TWI761501B - Film for sealing, sealing structure, and manufacturing method of sealing structure - Google Patents

Abstract

The present invention is a sealing film (2), which is composed of a resin composition containing: a thermosetting component, an inorganic filler, and a carboxyl group-containing elastomer having a carboxyl group equivalent weight of 270 to 4300 g/eq.; and , the content of the carboxyl group-containing elastomer, based on the total amount of the thermosetting component and the carboxyl group-containing elastomer, is less than 40% by mass.

Description

Film for sealing, sealing structure, and manufacturing method of sealing structure

The present invention relates to a film for sealing, a sealing structure, and a method for producing the sealing structure.

In recent years, with the development of electronic equipment, such as smart phones, etc., which are produced on the premise of being portable, semiconductor devices are being reduced in size and thickness. The demand for change is high. Therefore, various technologies for encapsulating electronic components having movable parts such as surface acoustic wave (SAW) elements are being studied. A SAW element is an electronic component in which regular comb-shaped electrodes are formed on a piezoelectric film or a piezoelectric substrate, and is an electronic component capable of extracting electrical signals in a specific frequency band using surface acoustic waves.

When encapsulating such an electronic component having a movable portion, it is necessary to provide a space for securing the movability of the movable portion. For example, in a SAW element, if another substance adheres to the surface on which the comb-shaped electrodes are formed, desired frequency characteristics cannot be obtained, and therefore it becomes necessary to form a hollow structure.

Conventionally, in order to form a hollow structure, a sealing method in which a rib or the like is formed on a piezoelectric substrate and then a lid is closed (Patent Document 1) has been performed. However, in this method, since the number of steps increases and the height of the sealing portion is high, there is a problem that it is difficult to reduce the thickness of the electronic component device.

Therefore, there has been proposed a method of preparing a hollow structure in which the wafer on which the comb-shaped electrodes are formed is inverted via bumps, and performing wafer sealing in a state in which a hollow region is provided between the substrate and the wafer. A wafer is mounted on a substrate (for example, Patent Documents 2 and 3). [Prior Art Literature] (Patent Literature)

Patent Document 1: Japanese Patent Laid-Open No. 2002-16466 Patent Document 2: Japanese Patent No. 4989402 Patent Document 3: Japanese Patent Laid-Open No. 2016-175976

[Problems to be Solved by the Invention] When the sealed body is sealed with the hollow region provided between the substrate and the sealed body to obtain a hollow sealed structure (for example, an electronic component device), it is necessary to suppress the sealing material (structure The resin composition of the sealing film) flows into the hollow region. On the other hand, in the methods of Patent Documents 2 and 3, since the elastomer component is contained in a high concentration, even if the flow of the sealing material into the hollow region can be suppressed, there is still a concern that the glass transition temperature (Tg) of the cured product is greatly lowered, And the reliability (especially thermal reliability) of a hollow sealing structure falls. For example, when the thermosetting component and the elastomer component form a sea-island structure, Tg derived from the elastomer component exists in the low temperature region, but since the thermal expansion coefficient of the resin changes greatly before and after Tg, the elasticity of high concentration The body composition is one of the reasons for reducing the reliability of the hollow sealing structure.

Accordingly, an object of the present invention is to provide a sealing film capable of sufficiently suppressing the flow of a sealing material into a substrate and a to-be-sealed body, a sealing structure using the sealing film, and a method for producing the sealing structure. The hollow area between, and can form a hardened product with sufficient glass transition temperature. [Technical means to solve the problem]

The present inventors have conducted research on the premise that the less the amount of the elastomer to be added, the better, from the viewpoint of avoiding a decrease in Tg. Furthermore, from the viewpoint of sufficiently suppressing the flow of the sealing material (the resin composition constituting the sealing film) into the hollow region, the state and action of the ideal elastomer component are considered as follows. (1) From the viewpoint that the elastomer component acts as a resistance to the flow of the resin composition and can suppress the flow of the resin composition, the shape of the elastomer component in the resin composition is preferably linear rather than excessively coiled. (2) From the viewpoint that the flow of the resin composition is restrained by the elastomer component and the flow of the resin component can be suppressed, it is preferable that the elastomer component is pseudo-polymerized by intermolecular interaction.

As a result of intensive studies from the above viewpoints, the present inventors found that by using an elastomer having a specific carboxyl group equivalent, the amount of the elastomer component to be added can be reduced, and the resin composition can be sufficiently suppressed from flowing into the hollow region, thereby completing the present invention.

That is, one aspect of the present invention relates to a sealing film comprising a resin composition containing a thermosetting component, an inorganic filler, and a carboxyl group-containing elastic material having a carboxyl group equivalent weight of 270 to 4300 g/eq. Furthermore, the content of the carboxyl group-containing elastomer is less than 40% by mass based on the total amount of the thermosetting component and the carboxyl group-containing elastomer. According to this sealing film, it is possible to sufficiently suppress the sealing material from flowing into the hollow region between the substrate and the body to be sealed. That is, the said film for sealing is excellent in the hollow non-filling property. Moreover, according to the said film for sealing, the hardened|cured material which has a sufficient glass transition temperature (Tg) can be formed.

The content of the elastomer component including the carboxyl group-containing elastomer contained in the resin composition may be 2 mass % or more and less than 40 mass % based on the total amount of the thermosetting component and the elastomer component. . In this case, the hollow non-filling property is more excellent, and it is easy to obtain a more sufficient Tg after hardening.

The content of the structural unit having a carboxyl group in the carboxyl group-containing elastomer may be 2 to 35 mol % based on the total amount of the structural units constituting the carboxyl group-containing elastomer. In this case, the hollow non-filling property is more excellent, and it is easy to obtain a more sufficient Tg after hardening.

The above-mentioned carboxyl group-containing elastomer may contain a (meth)acrylic acid-derived structural unit. In this case, the hollow non-filling property is more excellent, and it is easy to obtain a more sufficient Tg after hardening.

The weight average molecular weight of the carboxyl group-containing elastomer may be 300,000 to 10,000,000. In this case, the hollow non-filling property is more excellent, and it is easy to obtain a more sufficient Tg after hardening.

The above-mentioned thermosetting component may contain epoxy resin and phenol resin. In this case, the physical properties (for example, heat resistance (Tg) and dimensional stability (thermal expansion coefficient)) of the cured film and the reliability of the SAW element can be improved.

Content of the said inorganic filler may be 90 mass % or less based on the total mass of the said film for sealing. In this case, it is easy to obtain excellent embedding properties with respect to the to-be-sealed body.

The film thickness of the said sealing film may be 20-400 micrometers.

The above-described film for sealing can be suitably used for sealing a body to be sealed, which is provided on a substrate with bumps interposed therebetween.

One aspect of the present invention relates to a method for producing a sealing structure, which prepares a hollow structure including a substrate and a to-be-sealed body provided on the substrate with bumps interposed therebetween, wherein the substrate and the above-mentioned A hollow area is provided between the bodies to be sealed; and the body to be sealed is sealed by the film for sealing of the present invention. According to this method, the flow of the sealing material into the hollow region between the substrate and the body to be sealed can be sufficiently suppressed. Moreover, since the to-be-hardened object can be sealed with the hardened|cured material which has sufficient Tg, the sealing structure excellent in reliability (thermal reliability) can be obtained.

In the above-described manufacturing method, the body to be sealed may be a SAW element having electrodes on the side of the hollow region. In the above-mentioned manufacturing method, the sealing material can be sufficiently suppressed from adhering to the surface having the electrodes of the SAW element, and the SAW element can be sealed with a cured product having a sufficient Tg. Therefore, according to the above-described manufacturing method, the reliability of the SAW element can be improved. Moreover, for the same reason, the above-mentioned manufacturing method can improve the yield when manufacturing the sealing structure (hollow sealing structure) provided with such a to-be-sealed body.

One aspect of the present invention relates to a sealing structure including: a substrate; a body to be sealed provided on the substrate with bumps interposed therebetween; The body to be sealed is sealed; and a hollow region is provided between the substrate and the body to be sealed. In this sealing structure, the hollow region is sufficiently secured, and the body to be sealed is sealed with a hardened material having a sufficient Tg.

In the above-described sealing structure, the body to be sealed may be a SAW element having electrodes on the side of the hollow region. In this sealing structure, the adhesion of the sealing material to the surface having the electrodes of the SAW element is sufficiently suppressed, and the SAW element is sealed by the hardened material having a sufficient Tg. Therefore, the reliability of the SAW element is excellent. [Effect of invention]

According to the present invention, it is possible to provide a sealing film capable of sufficiently suppressing the flow of a sealing material between a substrate and a body to be sealed, a sealing structure using the sealing film, and a method for producing the sealing structure. , and can form a hardened product with a sufficient glass transition temperature (Tg).

In the numerical range represented using "-" in this specification, the numerical value described before and after "-" is included as a minimum value and a maximum value, respectively. In the numerical range described in steps in this specification, the upper limit or the lower limit of the numerical range in one stage can be replaced with the upper limit or the lower limit of the numerical range in another stage. In the numerical range described in this specification, the upper limit or the lower limit of this numerical range can be replaced with the numerical value shown in an Example. "A or B" means that any one of A and B may be included, or both of them may be included. The materials exemplified in this specification may be used alone or in combination of two or more, unless otherwise specified. In this specification, when there are plural substances in the composition to correspond to each component, unless otherwise specified, the content of each component in the composition means the total amount of the plural substances present in the composition.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

<Film for sealing> The film for sealing according to the present embodiment is a film-like resin composition containing a thermosetting component, an inorganic filler, and an elastomer component (softener, flexibilizer), that is, a carboxyl group equivalent of 270. -4300 g/eq. of carboxyl-containing elastomer. In the present embodiment, the content of the carboxyl group-containing elastomer having a carboxyl group equivalent of 270 to 4300 g/eq. may be less than 40 mass % based on the total amount of the thermosetting component and the carboxyl group-containing elastomer. Moreover, in the present embodiment, the content of the elastomer component (including the carboxyl group-containing elastomer) contained in the resin composition may be 2 mass % or more based on the total amount of the thermosetting component and the elastomer component. and less than 40% by mass.

The sealing film of the present embodiment is suitable for use with a hollow structure including a substrate, a body to be sealed (for example, an electronic component such as a SAW element) provided on the substrate, and a body to be sealed provided on the substrate and the body to be sealed the hollow area in between. According to the above-described film for sealing, it is possible to sufficiently suppress the sealing material from flowing into the hollow region between the substrate and the body to be sealed. Moreover, according to the said film for sealing, since the hardened|cured material which has a sufficient glass transition temperature can be formed, the sealing structure excellent in reliability (thermal reliability) can be obtained. The reason why such an effect can be obtained is unknown, but the present inventors speculate as follows.

That is, first, when the carboxyl group equivalent of the elastomer is less than 270 g/eq., the polarity of the elastomer increases, so it is presumed that the molecular chain of the elastomer has a coil-like structure in the sealing film (in the resin composition). As described above, when the elastic body is excessively coiled, it is considered that the resistance effect, which can suppress the fluidity of the resin composition in the sealing film, is small. Therefore, in order to sufficiently suppress the flow of the sealing material into the hollow region, it is presumed that a large amount of the elastomer component needs to be added. On the other hand, when the carboxyl group equivalent is larger than 4300 g/eq., the polarity of the elastomer decreases, so it is presumed that the molecular chain of the elastomer has a nearly linear structure in the sealing film (in the resin composition), but the polar group also That is, there are fewer carboxyl groups, so it is speculated that the interaction between the molecular chains is smaller. In this case, since the interaction between molecular chains is small, the effect of suppressing the fluidity of the resin composition in the sealing film by adding the elastomer component is presumably obtained only with the elastomer component. Add the corresponding effect. On the other hand, the film for sealing of this embodiment contains the elastomer whose carboxyl group equivalent is 270-4300 g/eq. It is presumed that the elastomer maintains a straight chain shape in the resin composition, and further, the molecular chains of the elastomer are pseudo-polymerized by the interaction of the carboxyl groups (that is, the molecular chains of the elastomer form a three-dimensional network). Therefore, in the above-mentioned film for sealing, the addition amount of the elastomer component can be made smaller than that in the past, and as a result, it is presumed that the above-mentioned effect can be obtained.

In addition, when the sealing film contains a high concentration of the elastomer component, it is presumed that due to the influence of the Tg derived from the elastomer component in the low temperature region, the amount of thermal expansion at the time of assembling the electronic component device changes more, and the Defects (warping, cracking, etc.) are prone to occur. On the other hand, in the film for sealing of this embodiment, since content of an elastomer component is in the said range, it can reduce the trouble at the time of packaging.

In addition, when a high concentration of an elastomer component is contained in the film for sealing, sufficient embedding properties with respect to a to-be-sealed body may not be obtained. On the other hand, in the film for sealing of this embodiment, since the addition amount of an elastomer component can be reduced, sufficient embedding property with respect to a to-be-sealed body can be easily obtained.

(Thermosetting component) As a thermosetting component, a thermosetting resin, a hardening agent, a hardening accelerator, etc. are mentioned. The thermosetting component may contain a thermosetting resin without containing a curing agent and/or a curing accelerator.

[Thermosetting resin] Examples of the thermosetting resin include epoxy resin, phenoxy resin, cyanate resin, thermosetting polyimide, melamine resin, urea resin, unsaturated polyester, alkyd Resin, Polyurethane, etc. From the viewpoint of easy control of the fluidity and hardening reactivity of the resin, epoxy resins are preferred.

As an epoxy resin, if it is resin which has two or more epoxy groups in one molecule, it can be used without a restriction|limiting in particular. Examples of epoxy resins include bisphenol A type epoxy resin, bisphenol AP type epoxy resin, bisphenol AF type epoxy resin, bisphenol B type epoxy resin, bisphenol BP type epoxy resin, bisphenol BP type epoxy resin, Phenol C type epoxy resin, bisphenol E type epoxy resin, bisphenol F type epoxy resin, bisphenol G type epoxy resin, bisphenol M type epoxy resin, bisphenol S type epoxy resin (hexanediol Bisphenol S diglycidyl ether, etc.), bisphenol P type epoxy resin, bisphenol PH type epoxy resin, bisphenol TMC type epoxy resin, bisphenol Z type epoxy resin, phenol novolac type epoxy resin Resin, biphenyl type epoxy resin, naphthalene type epoxy resin, dicyclopentadiene type epoxy resin, bixylenol type epoxy resin (bixylenol diglycidyl ether, etc.), hydrogenated bisphenol A type epoxy resins (hydrogenated bisphenol A glycidyl ether, etc.); and, dibasic acid-modified diglycidyl ether type epoxy resins of these resins; aliphatic epoxy resins, etc. As for the epoxy resin, one type may be used alone, or two or more types may be used in combination.

The epoxy resin may be a liquid epoxy resin (liquid epoxy resin) at 25° C. from the viewpoint of easily suppressing the occurrence of cracks and cracks on the surface of the film. Examples of liquid epoxy resins include bisphenol A type glycidyl ether, bisphenol AD type glycidyl ether, bisphenol S type glycidyl ether, bisphenol F type glycidyl ether, Hydrogenated bisphenol A glycidyl ether, ethylene oxide adduct bisphenol A glycidyl ether, propylene oxide adduct bisphenol A glycidyl ether, glycidyl ether of naphthalene resin, 3-functional or 4-functional glycidylamine, etc. In addition, "liquid state at 25 degreeC" means that the viscosity at 25 degreeC measured by an E-type viscometer is 400 Pa･s or less.

Examples of commercially available epoxy resins include trade name "jER825" (bisphenol A epoxy resin, epoxy group equivalent: 175 g/eq.) manufactured by Mitsubishi Chemical Corporation, manufactured by Mitsubishi Chemical Corporation, for example. trade name "jER806" (bisphenol F type epoxy resin, epoxy equivalent: 160 g/eq.), trade name "HP-4032D" manufactured by DIC Co., Ltd. (naphthalene type epoxy resin, epoxy equivalent : 141g/eq.), trade name "EXA-4850" manufactured by DIC Co., Ltd., and other soft and tough epoxy resins; trade name "HP-4700" manufactured by DIC Co., Ltd. (tetrafunctional naphthalene type epoxy resin) , trade name "HP-4750" (3-functional naphthalene type epoxy resin), trade name "HP-4710" (tetra-functional naphthalene type epoxy resin), trade name "EPICLON N-770" (phenol novolak type epoxy resin) resin), trade name "EPICLON N-660" (cresol novolak type epoxy resin) and trade name "EPICLONHP-7200H" (dicyclopentadiene type epoxy resin); trade name manufactured by Nippon Kayaku Co., Ltd. "EPPN-502H" (triphenylmethane type epoxy resin) and trade name "NC-3000" (biphenyl alkyl type epoxy resin); trade name "ESN- 355” (naphthalene type epoxy resin); trade name “YX-8800” (anthracene type epoxy resin) manufactured by Mitsubishi Chemical Co., Ltd., trade name “ESCN-190-2” manufactured by Sumitomo Chemical Co., Ltd. cresol novolac epoxy resin), etc. These epoxy resins may be used alone or in combination of two or more.

From the viewpoint of easily obtaining excellent fluidity, the content of the thermosetting resin is preferably 1 mass % or more, more preferably 3 mass %, and still more preferably 4 mass % based on the total mass of the sealing film. % by mass or more, particularly preferably 5% by mass or more, very preferably 10% by mass or more, and very preferably 15% by mass or more. From the viewpoint of easily suppressing the occurrence of cracks and cracks on the film surface, the content of the thermosetting resin is preferably 30% by mass or less, more preferably 25% by mass or less, based on the total mass of the sealing film, and still more Preferably it is 20 mass % or less. The above upper limit value and lower limit value can be arbitrarily combined. Therefore, the content of the thermosetting resin may be, for example, 1 to 30 mass %, 3 to 30 mass %, 4 to 25 mass %, or 4 to 25 mass % based on the total mass of the sealing film. 5-25 mass %, 10-20 mass % may be sufficient, and 15-20 mass % may be sufficient. In addition, in the same description below, the upper limit value and the lower limit value described individually can also be combined arbitrarily.

When the resin composition is an epoxy resin composition containing an epoxy resin, the content of the epoxy resin is based on the total mass of the thermosetting resin from the viewpoint of easily obtaining a cured product having excellent thermal conductivity , preferably 50% by mass or more, more preferably 80% by mass or more, still more preferably 90% by mass or more. The content of the epoxy resin may be 100% by mass based on the total mass of the thermosetting resin.

The content of the liquid epoxy resin is preferably 0.5% by mass or more, more preferably 1% by mass or more, based on the total mass of the sealing film, from the viewpoint of easily suppressing the occurrence of cracks and cracks on the film surface, and further More preferably, it is 3 mass % or more, particularly preferably 5 mass % or more, very preferably 7 mass % or more, and very preferably 9 mass % or more. The content of the liquid epoxy resin is preferably 20 mass based on the total mass of the sealing film from the viewpoint of easily suppressing an excessive increase in the viscosity of the film and easily suppressing edge fusion. % or less, more preferably 15 mass % or less, still more preferably 13 mass % or less. Therefore, the content of the liquid epoxy resin may be 0.5 to 20 mass %, 1 to 20 mass %, 3 to 15 mass %, or 3 to 15 mass % based on the total mass of the sealing film. 5-15 mass %, 7-13 mass % may be sufficient, and 9-13 mass % may be sufficient.

The content of the liquid epoxy resin is preferably 20% by mass or more, more preferably 30% by mass or more, based on the total mass of the thermosetting resin, from the viewpoint of easily suppressing the occurrence of cracks and cracks on the film surface. More preferably, it is 50 mass % or more. The content of the liquid epoxy resin is preferably 95% by mass or less based on the total mass of the thermosetting resin, from the viewpoints of easily suppressing excessive increase in the viscosity of the film and easily suppressing edge fusion, More preferably, it is 90 mass % or less, and still more preferably 80 mass % or less. Therefore, the content of the liquid epoxy resin may be 20 to 95 mass %, 30 to 90 mass %, or 50 to 80 mass % based on the total mass of the thermosetting resin. The content of the liquid epoxy resin may be 100% by mass based on the total mass of the thermosetting resin.

[Curing agent] Although it does not specifically limit as a curing agent, A phenol type curing agent (for example, a phenol resin), an acid anhydride type curing agent, an active ester type curing agent, a cyanate ester type curing agent, etc. are mentioned. When the thermosetting resin includes an epoxy resin, as a curing agent, as long as it is a compound having two or more functional groups capable of reacting with an epoxy group in one molecule, it can be used without particular limitation. Moreover, as such a hardening|curing agent, a phenol resin, an acid anhydride, etc. are mentioned. A hardener may be used individually by 1 type, and may use 2 or more types together. As the curing agent, a phenol resin is preferred from the viewpoint of easily obtaining a cured product having excellent thermal conductivity. A hardener may be used individually by 1 type, and may use 2 or more types together.

As the phenol resin, a known phenol resin can be used without particular limitation as long as it has two or more phenolic hydroxyl groups in one molecule. Examples of phenol resins include resins obtained by condensing or co-condensing phenols and/or naphthols and aldehydes under an acidic catalyst, biphenyl skeleton type phenol resins, p-xylene modified phenol resins, m-xylene/para-xylene modified phenol resin, melamine modified phenol resin, terpene modified phenol resin, dicyclopentadiene modified phenol resin, cyclopentadiene modified phenol resin, polycyclic aromatic ring modified phenol resin, xylene modified naphthol resin, etc. As phenols, phenol, cresol, xylenol, resorcinol, catechol, bisphenol A, bisphenol F, etc. are mentioned. As naphthols, α-naphthol, β-naphthol, dihydroxynaphthalene, etc. are mentioned. As aldehydes, formaldehyde, acetaldehyde, propionaldehyde, benzaldehyde, salicylaldehyde, etc. are mentioned.

Commercially available phenol resins include trade name "PAPS-PN2" (novolak-type phenol resin) manufactured by Asahi Organic Materials Co., Ltd.; trade name "SK Resin HE200C-7" manufactured by Air Water Co., Ltd. (biphenyl alkyl type phenol resin), trade name "HE910-10" (triphenylmethane type phenol resin); trade names "MEH-7000", "DL-92", "Meiwa Chemical Co., Ltd. H-4" and "HF-1M"; trade names "LVR-8210DL", "ELP" series and "NC" series manufactured by Qunrong Chemical Industry Co., Ltd., trade names manufactured by Nippon Steel & Sumitomo Metal Chemical Co., Ltd. "SN-100, SN-300, SN-395, SN-400" (naphthalene-type phenol resin); and the trade name "HP-850N" (novolak-type phenol resin) manufactured by Hitachi Chemical Co., Ltd.

From the viewpoint of excellent curability of the thermosetting resin, the content of the curing agent may be 1 to 20% by mass, 2 to 15% by mass, or 2 to 15% by mass based on the total mass of the sealing film. 3 to 10 mass %.

When the thermosetting resin contains an epoxy resin, the molar number M1 of the epoxy group in the epoxy resin and the molar number M2 of the functional group (phenolic hydroxyl group, etc.) capable of reacting with the epoxy group in the curing agent The ratio (M1/M2) may be 0.7 or more, 0.8 or more, or 0.9 or more, and may be 2.0 or less, 1.8 or less, or 1.7 or less. Therefore, the ratio (M1/M2) is preferably 0.7 to 2.0, more preferably 0.8 to 1.8, and still more preferably 0.9 to 1.7. When the said ratio is 0.7 or more or 2.0 or less, unreacted epoxy resin and/or unreacted hardener are less likely to remain, and desired cured product properties are easily obtained.

[Hardening Accelerator] As the curing accelerator, it can be used without particular limitation, and is preferably at least one selected from the group consisting of an amine-based curing accelerator and a phosphorus-based curing accelerator. In particular, the hardening accelerator is preferably an amine-based hardening accelerator, more preferably from the viewpoint of easily obtaining a cured product having excellent thermal conductivity, from the viewpoint of abundant derivatives, and from the viewpoint of being easy to obtain a desired activation temperature. is at least one selected from the group consisting of imidazole compounds, aliphatic amines and alicyclic amines, and more preferably imidazole compounds. As an imidazole compound, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, etc. are mentioned. A hardening accelerator may be used individually by 1 type, and may use 2 or more types together. As a commercial item of a hardening accelerator, "2P4MZ" and "1B2MZ" by Shikoku Chemical Industry Co., Ltd., etc. are mentioned.

The content of the curing accelerator is preferably within the following range based on the thermosetting resin (epoxy resin, etc.) and the curing agent (phenol resin, etc.). From the viewpoint of easily obtaining a sufficient hardening acceleration effect, the content of the hardening accelerator is preferably 0.01 mass % or more, more preferably 0.1 mass % or more, and further more preferably 0.3 mass % or more. From the viewpoints that curing does not progress easily in the steps of manufacturing the sealing film (such as coating and drying) or during storage of the sealing film, and it is easy to prevent cracking of the sealing film and forming defects due to an increase in melt viscosity, The content of the hardening accelerator is preferably 5% by mass or less, more preferably 3% by mass or less, and still more preferably 1.5% by mass or less. From these viewpoints, the content of the hardening accelerator is preferably 0.01 to 5 mass %, more preferably 0.1 to 3 mass %, and still more preferably 0.3 to 1.5 mass %.

(Inorganic Filler) As the inorganic filler, conventionally known inorganic fillers can be used, and are not particularly limited. Examples of the constituent material of the inorganic filler include silicas (amorphous silica, crystalline silica, fused silica, spherical silica, synthetic silica, hollow silica, etc.) , barium sulfate, barium titanate, talc, clay, mica powder, magnesium carbonate, calcium carbonate, aluminum oxide (alumina), aluminum hydroxide, magnesium oxide, magnesium hydroxide, silicon nitride, aluminum nitride, aluminum borate, nitrogen Boronide, barium titanate, strontium titanate, calcium titanate, magnesium titanate, bismuth titanate, titanium oxide, barium zirconate, calcium zirconate, etc. From the viewpoints that the effect of improving the dispersibility in the resin composition and the effect of suppressing the precipitation in the varnish are easily obtained by surface modification (for example, surface treatment with a silane compound), etc., and the desired cured film is easily obtained Characteristics From the viewpoint of having a small thermal expansion coefficient, it is preferable to include an inorganic filler such as silica. From the viewpoint of obtaining high thermal conductivity, an inorganic filler containing alumina is preferred. The inorganic filler may be used alone or in combination of two or more.

Surface modification of inorganic filler materials is possible. The method of surface modification is not specifically limited. Surface modification using a silane coupling agent is preferable from the viewpoints of easy handling, abundant functional groups, and easy imparting of desired properties.

Examples of the silane coupling agent include alkyl silane, alkoxy silane, vinyl silane, epoxy silane, amino silane, acryl silane, methacryloyl silane, mercapto silane, thioether silane, isopropyl silane Cyanate silane, sulfur silane, styryl silane, alkyl chlorosilane, etc.

Specific examples of the silane coupling agent include methyltrimethoxysilane, dimethyldimethoxysilane, trimethylmethoxysilane, methyltriethoxysilane, and methyltriphenoxysilane , ethyltrimethoxysilane, n-propyltrimethoxysilane, diisopropyldimethoxysilane, isobutyltrimethoxysilane, diisobutyldimethoxysilane, isobutyltriethoxy Silane, n-hexyltrimethoxysilane, n-hexyltriethoxysilane, cyclohexylmethyldimethoxysilane, n-octyltriethoxysilane, n-decylmethoxysilane, phenyltrimethoxysilane Silane, diphenyldimethoxysilane, triphenylsilanol, methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, n-octyldimethylchlorosilane, tetraethoxysilane , 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-(2-aminoethyl)aminopropyltrimethoxysilane, 3-(2-aminopropyltrimethoxysilane Ethyl)aminopropylmethyldimethoxysilane, 3-phenylaminopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyl Dimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, bis(3-(triethyl)disulfide oxysilyl)propyl), bis(3-(triethoxysilyl)propyl) tetrasulfide, vinyltriacetoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane , vinyltriisopropoxysilane, allyltrimethoxysilane, diallyldimethylsilane, 3-methylpropoxypropyltrimethoxysilane, 3-methylpropoxysilane Propylmethyldimethoxysilane, 3-Methylpropionyloxypropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3 -Mercaptopropyltriethoxysilane, N-(1,3-dimethylbutylene)-3-aminopropyltriethoxysilane, aminosilane (phenylaminosilane, etc.), etc. A silane coupling agent may be used individually by 1 type, and may use 2 or more types together.

The average particle size of the inorganic filler is preferably 0.01 μm or more, more preferably 0.1 μm or more, still more preferably 0.3 μm or more, from the viewpoint of easily suppressing aggregation of the inorganic filler and easily dispersing the inorganic filler. Preferably, it is 0.5 μm or more. The average particle size of the inorganic filler is preferably 25 μm or less, more preferably 10 μm or less, and even more preferably 25 μm or less, from the viewpoint of easily suppressing precipitation of the inorganic filler in the varnish, thereby facilitating the production of a homogeneous sealing film. 5μm or less. From these viewpoints, the average particle diameter of the inorganic filler is preferably 0.01 to 25 μm, more preferably 0.01 to 10 μm, still more preferably 0.1 to 10 μm, particularly preferably 0.3 to 5 μm, and most preferably 0.5 to 5 μm. The average particle diameter of the inorganic filler may be 10 to 18 μm.

From the viewpoint of excellent fluidity of the resin composition, it is preferable to use a combination of a plurality of inorganic fillers having mutually different average particle diameters. In the combination of inorganic fillers, the maximum average particle diameter is preferably 15 to 25 μm. Preferably, an inorganic filler having an average particle diameter of 15 to 25 μm, an inorganic filler having an average particle diameter of 0.5 to 2.5 μm, and an inorganic filler having an average particle diameter of 0.1 to 1.0 μm are used in combination.

"Average particle size" refers to the particle size at a point corresponding to 50% of the volume when the cumulative frequency distribution curve based on the particle size is obtained by taking the total volume of the particles as 100%, and the particle size can be used The particle size distribution measurement apparatus used the laser diffraction scattering method. The average particle diameter of each inorganic filler after the combination can be confirmed from the average particle diameter of each inorganic filler at the time of mixing, and can be confirmed by measuring the particle size distribution.

As a commercial item of an inorganic filler, "DAW-20" by Denka Co., Ltd.; "SC550O-SXE" and "SC2050-KC" by Admatechs Co., Ltd. are mentioned.

From the viewpoint of improving thermal conductivity and from the viewpoint of easily suppressing the increase in warpage of the sealing structure (for example, electronic component devices such as semiconductor devices) due to the difference in thermal expansion coefficient with the body to be sealed, inorganic fillers The content may be 70 mass % or more, 75 mass % or more, 80 mass % or more, or 84 mass % or more based on the total mass of the sealing film. From the viewpoint of easily suppressing the cracking of the sealing film in the drying step when the sealing film is produced, and from the viewpoint of suppressing the decrease in fluidity due to the increase in the melt viscosity of the sealing film, and the ease of fully sealing the to-be-sealed body (electronic parts, etc.) In terms of the content of the inorganic filler, based on the total mass of the sealing film, it may be 93 mass % or less, 91 mass % or less, 90 mass % or less, or 88 mass % or less. . From these viewpoints, the content of the inorganic filler may be 70 to 93% by mass, 75 to 91% by mass, 80 to 91% by mass, or 80 to 91% by mass based on the total mass of the sealing film. 80-90 mass % may be sufficient, and 84-88 mass % may be sufficient. In addition, the said content is content of the inorganic filler excluding the quantity of a surface treatment agent.

(Elastomer) The elastomer component includes a carboxyl group-containing elastomer having a carboxyl group equivalent weight of 270 to 4300 g/eq. Here, the "carboxyl group equivalent" means the mass of the carboxyl group-containing elastomer per equivalent (1 eq.) of carboxyl groups that the carboxyl group-containing elastomer has. The carboxyl group equivalent can be judged by the feeding amount of the monomer component. In addition, the carboxyl group equivalent can be measured by a titration method.

The carboxyl group equivalent of the carboxyl group-containing elastomer may be 340 g/eq. or more, or may It may be 400 g/eq. or more, 600 g/eq. or more, or 800 g/eq. or more. The carboxyl group equivalent of the carboxyl group-containing elastomer may be 4,000 g/eq. or less, or may be 3000 g/eq. or less, and may be 2000 g/eq. or less. From these viewpoints, the carboxyl group equivalent of the carboxyl group-containing elastomer may be 340 to 4000 g/eq., 400 to 4000 g/eq, 600 to 3000 g/eq., or 800 to 2000 g/eq. ..

The carboxyl group-containing elastomer preferably contains a (meth)acrylic acid-derived structural unit represented by the following formula (1) as a structural unit having a carboxyl group.

式(1)中，R¹ 表示氫原子或甲基。

In formula (1), R ¹ represents a hydrogen atom or a methyl group.

From the viewpoint of suppressing the elastic body from becoming excessively coiled, it becomes easier to obtain the effect of suppressing the fluidity of the resin composition, the content of the structural unit having a carboxyl group in the carboxyl group-containing elastomer is such that the content of the carboxyl group-containing The total amount of the structural units of the elastomer may be 2 mol % or more, 4 mol % or more, or 6 mol % or more based on the basis. From the viewpoint that the molecular chains of the elastomer easily form a closer three-dimensional network and the hollow non-filling property becomes more favorable, the content of the structural unit having a carboxyl group is the total amount of the structural unit constituting the carboxyl group-containing elastomer. The amount may be 39 mol % or less, 37 mol % or less, 35 mol % or less, 31 mol % or less, or 29 mol % or less, as a reference. From these viewpoints, the content of the structural unit having a carboxyl group may be 2 to 35 mol %, 4 to 31 mol %, or 6 to 29 mol %. From the same viewpoint, the content of the structural unit represented by the above formula (1) may be within the above range.

The carboxyl group-containing elastomer can be a copolymer composed of a plurality of different structural units (eg, random copolymer, block copolymer, etc.). Moreover, the carboxyl group-containing elastomer may further have other structural units other than the structural unit having a carboxyl group. Examples of other structural units include those having the following groups: alkyl ester group (-C(=O)-O-R (R represents an alkyl group which may have a substituent)), nitrile group (-C≡N) , hydroxyl (-OH), allyl, etc. As R in an alkyl ester group, a methyl group, an ethyl group, a butyl group, etc. are mentioned, for example. The carboxyl group-containing elastomer is preferably a copolymer of (meth)acrylic acid and other monomers ((meth)acrylic acid copolymer).

As a structural unit which has an alkyl ester group, the structural unit derived from the alkyl (meth)acrylate represented by following formula (2) is mentioned, for example. That is, the carboxyl group-containing elastomer may be a copolymer of a monomer having a carboxyl group and an alkyl (meth)acrylate (a carboxyl group-containing alkyl (meth)acrylate copolymer), preferably (meth)acrylic acid and Copolymers of (meth)acrylates ((meth)acrylic acid-(meth)acrylic acid alkyl ester copolymers).

式(2)中，R² 表示氫原子或甲基，R表示可具有取代基之烷基。

In formula (2), R ² represents a hydrogen atom or a methyl group, and R represents an optionally substituted alkyl group.

The content of the structural unit represented by the above formula (2) in the carboxyl group-containing elastomer from the viewpoint of being more excellent in non-filling properties in the hollow and easily obtaining a more sufficient Tg after curing is to constitute the structure of the carboxyl group-containing elastomer The total amount of cells may be 65 mol % or more, 69 mol % or more, or 71 mol % on a basis, and may be 98 mol % or less, 96 mol % or less, or 94 mol % or less. Therefore, the content of the structural unit represented by the above formula (2) may be, for example, 65 to 98 mol % or 69 to 96 mol % based on the total amount of the structural units constituting the carboxyl group-containing elastomer. , can also be 71 to 94 mol%.

Moreover, as a structural unit which has a nitrile group, the structural unit derived from (meth)acrylonitrile represented by following formula (3) is mentioned, for example.

式(3)中，R³ 表示氫原子或甲基。

In formula (3), R ³ represents a hydrogen atom or a methyl group.

The content of the structural unit represented by the above formula (3) in the carboxyl group-containing elastomer from the viewpoint of being more excellent in non-filling properties in the hollow and easily obtaining a more sufficient Tg after curing is used to constitute the structure of the carboxyl group-containing elastomer The total amount of units may be 65 to 98 mol %, 69 to 96 mol %, or 71 to 94 mol % as a basis.

The carboxyl group-containing elastomer preferably has a structural unit represented by the above formula (1) and a structural unit represented by the above formula (2) from the viewpoint of being more excellent in the hollow non-filling property and easily obtaining a more sufficient Tg after curing. The structural unit represented by and/or the structural unit represented by the above formula (3).

The weight-average molecular weight Mw of the carboxyl group-containing elastomer is from the viewpoint of being more excellent in non-filling properties in the hollow, from the viewpoint of easily obtaining a more sufficient Tg after curing, and from the viewpoint of being able to obtain sufficient embedding property for the sealed body. , may be 300,000 or more, 400,000 or more, or 500,000 or more, and may be 10 million or less, 8 million or less, 7 million or less, or 2 million or less. Therefore, the weight average molecular weight Mw of the carboxyl group-containing elastomer may be, for example, 300,000 to 10 million, 400,000 to 8 million, 500,000 to 7 million, or 500,000 to 2 million. The weight average molecular weight is a polystyrene-equivalent value obtained by gel permeation chromatography (GPC) using a calibration curve based on standard polystyrene.

When the carboxyl group-containing elastomer is in the form of particles, the average particle diameter of the elastomer is not particularly limited. The average particle diameter of the elastomer may be, for example, 50 μm or less, from the viewpoint of being excellent in embedding properties between objects to be sealed. From the viewpoint of excellent dispersibility of the carboxyl group-containing elastomer, the average particle diameter of the elastomer may be 0.1 μm or more.

The carboxyl group-containing elastomer of the present embodiment can be obtained by polymerizing a polymerizable monomer having a carboxyl group by a conventionally known method, or by a conventionally known method, by polymerizing a polymerizable monomer having a carboxyl group with It is obtained by copolymerizing a polymerizable monomer having no carboxyl group. For example, a carboxyl group-containing elastomer can be obtained by copolymerizing (meth)acrylic acid with an alkyl (meth)acrylate and/or (meth)acrylonitrile. In the present embodiment, the carboxyl group equivalent can be adjusted within a desired range by adjusting the amount of the polymerizable monomer used. Moreover, in this embodiment, after obtaining a polymer by the above-mentioned method, the carboxyl group equivalent can be adjusted by substituting a part of carboxyl groups by methods such as esterification.

During the polymerization, a polymerization initiator can be used. As a polymerization initiator, a thermal radical polymerization initiator, a photoradical polymerization initiator, an anionic polymerization initiator, and a cationic polymerization initiator are mentioned.

The content of the carboxyl group-containing elastomer may be less than 40% by mass based on the total amount of the thermosetting component and the carboxyl group-containing elastomer. In the present embodiment, by setting the content of the elastomer component within the above-mentioned range, the film for sealing has a sufficient Tg after curing, and a sealing structure excellent in reliability can be obtained. From the viewpoint of making the hollow non-filling property more favorable, the content of the carboxyl group-containing elastomer may exceed 0 mass % or may be 2 mass % based on the total amount of the thermosetting component and the carboxyl group-containing elastomer. As mentioned above, 4 mass % or more may be sufficient, 8 mass % or more may be sufficient, and 12 mass % or more may be sufficient. The content of the carboxyl group-containing elastomer is taken as the total amount of the thermosetting component and the carboxyl group-containing elastomer from the viewpoint of achieving a more sufficient Tg after curing and obtaining sufficient embeddability for the body to be sealed. The reference value may be 35 mass % or less, 30 mass % or less, or 25 mass % or less. Therefore, the content of the carboxyl group-containing elastomer, based on the total amount of the thermosetting component and the carboxyl group-containing elastomer, may be, for example, more than 0 mass % and less than 40 mass %, or may be 2 mass % or more and less than 40 mass % , 4-35 mass % may be sufficient, 8-30 mass % may be sufficient, and 12-25 mass % may be sufficient.

In the present embodiment, the total amount of the thermosetting component, the inorganic filler, and the carboxyl group-containing elastomer in the sealing film may be 80% by mass or more, or 90% by mass based on the total mass of the sealing film. % or more, 95 mass % or more may be sufficient, and 100 mass % may be sufficient.

The elastomer component (for example, a carboxyl group-containing elastomer) is a thermoplastic resin, and the glass transition temperature (Tg) of the elastomer component measured by a dynamic viscoelasticity measuring device is preferably 20°C or lower; The elastic modulus at 25° C. measured by a dynamic viscoelasticity measuring device is preferably 5 MPa or less.

The sealing film of the present embodiment may contain other elastomers other than the above-mentioned carboxyl group-containing elastomer within a range that does not affect the present invention. Examples of other elastomers include polybutadiene particles, styrene butadiene particles, acrylic elastomers, polysiloxane powder, silicone oil, and silicone oligomers.

In the sealing film of the present embodiment, the content of the elastomer component (including the carboxyl group-containing elastomer) is preferably 2% by mass or more and less than 40% by mass based on the total amount of the thermosetting component and the elastomer component. %. That is, even when the elastomer component contains other elastomers other than the carboxyl group-containing elastomer, the total amount of the elastomer component is preferably 2 based on the total amount of the thermosetting component and the elastomer component. mass % or more and less than 40 mass %. In this case, the film for sealing has a more sufficient Tg after curing, and a sealing structure with more excellent reliability can be obtained. The content of the elastomer component may be 4% by mass or more, or 8% by mass or more, based on the total amount of the thermosetting component and the elastomer component, from the viewpoint of making the hollow non-filling property more favorable. , may be 12 mass % or more. The content of the elastomer component is based on the total amount of the thermosetting component and the elastomer component from the viewpoint of achieving a more sufficient Tg after curing and obtaining sufficient embeddability for the sealed body , may be 35 mass % or less, may be 30 mass % or less, and may be 25 mass % or less. Therefore, the content of the elastomer component may be, for example, 4 to 35% by mass, 8 to 30% by mass, or 12 to 25% by mass based on the total amount of the thermosetting component and the elastomer component. .

The content of the carboxyl group-containing elastomer in the elastomer component may be 80% by mass or more, or 90% by mass, based on the total mass of the elastomer component, from the viewpoint of making the hollow non-filling property more favorable. As mentioned above, 95 mass % or more may be sufficient. The content of the carboxyl group-containing elastomer in the elastomer component may be 100% by mass or less. Therefore, the content of the carboxyl group-containing elastomer in the elastomer component may be, for example, 80 to 100% by mass based on the total mass of the elastomer component. The elastomer component may contain substantially only the carboxyl group-containing elastomer.

(Other components) The sealing film of the present embodiment may further contain other additives. Specific examples of such additives include pigments, dyes, mold release agents, antioxidants, surface tension modifiers, and the like.

Moreover, the film for sealing of this embodiment may contain a solvent (for example, the solvent used when manufacturing the film for sealing). As the solvent, a conventionally known organic solvent may be used. The organic solvent may be a solvent capable of dissolving components other than the inorganic filler, and examples thereof include aliphatic hydrocarbons, aromatic hydrocarbons, terpenes, halogens, esters, ketones, alcohols, Aldehydes, etc. A solvent may be used individually by 1 type, and may use 2 or more types together.

The solvent may be at least one selected from the group consisting of esters, ketones, and alcohols, from the viewpoint of a small environmental load and the ease of dissolving the thermosetting component. Among them, when the solvent is a ketone, it is particularly easy to dissolve the thermosetting component. The solvent may be selected from the group consisting of acetone, methyl ethyl ketone, and methyl isobutyl ketone from the viewpoint of less volatilization at room temperature (25° C.) and easy removal during drying. at least one.

The content of the solvent (organic solvent, etc.) contained in the film for sealing is preferably within the following range based on the total mass of the film for sealing. The content of the solvent may be 0.2 mass % or more from the viewpoint of easily suppressing the occurrence of defects such as cracking of the sealing film due to brittleness, and the case where the minimum melt viscosity is increased and the embedding property is lowered. It may be 0.3 mass % or more, 0.5 mass % or more, 0.6 mass % or more, or 0.7 mass % or more. From the viewpoint of easily suppressing the problems that the adhesiveness of the sealing film becomes too strong and the workability is lowered, and the problems such as foaming caused by the volatilization of the solvent (organic solvent, etc.) during the thermal curing of the sealing film, the content of the solvent , may be 1.5 mass % or less, or 1 mass % or less. From these viewpoints, the content of the solvent may be 0.2 to 1.5 mass %, 0.3 to 1 mass %, 0.5 to 1 mass %, 0.6 to 1 mass %, or 0.7 to 0.7 mass %. 1 mass %.

The thickness of the sealing film may be 20 μm or more, 30 μm or more, 50 μm or more, or 100 μm or more, from the viewpoint of easily suppressing in-plane thickness variation during coating. The thickness of the sealing film may be 400 μm or less, 250 μm or less, 200 μm or less, or 150 μm or less, from the viewpoint of easily obtaining a certain degree of drying in the depth direction during coating. From these viewpoints, the thickness of the film for sealing may be 20 to 400 μm, 20 to 250 μm, 30 to 250 μm, 50 to 200 μm, or 100 to 150 μm. Moreover, the thickness of the film for sealing of a plurality of sheets can also be laminated|stacked, and the film for sealing with a thickness exceeding 250 micrometers can also be manufactured.

From the viewpoint of reliability (thermal reliability) of the obtained sealing structure, the glass transition temperature Tg after curing of the film for sealing may be 80 to 150° C., 90 to 140° C., or 100° C. ~130°C. The glass transition temperature Tg of the film for sealing can be adjusted by the type and content of the thermosetting component, the type and content of the elastomer component, and the like. The glass transition temperature Tg can be measured by the method described in the examples.

From the viewpoint of forming a hollow structure, the minimum value (minimum melt viscosity) of the melt viscosity of the sealing film at 60 to 140°C may be 1000 to 20000 Pa･s, 3000 to 15000 Pa･s, or 5000～12000Pa･s. The said minimum melt viscosity can be calculated|required by carrying out the method described, and measuring the melt viscosity of the film for sealing.

As described above, the sealing film of the present embodiment can be suitably used for sealing the body to be sealed in the hollow structure, but the structure to be sealed does not need to have a hollow structure. The sealing film of the present embodiment can also be used for, for example, sealing of semiconductor devices, embedding of electronic components arranged on printed wiring boards, and the like.

The sealing film of the present embodiment can also be used as, for example, a support-attached sealing film. The supporting body-attached sealing film 10 shown in FIG. 1 includes a supporting body 1 and a sealing film 2 provided on the supporting body 1 .

As the support 1, a polymer film, a metal foil, or the like can be used. Examples of polymer films include: polyolefin films such as polyethylene films and polypropylene films; vinyl films such as polyvinyl chloride films; polyester films such as polyethylene terephthalate films; polycarbonate films; acetate fibers plain film; tetrafluoroethylene film, etc. As metal foil, copper foil, aluminum foil, etc. are mentioned.

The thickness of the support body 1 is not particularly limited, but from the viewpoint of excellent workability and drying properties, it may be 2 to 200 μm. When the thickness of the support body 1 is 2 μm or more, the failure of the support body to be broken during coating, the failure of the support body to bend due to the weight of the varnish, and the like are easily suppressed. When the thickness of the support body 1 is 200 μm or less, in the drying step, when hot air is blown from both the coated surface and the back surface, it is easy to suppress the inconvenience that the drying of the solvent in the varnish is hindered.

In this embodiment, the support body 1 may not be used. Moreover, the protective layer may be arrange|positioned at the opposite side to the support body 1 of the film 2 for sealing, and the purpose of this protective layer is to protect the film for sealing. By forming a protective layer on the film 2 for sealing, workability|operativity can be improved, and when winding, it can avoid the inconvenience that the film for sealing sticks to the back surface of a support body.

As the protective layer, a polymer film, a metal foil, or the like can be used. Examples of polymer films include: polyolefin films such as polyethylene films and polypropylene films; vinyl films such as polyvinyl chloride films; polyester films such as polyethylene terephthalate films; polycarbonate films; acetate fibers plain film; tetrafluoroethylene film, etc. As a metal foil, a copper foil, an aluminum foil, etc. can be illustrated.

<The manufacturing method of the film for sealing> The film for sealing of this embodiment can be specifically manufactured as follows.

First, a varnish (varnish-like resin composition) is prepared by mixing the constituent components (thermosetting resin, hardener, hardening accelerator, inorganic filler, elastomer component, solvent, etc.) of the resin composition of the present embodiment. . The mixing method is not particularly limited, and a mill, a mixer, and a stirring blade can be used. The solvent (organic solvent) can be used to prepare a varnish by dissolving and dispersing the material of the sealing film, that is, the constituent components of the resin composition, or can be used to assist in the preparation of a varnish. Most of the solvent can be removed by the drying step after coating.

A film for sealing can be produced by applying the varnish produced in this way on a support (a film-like support or the like), and then heating and drying by blowing hot air or the like. The coating method is not particularly limited, and for example, a notch coater, a bar coater, a kiss coater, a roll coater, and a gravure coater can be used. , die coater and other coating devices.

<The sealing structure and its manufacturing method> The sealing structure of this embodiment is provided with the to-be-sealed body and the sealing part for sealing the to-be-sealed body. The sealing portion is the cured product of the sealing film of the present embodiment, and includes the cured product of the resin composition of the present embodiment. The sealing structure may be a hollow sealing structure having a hollow structure. The hollow sealing structure includes, for example, a substrate, a to-be-sealed body provided on the substrate, a hollow region provided between the substrate and the to-be-sealed body, and a sealing portion for sealing the to-be-sealed body. The sealing structure of the present embodiment may include a plurality of bodies to be sealed. A plurality of to-be-sealed bodies may be of the same type or different from each other.

The sealing structure is, for example, an electronic component device. An electronic component device includes electronic components as a to-be-sealed body. Examples of electronic components include semiconductor elements, semiconductor wafers, integrated circuits, semiconductor devices, filters such as SAW filters, passive components such as sensors, and the like. A semiconductor element obtained by singulating a semiconductor wafer can be used. The electronic component device may be a semiconductor device including a semiconductor element or a semiconductor wafer as an electronic component, a printed wiring board, or the like. When the electronic component device has a hollow structure, that is, when the electronic component device is a hollow sealed structure, the body to be sealed has a movable portion on the surface of the hollow region side (substrate side), for example, through the bumps. arranged on the substrate. As such a to-be-sealed body, electronic components, such as a SAW element (SAW device), such as a SAW filter, and an acceleration sensor (acceleration sensor), are mentioned, for example. When the body to be sealed is a SAW filter, among the surfaces of the piezoelectric substrate, the surface on the side where a pair of comb-shaped electrodes, that is, an interdigital transducer (IDT) is mounted, becomes a movable portion.

Next, the manufacturing method of the hollow sealing structure performed using the film for sealing of this embodiment is demonstrated. Here, the case where the hollow sealing structure is an electronic component device and the body to be sealed is a SAW element will be described.

FIG. 2 is a schematic cross-sectional view for explaining an embodiment of a method of manufacturing a hollow sealing structure, that is, an embodiment of a method of manufacturing an electronic component device, that is, a semiconductor device. In the manufacturing method of the present embodiment, first, as a body to be sealed (object to be embedded), a hollow structure is prepared, and the hollow structure includes a substrate 30 and a plurality of the substrates 30 arranged in parallel on the substrate 30 with the bumps 40 interposed therebetween. In the surface acoustic wave (SAW) element 20, the SAW element 20 side surface of the substrate 30 faces the sealing film 2 side surface of the support-attached sealing film 10 (FIG. 2(a)). Here, the hollow structure 60 has the hollow region 50, and the SAW element 20 has a movable portion on the surface 20a on the side of the hollow region 50 (the side of the substrate 30).

Next, after the SAW element 20 is embedded in the sealing film 2 by pressing (laminating) the sealing film 2 against the SAW element 20 under heating, the sealing film 2 in which the SAW element 20 is embedded is cured. , to obtain a cured product of the sealing film (the sealing portion of the cured product including the resin composition) 2a (Fig. 2(b)). Thereby, the electronic component device 100 can be obtained.

It does not specifically limit as a laminator used for lamination, For example, the laminator of a roll type, a balloon type, etc. is mentioned. From the viewpoint of excellent embeddability, the laminator may be a bladder-type laminator capable of vacuum pressurization.

Lamination is usually carried out below the softening point of the support. The lamination temperature (sealing temperature) is preferably in the vicinity of the minimum melt viscosity of the film for sealing. The lamination temperature is, for example, 60 to 140°C. The pressure at the time of lamination differs depending on the size, density, etc. of the to-be-sealed body to be embedded (eg, electronic components such as semiconductor elements). The pressure at the time of lamination may be, for example, in the range of 0.2 to 1.5 MPa, or in the range of 0.3 to 1.0 MPa. The lamination time is not particularly limited, and may be 20 to 600 seconds, 30 to 300 seconds, or 40 to 120 seconds.

Hardening of the film for sealing can be carried out, for example, in the atmosphere or under an inert gas. The hardening temperature (heating temperature) is not particularly limited, and may be 80 to 280°C, 100 to 240°C, or 120 to 200°C. When the curing temperature is 80° C. or higher, the curing of the sealing film can be sufficiently advanced, and the occurrence of failures tends to be suppressed. When the hardening temperature is 280° C. or lower, the occurrence of thermal damage to other materials tends to be suppressed. The hardening time (heating time) is not particularly limited, and may be 30 to 600 minutes, 45 to 300 minutes, or 60 to 240 minutes. When the hardening time is within these ranges, the hardening of the sealing film can sufficiently progress, and more favorable production efficiency can be obtained. In addition, as for the hardening conditions, a plurality of conditions may be combined.

In the present embodiment, a plurality of electronic component devices 200 can be obtained by further dividing the electronic component devices 100 into pieces by a cutting machine or the like ( FIG. 2( c )).

The above-described method for producing a hollow sealing structure of the present embodiment can ensure excellent embedding properties with respect to the body to be sealed (for example, the SAW element 20 ), and can sufficiently suppress the flow of the sealing material into the hollow region between the substrate 30 and the body to be sealed 50.

In the present embodiment, after the SAW element 20 is sealed with the sealing film 20 according to the lamination method, the sealing film 2 is thermally cured to obtain a hollow sealing structure (electronic component device), which is The hollow sealing structure includes the SAW element 20 embedded in the hardened material 2a, and the sealing structure can also be obtained by compression molding using a compression molding device, or by using a hydraulic press. Press-forming was carried out to obtain a sealing structure. The temperature (sealing temperature) when the body to be sealed is sealed by compression molding and hydraulic pressing can be the same as the lamination temperature described above.

As mentioned above, although the preferable embodiment of this invention was described, this invention is not necessarily limited to the said embodiment, It can change suitably in the range which does not deviate from the summary. [Example]

Hereinafter, the present invention will be described in further detail using examples, but the present invention is not limited to these examples at all.

The following materials were used in Examples and Comparative Examples. (Thermosetting resin) A1: Bisphenol F-type epoxy resin (manufactured by Mitsubishi Chemical Corporation, trade name "jER806", epoxy group equivalent: 160 g/eq.) (hardening agent) B1: Novolak-type phenol resin (manufactured by Meiwa Chemical Co., Ltd., trade name "DL-92", phenolic hydroxyl equivalent: 107 g/eq.) (hardening accelerator) C1: Imidazole (manufactured by Shikoku Chemical Industry Co., Ltd., trade name "2P4MZ") (Elastomer) D1 to D7: Carboxyl group-containing elastomer (inorganic filler) E1: Alumina (manufactured by Denka Co., Ltd., trade name "DAW-20", average particle size: 20 μm)

<Synthesis of Carboxyl Group-Containing Elastomer> (Synthesis Examples 1 to 7) Carboxyl group-containing elastomers D1 to D7 were synthesized in the following procedure. First, acrylic acid (molecular weight: 72) and methyl acrylate (molecular weight: 86) were mixed with 55 g of 2,2'-azobis[2-(2-imidazolin-2-yl] according to the blending amounts shown in Table 1. ) propane] was dissolved in 500 g of methanol to obtain a mixed solution. Here, the total amount of acrylic acid and methyl acrylate was set to 500 g. Next, 960 g of deionized water was put into a 3-liter synthesis flask, and the temperature was raised to 90° C. while stirring in a nitrogen atmosphere. After pouring the said mixed solution into this flask over 2 hours, it stirred at 90 degreeC for 4 to 6 hours. After stirring, the obtained reaction solution was cooled. Next, the product in the reaction solution was washed with deionized water. The water washing was performed four times, and the amount of deionized water used for each time was set to an amount three times the mass of the product. The product after washing with water was dried to obtain a carboxyl group-containing elastomer (acrylic acid-methyl acrylate copolymer).

Table 1 shows the carboxyl group equivalent, weight average molecular weight (Mw), and content of acrylic acid-derived structural units of the carboxyl group-containing elastomer. The carboxyl group equivalent is judged by the feeding amount of each monomer. The weight average molecular weight (Mw) was calculated according to a standard polystyrene conversion method using gel permeation chromatography (GPC). The measurement conditions of GPC are as follows.・Measuring device: High-speed GPC device (HLC-8220GPC manufactured by Tosoh Corporation) ・Column: TSKguardcolumn SuperHZ-H (manufactured by Tosoh Corporation) ・Solvent: Tetrahydrofuran

[Table 1]

<Preparation of sealing film (film-like epoxy resin composition)> (Example 1) 100 g of MEK (methyl ethyl ketone) was put into a 1 L (liter) polyethylene container, and 900 g of inorganic filler E1 was added, 51 g of epoxy resin A1 and 34 g of hardener B1 were added and stirred. Next, 15 g of elastomer D1 was added, and it was further stirred for 3 hours. 0.3 g of hardening accelerator C1 was added and stirred for a further 3 hours. The obtained mixed solution was filtered through a nylon-made #150 mesh (106 μm opening), and the filtrate was extracted. Thereby, a varnish-like epoxy resin composition was obtained. Using a coater, the varnish-like epoxy resin composition was coated on a PET film under the following conditions. Thereby, a film for sealing with a thickness of 200 μm was produced on the support.・Coating head method: Cutaway wheel ・Coating and drying speed: 0.3 m/min ・Drying conditions (temperature/furnace length): 80°C/1.5m (meter), 100°C/1.5m ・Film support Body: PET film with a thickness of 38 μm

A protective layer (polyethylene terephthalate film with a thickness of 50 μm) was arranged on the side opposite to the support in the film for sealing, thereby protecting the surface of the film for sealing. The same applies to the following Examples and Comparative Examples.

(Examples 2 to 5 and Comparative Examples 1 to 2) The same procedure as in Example 1 was carried out, except that the elastomers D2 to D7 were used as the elastomers in place of the elastomer D1 to obtain a varnish-like epoxy resin composition. . Except having used this varnish-like epoxy resin composition, it carried out similarly to Example 1, and produced the film for sealing with a thickness of 200 micrometers on a support body (PET film).

(Example 6) Except having used 57g of epoxy resin A1, used 38g of hardener B1, and used 5g of elastomer D3, it carried out similarly to Example 3, and obtained the varnish-like epoxy resin composition. Except having used this varnish-like epoxy resin composition, it carried out similarly to Example 3, and produced the film for sealing with a thickness of 200 micrometers on a support body (PET film).

(Example 7) Except having used 39 g of epoxy resin A1, used 26 g of hardener B1, and used 35 g of elastomer D3, it carried out similarly to Example 3, and obtained the varnish-like epoxy resin composition. Except having used this varnish-like epoxy resin composition, it carried out similarly to Example 3, and produced the film for sealing with a thickness of 200 micrometers on a support body (PET film).

(Comparative Example 3) A varnish-like epoxy resin composition was obtained in the same manner as in Example 1, except that 60 g of epoxy resin A1 was used, 40 g of hardener B1 was used, and an elastic component was not used. Except having used this varnish-like epoxy resin composition, it carried out similarly to Example 1, and produced the film for sealing with a thickness of 200 micrometers on a support body (PET film).

(Comparative example 4) Except having used 36 g of epoxy resin A1, used 24 g of hardener B1, and used 41 g of elastomer D3, it carried out similarly to Example 3, and obtained the varnish-like epoxy resin composition. Except having used this varnish-like epoxy resin composition, it carried out similarly to Example 3, and produced the film for sealing with a thickness of 200 micrometers on a support body (PET film).

<Evaluation method> The following methods were used to evaluate the flow rate, the embedding property, the hollow non-filling property, and the glass transition temperature of the sealing film after curing.

(1) Flow rate (flow rate) Using a punch, the film for sealing provided with the support and the protective film prepared in the examples and the comparative examples was punched out into a circle with a diameter of 4 mm to prepare an evaluation test. Sample. Next, the protective film of the evaluation sample was peeled off, and five evaluation samples (film for sealing with a support, reference numeral 10 in FIG. 3 ) were arranged according to the arrangement shown in (a) of FIG. 3 . on a silicon wafer (5cm×5cm, symbol 4 in Figure 3). At this time, the surface on the side of the film for sealing is made to face the silicon wafer. Next, after peeling off the support from the evaluation sample, as shown in FIG. 3(b), a glass plate (5 cm×5 cm, thickness 3.0 mm, symbol 5 in FIG. 3 ) was placed on the evaluation sample. On the sample, a 470 g iron plate (5 cm x 5 cm, reference numeral 6 in Fig. 3) was placed on a glass plate to obtain a laminate. This layered product was put into an oven at 70°C and kept for 30 minutes. Then, the laminated body was taken out from the oven and left at room temperature for 30 minutes, and then the maximum diameter of the sealing film on the silicon wafer was measured. The flow rate (flow rate) was calculated from the diameter of the initial sealing film of 4 mm and the maximum diameter of the sealing film after the test. The flow rate was obtained by the following formula. Flow rate=(maximum diameter of the film for sealing after the test/4 mm)×100 The average value of the obtained five points of the flow rate was defined as the flow rate in the evaluation.

(2) Embedding properties and hollow non-filling properties at a sealing temperature of 70°C The following methods were used to evaluate the embedding properties and hollow non-filling properties at a sealing temperature of 70°C. First, the produced sealing film (sealing film including a support and a protective film) was cut into a rectangle of 8 mm×8 cm to produce an evaluation sample. Moreover, the board|substrate (5 cm*5 cm, thickness 0.2 mm) provided with the through-hole (2 mm in diameter) in the center of the main surface was prepared. Next, a PET film (5 cm×5 cm, thickness 0.38 mm) provided with a through hole (diameter 4 mm) in the center was placed on a glass plate, and the substrate provided with the through hole was placed thereon. Next, the protective film of the evaluation sample was peeled off, and the evaluation sample (the sealing film provided with the support) was placed on the substrate with the sealing film facing the substrate side so that the through hole of the substrate was covered with the sealing film. superior. Next, a 470-g iron plate (5 cm×5 cm) was placed on the evaluation sample to obtain a layered body. The obtained laminate was heated for 1 hour in an oven (trade name "SAFETY OVEN SPH-201" manufactured by ESPEC Co., Ltd.) at 70°C.

After heating, use a digital microscope to observe whether the resin flows into the glass plate side from the through hole due to the melting of the sealing film, and the inflow amount of the resin (the maximum diameter of the resin layer after spreading on the glass surface), and based on the following criteria, Evaluate embeddability and hollow non-filling. [Embedding properties] A: Until the resin reaches the substrate B: The resin does not reach the substrate [Hollow non-filling properties] A: The maximum diameter of the resin layer flowing in ≦ 2.1 mm B: The maximum diameter of the resin layer flowing in is > 2.1 mm but ≦2.3mm C: The maximum diameter of the resin layer flowing in> 2.3mm

(3) Glass transition temperature Tg after hardening of the film for sealing The films for sealing of Examples and Comparative Examples were laminated on copper foil under the following conditions to obtain a film for sealing with copper foil.・Laminator device: Vacuum pressure laminator MVLP-500 manufactured by Meiki Seisakusho ・Lamination temperature: 110°C ・Lamination pressure: 0.5MPa ・Evacuation time: 30 seconds ・Lamination time: 40 seconds

The sealing film with copper foil is pasted on a stainless steel (SUS) plate, and the sealing film is hardened according to the following conditions to obtain a cured product of the sealing film with copper foil (epoxy with copper foil) Resin hardened body) ・Oven: SAFETY OVEN SPH-201 manufactured by ESPEC Co., Ltd. ・Oven temperature: 140°C ・Time: 120 minutes

After peeling the copper foil from the cured product of the film for sealing with copper foil, the cured product of the film for sealing was cut into 4 mm×30 mm to prepare a test piece. The glass transition temperature of the produced test piece was measured under the following conditions. In this evaluation, when the glass transition temperature is 100° C. or higher, it is judged that the glass transition temperature is sufficient.・Measuring device: DVE (DVE-V4 manufactured by RHEOLOGY Co., Ltd.) ・Measuring temperature: 25 to 300°C ・Heating rate: 5°C/min

<Evaluation results> The evaluation results are shown in Tables 2 and 3. In addition, the unit of the addition amount of each material in Table 2 and Table 3 is (g). In addition, the content (mass %) of the elastomer is the content based on the total amount of the thermosetting component (thermosetting resin, hardener, and hardening accelerator) and the elastomer component.

[Table 2]

[table 3]

1‧‧‧Support body 2‧‧‧Seal film 2a‧‧‧Cutting of the sealing film (sealing part) 4‧‧‧Silicon wafer 5‧‧‧Glass plate 6‧‧‧Iron plate 10‧ ‧‧Film for sealing with support 20‧‧‧Surface acoustic wave element (sealed body) 20a‧‧‧Surface acoustic wave element on the hollow region side (substrate side) surface 30‧‧‧Substrate 40‧‧‧Bumps 50‧‧‧Hollow region 60‧‧‧Hollow structure 100, 200‧‧‧Hollow sealing structure (sealing structure)

Fig. 1 is a schematic cross-sectional view showing a support-attached sealing film having a sealing film according to an embodiment. FIG. 2 is a schematic cross-sectional view for explaining an embodiment of a method for producing a hollow sealing structure. FIG. 3 is a diagram showing the evaluation method of the flow rate in the Example.

Domestic storage information (please note in the order of storage institution, date and number) None

Foreign deposit information (please note in the order of deposit country, institution, date and number) None

1: Support body

2: Film for sealing

10: Sealing film with support

Claims (19)

A sealing film, which is composed of a resin composition containing a thermosetting component, an inorganic filler, and a carboxyl group-containing elastomer having a carboxyl group equivalent of 270 to 4300 g/eq.; and, the aforementioned carboxyl group-containing elastomer Content is less than 40 mass % based on the total amount of the said thermosetting component and the said carboxyl group-containing elastomer. The sealing film according to claim 1, wherein the content of the elastomer component including the carboxyl group-containing elastomer contained in the resin composition is based on the total amount of the thermosetting component and the elastomer component. In total, it is 2 mass % or more and less than 40 mass %. The sealing film according to claim 1, wherein the content of the structural unit having a carboxyl group in the carboxyl group-containing elastomer is 2 to 35 mol based on the total amount of the structural units constituting the carboxyl group-containing elastomer. Ear%. The sealing film according to claim 2, wherein the content of the structural unit having a carboxyl group in the carboxyl group-containing elastomer is 2 to 35 mol based on the total amount of the structural units constituting the carboxyl group-containing elastomer. Ear%. The film for sealing according to any one of claims 1 to 4, wherein the carboxyl group-containing elastomer includes a (meth)acrylic acid-derived structural unit. The film for sealing according to any one of claims 1 to 4, wherein the carboxyl group-containing elastomer has a weight average molecular weight of 300,000 to 10,000,000. The sealing film according to claim 5, wherein the carboxyl group-containing elastomer has a weight average molecular weight of 300,000 to 10,000,000. The film for sealing according to any one of claims 1 to 4, wherein the thermosetting component contains an epoxy resin and a phenol resin. The sealing film according to claim 5, wherein the thermosetting component contains an epoxy resin and a phenol resin. The sealing film according to any one of claims 1 to 4, wherein the content of the inorganic filler is 90% by mass or less based on the total mass of the sealing film. The sealing film according to claim 5, wherein the content of the inorganic filler is 90% by mass or less based on the total mass of the sealing film. The film for sealing as described in any one of Claims 1-4 whose film thickness is 20-400 micrometers. The sealing film according to claim 5, wherein the film thickness is 20 to 400 μm. The film for sealing according to any one of Claims 1 to 4, wherein the film for sealing is used to seal a body to be sealed, and the body to be sealed is provided on a substrate with a bump therebetween. The sealing film according to claim 5, wherein the sealing film is used to seal a body to be sealed, and the body to be sealed is provided on a substrate with a bump therebetween. A method of manufacturing a sealing structure, which prepares a hollow structure including a substrate and a body to be sealed provided on the substrate with bumps interposed therebetween, and a sealing body is provided between the substrate and the body to be sealed A hollow area; and the sealed body is sealed by the film for sealing according to any one of claims 1 to 15. The method of manufacturing a sealing structure according to claim 16, wherein the body to be sealed is a surface acoustic wave element having electrodes on the side of the hollow region. A sealing structure comprising: a substrate; a body to be sealed provided on the substrate with a bump therebetween; and a cured product of the sealing film according to any one of claims 1 to 15, which is used for The sealed body is sealed; and a hollow region is provided between the substrate and the sealed body. The sealing structure according to claim 18, wherein the body to be sealed is a surface acoustic wave element having electrodes on the side of the hollow region.

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