JP7380687B2 - Adhesive composition and its selection method, adhesive film and its manufacturing method, and adhesive body and its manufacturing method - Google Patents

Description

The present invention relates to an adhesive composition and a method for selecting the same, an adhesive film and a method for manufacturing the same, and an adhesive body and a method for manufacturing the same.

Conventionally, semiconductor devices are manufactured through the following steps. First, a semiconductor wafer is attached to a dicing adhesive sheet, and in this state, the semiconductor wafer is diced into semiconductor chips. After that, a pickup process, a mounting process, a reflow process, a die bonding process, etc. are performed. Patent Document 1 describes an adhesive sheet (dicing/die bonding) that has both an adhesive film that has the function of fixing a semiconductor wafer in the dicing process and an adhesive film that has the function of bonding the semiconductor chip to the substrate in the die bonding process. An integrated sheet) is disclosed.

In recent years, with the evolution of semiconductor devices for small devices such as smartphones, the manufacturing process of conventional semiconductor devices has also changed significantly. For example, a process using an adhesive sheet (integrated dicing/die bonding sheet) described in Patent Document 1 that does not involve a dicing process and a die bonding process, or a process that does not involve a reflow process is being put into practical use. . In addition, the structure of the ultrasonic fingerprint authentication sensor module applied to smartphones includes, for example, a structure in which a sensor chip is assembled into a semiconductor package and then bonded to a cover glass, and a structure in which a semiconductor package is bonded to a cover glass. Structures such as these are known. Adhesive films used in such ultrasonic fingerprint authentication modules are required to be cured at low temperatures (e.g., below 100°C), and from the viewpoint of authentication accuracy, The difference in elastic modulus is small when temperature changes within a conceivable range (e.g. 20 to 65°C), and the elastic modulus is higher than a certain level even at high temperatures within that temperature range (e.g. 65°C). It is required to have elastic modulus characteristics. In order to meet such demands, selection of the adhesive composition constituting the adhesive film is particularly important.

Japanese Patent Application Publication No. 2007-288170

However, in the manufacture of semiconductor devices, etc., it is difficult to predict in advance whether an adhesive composition to be used as an adhesive film will have the above-mentioned elastic modulus characteristics after curing, and it is difficult to predict in advance whether the adhesive composition will have the above-mentioned elastic modulus characteristics after curing. There are many things I don't understand.

The present invention has been made in view of these circumstances, and its main purpose is to provide a novel method for selecting an adhesive composition for use in adhesive films.

As a result of intensive studies by the present inventors, the calorific value of the adhesive composition and the calorific value of the heated product obtained by heating the adhesive composition at a low temperature (for example, 100°C or less) were determined by differential scanning calorimetry. The ratio of the calorific value of the heated material to the calorific value of the adhesive composition when measured by (DSC) (calorific value of the heated material/calorific value of the adhesive composition) is used as an index for predicting low-temperature curability. Found it useful. Based on this knowledge, as a result of further studies, it was discovered that an adhesive composition in which the ratio is within a specific range has excellent low-temperature curability and excellent elastic modulus characteristics after curing, and the present invention was completed. I ended up doing it.

One aspect of the present invention provides a method for selecting an adhesive composition containing a thermoplastic resin, a thermosetting resin, and a cationic polymerization initiator. The method for selecting this adhesive composition is to measure the calorific value of the adhesive composition and the calorific value of the heated product obtained by heating the adhesive composition at 90°C for 2 hours, at a measurement temperature range of 30 to 300°C. An adhesive composition whose calorific value of the heated material is 10% or less of the calorific value of the adhesive composition when measured by differential scanning calorimetry at a heating rate of 10°C/min is considered good. The method includes a step of determining.

Such an adhesive composition selection method is useful for predicting in advance whether an adhesive composition to be used as an adhesive film will have the above elastic modulus characteristics after curing.

The thermoplastic resin may be a phenoxy resin. The adhesive composition may further contain an inorganic filler. The content of the inorganic filler may be 100 parts by mass or more based on 100 parts by mass of the total thermoplastic resin. The adhesive composition may further contain epoxidized polybutadiene rubber.

Another aspect of the present invention is a method for producing an adhesive film, comprising a step of forming an adhesive layer on a carrier film, the adhesive layer being made of an adhesive composition determined to be good by the above adhesive composition selection method. I will provide a.

Another aspect of the present invention provides an adhesive film comprising a carrier film and an adhesive layer made of an adhesive composition determined to be good by the above adhesive composition selection method.

Another aspect of the present invention is that the first member, the adhesive layer made of an adhesive composition determined to be good by the adhesive composition selection method described above, and the second member are arranged in this order. A step of preparing a stacked laminate and heating the laminate forms a cured layer made of a cured adhesive composition, and connects the first member and the second member via the cured layer. The present invention provides a method for producing a bonded body, which includes a step of obtaining a bonded body to which a member is bonded. The temperature at which the laminate is heated may be 100° C. or lower. The first member may be an electronic component and the second member may be a circuit board. The adhesive body may be a fingerprint authentication module.

Another aspect of the present invention is a first member, a second member, and an adhesive composition disposed between the first member and the second member, which is determined to be good by the above method for selecting the adhesive composition. The present invention provides an adhesive body comprising a cured product layer of a cured adhesive composition. The first member may be an electronic component and the second member may be a circuit board. The adhesive body may be a fingerprint authentication module.

Another aspect of the present invention is an adhesive composition containing a thermoplastic resin, a thermosetting resin, and a cationic polymerization initiator. When the calorific value of the heated object obtained by heating at 90°C for 2 hours is measured by differential scanning calorimetry under the conditions of a measurement temperature range of 30 to 300°C and a temperature increase rate of 10°C/min, the heating value of the heated object is Provided is an adhesive composition in which the amount of heat generated is 10% or less with respect to the calorific value of the adhesive composition.

The thermoplastic resin may be a phenoxy resin. The adhesive composition may further contain an inorganic filler. The content of the inorganic filler may be 100 parts by mass or more based on 100 parts by mass of the total thermoplastic resin. The adhesive composition may further contain epoxidized polybutadiene rubber.

According to the present invention, a novel method for selecting an adhesive composition for use in an adhesive film is provided. Further, according to the present invention, there are provided an adhesive film and a method for manufacturing the same, and an adhesive body and a method for manufacturing the same based on the method for selecting such an adhesive composition. Further, according to the present invention, an adhesive composition is provided that has excellent low-temperature curability and excellent elastic modulus characteristics after curing.

FIG. 1 is a schematic cross-sectional view showing one embodiment of an adhesive film. FIG. 2 is a schematic cross-sectional view showing one embodiment of a method for manufacturing an adhesive body, and FIGS. 2(a) and 2(b) are schematic cross-sectional views showing each step.

Embodiments of the present invention will be described below with appropriate reference to the drawings. However, the present invention is not limited to the following embodiments. In the following embodiments, the constituent elements (including steps, etc.) are not essential unless otherwise specified. 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.

The same applies to the numerical values and their ranges in this specification, and they do not limit the present invention. In this specification, a numerical range indicated using "-" indicates a range that includes the numerical values written before and after "-" as the minimum and maximum values, respectively. In the numerical ranges described step by step in this specification, the upper limit value or lower limit value described in one numerical range may be replaced with the upper limit value or lower limit value of another numerical range described step by step. good. Further, in the numerical ranges described in this specification, the upper limit or lower limit of the numerical range may be replaced with the value shown in the Examples.

As used herein, (meth)acrylate means acrylate or the corresponding methacrylate. The same applies to other similar expressions such as (meth)acryloyl group and (meth)acrylic copolymer.

[Method for selecting adhesive composition]
The method for selecting an adhesive composition in one embodiment includes selecting an adhesive composition containing a thermoplastic resin, a thermosetting resin, and a cationic polymerization initiator, and determining the amount of heat generated by the adhesive composition, When the calorific value of the heated product obtained by heating the agent composition at 90 ° C. for 2 hours was measured by differential scanning calorimetry under the conditions of a measurement temperature range of 30 to 300 ° C. and a temperature increase rate of 10 ° C./min, The method includes a step of determining as good an adhesive composition in which the calorific value of the heated object is 10% or less of the calorific value of the adhesive composition. According to the selection method, it is possible to predict in advance whether an adhesive composition to be used as an adhesive film has excellent low-temperature curability and excellent elastic modulus characteristics after curing. That is, in the selection method, adhesive compositions that are judged to be good tend to have excellent low-temperature curability and excellent elastic modulus characteristics after curing.

Differential scanning calorimetry can be performed using, for example, a differential scanning calorimeter (DSC Q1000, manufactured by TA Instruments Japan). The measurement conditions may be, for example, such that air is introduced at a flow rate of 10 mL/min, maintained at 30°C, and then raised at a rate of 10°C/min within a temperature range of 30 to 300°C.

The calorific value of the adhesive composition is determined, for example, by the following procedure. First, an adhesive film made of an adhesive composition is prepared. At this time, the adhesive film may be in a B-stage state. Next, differential scanning calorimetry is performed using the adhesive film under the above conditions. As a result, changes in the amount of heat generated as the adhesive film hardens are observed. Based on the observed change in calorific value, the calorific value of the adhesive composition can be determined. The calorific value of the adhesive composition can be said to be the calorific value when curing the adhesive composition.

The calorific value of the heated product obtained by heating the adhesive composition at 90° C. for 2 hours can be determined, for example, by the following procedure. In measuring the calorific value of the adhesive composition described above, an adhesive film similar to the adhesive film made of the adhesive composition used is separately prepared. Next, the adhesive film is heated at 90° C. for 2 hours using a heating device such as a heating oven to obtain a heated adhesive film. Next, differential scanning calorimetry is performed under the above conditions using the heated adhesive film. As a result, changes in the amount of heat generated as the adhesive film is cured by the heated material are observed. Based on the observed change in the calorific value, the calorific value of the heated product obtained by heating the adhesive composition at 90° C. for 2 hours can be determined. The calorific value of the heated material obtained by heating the adhesive composition at 90° C. for 2 hours can be said to be the calorific value when curing the heated material.

The calorific value of the heated adhesive composition (adhesive film) is 10% or less of the calorific value of the adhesive composition. Adhesive compositions (adhesive films) that meet these conditions tend to have excellent low-temperature curability and excellent elastic modulus characteristics after curing. The calorific value of the heated adhesive composition (adhesive film) may be 9% or less, 7% or less, 5% or less, or 3% or less with respect to the calorific value of the adhesive composition. In addition, the fact that the calorific value of the heated product of the adhesive composition (adhesive film) is 10% or less of the calorific value of the adhesive composition means that the adhesive composition (adhesive film) is heated at 90°C, This means that the curing reaction has progressed by 90% or more by heating under the conditions of time. Therefore, in the selection method, it can be said that an adhesive composition that is determined to be good has excellent low-temperature curability. Such adhesive compositions can be useful, for example, in making adhesive films used to manufacture ultrasonic fingerprint authentication modules.

<Adhesive composition>
In the adhesive composition selection method of this embodiment, an adhesive composition containing a thermoplastic resin, a thermosetting resin, and a cationic polymerization initiator can be selected. Each component of such an adhesive composition will be explained below. Note that the adhesive composition to be selected preferably does not contain conductive particles. The content of the conductive particles may be 1% by mass or less, 0.5% by mass or less, 0.1% by mass or less, or 0.01% by mass or less, based on the total amount of the adhesive composition.

(Thermoplastic resin)
The thermoplastic resin is a resin that has 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 phenoxy resin from the viewpoint of having excellent reactivity, high elastic modulus, and high Tg as an adhesive film for fingerprint authentication. In addition, thermoplastic resins include (meth)acrylic copolymers with reactive groups (hereinafter referred to as "reactive group-containing") from the viewpoint of excellent shrinkage, heat resistance, and peelability as adhesive films for semiconductor processing. meth)acrylic copolymer). Other examples of thermoplastic resins include polyurethane resin, polybutadiene rubber, and the like. The thermoplastic resins may be used alone or in combination of two or more.

Examples of the phenoxy resin include bisphenol A type, bisphenol F type, and a mixed type of bisphenol A type and bisphenol B type. The phenoxy resin may be a mixed type of bisphenol A type and bisphenol B type.

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 an acrylic rubber. Acrylic rubber, for example, may be formed by copolymerizing a monomer selected from (meth)acrylic ester and acrylonitrile, with acrylic ester as the main component. Therefore, the copolymerization component may not contain acrylonitrile.

Examples of (meth)acrylic esters include methyl acrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate, butyl acrylate, isobutyl acrylate, hexyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate, methyl methacrylate, ethyl methacrylate, propyl Examples include methacrylate, isopropyl acrylate, butyl methacrylate, isobutyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, 2-ethylhexyl methacrylate, and lauryl methacrylate. The (meth)acrylic ester may be butyl acrylate or ethyl acrylate.

The reactive group-containing (meth)acrylic copolymer may be a (meth)acrylic copolymer containing a (meth)acrylic monomer having a reactive group as a copolymerization component. Such a (meth)acrylic copolymer can be obtained by copolymerizing a (meth)acrylic monomer having a reactive group with a (meth)acrylic acid ester, acrylonitrile, or the like.

From the viewpoint of improving heat resistance, the reactive group in the (meth)acrylic monomer having a reactive group may be an epoxy group, a carboxy group, an acryloyl group, a methacryloyl group, a hydroxyl group, or an episulfide group. From the viewpoint of properties, the reactive group may be an epoxy group or a carboxy group.

The reactive group-containing (meth)acrylic copolymer may be a (meth)acrylic copolymer containing a (meth)acrylic monomer having an epoxy group as a copolymerization component. Examples of the (meth)acrylic monomer having an epoxy group include glycidyl acrylate, 4-hydroxybutyl acrylate glycidyl ether, 3,4-epoxycyclohexylmethyl acrylate, glycidyl methacrylate, 4-hydroxybutyl methacrylate glycidyl ether, 3,4-epoxy Examples include cyclohexylmethyl methacrylate. The (meth)acrylic monomer having a reactive group may be glycidyl acrylate or glycidyl methacrylate from the viewpoint of heat resistance.

When the (meth)acrylic copolymer having a reactive group contains glycidyl acrylate or glycidyl methacrylate as a copolymerization component, the total content of these is 0.1 to 20% by mass, based on the total amount of the copolymerization component. It may be 0.5 to 15% by weight, or 1.0 to 10% by weight. When the content is within the above range, it tends to be easier to achieve higher levels of flexibility, adhesiveness, and releasability of the adhesive film.

The (meth)acrylic copolymer having a reactive group may be obtained by a polymerization method such as pearl polymerization or solution polymerization. Examples of commercially available (meth)acrylic copolymers having reactive groups include HTR-860P-3CSP (trade name, manufactured by Nagase ChemteX Corporation).

The Tg of the thermoplastic resin is not particularly limited, but may be, for example, -50 to 80°C. When the Tg of the thermoplastic resin is 80° C. or lower, flexibility of the adhesive film tends to be easily ensured. Furthermore, if there are irregularities when pasting on an adherend, it tends to follow easily and has appropriate adhesion. When the Tg of the thermoplastic resin is −50° C. or higher, the flexibility of the adhesive film is prevented from becoming too high, and excellent handleability, adhesiveness, and releasability tend to be achieved.

The Tg of a thermoplastic resin is the midpoint glass transition temperature value obtained by differential scanning calorimetry (DSC). Specifically, the Tg of a thermoplastic resin should be calculated by measuring the change in calorific value under the conditions of a heating rate of 10 ° C / min and a measurement temperature of -80 to 80 ° C, and by a method in accordance with JIS K 7121:1987. I can do it.

The weight average molecular weight of the thermoplastic resin may be 40,000 or more and 2,000,000 or less. When the weight average molecular weight is 40,000 or more, heat resistance tends to be easily ensured. When the weight average molecular weight is 2,000,000 or less, a decrease in flow and adhesiveness tends to be easily suppressed. From the above viewpoint, the weight average molecular weight of the thermoplastic resin may be 500,000 or more and 2,000,000 or more, or 1,000,000 or more and 2,000,000 or less. Note that the weight average molecular weight is a polystyrene equivalent value obtained by gel permeation chromatography (GPC) using a standard polystyrene calibration curve.

(thermosetting resin)
The thermosetting resin can be used without particular limitation as long as it is a resin that hardens with heat. Examples of the thermosetting resin include epoxy resin, acrylic resin, silicone resin, phenol resin, thermosetting polyimide resin, polyurethane resin, melamine resin, and urea resin. The thermosetting resin may be used alone or in combination of two or more. The thermosetting resin may include an epoxy resin.

The epoxy resin is not particularly limited as long as it hardens and has heat resistance. Examples of the epoxy resin include bifunctional epoxy resins such as bisphenol A epoxy, phenol novolak epoxy resins, novolac epoxy resins such as cresol novolac epoxy resins, polyfunctional epoxy resins, glycidylamine epoxy resins, and heterocyclic epoxy resins. Examples include epoxy resins having a polycyclic ring, epoxy resins having an alicyclic ring, and epoxidized polybutadiene rubber. Among these, the epoxy resin may contain an epoxy resin having an alicyclic ring because it has excellent elastic modulus characteristics. Since the epoxy resin has excellent handling properties, it may further contain epoxidized polybutadiene rubber in addition to the epoxy resin having an alicyclic ring.

Commercially available epoxy resins having an alicyclic ring include, for example, HP-7200L, HP-7200H, HP-7200 (all manufactured by DIC Corporation), XD-1000 (manufactured by Nippon Kayaku Co., Ltd.), Celloxide 2021P, Examples include Celloxide 2081 (all manufactured by Daicel Corporation), Syna-Epoxy 28 (manufactured by SYANASIA Corporation), and EHPE3150 (manufactured by Daicel Corporation).

Commercially available epoxidized polybutadiene rubbers include, for example, Epolead PB4700 (manufactured by Daicel Corporation), NISSO-PB-JP-100, and NISSO-PB-JP-200 (all manufactured by Nippon Soda Corporation).

The content of the thermosetting resin may be 10 to 450 parts by weight, 70 to 300 parts by weight, or 80 to 250 parts by weight based on 100 parts by weight of the total amount of thermoplastic resin. When the content of the thermosetting resin is within the above range, the thermosetting of the adhesive composition (adhesive film) can be easily completed at low temperatures (e.g., 100°C or less), and furthermore, shrinkage due to thermosetting can be suppressed. At the same time, it tends to be easier to achieve excellent adhesion after thermosetting.

(Cationic polymerization initiator)
The cationic polymerization initiator can be used without particular limitation as long as it is a compound that generates acid or the like upon heating to initiate polymerization. Examples of cationic polymerization initiators include BF ₄ ^- , BR ₄ ^- (R represents a phenyl group substituted with two or more fluorine atoms or two or more trifluoromethyl groups), PF ₆ ^- , SbF ₆ Examples include onium salts such as sulfonium salts, phosphonium salts, ammonium salts, diazonium salts, and iodonium salts, which have , AsF ₆ ^- , etc. as a counter anion ^. One type of cationic polymerization initiator may be used alone, or two or more types may be used in combination.

From the viewpoint of low temperature curability, the cationic polymerization initiator may be a sulfonium salt, or may be a benzylsulfonium salt having a benzyl group. Commercially available benzylsulfonium salts include, for example, SI-45, SI-60, SI-80, SI-100, SI-150, SI-110, SI-360, SI-360, SI-B2A, and SI-B3A. , SI-B3, SI-B4, SI-B5 (all manufactured by Sanshin Kagaku Kogyo Co., Ltd.).

The content of the cationic polymerization initiator may be 1 to 15 parts by weight, 2 to 10 parts by weight, or 3 to 7 parts by weight based on 100 parts by weight of the total amount of thermoplastic resin. When the content of the cationic polymerization initiator is within the above range, thermal curing of the adhesive composition (adhesive film) is easily completed at low temperatures (e.g., 100°C or less), and the adhesive composition (adhesive film) is Storage stability tends to improve.

(Inorganic filler)
The adhesive composition may further contain an inorganic filler. Examples of the inorganic filler include nonmetallic inorganic fillers such as silica, alumina, boron nitride, titania, glass, iron oxide, and ceramic. One type of inorganic filler may be used alone, or two or more types may be used in combination. The inorganic filler can be appropriately selected depending on the desired function. The inorganic filler may be silica.

The surface of the inorganic filler may be treated with a silane coupling agent or the like. Examples of the silane coupling agent include trimethoxyphenylsilane, dimethyldimethoxyphenylsilane, triethoxyphenylsilane, dimethoxymethylphenylsilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris(2-methoxyethoxy)silane, N- (2-aminoethyl)-3-aminopropylmethyldimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3- Glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-isocyanatepropyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-Mercaptopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-(1,3-dimethylbutylidene)-3-(triethoxysilyl)-1-propanamine, N,N'-bis(3- Examples include (trimethoxysilyl)propyl)ethylenediamine, polyoxyethylenepropyltrialkoxysilane, and polyethoxydimethylsiloxane. One type of silane coupling agent may be used alone, or two or more types may be used in combination.

The content of the inorganic filler may be 100 parts by mass or more, 200 parts by mass or more, 300 parts by mass or more, 400 parts by mass or more, or 500 parts by mass or more, based on 100 parts by mass of the total amount of the thermoplastic resin. It may be less than 800 parts by mass or less than 800 parts by mass. When the content of the inorganic filler is within the above range, the elastic modulus characteristics of the adhesive composition (adhesive film) after curing tend to improve.

(Other ingredients)
The adhesive composition may further contain organic fillers such as carbon, rubber filler, silicone fine particles, polyamide fine particles, and polyimide fine particles as other components. The content of other components may be 0.1 to 50 parts by mass based on 100 parts by mass of the total thermoplastic resin.

(Organic solvent)
The adhesive composition can be diluted with an organic solvent and used as a varnish, if necessary. The organic solvent is not particularly limited, but can be appropriately selected based on the boiling point in consideration of volatility during film formation and the like. From the viewpoint of suppressing the curing of the film during film formation, the organic solvent includes, for example, methanol, ethanol, 2-methoxyethanol, 2-ethoxyethanol, 2-butoxyethanol, methyl ethyl ketone, acetone, methyl isobutyl ketone, toluene, An organic solvent with a relatively low boiling point such as xylene may also be used. The organic solvent may be an organic solvent with a relatively high boiling point, such as dimethylacetamide, dimethylformamide, N-methyl-2-pyrrolidone, or cyclohexanone, from the viewpoint of improving film-forming properties. The organic solvents may be used alone or in combination of two or more.

The content of the organic solvent may be 20 to 400 parts by weight based on 100 parts by weight of the total adhesive composition.

[Adhesive film]
An adhesive film of one embodiment includes a carrier film and an adhesive layer made of an adhesive composition determined to be good by the above adhesive composition selection method. FIG. 1 is a schematic cross-sectional view showing one embodiment of an adhesive film. The adhesive film 10 includes a carrier film 1 and an adhesive layer 3. The adhesive film 10 may further include a protective film 5 on the surface of the adhesive layer 3 opposite to the carrier film 1 .

(carrier film)
The material of the carrier film 1 is not particularly limited as long as it can sufficiently withstand the tension applied during the manufacturing process of the adhesive film 10 and the manufacturing process of the semiconductor device. The carrier film 1 may be transparent from the viewpoint of visibility of the adhesive layer 3 and further the protective film 5 arranged thereon. Examples of the carrier film 1 include polyester films such as polyethylene terephthalate film; polytetrafluoroethylene film, polyethylene film, polypropylene film, polymethylpentene film, polyvinyl acetate film, poly-4-methylpentene-1, and ethylene-acetic acid. Examples include polyolefin films such as vinyl copolymers and ethylene-ethyl acrylate copolymers; plastic films such as polyvinyl chloride films and polyimide films. The carrier film 1 may have a single layer structure or a multilayer structure.

In order to increase the adhesion between the carrier film 1 and the adhesive layer 3, the surface of the carrier film 1 may be subjected to chemical or physical treatments such as corona treatment, chromic acid treatment, ozone exposure, flame exposure, high voltage electric shock exposure, and ionizing radiation treatment. surface treatment may be applied. The carrier film 1 may be a low surface energy film made of fluororesin. Examples of such films include A-63 (mold release agent: modified silicone type) manufactured by Teijin DuPont Films Ltd., A-31 (mold release agent: Pt silicone type) manufactured by Teijin DuPont Films Ltd. ) etc.

In order to prevent the adhesion between the carrier film 1 and the adhesive layer 3 from becoming too high, the surface of the carrier film 1 is coated with a silicone release agent, a fluorine release agent, a long chain alkyl acrylate release agent, etc. A mold release layer made of a mold release agent may be provided.

The thickness of the carrier film 1 can 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 pose no practical problems and are economically effective ranges.

(Adhesive layer)
The adhesive layer 3 is a layer made of an adhesive composition determined to be good by the above adhesive composition selection method, and is provided on the carrier film 1. As a method for forming the adhesive layer 3 on the carrier film 1, for example, a varnish of an adhesive composition is prepared, the varnish is applied to the carrier film 1, volatile components of the varnish are removed, and the adhesive is formed. Examples include a method of forming the adhesive layer 3, and a method of forming a film made of an adhesive composition in advance and transferring it to the carrier film 1.

The thickness of the adhesive layer 3 can be appropriately selected within a range that does not impair workability, and may be, for example, 1 to 200 μm, 3 to 150 μm, or 5 to 150 μm. When the thickness of the adhesive layer 3 is 1 μm or more, sufficient adhesiveness tends to be easily ensured, and when the thickness is 200 μm or less, the adhesive composition constituting the adhesive layer 3 does not protrude from the protective film 5. tends to be easily suppressed.

(Protective film)
Examples of the protective film 5 include polyester films such as polyethylene terephthalate film; polytetrafluoroethylene film, polyethylene film, polypropylene film, polymethylpentene film, polyvinyl acetate film, poly-4-methylpentene-1, and ethylene-acetic acid. Examples include polyolefin films such as vinyl copolymers and ethylene-ethyl acrylate copolymers; plastic films such as polyvinyl chloride films and polyimide films. The protective film 5 may have a single layer structure or a multilayer structure.

The thickness of the protective film 5 can 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 pose no practical problems and are economically effective ranges.

[Method for manufacturing adhesive film]
A method for manufacturing an adhesive film according to one embodiment includes a step of forming an adhesive layer made of an adhesive composition determined to be good by the above adhesive composition selection method.

In the method for manufacturing an adhesive film of this embodiment, for example, first, a varnish of an adhesive composition for the adhesive layer 3 is prepared. After coating this varnish on the carrier film 1, the adhesive layer 3 is formed by removing the solvent. Coating methods include knife coating, roll coating, spray coating, gravure coating, bar coating, curtain coating, and the like.

Note that the varnish is applied to a base material different from the carrier film 1, a film made of the adhesive composition is formed by removing the solvent, and the film made of the formed adhesive composition is applied to the carrier film 1. The adhesive layer 3 can also be formed by doing this.

Further, if necessary, the adhesive film manufacturing method may include a step of providing a protective film 5 on the surface of the adhesive layer 3 opposite to the carrier film 1. The protective film 5 can be attached to the surface of the adhesive layer 3 at a temperature in the range of 20 to 60°C.

[Method for manufacturing adhesive body]
In one embodiment, a method for manufacturing an adhesive body includes a first member, an adhesive layer made of an adhesive composition determined to be good by the above adhesive composition selection method, and a second member. A step of preparing a laminate in which the laminate is laminated in this order, and heating the laminate to form a cured material layer made of a cured product of the adhesive composition, and to bond the first member and the first member through the cured material layer. and obtaining a bonded body in which the second member is bonded.

FIG. 2 is a schematic cross-sectional view showing one embodiment of a method for manufacturing an adhesive body, and FIGS. 2(a) and 2(b) are schematic cross-sectional views showing each step. First, a laminate 20 in which a first member 11, an adhesive layer 13, and a second member 12 are laminated in this order is prepared (see FIG. 2(a)). The laminate 20 can be obtained, for example, by arranging the adhesive film described above on the first member 11 and then arranging the second member 12 on the adhesive film. At this time, thermocompression bonding may be performed. The thermocompression bonding conditions can be appropriately set depending on the types of the first member 11 and the second member 12.

The first member may be, for example, an electronic component such as a semiconductor chip, a capacitor, a diode, a sensor (for example, a fingerprint authentication sensor), or the like. The second member may be, for example, a circuit board such as a printed circuit board, a flexible printed circuit board, a glass epoxy board, a glass substrate, or a sensor board (for example, a fingerprint authentication sensor board).

Subsequently, by heating the laminate 20, the adhesive layer 13 is cured to form a cured material layer 13c made of a cured product of the adhesive composition, and the first member 11 is bonded via the cured material layer 13c. A bonded body 30 is obtained in which the and second member 12 are bonded together (see FIG. 2(b)). The device for heating the laminate 20 is not particularly limited as long as it can heat it, and may be a heating oven or the like. The conditions for heating the laminate 20 are as follows: The adhesive composition determined to be good by the adhesive composition selection method described above has excellent curability at low temperatures (for example, 100°C or lower). It's good.

[Adhesive body]
The adhesive body of one embodiment is determined to be good by the above-mentioned method for selecting an adhesive composition, the adhesive composition being disposed between a first member, a second member, and the first member and the second member. and a cured product layer made of a cured product of the adhesive composition.

The adhesive body 30 may be a semiconductor device. The semiconductor device may be a semiconductor device used in computers, mobile phones, televisions, motorcycles, automobiles, trains, ships, aircraft, etc. The adhesive composition 30 was manufactured because the adhesive composition determined to be good by the above adhesive composition selection method has excellent curability at low temperatures (for example, 100° C. or lower) and excellent elastic modulus characteristics. The semiconductor device may include an electronic component and a circuit board that require such properties in a process. An example of such a semiconductor device is an ultrasonic fingerprint authentication module.

In one embodiment, a method for manufacturing an adhesive body includes a first member, an adhesive layer made of an adhesive composition determined to be good by the above adhesive composition selection method, and a second member. A step of preparing a laminate in which the laminate is laminated in this order, and heating the laminate to form a cured material layer made of a cured product of the adhesive composition, and to bond the first member and the first member through the cured material layer. and obtaining a bonded body in which the second member is bonded.

[Adhesive composition]
The adhesive composition of one embodiment is an adhesive composition containing a thermoplastic resin, a thermosetting resin, and a cationic polymerization initiator, and the adhesive composition has a heating value of The calorific value of the heated material obtained by heating the material at 90°C for 2 hours was measured by differential scanning calorimetry under the conditions of a measurement temperature range of 30 to 300°C and a heating rate of 10°C/min. The calorific value is 10% or less of the calorific value of the adhesive composition. The components contained in the adhesive composition and their contents may be the same as those described in the selection method above.

The thermoplastic resin may be a phenoxy resin. The adhesive composition may further contain an inorganic filler. The content of the inorganic filler may be 100 parts by mass or more based on 100 parts by mass of the total thermoplastic resin. The adhesive composition may further contain epoxidized polybutadiene rubber.

EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples.

[Preparation of adhesive film]
(Preparation of varnish of adhesive composition)
Varnishes of the adhesive compositions of Production Examples 1 to 5 were prepared by mixing the materials shown in Table 1 in the proportions shown in Table 1 (unit: parts by mass) until uniform and vacuum degassing.

Details of each material are as follows.

(A) Component: Thermoplastic resin A-1: Phenotote ZX-1356-2 (trade name, manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., phenoxy resin)
A-2: KH-LT (trade name, manufactured by Hitachi Chemical Co., Ltd., glycidyl group-containing acrylic rubber, weight average molecular weight: 1.25 million, Tg: -40°C)

(B) Component: Thermosetting resin B-1: HP-7200L (trade name, manufactured by DIC Corporation, dicyclopentadiene type epoxy resin, epoxy equivalent: 247 g/eq)
B-2: Celloxide 2021P (trade name, manufactured by Daicel Corporation, bifunctional epoxy resin, epoxy equivalent: 252 g/eq)
B-3: Epolead PB4700 (trade name, manufactured by Daicel Corporation, epoxidized polybutadiene rubber, epoxy equivalent: 160 g/eq)

(C) Component: Cationic polymerization initiator C-1: Sanaid SI-B3A (trade name, manufactured by Sanshin Kagaku Kogyo Co., Ltd., benzyl sulfonium salt)
C-2: Sunaid SI-B7 (trade name, manufactured by Sanshin Chemical Industry Co., Ltd., benzylsulfonium salt)

(D) Component: Inorganic filler D-1: SC-2050-HLG (trade name, manufactured by Admatex Co., Ltd., surface treated silica filler)

(E) Component: Organic solvent E-1: Cyclohexanone

(Preparation of adhesive film)
The resulting adhesive composition varnish was applied onto a surface-release-treated polyethylene terephthalate film (carrier film, manufactured by Teijin DuPont Films Ltd., trade name: Teijin Tetron Film A-31B) with a thickness of 38 μm. After a drying process, an adhesive film was obtained that had an adhesive layer with a thickness of 20 μm on one side of the carrier film. A 20 μm thick polyethylene film (manufactured by Tamapoly Co., Ltd., trade name: NF-13) was attached as a protective film to the surface of the adhesive layer of the adhesive film opposite to the carrier film.

[Evaluation of adhesive film]
(Measurement of the ratio of the calorific value of the heated object to the calorific value of the adhesive composition)
Two adhesive films of Production Examples 1 to 5 were prepared. One adhesive film was heated in an oven at 90° C. for 2 hours to obtain a heated adhesive film, which is a heated adhesive film. Differential scanning calorimetry was carried out using the adhesive film without heat treatment (B stage state) and the adhesive film after heating under the conditions of a measurement temperature range of 30 to 300 °C and a temperature increase rate of 10 °C/min (measuring device: The calorific value of each was determined using a differential scanning calorimeter (manufactured by TA Instruments Japan, DSC Q1000). From the calculated calorific value, the ratio of the calorific value of the adhesive film (heated object) after heating to the calorific value of the adhesive film (adhesive composition) (calorific value of the adhesive film (heated object) after heating/adhesive film (adhesive) The calorific value of the agent composition) was determined as a percentage. The results are shown in Table 1.

(Evaluation of loss elasticity)
The 20 μm thick adhesive layer of the obtained adhesive films of Production Examples 1 to 5 was laminated onto a Teflon (registered trademark) sheet, and rolled (temperature 60°C, linear pressure 0.2 MPa, feed speed 0.5 m/min). ). Thereafter, the carrier film of the adhesive film was peeled off, and another adhesive layer with a thickness of 25 μm was superimposed on the adhesive layer on the Teflon (registered trademark) sheet, and laminated under pressure. By repeating this process, the layers were laminated until the thickness reached about 200 μm, and a rectangular parallelepiped with a width of 4 mm and a length of 33 mm was cut out. The cut out rectangular parallelepiped was heated at 90° C. for 2 hours to obtain an evaluation sample. The loss modulus E' of the obtained evaluation sample was measured using a dynamic viscoelasticity measuring instrument (manufactured by UBM Co., Ltd., product name: Rheogel-E4000), measurement mode: temperature dependence, amplitude: 10 μm, between chucks. Measured at distance: 20 mm, heating rate: 3°C/min, frequency: 10Hz, ratio of loss elastic modulus E' at 65°C to loss modulus E' at 30°C (maintenance rate of loss elastic modulus, 65°C The loss elastic modulus E'/loss elastic modulus E' at 30° C. was determined. The results are shown in Table 1.

The loss modulus E' at 65°C was evaluated based on the following criteria.
A: The loss modulus E' at 65°C is 3 GPa or more.
B: The loss modulus E' at 65° C. is 2 GPa or more and less than 3 GPa.
C: The loss modulus E' at 65° C. is 1 GPa or more and less than 2 GPa.
D: Loss modulus E' at 65°C is less than 1 GPa.

The retention rate of loss elasticity was evaluated based on the following criteria.
A: The retention rate of loss modulus is 0.8 or more.
B: The retention rate of loss modulus is 0.6 or more and less than 0.8.
C: The retention rate of loss modulus is 0.4 or more and less than 0.6.
D: The retention rate of loss modulus is less than 0.4.

(Evaluation of handling performance)
The adhesive films of Production Examples 1 to 3, which had excellent loss modulus evaluations, were evaluated for handling property by stretching the adhesive films by hand.

Handlability was evaluated based on the following criteria.
A: It did not break.
B: Broken.

As shown in Table 1, the adhesive films of Production Examples 1 to 3 satisfied the condition that the calorific value of the heated material was 10% or less of the calorific value of the adhesive composition. It was found that the adhesive films of Production Examples 1 to 3 had a high loss modulus E' at 65°C and a high ratio of the loss modulus E' at 65°C to the loss modulus E' at 30°C. On the other hand, the adhesive films of Production Examples 4 and 5, which do not satisfy the condition that the calorific value of the heated material is 10% or less of the calorific value of the adhesive composition, are insufficient in the evaluation of loss modulus. It turned out to be.

According to the present invention, a novel method for selecting an adhesive composition for use in an adhesive film is provided. Further, according to the present invention, there are provided an adhesive film and a method for manufacturing the same, and an adhesive body and a method for manufacturing the same based on the method for selecting such an adhesive composition. Further, according to the present invention, an adhesive composition is provided that has excellent low-temperature curability and excellent elastic modulus characteristics after curing.

DESCRIPTION OF SYMBOLS 1... Carrier film, 3, 13... Adhesive layer, 5... Protective film, 10... Adhesive film, 11... First member, 12... Second member, 13c... Cured material layer, 20... Laminate, 30... Adhesive body.

Claims (13)

A method for selecting an adhesive composition containing a thermoplastic resin, a thermosetting resin, a cationic polymerization initiator , and an inorganic filler, the method comprising:
The calorific value of the adhesive composition and the calorific value of the heated product obtained by heating the adhesive composition at 90°C for 2 hours were measured at a temperature range of 30 to 300°C and a heating rate of 10°C/min. a step of determining as good an adhesive composition in which the calorific value of the heated object is 10% or less of the calorific value of the adhesive composition when measured by differential scanning calorimetry under the conditions ,
The thermoplastic resin is a phenoxy resin,
The thermosetting resin includes an epoxy resin having an alicyclic ring,
the cationic polymerization initiator is a sulfonium salt,
A method for selecting an adhesive composition, wherein the content of the inorganic filler is 500 to 1000 parts by mass based on 100 parts by mass of the total amount of the thermoplastic resin. The method for selecting an adhesive composition according to claim 1 , wherein the thermosetting resin further includes epoxidized polybutadiene rubber. A method for manufacturing an adhesive film, comprising the step of forming an adhesive layer made of an adhesive composition determined to be good by the adhesive composition selection method according to claim 1 or 2 on a carrier film. carrier film,
An adhesive layer made of an adhesive composition determined to be good by the adhesive composition selection method according to claim 1 or 2 ;
Adhesive film. A first member, an adhesive layer made of an adhesive composition determined to be good by the method for selecting an adhesive composition according to claim 1 or 2 , and a second member are laminated in this order. a step of preparing a laminate containing;
A cured product layer made of a cured product of the adhesive composition is formed by heating the laminate, and the first member and the second member are bonded via the cured product layer. The process of obtaining a body,
A method for manufacturing an adhesive body, comprising: The method for manufacturing an adhesive body according to claim 5 , wherein the temperature at which the laminate is heated is 100°C or less. The method for manufacturing an adhesive body according to claim 5 or 6 , wherein the first member is an electronic component and the second member is a circuit board. The method for manufacturing an adhesive body according to any one of claims 5 to 7 , wherein the adhesive body is a fingerprint authentication module. a first member;
a second member;
A cured product comprising a cured product of an adhesive composition determined to be good by the adhesive composition selection method according to claim 1 or 2 , which is disposed between the first member and the second member. layer and
An adhesive body comprising: The adhesive body according to claim 9 , wherein the first member is an electronic component and the second member is a circuit board. The adhesive body according to claim 9 or 10 , which is a fingerprint authentication module. An adhesive composition containing a thermoplastic resin, a thermosetting resin, a cationic polymerization initiator, and an inorganic filler ,
The calorific value of the adhesive composition and the calorific value of the heated product obtained by heating the adhesive composition at 90°C for 2 hours were measured at a temperature range of 30 to 300°C and a heating rate of 10°C/min. When measured by differential scanning calorimetry under the following conditions, the calorific value of the heated object is 10% or less of the calorific value of the adhesive composition,
The thermoplastic resin is a phenoxy resin,
The thermosetting resin includes an epoxy resin having an alicyclic ring,
the cationic polymerization initiator is a sulfonium salt,
An adhesive composition in which the content of the inorganic filler is 500 to 1000 parts by mass based on 100 parts by mass of the total amount of the thermoplastic resin . 13. The adhesive composition of claim 12 , wherein the thermosetting resin further comprises epoxidized polybutadiene rubber.

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