JP2024090177A - Thermosetting adhesive composition and ultraviolet irradiated product thereof, laminated film, and connection body and method for producing same - Google Patents

Abstract

The present invention provides a thermosetting adhesive composition that has excellent adhesive strength and is capable of suppressing a decrease in workability when producing a laminated film.
[Solution] A thermosetting adhesive composition is disclosed. The thermosetting adhesive composition contains a thermosetting resin, an inorganic filler, and a photocleavable compound that is cleaved by irradiation with ultraviolet light to generate an amine compound. The thermosetting resin is a resin that is cured by heating in the presence of the amine compound. The content of the inorganic filler is 1 to 22 mass% based on the total amount of the thermosetting adhesive composition. After irradiation with ultraviolet light under conditions of an illuminance of 80 mW/ ^cm2 and an accumulated light amount of 600 mJ, the shear viscosity at 75°C is 3000 to 7000 Pa·s.
[Selection diagram] None

Description

This disclosure relates to a thermosetting adhesive composition and its ultraviolet-irradiated product, a laminated film, and a connection body and a method for producing the same.

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, and the semiconductor wafer is divided into individual semiconductor chips. Then, a pick-up 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.

JP 2007-288170 A JP 2009-209345 A

In recent years, with the evolution of semiconductor modules for small devices such as smartphones, the manufacturing process of semiconductor modules has also changed significantly from the conventional one. For example, the practical application of processes that do not perform dicing and die bonding processes is being promoted. Accordingly, the thermosetting adhesive composition used in the manufacturing process of semiconductor modules is also required to have different performance from the conventional one. In addition to this situation, the inventors have developed a thermosetting adhesive composition in which the curing reaction proceeds sufficiently at low temperatures of 85°C or less, assuming that a material with relatively low heat resistance will be used in the semiconductor module. When improvements were made based on a conventional thermosetting adhesive composition that has excellent low-temperature curing properties, it was found that although the development goal for low-temperature curing was achieved, the adhesive strength with resin members and the like was insufficient. On the other hand, if the adhesive strength of the thermosetting adhesive composition becomes too high, for example, when a laminated film is produced that includes a substrate film and an adhesive layer composed of a thermosetting adhesive composition provided on the substrate film, a protective film such as polyethylene arranged for the purpose of temporarily protecting the surface of the adhesive layer becomes difficult to peel off from the adhesive layer, and there is a concern that the workability will decrease.

Therefore, the main objective of the present disclosure is to provide a thermosetting adhesive composition that has excellent adhesive strength and can suppress a decrease in workability when producing a laminated film.

In order to solve the above problems, the present inventors conducted research on thermosetting adhesive compositions, focusing on the shear viscosity at 75°C, which is the possible bonding temperature. They discovered that by adjusting the content of inorganic filler within a certain range of shear viscosity at 75°C, it is possible to improve adhesive strength and suppress a decrease in workability when producing a laminated film, and thus completed the invention disclosed herein.

The present disclosure provides a thermosetting adhesive composition as described in [1] to [8], an ultraviolet irradiated product of the thermosetting adhesive composition as described in [9], a laminate film as described in [10], a method for producing a connection body as described in [11] to [14], and a connection body as described in [15] and [16].
[1] A thermosetting adhesive composition containing a thermosetting 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, the content of the inorganic filler is 1 to 22 mass% based on the total amount of the thermosetting adhesive composition, and the thermosetting adhesive composition has a shear viscosity of 3000 to 7000 Pa s at 75°C after irradiation with ultraviolet light under conditions of an illuminance of 80 mW/ ^cm2 and an accumulated light amount of 600 mJ.
[2] The thermosetting adhesive composition according to [1], wherein the photocleavable compound is a compound having an α-aminoacetophenone skeleton.
[3] The thermosetting adhesive composition according to [1] or [2], wherein the thermosetting resin comprises an epoxy resin, and the epoxy resin comprises an epoxy resin that is solid at 25°C.
[4] The thermosetting adhesive composition according to [3], wherein the content of the epoxy resin that is solid at 25°C is 4 to 8 mass% based on the total amount of the thermosetting adhesive composition.
[5] The thermosetting adhesive composition according to any one of [1] to [4], further comprising a thermoplastic resin, the content of the thermoplastic resin being 20 to 40 mass% based on the total amount of the thermosetting adhesive composition.
[6] The thermosetting adhesive composition according to [5], wherein the glass transition temperature of the thermoplastic resin is −50 to 20° C.
[7] The thermosetting adhesive composition according to any one of [1] to [6], which has a storage modulus at 75°C of 3 MPa or more after being irradiated with ultraviolet light under conditions of an illuminance of 80 mW/ ^cm2 and an accumulated light quantity of 600 mJ, and then heated at 75°C for 3 hours.
[8] The thermosetting adhesive composition according to any one of [1] to [7], which has a storage modulus at 35°C of 700 MPa or less after being irradiated with ultraviolet light under conditions of an illuminance of 80 mW/ ^cm2 and an accumulated light quantity of 600 mJ, and then heated at 75°C for 3 hours.
[9] An ultraviolet-irradiated product of a thermosetting adhesive composition obtained by irradiating the thermosetting adhesive composition according to any one of [1] to [8] with ultraviolet light, the ultraviolet-irradiated product of the thermosetting adhesive composition containing the thermosetting resin, the inorganic filler, and the amine compound, and having a shear viscosity at 75°C of 3000 to 7000 Pa·s.
[10] A laminate 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 [1] to [8].
[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 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 made of a thermosetting adhesive composition according to any one of [1] to [8]; and comprising the step of irradiating the adhesive layer with ultraviolet light prior to step (B).
[12] The method for producing a connection body described in [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 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 [9].
[14] The method for producing a connection body described in [13], 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.
[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 the thermosetting adhesive composition according to any one of [1] to [8].
[16] 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 irradiating the thermosetting adhesive composition described in [9].

According to the present disclosure, a thermosetting adhesive composition is provided that has excellent adhesive strength and is capable of suppressing a decrease in workability when a laminated film is produced. Also, according to the present disclosure, a product of such a thermosetting adhesive composition that has been irradiated with ultraviolet light is provided. Also, according to the present disclosure, an adhesive film is provided that includes an adhesive layer that is composed of such a thermosetting adhesive composition or a product thereof that has been irradiated with ultraviolet light is provided. Also, according to the present disclosure, a connection body that uses such a thermosetting adhesive composition or a product thereof that has been irradiated with ultraviolet light, and a method for producing the same are provided.

FIG. 1 is a cross-sectional view that illustrates a schematic diagram of one embodiment of a laminate film according to the present disclosure. 2A to 2C are cross-sectional views each showing a schematic state of a semiconductor module during a manufacturing process. 3A to 3C are cross-sectional views each showing a schematic state of a semiconductor module during a manufacturing process. FIG. 4 is a perspective view showing a schematic example of a punched product according to the present disclosure. FIG. 5 is a cross-sectional view taken along line VV shown in FIG. FIG. 6 is a cross-sectional view that shows a schematic state in which an adhesive piece and a cover film that covers the adhesive piece are picked up from a base film. 7A to 7C are cross-sectional views each showing a schematic state of a semiconductor module during the manufacturing process.

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

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

In this specification, the term "layer" includes structures that are formed over the entire surface when viewed in a plan view, as well as structures that are formed on only a portion of the surface. In this specification, the term "process" includes not only independent processes, but also processes that cannot be clearly distinguished from other processes, as long as the intended effect of the process is achieved.

In this specification, "(meth)acrylate" means at least one of acrylate and the corresponding methacrylate. The same applies to other similar expressions such as "(meth)acryloyl" and "(meth)acrylic acid". In addition, "(poly)" means both the case with and without the "poly" prefix.

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

[Laminated film]
Fig. 1 is a cross-sectional view showing a laminated film according to the present embodiment. The laminated film 10 shown in this figure includes a base film 1, an adhesive layer 3, and a cover film 5, in this order. The laminated 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 structure of the laminated film 10 will be described below.

<Base film>
The base film 1 is not particularly limited 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 base film 1 is preferably transparent from the viewpoint of visibility of the adhesive layer 3 disposed thereon. Examples of the base film 1 include polyester-based films such as polyethylene terephthalate films; polyolefin-based films such as homopolymers or copolymers, or mixtures thereof, such as 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 base film 1 may have a single layer structure or a multilayer structure.

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.

To increase the adhesion 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, chromate treatment, ozone exposure, flame exposure, high-voltage shock exposure, or ionizing radiation treatment. A film made of fluororesin with low surface energy may 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.

To prevent the adhesive layer 3 from having an excessively high adhesive strength to the base film 1, 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.

The adhesion between the base film 1 and the adhesive layer 3 is, for example, 0.5 N/m or more. This adhesion of 0.5 N/m or more makes it easier to prevent the adhesive layer 3 from accidentally peeling off from the base film 1 during the process of manufacturing the laminated film 10. The adhesion between the adhesive layer 3 and the base film 1 means the 90° peel strength, and more specifically, means the peel strength measured when a 20 mm wide sample in which the adhesive layer 3 is formed on the base film 1 is prepared and the adhesive layer is peeled off from the base film at an angle of 90° at a peel speed of 50 mm/min.

<Adhesive Layer>
The adhesive layer 3 is used for bonding circuit members together, and is preferably used for bonding, for example, a printed circuit board and an end of an FPC board (flexible printed circuit board), or a semiconductor chip and an end of an FPC board. The module 50A (connection 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 and the 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 obtained by processing 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 and the semiconductor chip C. The adhesive layer 16 may have the same composition as the adhesive piece 3c, or may have a different composition.

The module 50B shown in FIG. 3 is obtained by performing wire bonding on the module 50A shown in FIG. 2. Wire W1 electrically connects the semiconductor chip C and the printed circuit board 12, and wire W2 electrically connects the printed circuit board 12 and 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. The signals from the printed circuit board 12 are transmitted to the tip portion 15a of the FPC board 15.

The adhesive piece 3p (adhesive layer) is composed of a thermosetting adhesive composition (hereinafter, sometimes simply referred to as "adhesive composition") or its ultraviolet irradiated product. The adhesive composition contains a thermosetting resin, an inorganic filler, and a photocleavable compound (hereinafter, sometimes simply referred to as "photocleavable compound") that is cleaved by irradiation with ultraviolet light to generate an amine compound. The ultraviolet irradiated product of the adhesive composition contains a thermosetting resin, an inorganic filler, and an amine compound generated from the photocleavable compound by irradiation with ultraviolet light. The ultraviolet irradiated product of the adhesive composition may be an adhesive composition in which ultraviolet light has been irradiated to the adhesive composition. A thermosetting resin is a resin that is cured by heating in the presence of an amine compound. The amine compound may be, for example, a component that acts as a curing agent, a curing accelerator, or the like. The adhesive piece 3c (adhesive layer) is composed of a cured product of the adhesive composition or a cured product of an ultraviolet irradiated product of the adhesive composition.

After irradiation with ultraviolet light under conditions of an illuminance of 80 mW/ ^cm2 and an integrated light quantity of 600 mJ, the shear viscosity (melt viscosity) of the adhesive composition at 75°C is 3000 to 7000 Pa·s, and may be 3500 Pa·s or more, 4000 Pa·s or more, 4500 Pa·s or more, or 5000 Pa·s or more, and may be 6700 Pa·s or less, 6400 Pa·s or less, 6200 Pa·s or less, or 6000 Pa·s or less. By having the shear viscosity at 75°C in the above range, even if the tip portion 15a of the FPC board 15 has unevenness, the adhesive composition tends to be able to be arranged without a gap between the tip portion 15a and the member to be bonded (printed circuit board 12).

The shear viscosity of the above adhesive composition at 75 ° C. can be measured, for example, by the following procedure. First, a plurality of film-like adhesives made of the adhesive composition with a thickness of 25 μm are prepared. Next, the film-like adhesive is irradiated with ultraviolet light under conditions of an illuminance of 80 mW/ ^cm2 and an integrated light quantity of 600 mJ/ ^cm2 . Next, a plurality of film-like adhesives are laminated to a thickness of about 300 μm, and this laminate is punched out with a φ9 mm punch to prepare a measurement sample. A circular aluminum plate jig with a diameter of 8 mm is installed on a dynamic viscoelasticity device, and a measurement sample is set here. Next, the measurement is performed while raising the temperature to 100 ° C. at a heating rate of 5 ° C./min while applying a 5% strain at 35 ° C., and the viscosity at 75 ° C. is obtained, so that the shear viscosity at 75 ° C. can be measured. In the measurement, the frequency is constant at 1 Hz, the initial load is kept at 300 g, and the axial force is kept at 100 g.

In order to adjust the shear viscosity at 75° C. to a predetermined range, for example, the following method can be considered.
Method 1: The amount of inorganic filler contained in the adhesive composition is made relatively small.
Method 2: The amount of thermoplastic resin (for example, 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.

The photocleavable compound may be a compound having an α-aminoacetophenone skeleton. For example, when the following compound having an α-aminoacetophenone skeleton is irradiated with ultraviolet light, it 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).

The adhesive composition may, for example, satisfy the following condition 1.
Condition 1
After being irradiated with ultraviolet light at an illuminance of 80 mW/ ^cm2 and an accumulated light quantity of 600 mJ, and then heated at 75°C for 3 hours, the storage modulus at 75°C is 3 MPa or more.

An adhesive composition that satisfies condition 1 can be said to have excellent low-temperature curing properties. This has the advantage that components that make up module 50B can be made from materials with relatively low heat resistance. 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 a 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 themselves, and the use of phenolic resin makes it easier for the reaction to proceed.

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

The adhesive composition may, for example, satisfy the following condition 2.
Condition 2
After being irradiated with ultraviolet light at an illuminance of 80 mW/ ^cm2 and an accumulated light quantity of 600 mJ, and then heated at 75°C for 3 hours, the storage modulus at 35°C is 700 MPa or less.

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 related to condition 2 may be 700 MPa or less, 500 MPa or less, 400 MPa or less, or 350 MPa or less. The storage modulus related to condition 2 may be, for example, 50 MPa or more, 100 MPa or more, or 150 MPa or more.

In order to obtain an adhesive composition that satisfies condition 2, for example, the following method may be considered.
Method 1: The amount of thermoplastic resin (for example, acrylic rubber) contained in the adhesive composition is made relatively large.
Method 2: A thermoplastic resin having a relatively low glass transition temperature (Tg) is used.
Method 3: Use a thermosetting resin with a flexible skeleton.

The storage modulus at 75°C and 35°C can be measured, for example, by the following procedure. First, a plurality of film-like adhesives made of an adhesive composition having a thickness of 25 μm are prepared. Next, the film-like adhesive is irradiated with ultraviolet light under conditions of an illuminance of 80 mW/ ^cm2 and an integrated light quantity of 600 mJ/ ^cm2 . Next, a plurality of film-like adhesives after ultraviolet light irradiation are laminated to a thickness of about 300 μm, and the thickness is made into a size of 4 mm wide x 33 mm, and a measurement sample is prepared by heating at 75°C for 3 hours. The measurement sample thus prepared is set in a dynamic viscoelasticity device with a chuck distance of 20 mm, and a tensile load is applied to the measurement under conditions of a frequency of 10 Hz and a heating rate of 3°C/min, and the storage modulus at 35°C and 75°C is measured.

The laminated film 10 can be produced, for example, as follows. First, the adhesive composition constituting the adhesive layer 3 is dissolved in a solvent such as an organic solvent to prepare a coating liquid that is turned into a varnish. After this coating liquid is applied to the base film 1, the solvent is removed to form the adhesive layer 3. Examples of coating methods include knife coating, roll coating, spray coating, gravure coating, bar coating, and curtain coating. Next, a cover film 5 is attached to the surface of the adhesive layer 3 at room temperature (25°C) to 60°C. This allows the laminated film 10 to be obtained. Note that the laminated film 10 can also be obtained by forming the adhesive layer 3 on a wide base film, then laminating the cover film 5 to cover it to produce a laminated film, and cutting (slitting) this to a predetermined width.

<Punching products>
Fig. 4 is a perspective view showing a schematic diagram of a punched product produced from the laminate film 10. Fig. 5 is a cross-sectional view taken along the line V-V shown in Fig. 4. The punched product 20 shown in Figs. 4 and 5 includes 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 (the direction of the arrow X shown in Fig. 4) of the base film 1, and a cover film 5p covering the upper surface 3f of the adhesive pieces 3p and having the same shape as the adhesive pieces 3p.

The adhesive piece 3p is preferably applied to adhesion between a circuit member (semiconductor chip or printed circuit board) and the tip of an FPC board. The area of the adhesive piece 3p in a plan view is, for example, 1 to ¹⁰⁰ mm2, and may be 3 to 50 ^mm2 or 5 to ⁴⁰ mm2. With the punched product 20, the adhesive pieces 3p arranged in a line on the base film 1 can be picked up in sequence (see FIG. 6), and then each adhesive piece 3p can be placed in a predetermined area of the circuit member, so that adhesion between the circuit member and the FPC member can be efficiently performed.

The punched product 20 can be obtained, for example, through the following steps.
(a) A step of preparing a laminate film 10.
(b) A step of obtaining a plurality of adhesive pieces 3p arranged on the base film 1 in the longitudinal direction of the base film 1 by die-cutting the adhesive layer 3 and the cover film 5 in the laminated film 10.

<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, an inorganic filler, and a photocleavable compound. The adhesive composition may further contain, for example, a thermoplastic resin.

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.

Epoxy resins include, for example, bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, alicyclic epoxy resins, aliphatic chain epoxy resins, phenol novolac type epoxy resins, cresol novolac type epoxy resins, bisphenol A novolac type epoxy resins, diglycidyl ethers of biphenols, diglycidyl ethers of naphthalene diols, diglycidyl ethers of phenols, diglycidyl ethers of alcohols, and difunctional epoxy resins such as alkyl substituted, halogenated, and hydrogenated products thereof, novolac type epoxy resins, etc. In addition, other commonly known epoxy resins such as polyfunctional epoxy resins and heterocyclic epoxy resins may be applied. Note that components other than epoxy resins may be included as impurities to the extent that the properties are not impaired.

The epoxy resin may contain, for example, an epoxy resin that is solid at 25°C (hereinafter, may be referred to as "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 "liquid epoxy resin"). By containing a solid epoxy resin, the epoxy resin does not become sticky during film formation, and sticking to machines such as rolls can be suppressed, and there is a tendency that a decrease in workability when a laminated film is produced can be suppressed.

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

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), etc.

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.

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 novolac-type phenolic resins obtained by condensing or co-condensing phenols such as phenol, cresol, resorcin, catechol, bisphenol A, bisphenol F, phenylphenol, aminophenol, etc. and/or naphthols such as α-naphthol, β-naphthol, dihydroxynaphthalene, etc. with a compound having an aldehyde group such as formaldehyde under an acid catalyst, allylated bisphenol A, allylated bisphenol F, allylated naphthalenediol, phenol novolac, phenol aralkyl resins synthesized from phenols such as phenol and/or naphthols and dimethoxyparaxylene or bis(methoxymethyl)biphenyl, naphthol aralkyl resins, biphenyl aralkyl-type phenolic resins, and phenyl aralkyl-type phenolic resins.

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

The epoxy resin content is, for example, 15 to 45% by mass, and may be 20 to 40% by mass or 25 to 35% by mass, based on the total amount of the adhesive composition. When the epoxy resin content is within the above range, sufficient thermosetting properties are obtained, and curing tends to proceed even at low temperatures.

The content of solid epoxy resin relative to the total amount of epoxy resin is, for example, 10 to 30% by mass, and may be 12 to 28% by mass or 15 to 25% by mass. When the content of 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.

The content of the solid epoxy resin is, for example, 4 to 8 mass % based on the total amount of the adhesive composition, and may be 4.5 to 7.5 mass % or 5 to 7 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.

Inorganic filler The inorganic filler can be selected according to the desired function. Examples of inorganic fillers include metal (conductive) fillers such as silver powder, gold powder, and copper powder; and nonmetal (insulating) fillers such as silica, alumina, boron nitride, titania, glass, iron oxide, and ceramics. The inorganic filler may be, for example, a silica filler.

The surface of the inorganic filler may have an organic group. By modifying the surface of the inorganic filler with an organic group, the dispersibility in an organic solvent when preparing a varnish for forming the adhesive layer 3 can be improved. In addition, the shrinkage caused by the thermal curing of the adhesive layer 3 can be suppressed, and the adhesive layer 3 tends to have both a high elastic modulus and excellent peelability. The 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. The fact that the surface of the inorganic filler is modified with an organic group can be confirmed by ultraviolet-visible spectroscopy, infrared absorption spectroscopy, X-ray photoelectron spectroscopy, etc.

In formula (B-1), X represents an organic group selected from the group consisting of a phenyl group, a glycidoxy group, a (meth)acryloyl 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; and R ¹¹ , R ¹² , and R ¹³ each independently represent an alkyl group having 1 to 10 carbon atoms.

Examples of alkyl groups having 1 to 10 carbon atoms include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, isopropyl, and isobutyl groups.

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.

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

The content of the inorganic filler is 1 to 22% by mass based on the total amount of the adhesive composition. When the content of the inorganic filler is 22% by mass or less based on the total amount of the adhesive composition, the adhesive strength with the 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 too high, which tends to prevent the workability from decreasing. 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, 18% by mass or less, 16% by mass or less, or 14% by mass or less.

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 Omnirad907 (2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, manufactured by IGM Resins B.V.), Omnirad379EG (2-dimethylamino-2-(4-methyl-benzyl)-1-(4-morpholin-4-yl-phenyl)-butan-1-one, manufactured by IGM Resins B.V.), and the like. The photocleavable compound may be Omnirad379EG. Omnirad379EG contains an aliphatic amine with high basicity, and it is considered that, for example, proton elimination from a phenolic resin occurs easily, and the curing reaction proceeds easily. Omnirad is a registered trademark. As the photocleavable compound, a photoradical generator that generates radicals by 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, WPBG-165, and the like.

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

Thermoplastic resin: As the thermoplastic resin, a resin having thermoplasticity, or a resin having thermoplasticity at least in an uncured state and forming a crosslinked structure after heating can be used. From the viewpoint of excellent shrinkage, heat resistance, and peelability, 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").

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. In other words, the adhesive composition may be in an embodiment that contains a reactive group-containing (meth)acrylic copolymer and an inorganic filler.

Examples of (meth)acrylic copolymers 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 a monomer selected from a (meth)acrylic acid ester and acrylonitrile, with an acrylic acid ester as the main component.

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.

The reactive group-containing (meth)acrylic copolymer may be a reactive group-containing (meth)acrylic copolymer that contains 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 a (meth)acrylic monomer having a reactive group and the above-mentioned monomer.

From the viewpoint of improving heat resistance, examples of reactive groups include epoxy groups, carboxyl groups, (meth)acryloyl groups, hydroxyl groups, and episulfide groups. From the viewpoint of crosslinking, the reactive group may be an epoxy group or a carboxyl group.

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.

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.

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 conforming to JIS K7121:1987, measuring the change in heat quantity under conditions of a heating rate of 10°C/min and a measurement temperature of -80 to 80°C. Note that if the thermoplastic resin is a commercially available product, the value listed in the catalog or the like may be used.

The weight average molecular weight of the thermoplastic resin may be 100,000 to 2,000,000. If the weight average molecular weight is 100,000 or more, it is easier to ensure heat resistance. On the other hand, if the weight average molecular weight is 2,000,000 or less, it is easier to suppress a decrease in flow and a decrease in adhesion. 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 using a calibration curve of standard polystyrene in gel permeation chromatography (GPC).

The content of the thermoplastic resin is, for example, 20 to 40% by mass, or may be 22 to 38% by mass or 25 to 35% by 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.

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% by mass based on the total amount of the adhesive composition.

Organic Solvent The adhesive composition may be diluted with an organic solvent as necessary, and may be used as an adhesive varnish. The organic solvent is not particularly limited, but can be determined in consideration of the volatility during film formation from the boiling point. 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 the film is less likely to harden during film formation. Solvents with relatively high boiling points have the advantage of improving film formability.

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. A thickness of 1 μm or more for the adhesive layer 3 makes it easier to ensure sufficient adhesion, while a thickness of 200 μm or less makes it easier to prevent the adhesive composition constituting the adhesive layer 3 from spilling out of the base film 1 or cover film 5.

<Cover film>
There are no particular limitations on the cover film 5 as long as it can be easily peeled off from the adhesive layer 3. Examples of the cover film 5 include polyester films such as polyethylene terephthalate film; polyolefin films such as homopolymers 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 multilayer structure.

When the cover film 5 has a multi-layer 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, etc.

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

The thickness of the cover film 5 may be selected as appropriate 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.

[Method of manufacturing a connection body (semiconductor module)]
A method for producing the module 50B (connection body) shown in FIG. 3 using the punched product 20 will be described. FIG. 6 is a cross-sectional view that shows a schematic state in which 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 punched product 20 is moved in the direction of the arrow shown in FIG. 6 while the surface of the punched product 20 on the base film 1 side is abutted against a wedge-shaped member 60. As a result, as shown in FIG. 6, the adhesive piece 3p and the front of the cover film 5p are raised from the base film 1. In this state, the adhesive piece 3p and the cover film 5p are picked up by, for example, a pickup device 65 having suction force.

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, in this state, the adhesive piece 3p is irradiated with ultraviolet light. The illuminance of the ultraviolet light can be, for example, 10 to 200 mW/cm ^2. The integrated light amount of the 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 made of an ultraviolet-irradiated adhesive composition. Then, the adhesive piece 3p is provisionally pressure-bonded to the printed circuit board 12. The provisional pressure-bonding can be performed, for example, at a temperature of 60 to 85° C. and a pressing force of 0.1 to 2 MPa for 0.1 to 10 seconds. The provisional pressure-bonding causes the adhesive piece 3p to be semi-cured, thereby improving the adhesive force to the surface 12a. Then, the cover film 5p is peeled off from the adhesive piece 3p using an adhesive tape or the like. This causes the surface F1 of the adhesive piece 3p to be exposed.

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, for 0.1 to 10 seconds under conditions of a temperature of 60 to 85°C and a pressing force of 0.1 to 3 MPa.

Next, the adhesive piece 3p is cured. The curing process can be carried out, for example, at a temperature of 65-85°C for 30-240 minutes. As a result, the adhesive piece 3p becomes an adhesive piece 3c made of a cured product of the adhesive composition or a cured product of the adhesive composition irradiated with ultraviolet light, and the module 50A shown in Figure 2 is obtained (step (B)). Note that, from the viewpoint of the heat resistance of the members constituting the module 50A, the heating conditions in the above conditions 1 and 2 are set to 75°C for 3 hours. By heating the module 50A to a relatively low temperature, there is an advantage in that the material options are expanded.

Wire bonding is performed on module 50A (step (C)). This results in module 50B as shown in FIG. 3. The semiconductor module is then completed through a process in which wires W1 and W2 of module 50B are protected with a resin material, and a heating process that promotes the curing reaction of adhesive piece 3c. Note that an adhesive piece that has already been irradiated with ultraviolet light may be used to manufacture the connection body. When manufacturing a connection body using this adhesive piece, steps (A), (B), and (C) can be carried out in sequence.

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, the above embodiment illustrates a case where an adhesive piece 3p made of an adhesive composition is prepared in advance by die cutting, but an adhesive layer may be formed by preparing a coating liquid containing the adhesive composition and coating the coating liquid on the surface of the printed circuit board 12.

The present disclosure will be explained in detail below using examples, but the present disclosure is not limited to these examples.

(Examples 1 to 5 and Comparative Examples 1 to 4)
[Preparation of Laminated Film]
<Preparing materials>
To prepare the adhesive varnishes of the Examples and Comparative Examples, the following materials were prepared.

(1) Thermosetting Resin (1-1) Epoxy Resin EXA-830CRP (product name, manufactured by DIC Corporation, bisphenol F type epoxy resin, epoxy equivalent: 160 g/eq, liquid at 25° C.)
N-500P-10 (product name, manufactured by DIC Corporation, cresol novolac type epoxy resin, epoxy equivalent: 204 g/eq, solid at 25° C.)
(1-2) Phenolic resin MEH-7800M (product name, manufactured by Meiwa Chemical Industry Co., Ltd., phenylaralkyl type phenolic resin, hydroxyl group equivalent: 174 g/eq)
(2) Inorganic filler: SC-2050-HLG (product name, manufactured by Admatechs Co., Ltd., surface-treated silica filler)
(3) Photocleavable compound: Omnirad 379EG (product name, manufactured by IGM Resins B.V.)
(4) Thermoplastic resin: HTR-860P-3CSP (product name, manufactured by Nagase ChemteX Corporation, acrylic resin, weight average molecular weight: 800,000, Tg: 12°C)
(5) Organic solvent: Cyclohexanone

The materials and solvent shown in Table 1 were mixed and vacuum degassed to obtain an adhesive varnish. This adhesive varnish was applied to a 38 μm thick surface release-treated PET film as a base film. After a drying process, a film-like adhesive (adhesive layer) with a thickness of 25 μm was formed on one side of the PET film, and the first laminated film of Examples 1 to 5 and Comparative Examples 1 to 4 was obtained, which comprises a base film, an adhesive layer, and a cover film. Next, a dicing adhesive film (manufactured by Maxell Co., Ltd.) was attached as a cover film to the surface of the film-like adhesive of the first laminated film, to obtain the second laminated film of Examples 1 to 5 and Comparative Examples 1 to 4, which comprises a base film, an adhesive layer, and a cover film. A plurality of first laminated films and second laminated films were prepared.

[Evaluation of Laminated Film (Film-like Adhesive)]
<Measurement of shear viscosity>
The film-like adhesive of each first laminated film was irradiated with ultraviolet light under conditions of an illuminance of 80 mW/ ^cm2 and an accumulated light quantity of 600 mJ/ ^cm2 . The shear viscosity at 75 ° C of the film-like adhesive after ultraviolet light irradiation (B-stage state before ultraviolet light irradiation and heating at 75 ° C for 3 hours) was measured by the following method. That is, a thickness of about 300 μm was obtained by laminating a plurality of film-like adhesives having a thickness of 25 μm, and this laminate was punched out with a φ9 mm punch to prepare a measurement sample. A circular aluminum plate jig having a diameter of 8 mm was installed on a dynamic viscoelasticity device ARES (manufactured by TA instruments), and a measurement sample was further set here. Thereafter, the measurement was performed while heating to 100 ° C at a heating rate of 5 ° C / min while applying a 5% strain at 35 ° C. The frequency was constant at 1 Hz, the initial load was kept at 300 g, and the axial force was kept at 100 g. The results are shown in Table 1.

<Measurement of storage modulus>
The film-like adhesive of each first laminated film was irradiated with ultraviolet light under conditions of illuminance 80 mW/ ^cm2 and cumulative light quantity 600 mJ/ ^cm2 . A plurality of 25 μm thick film-like adhesives were laminated to a thickness of about 300 μm, which was cut into a size of 4 mm wide x 33 mm, and heated at 75 ° C for 3 hours to obtain a measurement sample. The measurement sample was set in a dynamic viscoelasticity device (Rheogel E-4000 (trade name), manufactured by UBM Co., Ltd.) with a chuck distance of 20 mm, and a tensile load was applied, and measurements were performed under conditions of a frequency of 10 Hz and a heating rate of 3 ° C / min, and the storage modulus at 35 ° C and 75 ° C was measured. The results are shown in Table 1.

<Measurement of Peel Strength Against Polyimide Film (PI Peel Strength)>
The peel strength of the film-like adhesive of each second laminate film against the polyimide film was measured by the following method. First, the second laminate film was punched out to a size of 3.2 mm x 3.2 mm. After peeling off 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 off from the film-like adhesive, and a polyimide film (Upilex 50S (trade name), manufactured by Ube Industries, Ltd.) having a size of 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 15 N for 1 second. Thereafter, the film-like adhesive was cured by heating at 75 ° C. for 3 hours to obtain a measurement sample. The PI peel strength was measured at a test speed of 50 mm / min with a 90-degree peel tester (manufactured by Tester Sangyo Co., Ltd.). The results are shown in Table 1.

<Evaluation of workability>
A polyethylene film (NF-13 (product name), Tamapoly Co., Ltd., thickness 25 μm) was placed as a protective film on the film-like adhesive of each first laminate film, and this was used as an evaluation sample. The protective film of the evaluation sample was pinched with tweezers to examine whether it was possible to peel off the protective film. When the protective film could be peeled off, it was rated as "A" for excellent workability, and when the protective film could not be peeled off, it was rated as "B".

As shown in Table 1, the laminated films (film-like adhesives) of Examples 1 to 5 had sufficiently high PI peel strength, and the protective film could be easily peeled off from the adhesive layer. From the above, it was confirmed that the thermosetting adhesive composition of the present disclosure has excellent adhesive strength and is capable of suppressing a decrease in workability when producing a laminated film.

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

Claims (16)

A thermosetting adhesive composition comprising a thermosetting resin, an inorganic filler, and a photocleavable compound that is cleaved by irradiation with ultraviolet light to generate an amine compound,
the thermosetting resin is a resin that is cured by heating in the presence of the amine compound,
The content of the inorganic filler is 1 to 22 mass% based on the total amount of the thermosetting adhesive composition,
After being irradiated with ultraviolet light under conditions of an illuminance of 80 mW/ ^cm2 and an accumulated light quantity of 600 mJ, the shear viscosity at 75°C is 3000 to 7000 Pa·s;
A thermosetting adhesive composition. The photocleavable compound is a compound having an α-aminoacetophenone skeleton.
The thermosetting adhesive composition of claim 1 . The thermosetting resin includes an epoxy resin, and the epoxy resin includes an epoxy resin that is solid at 25°C.
The thermosetting adhesive composition according to claim 1 or 2. The content of the epoxy resin that is solid at 25°C is 4 to 8 mass% based on the total amount of the thermosetting adhesive composition.
The thermosetting adhesive composition according to claim 3. Further comprising a thermoplastic resin,
The content of the thermoplastic resin is 20 to 40 mass% based on the total amount of the thermosetting adhesive composition.
The thermosetting adhesive composition according to claim 1 or 2. The glass transition temperature of the thermoplastic resin is −50 to 20° C.
The thermosetting adhesive composition according to claim 5 . After being irradiated with ultraviolet light at an illuminance of 80 mW/ ^cm2 and an accumulated light quantity of 600 mJ, and then heated at 75°C for 3 hours, the storage modulus at 75°C is 3 MPa or more.
The thermosetting adhesive composition according to claim 1 or 2. After being irradiated with ultraviolet light at an illuminance of 80 mW/ ^cm2 and an accumulated light quantity of 600 mJ, and then heated at 75°C for 3 hours, the storage modulus at 35°C is 700 MPa or less.
The thermosetting adhesive composition according to claim 1 or 2. 3. A thermosetting adhesive composition according to claim 1 or 2, which is irradiated with ultraviolet light,
The composition contains the thermosetting resin, the inorganic filler, and the amine compound,
The shear viscosity at 75°C is 3000 to 7000 Pa·s.
A thermosetting adhesive composition irradiated with ultraviolet light. A base film;
an adhesive layer provided on a surface of the base film;
Equipped with
The adhesive layer is composed of the thermosetting adhesive composition according to claim 1 or 2.
Laminated film. (A) providing 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;
(C) wire bonding the first circuit member and the second circuit member;
in this order,
The adhesive layer is formed of the thermosetting adhesive composition according to claim 1 or 2,
The method includes a step of irradiating the adhesive layer with ultraviolet light prior to the step (B).
A method for manufacturing a connector. 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.
The method for producing the connection body according to claim 11 . (A) providing 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;
(C) wire bonding the first circuit member and the second circuit member;
in that order,
The adhesive layer is formed by irradiating the thermosetting adhesive composition according to claim 9 with ultraviolet light.
A method for manufacturing a connector. 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.
The method for producing the connection body according to claim 13. a first circuit member;
a second circuit member;
an adhesive layer disposed between the first and second circuit members;
Equipped with
The adhesive layer is composed of a cured product of the thermosetting adhesive composition according to claim 1 or 2.
Connection body. a first circuit member;
a second circuit member;
an adhesive layer disposed between the first and second circuit members;
Equipped with
The adhesive layer is formed of a cured product of the ultraviolet ray irradiated thermosetting adhesive composition according to claim 9.
Connection body.

Images