tensile load was applied, and measurements were performed at a frequency of 10 Hz and a heating rate of 3°C / min to measure the storage modulus at 95°C and 35°C. The results are shown in Table 1.

[0100] <Measurement of die shear strength> The die shear strength of the film adhesive after curing was measured using the following method. A dicing tape (manufactured by Resonac Co., Ltd., thickness 110 μm) having a base film and an adhesive layer was prepared, and the prepared film adhesive (thickness 25 μm) was attached to it to prepare a dicing and die bonding integrated film including a dicing tape and an adhesive layer made of the film adhesive provided on the adhesive layer of the dicing tape. Next, a semiconductor wafer (thickness 400 μm) was laminated on the adhesive layer side of the dicing and die bonding integrated film at a stage temperature of 70° C. to prepare a dicing sample.

[0101] The prepared diced sample was cut using a fully automatic dicer DFD-6361 (manufactured by Disco Corporation). Cutting was performed using a step cut method using two blades, and dicing blades ZH05-SD2000-N1-FF and ZH05-SD2000-N1-EE (both manufactured by Disco Corporation) were used. The cutting conditions were a blade rotation speed of 4000 rpm, a cutting speed of 50 mm / sec, and a chip size of 5 mm x 5 mm. The first cutting step was performed so that approximately 200 μm of the semiconductor wafer remained, and then the second cutting step was performed so that approximately 20 μm of cuts were made in the dicing tape.

[0102] Next, a semiconductor chip formed from the semiconductor wafer was picked up using a pickup collet. The pickup was performed by pushing up using a single central pin. The pickup conditions were a push-up speed of 20 mm / s and a push-up height of 450 μm. In this way, a semiconductor chip with an adhesive piece was obtained.

[0103] The die shear strength after curing was measured using the resulting semiconductor chip with adhesive strip. The semiconductor chip was thermocompression bonded onto solder resist (Taiyo Holdings Co., Ltd., product name: AUS-308). The compression bonding conditions were a temperature of 95°C, a time of 1 second, and a pressure of 0.6 MPa. The sample obtained by compression bonding was then placed in a dryer and cured by heating at 95°C for 3 hours. Next, the cured sample was subjected to a universal bond tester (manufactured by Nordson Advanced Technologies Co., Ltd., product name: Series 4000) to measure the die shear strength after curing between the semiconductor chip and solder resist. The measurement conditions were 6.7 MPa / sec, and a stage temperature of 95°C. The results are shown in Table 1.

[0104]

[0105] <Evaluation of Changes in Shear Viscosity Over Time> The shear viscosity at 95°C of the film adhesive of Example 1 was measured every week. Specifically, eight test pieces of a predetermined size were cut out of the film adhesive. These were laminated using a rubber roll on a hot plate at 70°C to prepare a 300 μm thick laminate. This laminate was punched out with a φ9 mm punch to prepare a sample. The sample was attached to the measurement jig of a rotational viscoelasticity measuring device (manufactured by TA Instruments Japan, product name: ARES-RDA). The gap of the measurement jig was adjusted so that the load applied to the sample at this point was 10 to 15 g. The viscoelasticity of the sample was then measured under the following conditions. Measurements were continued until two weeks had elapsed, and the sample was left at room temperature (25°C) until measurements were performed. The results are shown in Table 2. Measurement conditions: Disc plate: Aluminum, circular (8 mm diameter) Measurement frequency: 1 Hz Heating rate: 5°C / min Distortion: 5% Measurement temperature: 35-100°C Initial load: 300 g

[0106]

[0107] As shown in Table 1, it was found that the curing reaction of the adhesive compositions of Examples 1 to 3 proceeded sufficiently under low-temperature conditions of 100°C or less. Furthermore, as shown in Table 2, no increase in shear viscosity was observed for the adhesive composition of Example 1 even after two weeks. It is presumed that a similar trend is observed for the adhesive compositions of Examples 2 and 3, which contain a lower amount of curing accelerator than Example 1. From the above results, it was confirmed that the thermosetting adhesive composition of the present disclosure allows the curing reaction to proceed sufficiently under low-temperature conditions, and furthermore, it is possible to sufficiently suppress an increase in shear viscosity over time.

[0108] 1...base film, 3...adhesive layer, 3c, 3p...adhesive pieces, 5, 5p...cover film, 10...laminated film, 12...printed circuit board, 15...FPC board, 15a...tip portion, 20...punched product, 50A, 50B...module (connector), C...semiconductor chip, W1, W2...wire

Claims

1. A thermosetting adhesive composition comprising an epoxy resin, an elastomer, and a curing accelerator, the curing accelerator being a compound that generates a heterocyclic amine compound when heated.

2. The thermosetting adhesive composition according to claim 1, wherein the heterocyclic amine compound is an aromatic heterocyclic amine compound.

3. The thermosetting adhesive composition according to claim 1, wherein the heterocyclic amine compound is a compound having a pyrazole ring or a compound having an imidazole ring.

4. The thermosetting adhesive composition according to any one of claims 1 to 3, wherein the curing accelerator is a compound that deprotects a protecting group by heating to generate a heterocyclic amine compound.

5. The thermosetting adhesive composition according to claim 4, wherein the protecting group is a substituted amide group.

6. The thermosetting adhesive composition according to any one of claims 1 to 3, which has a reaction rate of 50% or more after being heated at 95°C for 3 hours.

7. The thermosetting adhesive composition according to any one of claims 1 to 3, further comprising an epoxy resin curing agent, wherein the epoxy resin curing agent is a phenolic resin.

8. The thermosetting adhesive composition according to any one of claims 1 to 3, further comprising an inorganic filler.

9. The thermosetting adhesive composition according to any one of claims 1 to 3, having a shear viscosity at 95°C of 100 to 12,000 Pa·s.

10. A laminated film comprising: a base film; and an adhesive layer provided on a surface of the base film, the adhesive layer being composed of the thermosetting adhesive composition according to any one of claims 1 to 3.

11. A method for producing a connection, comprising the steps of: (A) preparing a laminate comprising a first circuit member, a second circuit member, and an adhesive layer disposed between the first circuit member and the second circuit member; (B) heating the laminate at 90 to 110°C for 30 to 240 minutes; and (C) wire bonding the first circuit member and the second circuit member, in this order; wherein the adhesive layer is composed of a thermosetting adhesive composition according to any one of claims 1 to 3.

12. The method for producing a connection body according to claim 11, wherein the first circuit member is one selected from the group consisting of a printed circuit board and a semiconductor chip, and the second circuit member is a flexible printed circuit board.

13. A connection comprising: a first circuit member; a second circuit member; and an adhesive layer disposed between the first circuit member and the second circuit member, wherein the adhesive layer is formed from a cured product of the thermosetting adhesive composition according to any one of claims 1 to 3.

Images