Thermosetting adhesive composition, ultraviolet-irradiated product of same, laminated film, and method for producing connection body

Abstract

Disclosed is a thermosetting adhesive composition comprising: a thermosetting resin; a thermoplastic resin; an inorganic filler; and a photofragmenting compound that undergoes fragmentation upon irradiation with ultraviolet rays and that generates an amine compound. The thermosetting resin cures when heated in the presence of an amine compound. After irradiation with ultraviolet rays with an illuminance of 80 mW / cm2 and a cumulative amount of light of 600 mJ / cm2, shear viscosity at 75°C is 100-6000 Pa･s. After irradiation with ultraviolet rays with an illuminance of 80 mW / cm2 and a cumulative amount of light of 600 mJ / cm2 and then heating at 75°C for three hours, the storage modulus at 35°C is 100-4000 MPa.

Description

Thermosetting adhesive composition and ultraviolet irradiated product thereof, laminated film, and connection body and method for producing the same

[0001] The present disclosure relates to a thermosetting adhesive composition and an ultraviolet-irradiated product thereof, a laminated film, and 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 involve dicing or die bonding are being commercialized. Accordingly, different performance is being required for 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 85°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. However, it was discovered that voids may occur at the interface between the film-like adhesive and the component when a die-bonding process is performed using a film-like adhesive composed of the thermosetting adhesive composition. Since voids at the interface between the film-like adhesive and the component can result in a decrease in adhesive strength, it is necessary to suppress the occurrence of voids.

[0005] The main object of the present disclosure is to provide a thermosetting adhesive composition that can suppress the occurrence of voids at the interface between a film-like adhesive and a component when a die bonding process is carried out using a film-like adhesive made of the thermosetting adhesive composition.

[0006] In order to solve the above-mentioned problems, the present inventors conducted research on thermosetting adhesive compositions, focusing mainly on the shear viscosity at 75°C, which is a possible compression bonding temperature. They found that when the shear viscosity at 75°C is within a predetermined range and the storage modulus after curing at 35°C is within a predetermined range, the occurrence of voids can be suppressed during the die bonding process, and thus completed the invention of the present disclosure.

[0007] The present disclosure provides a thermosetting adhesive composition according to [1] to [7], a product obtained by irradiating the thermosetting adhesive composition according to [8] with ultraviolet light, a laminated film according to [9], a method for producing a connection body according to

[10] to

[13] , and a connection body according to

[14] and

[15] . [1] A thermosetting adhesive composition containing a thermosetting resin, a thermoplastic resin, an inorganic filler, and a photocleavable compound that is cleaved by irradiation with ultraviolet light to generate an amine compound, wherein the thermosetting resin is a resin that is cured by heating in the presence of the amine compound, and the illuminance is 80 mW / cm. ２ and an integrated light intensity of 600 mJ / cm ２ After being irradiated with ultraviolet light under the conditions of ２ and an integrated light intensity of 600 mJ / cm ２ [2] A thermosetting adhesive composition having a storage modulus of 100 to 4000 MPa at 35°C after being irradiated with ultraviolet light under the conditions of

[0041] and then heated at 75°C for 3 hours. ２ and an integrated light intensity of 600 mJ / cm ２ [1] The thermosetting adhesive composition according to [1], wherein the thermosetting adhesive composition has a storage modulus of 10 MPa or more after being irradiated with ultraviolet light under the conditions of [1] to [2] and then heated at 75°C for 3 hours. [3] The thermosetting adhesive composition according to [1] or [2], wherein the content of the thermoplastic resin is 5 to 35 mass% based on the total amount of the thermosetting adhesive composition. [4] The thermosetting adhesive composition according to any of [1] to [3], wherein the content of the inorganic filler is 45 mass% or less based on the total amount of the thermosetting adhesive composition. [5] The thermosetting adhesive composition according to any of [1] to [4], wherein the photocleavable compound is a compound having an α-aminoacetophenone skeleton. [6] The thermosetting adhesive composition according to any of [1] to [5], wherein the reaction rate calculated by substituting the calorific values ​​C1 and C2 in the temperature range of 50 to 200°C, respectively, obtained from a DSC curve obtained by differential scanning calorimetry at a heating rate of 10°C / min, into the following formula, is 45% or more. Reaction rate (%) = (C1 - C2) / C1 × 100 [wherein C1 is the illuminance of the thermosetting adhesive composition at 80 mW / cm２ and an integrated light intensity of 600 mJ / cm ２ C2 indicates the amount of heat generated by the resin composition after ultraviolet irradiation under the conditions of an illuminance of 80 mW / cm for the thermosetting adhesive composition. ２ and an integrated light intensity of 600 mJ / cm ２and further heating at 75°C for 3 hours.] [7] The thermosetting adhesive composition according to any one of [1] to [6], wherein the glass transition temperature of the thermoplastic resin is -50 to 20°C. [8] An ultraviolet-irradiated product of a thermosetting adhesive composition obtained by irradiating the thermosetting adhesive composition according to any one of [1] to [7] with ultraviolet light, the thermosetting adhesive composition comprising the thermosetting resin, the thermoplastic resin, the inorganic filler, and the amine compound, the thermosetting adhesive composition having a shear viscosity of 100 to 6000 Pa s at 75°C, and a storage modulus of 100 to 4000 MPa at 35°C after heating at 75°C for 3 hours. [9] 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 [7].

[10] A method for producing a connection body, 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 65 to 85°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 [7], and the step (B) includes a step of irradiating the adhesive layer with ultraviolet light.

[11] A method for producing a connection body according to

[10] , 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.

[12] 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 and second circuit members; (B) heating the laminate at 65 to 85°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 an ultraviolet-irradiated product of the thermosetting adhesive composition described in [8].

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

[12] , 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.

[14] A connection body comprising a first circuit member, a second circuit member, and an adhesive layer disposed between the first and second circuit members, the adhesive layer being composed of a cured product of the thermosetting adhesive composition according to any one of [1] to [7].

[15] A connection body comprising a first circuit member, a second circuit member, and an adhesive layer disposed between the first and second circuit members, the adhesive layer being composed of a cured product of an ultraviolet-irradiated product of the thermosetting adhesive composition according to [8].

[0008] According to the present disclosure, a thermosetting adhesive composition is provided that can suppress the generation of voids at the interface between a film-like adhesive and a member when a die bonding process is performed using a film-like adhesive comprising the thermosetting adhesive composition. The present disclosure also provides a product of such a thermosetting adhesive composition irradiated with ultraviolet light. The present disclosure also provides an adhesive film having an adhesive layer composed of such a thermosetting adhesive composition or a product thereof irradiated with ultraviolet light. The present disclosure also provides a connection body using such a thermosetting adhesive composition or a product thereof irradiated with ultraviolet light, and a method for manufacturing 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 composed of a thermosetting adhesive composition (hereinafter sometimes simply referred to as the "adhesive composition") or a UV-irradiated version thereof. The adhesive composition contains a thermosetting resin, a thermoplastic resin, an inorganic filler, and a photocleavable compound (hereinafter sometimes simply referred to as the "photocleavable compound") that is cleaved by UV irradiation to generate an amine compound. The UV-irradiated version of the adhesive composition contains a thermosetting resin, a thermoplastic resin, an inorganic filler, and an amine compound generated from the photocleavable compound by UV irradiation. The UV-irradiated version of the adhesive composition may be an adhesive composition obtained by irradiating an adhesive composition with UV rays. A thermosetting resin is a resin that cures when heated in the presence of an amine compound. The amine compound may be a component that acts as, for example, a curing agent, a curing accelerator, or the like. The adhesive piece 3c (adhesive layer) is composed of a cured version of the adhesive composition or a cured version of the UV-irradiated version of the adhesive composition.

[0024] Illuminance 80mW / cm ２ and an integrated light intensity of 600 mJ / cm ２ After irradiation with ultraviolet light under the above conditions, the shear viscosity (melt viscosity) of the adhesive composition at 75°C is 100 to 6000 Pa·s, and may be 500 Pa·s or more, 1000 Pa·s or more, 2000 Pa·s or more, or 3000 Pa·s or more, or 5500 Pa·s or less, or 5000 Pa·s or less. Having a shear viscosity at 75°C within this range tends to enable the adhesive composition to be positioned without gaps between the tip end 15a of the FPC board 15 and the member to be bonded (printed circuit board 12), even if the tip end 15a has irregularities. Furthermore, having a shear viscosity at 75°C within this range tends to enable the generation of voids at the interface between the film adhesive and the member to be bonded after thermocompression bonding with a force of 30 N or more for 3 seconds or more on a 75°C stage.

[0025] The shear viscosity of the adhesive composition at 75°C can be measured, for example, by the following procedure. First, a plurality of film-like adhesives each having a thickness of 25 µm are prepared from the adhesive composition. Then, the film-like adhesives are exposed to an illuminance of 80 mW / cm. ２ and an integrated light intensity of 600 mJ / cm２ The film-like adhesive is then irradiated with ultraviolet light under the conditions of . Next, multiple layers of the film-like adhesive 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 the dynamic viscoelasticity apparatus, and the measurement sample is set thereon. Next, measurements are performed while applying a 5% strain at 35°C and raising the temperature to 100°C at a heating rate of 5°C / min, and the viscosity at 75°C is determined, thereby measuring the shear viscosity at 75°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 75°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 thermoplastic resin (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. Method 4: A thermoplastic resin with a relatively low glass transition temperature (Tg) is used.

[0027] Illuminance 80mW / cm ２ and an integrated light intensity of 600 mJ / cm ２ After being irradiated with ultraviolet light under the conditions above and further heated at 75°C for 3 hours, the storage modulus at 35°C is 100 to 4000 MPa, and may be 300 MPa or more, 500 MPa or more, 700 MPa or more, or 900 MPa or more, or 3800 MPa or less, 3500 MPa or less, 3200 MPa or less, 3000 MPa or less, or 2800 MPa or less. When the storage modulus at 35°C is within the above range, internal stress in the adhesive piece 3c is easily alleviated, and warping of the module 50B can be suppressed.

[0028] The following methods can be considered to adjust the storage modulus at 35°C to fall within a predetermined range: Method 1: The amount of thermoplastic resin (e.g., acrylic rubber) contained in the adhesive composition is relatively large. Method 2: A thermoplastic resin with a relatively low glass transition temperature (Tg) is used. Method 3: A thermosetting resin with a flexible skeleton is used.

[0029] The photocleavable compound may be a compound having an α-aminoacetophenone skeleton. For example, when irradiated with ultraviolet light, the following compound having an α-aminoacetophenone skeleton undergoes α-cleavage and deblocking to generate an amine compound having a radical (carboradical) as one component. The photocleavable compound may be a compound that is cleaved by irradiation with ultraviolet light to generate an amine compound having a radical (carboradical).

[0030]

[0031]

[0032] The adhesive composition may satisfy, for example, the following condition 1: Condition 1: Illuminance of 80 mW / cm ２ and an integrated light intensity of 600 mJ / cm ２ After being irradiated with ultraviolet light under the conditions of (1) above and then heated at 75°C for 3 hours, the storage modulus at 75°C is 10 MPa or more.

[0033] 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 a phenolic resin together with an epoxy resin as the thermosetting 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.

[0034] 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 10 MPa or more, 15 MPa or more, or 20 MPa or more. The storage modulus according to condition 1 may be, for example, 1000 MPa or less, 900 MPa or less, or 800 MPa or less. The higher the storage modulus according to condition 1, the easier it tends to be to perform wire bonding.

[0035] The storage modulus at 35°C and 75°C can be measured, for example, by the following procedure. First, a plurality of film-like adhesives each having a thickness of 25 µm are prepared from the adhesive composition. Then, the film-like adhesives are exposed to an illuminance of 80 mW / cm. ２ and an integrated light intensity of 600 mJ / cm ２ The film-like adhesive is then irradiated with ultraviolet light under the conditions of 10 Hz and 3°C / min. Next, multiple layers of the film-like adhesive after ultraviolet light irradiation are laminated to a thickness of approximately 300 μm, which are then cut into a size of 4 mm wide x 33 mm, and heated at 75°C for 3 hours to prepare a measurement sample. The prepared measurement sample is set 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 35°C and 75°C.

[0036] It is preferable that the adhesive composition undergoes a curing reaction to some extent after heat treatment at 75°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 substituting the calorific values ​​C1 and C2, respectively, determined from DSC curves obtained by differential scanning calorimetry at a temperature rise rate of 10°C / min, into the following formula is, for example, 45% or more, or may be 50% or more, 55% or more, or 60% or more. Reaction rate (%) = (C1 - C2) / C1 × 100

[0037] The heat generation amount C1 is determined by the heat-curable adhesive composition at an illuminance of 80 mW / cm ２ and an integrated light intensity of 600 mJ / cm ２The calorific value C2 is the calorific value (unit: J / g) of the resin composition after it has been irradiated with ultraviolet light under the conditions of an illuminance of 80 mW / cm for the thermosetting adhesive composition. ２ and an integrated light intensity of 600 mJ / cm ２ The calorific value (unit: J / g) is measured for a resin composition after it has been irradiated with ultraviolet light under the conditions of (1) and further heated at 75°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 the measurement is 50 to 200°C. A reaction rate of 45% or more can suppress deterioration over time after the manufacturing process, and tends to result in excellent reliability.

[0038] 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.

[0039] <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.

[0040] 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.

[0041] 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.

[0042] <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 a thermosetting resin, a thermoplastic resin, an inorganic filler, and a photocleavable compound.

[0043] Thermosetting resins are resins that are cured by heating in the presence of an amine compound. The thermosetting resin may be, for example, an epoxy resin. The thermosetting resin may also be a combination of an epoxy resin and an epoxy resin curing agent.

[0044] Examples of epoxy resins include bisphenol A epoxy resins, bisphenol F epoxy resins, bisphenol S epoxy resins, alicyclic epoxy resins, aliphatic linear 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.

[0045] 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.

[0046] 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).

[0047] 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.

[0048] The epoxy resin curing agent may be a commonly used known 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.

[0049] 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.

[0050] The content of the thermosetting resin (e.g., the total of the epoxy resin and the phenolic resin) is, for example, 35 to 75 mass %, or may be 40 to 70 mass %, or 45 to 65 mass %, based on the total amount of the adhesive composition. When the content of the thermosetting 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.

[0051] The content of the epoxy resin is, for example, 15 to 45 mass %, or may be 20 to 40 mass %, or 25 to 35 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.

[0052] The content of the solid epoxy resin relative to the total amount of epoxy resin may be, for example, 10% by mass or more, 12% by mass or more, or 15% by mass or more, and may be 60% by mass or less, 55% by mass or less, 50% by mass or less, 45% by mass or less, 40% by mass or less, 35% by mass or less, or 30% by mass or less. 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.

[0053] The content of the solid epoxy resin may be, for example, 4% by mass or more, 4.5% by mass or more, or 5% by mass or more, and 25% by mass or less, 20% by mass or less, 18% by mass or less, 15% by mass or less, 12% by mass or less, 10% by mass or less, or 8% by mass or less, 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.

[0054] The content of the phenolic resin is, for example, 5 to 45 mass %, or may be 10 to 40 mass %, or 15 to 35 mass %, based on the total amount of the adhesive composition.

[0055] Thermoplastic Resin The thermoplastic resin may be a resin having thermoplasticity, or a resin that has thermoplasticity at least in an uncured state and forms a crosslinked structure after heating. The thermoplastic resin 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.

[0056] When the thermoplastic resin contains a reactive group-containing (meth)acrylic copolymer, the adhesive composition may be in an embodiment that does not contain a thermosetting resin, i.e., the adhesive composition may be in an embodiment that contains a reactive group-containing (meth)acrylic copolymer, an inorganic filler, and a photocleavable compound.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] The glass transition temperature (Tg) of the thermoplastic resin is, for example, -50 to 20°C, and may be -30 to 15°C. When the Tg of the thermoplastic resin 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 thermoplastic resin 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 easily follows the irregularities, and excellent adhesiveness can be achieved.

[0063] The Tg of a thermoplastic resin is the midpoint glass transition temperature obtained by differential scanning calorimetry (DSC). Specifically, the Tg of a thermoplastic resin 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 thermoplastic resin is commercially available, the value listed in the catalog or the like may be used.

[0064] The weight-average molecular weight of the thermoplastic resin 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 thermoplastic resin 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.

[0065] The content of the thermoplastic resin is, for example, 5 to 35 mass %, or may be 8 to 33 mass %, 12 to 30 mass %, or 15 to 27 mass %, based on the total amount of the adhesive composition. When the content of the thermosetting 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.

[0066] 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.

[0067] 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.

[0068]

[0069] 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.

[0070] 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.

[0071] 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.

[0072] 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.

[0073] The content of the inorganic filler may be 45% by mass or less, based on the total amount of the adhesive composition. When the content of the inorganic filler is 45% by mass or less, based on the total amount of the adhesive composition, the occurrence of voids at the interface between the film-like adhesive and the member during the die bonding process tends to be suppressed. The content of the inorganic filler may be 40% by mass or less, 30% by mass or less, 20% by mass or less, or 10% by mass or less, based on the total amount of the adhesive composition, or may be 0.1% by mass or more, 0.5% by mass or more, 1% by mass or more, 3% by mass or more, 5% by mass or more, 10% by mass or more, 15% by mass or more, 20% by mass or more, 25% by mass or more, or 30% by mass or more.

[0074] Photocleavable Compound The photocleavable compound is cleaved by irradiation with ultraviolet light to generate an amine compound. As described above, the photocleavable compound may be, for example, a compound having an α-aminoacetophenone skeleton. Examples of such compounds include Omnirad 907 (2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, manufactured by IGM Resins B.V.) and Omnirad 379EG (2-dimethylamino-2-(4-methyl-benzyl)-1-(4-morpholin-4-yl-phenyl)-butan-1-one, manufactured by IGM Resins B.V.). The photocleavable compound may be Omnirad 379EG. Omnirad 379EG contains a highly basic aliphatic amine, which is thought to facilitate proton elimination from, for example, a phenolic resin, facilitating the curing reaction. Omnirad is a registered trademark. As the photocleavable compound, a photoradical generator that generates radicals upon irradiation with ultraviolet light, or a photobase generator that generates a base, may be used. Examples of photobase generators include the WPBG series manufactured by Fujifilm Corporation. Specific examples of photobase generators include WPBG-027, WPBG-140, and WPBG-165.

[0075] The content of the photocleavable compound is, for example, 0.1 to 5 mass %, or may be 0.5 to 4.5 mass %, 1 to 4 mass %, or 2 to 3.5 mass %, based on the total amount of the adhesive composition. When the content of the photocleavable compound is within the above range, it tends to be possible to promote thermosetting and to ensure a long work life.

[0076] 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.

[0077] 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.

[0078] 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.

[0079] <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.

[0080] 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.

[0081] 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. Specifically, it 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 peel 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.

[0082] 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.

[0083] [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.

[0084] 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). When the adhesive piece 3p is made of an adhesive composition, for example, the adhesive piece 3p is irradiated with ultraviolet light in this state. The illuminance of the ultraviolet light is, for example, 10 to 200 mW / cm. ２ The integrated amount of ultraviolet light can be, for example, 300 to 900 mJ / cm ２ By irradiating the adhesive piece 3p with ultraviolet light, the adhesive piece 3p can be composed of an ultraviolet-irradiated adhesive composition. Thereafter, the adhesive piece 3p is temporarily pressure-bonded to the printed circuit board 12. The temporary pressure-bonding 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 temporary pressure-bonding 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.

[0085] 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.

[0086] Next, the adhesive pieces 3p are cured. The curing can be carried out, for example, at a temperature of 65 to 85°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 or a cured product of the adhesive composition after UV irradiation, 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 75°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.

[0087] 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. Note that an adhesive piece that has already been irradiated with ultraviolet light may be used to manufacture the connection body. When manufacturing the connection body using this adhesive piece, steps (A), (B), and (C) can be performed sequentially.

[0088] 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.

[0089] The present disclosure will be specifically described below using examples, but the present disclosure is not limited to these examples.

[0090] Examples 1 to 9 and Comparative Examples 1 to 4 [Preparation of Laminated Films] <Preparation of Materials> The following materials were prepared to prepare adhesive varnishes for the Examples and Comparative Examples.

[0091] (1) Thermosetting Resins (1-1) Epoxy Resins 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) (1-2) Phenolic Resins MEH-7800M (trade name, manufactured by Meiwa Kasei Co., Ltd. (currently UBE Corporation), phenylaralkyl type phenolic resin, hydroxyl equivalent: 174 g / eq) H-4 (trade name, manufactured by Meiwa Kasei Co., Ltd. (currently UBE Corporation), phenylaralkyl type phenolic resin, hydroxyl equivalent: 105 g / eq) (2) Thermoplastic Resins SG-P3 solvent change product (trade name, manufactured by Nagase ChemteX Corporation, acrylic resin, weight average molecular weight: 800,000, Tg: 12°C) (3) Inorganic filler SC-2050-HLG (trade name, manufactured by Admatechs Co., Ltd., surface-treated silica filler) (4) Photocleavable compound Omnirad379EG (trade name, manufactured by IGM Resins B.V.) (5) Coupling agent A-189 (trade name, manufactured by Momentive Performance Materials Japan LLC, γ-mercaptopropyltrimethoxysilane, silane coupling agent) Z-6119 (trade name, manufactured by Dow Toray Co., Ltd., 3-ureidopropyltriethoxysilane, silane coupling agent) (6) Organic solvent Cyclohexanone

[0092] An adhesive varnish was obtained by mixing the materials and solvent shown in Tables 1 and 2 and vacuum degassing the mixture. 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-like adhesive (adhesive layer) was formed on one side of the PET film, resulting in first laminate films of Examples 1 to 9 and Comparative Examples 1 to 4, each comprising a base film, an adhesive layer, and a cover film. Next, a dicing adhesive film was attached as a cover film to the surface of the film-like adhesive of the first laminate film, resulting in second laminate films of Examples 1 to 9 and Comparative Examples 1 to 4, each comprising a base film, an adhesive layer, and a cover film. Multiple first and second laminate films were prepared.

[0093] [Evaluation of Laminated Films (Film-like Adhesives)] <Measurement of Shear Viscosity> The film-like adhesive of each first laminated film was measured at an illuminance of 80 mW / cm ２ and an integrated light intensity of 600 mJ / cm ２ UV irradiation was performed under the following conditions. The shear viscosity at 75°C of the film-like adhesive after UV irradiation (in a B-stage state before UV irradiation and heating at 75°C for 3 hours) was measured using the following method. Specifically, multiple 25 μm thick film-like adhesives were laminated to a thickness of approximately 300 μm, and this laminate was punched out with a φ9 mm punch to prepare a measurement sample. An 8 mm diameter circular aluminum plate was installed in an ARES dynamic viscoelasticity analyzer (manufactured by TA Instruments), and the measurement sample was placed on this. Measurements were then taken while applying a 5% strain at 35°C and increasing the temperature to 100°C at a heating 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 Tables 1 and 2.

[0094] <Measurement of storage modulus> The film-like adhesive of each first laminated film was measured at an illuminance of 80 mW / cm ２ and an integrated light intensity of 600 mJ / cm ２The sample was irradiated with ultraviolet light under the following conditions. 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 heated at 75°C for 3 hours to obtain a measurement sample. The measurement sample was set in a dynamic viscoelasticity apparatus (Rheogel E-4000 (trade name), manufactured by UBM Corporation) with a chuck distance of 20 mm, and a tensile load was applied, followed by measurement at a frequency of 10 Hz and a heating rate of 3°C / min, to measure the storage modulus at 35°C and 75°C. The results are shown in Tables 1 and 2.

[0095] <Measurement of calorific value and calculation of reaction rate> The reaction rate of the film adhesive was measured by the following method. ２ and the cumulative light amount is 600 mJ / cm ２ The film-like adhesive was irradiated with ultraviolet light under the following conditions: 10 mg of the UV-irradiated film-like 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 and a measurement temperature range of 30 to 300°C. The calorific value was analyzed using a partial area analysis method. Analysis was instructed for a temperature range of 50 to 200°C on the DSC curve, and the total calorific value (unit: J / g) was calculated by specifying a baseline for the analysis temperature range and integrating the peak area. This was designated the calorific value C1.

[0096] After UV irradiation, the film adhesive was placed in an oven set at 75°C and heat-treated for 3 hours. Using the heat-treated sample, the calorific value (unit: J / g) in the temperature range of 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. The two obtained values ​​of calorific value C1 and calorific value C2 were substituted into the following formula to calculate the reaction rate. The results are shown in Tables 1 and 2. Reaction rate (%) = (C1 - C2) / C1 x 100

[0097] <Measurement of Peel Strength Against Polyimide Film (PI Peel Strength)> The peel strength of the film-like adhesive of each second laminate film against a polyimide film was measured by the following method. First, an illuminance of 80 mW / cm was applied to the film-like adhesive of each second laminate film. ２ and an integrated light intensity of 600 mJ / cm ２ The second laminate film was then punched out to a size of 3.2 mm x 3.2 mm. After peeling the base film from the second laminate film, the film adhesive was attached to an organic substrate and temporarily pressed on a stage at 75°C with a pressure of 1.0 N for 0.5 seconds. Next, the cover film was peeled from the film adhesive, and a 5 mm x 100 mm polyimide film (UPILEX 50S (trade name), manufactured by Ube Industries, Ltd.) was attached to the film adhesive and permanently pressed on a stage at 75°C with a force of 30 N for 3 seconds. The film adhesive was then cured by heating at 75°C for 3 hours to obtain a measurement sample. PI peel strength was measured at a test speed of 50 mm / min using a 90-degree peel tester (manufactured by Tester Sangyo Co., Ltd.). The results are shown in Tables 1 and 2.

[0098] <Confirmation of voids after thermocompression bonding> The film-like adhesive of each second laminated film was subjected to an illuminance of 80 mW / cm ２ and an integrated light intensity of 600 mJ / cm ２The second laminate film was then punched to a size of 3.2 mm x 3.2 mm. After peeling the base film from the second laminate film, the film-like adhesive was attached to an organic substrate and temporarily pressed on a stage at 75 ° C with a pressure of 1.0 N for 0.5 seconds. Next, the cover film was peeled from the film-like adhesive, and a polyimide film (Upilex 50S (trade name), manufactured by Ube Industries, Ltd.) measuring 5 mm x 100 mm was attached to the film-like adhesive and permanently pressed on a stage at 75 ° C with a force of 30 N for 3 seconds to prepare a test specimen. The test specimen was then visually inspected from the polyimide film side for the presence or absence of voids. If no voids were observed and it was predicted that no voids would be observed even if multiple test specimens were prepared, the test specimen was evaluated as "A." If no voids were observed and there was a risk that voids would be observed in some of the test specimens when multiple test specimens were prepared, the test specimen was evaluated as "B." If voids were observed, the test specimen was evaluated as "C." The results are shown in Tables 1 and 2.

[0099]

[0100]

[0101] As shown in Tables 1 and 2, the laminate films (film-like adhesives) of Examples 1 to 9 had reduced voids after thermocompression bonding compared to the laminate films (film-like adhesives) of Comparative Examples 1 to 4. From the above, it was confirmed that the thermosetting adhesive composition of the present disclosure can suppress the generation of voids at the interface between the film-like adhesive and the member when a die bonding process is carried out using a film-like adhesive comprising the thermosetting adhesive composition.

[0102] 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 containing a thermosetting resin, a thermoplastic resin, an inorganic filler, and a photocleavable compound that is cleaved by irradiation with ultraviolet light to generate an amine compound, wherein the thermosetting resin is a resin that is cured by heating in the presence of the amine compound, and the illuminance is 80 mW / cm. ２ and an integrated light quantity of 600 mJ / cm ２ After being irradiated with ultraviolet light under the conditions of ２ and an integrated light quantity of 600 mJ / cm ２ and then heated at 75° C. for 3 hours, the thermosetting adhesive composition having a storage modulus of 100 to 4000 MPa at 35° C.

2. Illuminance 80mW / cm ２ and an integrated light quantity of 600 mJ / cm ２ 2. The thermosetting adhesive composition according to claim 1, wherein after being irradiated with ultraviolet light under the conditions of (a) above and further heated at 75° C. for 3 hours, the thermosetting adhesive composition has a storage modulus at 75° C. of 10 MPa or more.

3. The thermosetting adhesive composition according to claim 1 or 2, wherein the content of the thermoplastic resin is 5 to 35 mass % based on the total amount of the thermosetting adhesive composition.

4. The thermosetting adhesive composition according to claim 1 or 2, wherein the content of the inorganic filler is 45 mass% or less based on the total amount of the thermosetting adhesive composition.

5. The thermosetting adhesive composition according to claim 1 or 2, wherein the photocleavable compound is a compound having an α-aminoacetophenone skeleton.

6. The thermosetting adhesive composition according to claim 1 or 2, wherein the reaction rate calculated by substituting the heat generation amount C1 and the heat generation amount C2 in the temperature range of 50 to 200°C, which are respectively determined from a DSC curve obtained by differential scanning calorimetry at a heating rate of 10°C / min, into the following formula, is 45% or more: Reaction rate (%) = (C1 - C2) / C1 x 100 [wherein C1 is the amount of heat generation at an illuminance of 80 mW / cm for the thermosetting adhesive composition] ２ and an integrated light quantity of 600 mJ / cm ２ C2 indicates the amount of heat generated by the resin composition after it is irradiated with ultraviolet light under the conditions of an illuminance of 80 mW / cm ２ and an integrated light quantity of 600 mJ / cm ２ and then heated at 75° C. for 3 hours.] 7. The thermosetting adhesive composition according to claim 1 or 2, wherein the glass transition temperature of the thermoplastic resin is -50 to 20°C.

8. An ultraviolet-irradiated thermosetting adhesive composition obtained by irradiating the thermosetting adhesive composition according to claim 1 or 2 with ultraviolet light, the thermosetting adhesive composition containing the thermosetting resin, the thermoplastic resin, the inorganic filler, and the amine compound, the thermosetting adhesive composition having a shear viscosity of 100 to 6000 Pa·s at 75°C, and a storage modulus of 100 to 4000 MPa at 35°C after being heated at 75°C for 3 hours.

9. 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 claim 1 or 2.

10. 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 65 to 85°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 described in claim 1 or 2; and comprising the step of irradiating the adhesive layer with ultraviolet light prior to step (B).

11. The method for producing a connection body according to claim 10, 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.

12. 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 and second circuit members; (B) heating the laminate at 65-85°C for 30-240 minutes; and (C) wire bonding the first circuit member and the second circuit member, in this order; wherein the adhesive layer is formed from an ultraviolet-irradiated product of the thermosetting adhesive composition described in claim 8.

13. The method for producing a connection body according to claim 12, 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.

14. A connection comprising: a first circuit member; a second circuit member; and an adhesive layer disposed between the first and second circuit members, the adhesive layer being formed from a cured product of the thermosetting adhesive composition according to claim 1 or 2.

15. A connection body comprising: a first circuit member; a second circuit member; and an adhesive layer disposed between the first and second circuit members, the adhesive layer being formed from a cured product of ultraviolet irradiated thermosetting adhesive composition according to claim 8.

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