TW201843286A - Sealing film, sealed structure, and method for producing sealed structure - Google Patents

Abstract

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

Description

Sealing film, sealing structure, and method for manufacturing sealing structure

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

In recent years, along with the development of electronic devices such as smart phones and the premise of making portable devices, semiconductor devices have been miniaturized and thinned. Similarly, the electronic components used in these devices have been miniaturized and thinned. The demand for transformation is high. Therefore, various technologies for packaging electronic components having a movable portion such as a surface acoustic wave (SAW: Surface Acoustic Wave) device are being studied. A SAW element is an electronic part that has regular comb electrodes formed on a thin film of a piezoelectric body or a piezoelectric substrate, and is an electronic part that can use surface acoustic waves to capture electrical signals in a specific frequency band.

When packaging such an electronic component having a movable portion, it is necessary to provide a space for ensuring the mobility of the movable portion. For example, in a SAW element, if another substance adheres to the surface on which the comb-shaped electrode is formed, a desired frequency characteristic cannot be obtained, and it becomes necessary to form a hollow structure.

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

Therefore, a method has been proposed that prepares a hollow structure and performs wafer sealing in a state where a hollow region is provided between a substrate and a wafer, and the hollow structure is a wafer in which a comb electrode is formed with bumps interposed therebetween. The wafer is mounted on a substrate (for example, Patent Documents 2 and 3). [Prior Art Literature] (Patent Literature)

Patent Document 1: Japanese Patent Application Publication No. 2002-16466 Patent Document 2: Japanese Patent Application No. 4898402 Patent Document 3: Japanese Patent Application Publication No. 2016-175976

[Problems to be Solved by the Invention] When a sealed body is sealed in a state where a hollow region is provided between a substrate and a sealed body to obtain a hollow sealed structure (for example, an electronic component device), it is necessary to suppress a sealing material (composition 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 at a high concentration, even if the sealing material can be prevented from flowing into the hollow region, there is still a concern that the glass transition temperature (Tg) of the hardened material is significantly reduced, In addition, the reliability (especially thermal reliability) of the hollow seal structure is reduced. For example, when the thermosetting component and the elastomer component form a sea-island structure, it is estimated that Tg derived from the elastomer component will exist in the low temperature region, but the thermal expansion rate of the resin will greatly change before and after Tg, so high concentration of elasticity The body composition is one of the reasons for reducing the reliability of the hollow seal structure.

Therefore, an object of the present invention is to provide a sealing film, a sealing structure obtained by using the sealing film, and a method for manufacturing the sealing structure. The sealing film can sufficiently prevent a sealing material from flowing into a substrate and a sealed body. It is a hollow region between them and can form a hardened material with a sufficient glass transition temperature. [Technical means to solve the problem]

From the viewpoint of avoiding a decrease in Tg, the present inventors conducted research on the premise that the less the amount of the elastomer added, the better. Further, from the viewpoint of sufficiently suppressing the sealing material (the resin composition constituting the sealing film) from flowing into the hollow region, the state and action of the ideal elastomer component are considered as follows. (1) The shape of the elastomer component in the resin composition is more linear than the excessive cluster shape from the viewpoint that the elastomer component becomes a resistance to flow of the resin composition and can suppress the flow of the resin composition. (2) From the viewpoint of restricting the flow of the resin composition by the elastomer component and suppressing the flow of the resin component, it is preferred that the elastomer component be pseudo-polymerized due to an intermolecular interaction.

As a result of intensive research based on the above viewpoints, the present inventors have found that the use of an elastomer having a specific carboxyl equivalent can reduce the addition amount of the elastomer component and sufficiently suppress the resin composition from flowing into the hollow region, thereby completing the present invention.

That is, one aspect of the present invention relates to a sealing film composed of a resin composition containing a thermosetting component, an inorganic filler, and a carboxyl group-containing elasticity having a carboxyl equivalent of 270 to 4300 g / eq. 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 above-mentioned sealing film is excellent in hollow non-filling property. Moreover, according to the said sealing film, the hardened | cured material which has sufficient glass transition temperature (Tg) can be formed.

The content of the elastomer component containing the carboxyl group-containing elastomer contained in the resin composition may be 2% by mass or more and less than 40% by mass based on the total amount of the thermosetting component and the elastomer component. . At this time, the hollow non-filling property is more excellent, and more sufficient Tg is easily obtained after hardening.

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

The carboxyl group-containing elastomer may include a structural unit derived from (meth) acrylic acid. At this time, the hollow non-filling property is more excellent, and more sufficient Tg is easily obtained after hardening.

The weight average molecular weight of the carboxyl group-containing elastomer may be 300,000 to 10 million. At this time, the hollow non-filling property is more excellent, and more sufficient Tg is easily obtained after hardening.

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

The content of the inorganic filler may be 90% by mass or less based on the total mass of the sealing film. In this case, it is easy to obtain an excellent embedding property with respect to the sealed body.

The film thickness of the sealing film may be 20 to 400 μm.

The said sealing film can be used suitably for the purpose of sealing the to-be-sealed body provided on the board | substrate via a bump.

One aspect of the present invention relates to a method for manufacturing a sealed structure, which prepares a hollow structure including a substrate and a to-be-sealed body provided on the substrate via a bump, and the substrate and the substrate A hollow region is provided between the sealed bodies, and the sealed body is sealed by the sealing film of the present invention. According to this method, 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, since the hardened | cured material can be sealed by the hardened | cured material which has sufficient Tg, the sealing structure excellent in reliability (thermal reliability) can be obtained.

In the above manufacturing method, the sealed body may be a SAW element having an electrode on a hollow region side. In the manufacturing method described above, it is possible to sufficiently suppress the sealing material from adhering to the electrode-equipped surface of the SAW element, and to seal the SAW element with a hardened material having a sufficient Tg. Therefore, according to the above manufacturing method, the reliability of the SAW element can be improved. Further, for the same reason, the above-mentioned manufacturing method can improve the yield when manufacturing a sealed structure (hollow sealed structure) having such a sealed body.

One aspect of the present invention relates to a sealing structure including: a substrate; a to-be-sealed body provided on the substrate via a bump; and the hardened object of the sealing film of the present invention, which is used for The sealed body is sealed, and a hollow region is provided between the substrate and the sealed body. In this sealing structure, a hollow region is sufficiently secured, and the body to be sealed is sealed with a hardened material having a sufficient Tg.

In the above-mentioned sealed structure, the to-be-sealed body may be a SAW element having an electrode on a hollow region side. In this sealing structure, it is sufficiently suppressed that the sealing material adheres to the surface of the SAW element having the electrode, and the SAW element is sealed with a hardened material having a sufficient Tg. Therefore, the reliability of the SAW element is excellent. [Effect of the invention]

According to the present invention, it is possible to provide a sealing film, a sealing structure obtained by using the sealing film, and a method for manufacturing the sealing structure. The sealing film can sufficiently prevent a sealing material from flowing between the substrate and the object to be sealed. And can form a hardened product with a sufficient glass transition temperature (Tg).

The numerical ranges indicated by "~" in this specification include the numerical values described before and after "~" as the minimum and maximum values, respectively. In the numerical ranges described stepwise in this specification, the upper limit or lower limit of the numerical range at one stage may be replaced with the upper limit or lower limit of the numerical range at another stage. Among the numerical ranges described in this specification, the upper limit value or lower limit value of the numerical range may be replaced with the numerical values shown in the examples. "A or B" means that either one of A and B may be included, or both. Unless otherwise specified, the materials exemplified in this specification may be used alone or in combination of two or more. In the present specification, when a plurality of substances are present in the composition in accordance with each component, the content of each component in the composition means the total amount of the plurality of substances present in the composition unless otherwise specified.

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

<Seal film> The seal film of this embodiment is a film-like resin composition containing a thermosetting component, an inorganic filler, and an elastomer component (softener, flexibilizer), that is, a carboxy equivalent of 270 ~ 4300g / eq. Carboxyl group-containing elastomer. In this embodiment, the content of the carboxyl group-containing elastomer having a carboxyl equivalent of 270 to 4300 g / eq. May be less than 40% by mass based on the total amount of the thermosetting component and the carboxyl group-containing elastomer. In this embodiment, the content of the elastomer component (including the carboxyl group-containing elastomer) contained in the resin composition may be 2% by 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 this embodiment is suitable for use in a hollow structure including a substrate, a sealed body (such as an electronic component such as a SAW element) provided on the substrate, and the substrate and the sealed body. Hollow area between. According to the sealing film, it is possible to sufficiently suppress the sealing material from flowing into a hollow region between the substrate and the body to be sealed. In addition, according to the above-mentioned sealing film, a cured product having a sufficient glass transition temperature can be formed, and therefore, a sealed 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 that it is as follows.

That is, first, when the carboxyl equivalent of the elastomer is less than 270 g / eq., The polarity of the elastomer becomes large. Therefore, it is estimated that the molecular chain of the elastomer has a string-like structure in the sealing film (in the resin composition). As described above, when the elastic body is excessively string-like, it is considered that the resistance effect is small, and the resistance effect can suppress the fluidity of the resin composition in the sealing film. Therefore, in order to sufficiently suppress the sealing material from flowing into the hollow region, it is estimated that a large amount of an elastomer component needs to be added. On the other hand, when the carboxy equivalent is greater than 4300 g / eq., The polarity of the elastomer becomes small. Therefore, it is estimated 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 has That is, there are fewer carboxyl groups, so it is speculated that the interaction between the molecular chains is small. At this time, since the interaction between the molecular chains is small, the effect of suppressing the fluidity of the resin composition in the sealing film by adding the elastomer component is presumed to be obtained only with the elastomer component. Add the amount corresponding effect. In contrast, the sealing film of this embodiment contains an elastomer having a carboxyl equivalent of 270 to 4300 g / eq. It is presumed that this elastomer maintains a linear shape in the resin composition. Further, the molecular chains of this elastomer are pseudo-polymerized due to the interaction of carboxyl groups (that is, the molecular chains of the elastomer form a three-dimensional network with each other). Therefore, the said sealing film can reduce the addition amount of an elastomer component compared with the past, and as a result, it is estimated that the said effect can be acquired.

When the sealing film contains a high concentration of an elastomer component, it is presumed that the influence of Tg derived from the elastomer component in the low-temperature region causes a large change in the amount of thermal expansion during the construction of the electronic device. It is easy to cause a bad condition (warping, cracking, etc.). On the other hand, since the content of the elastomer component in the sealing film of this embodiment is within the above-mentioned range, it is possible to reduce a problem at the time of assembly.

When the sealing film contains a high concentration of an elastomer component, sufficient embedding properties with respect to the object to be sealed may not be obtained. On the other hand, since the addition amount of an elastomer component can be reduced in the sealing film of this embodiment, it is easy to obtain sufficient embedding property with respect to a to-be-sealed body.

(Thermosetting component) Examples of the thermosetting component include a thermosetting resin, a curing agent, and a curing accelerator. The thermosetting component may contain a thermosetting resin without containing a hardener and / or a hardening accelerator.

[Thermosetting resin] Examples of the thermosetting resin include epoxy resin, phenoxy resin, cyanate resin, thermosetting polyimide, melamine resin, urea resin, unsaturated polyester, and alkyd. Resin, polyurethane, etc. From the viewpoint of easily controlling the fluidity and curing reactivity of the resin, an epoxy resin is preferred.

As the epoxy resin, any resin having two or more epoxy groups in one molecule can be used without particular limitation. Examples of the epoxy resin 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, and bisphenol 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 diepoxypropyl ether, etc.), bisphenol P epoxy resin, bisphenol PH epoxy resin, bisphenol TMC epoxy resin, bisphenol Z epoxy resin, phenol novolac 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 epoxy propyl ether, etc.); and diacid modified epoxy resins of these resins; aliphatic epoxy resins, and the like. An epoxy resin may be used individually by 1 type, and may use 2 or more types together.

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

Examples of commercially available epoxy resins include the product name "jER825" (bisphenol A epoxy resin, epoxy equivalent: 175 g / eq.) Manufactured by Mitsubishi Chemical Corporation, and Mitsubishi Chemical Corporation. Trade name "jER806" (bisphenol F-type epoxy resin, epoxy equivalent: 160 g / eq.), Trade name "HP-4032D" (naphthalene-type epoxy resin, epoxy equivalent) manufactured by DIC Corporation : 141g / eq.), Soft and strong epoxy resin such as "EXA-4850" manufactured by DIC Corporation; trade name "HP-4700" (4-functional naphthalene-type epoxy resin) manufactured by DIC Corporation , Trade name "HP-4750" (3-functional naphthalene type epoxy resin), trade name "HP-4710" (4-functional naphthalene type epoxy resin), trade name "EPICLON N-770" (phenol novolac type epoxy resin Resin), trade name "EPICLON N-660" (cresol novolac-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" (biphenylalkyl type epoxy resin) Grease); Nippon Steel & Sumitomo Chemical Co., Ltd. trade name "ESN-355" (naphthalene-type epoxy resin); Mitsubishi Chemical Co., Ltd. trade name "YX-8800" (anthracene-type epoxy resin), Trade name "ESCN-190-2" (o-cresol novolac epoxy resin) manufactured by Sumitomo Chemical Co., Ltd., etc. These epoxy resins may be used individually or in combination of 2 or more types.

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

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. It is preferably 50% by mass or more, more preferably 80% by mass or more, and even 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.

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

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

[Hardener] The hardener is not particularly limited, and examples thereof include a phenol-based hardener (for example, a phenol resin), an acid anhydride-based hardener, an active ester-based hardener, and a cyanate-based hardener. When a thermosetting resin contains an epoxy resin, as a hardener, if it is a compound which has 2 or more functional groups which can react with an epoxy group in a molecule | numerator, it can be used without a restriction | limiting in particular. Examples of such a curing agent include phenol resins and acid anhydrides. A hardening agent may be used individually by 1 type, and may use 2 or more types together. As a hardening | curing agent, a phenol resin is preferable from a viewpoint of being easy to obtain the hardened | cured material which has the outstanding thermal conductivity. A hardening agent may be used individually by 1 type, and may use 2 or more types together.

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

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

From the viewpoint of excellent curability of the thermosetting resin, the content of the curing agent may be 1 to 20% by mass, or 2 to 15% by mass, or may be based on the total mass of the sealing film. 3 to 10% by 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 hardener are M2. 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 above ratio is 0.7 or more or 2.0 or less, it is difficult to leave unreacted epoxy resin and / or unreacted hardener, and it is easy to obtain desired cured product characteristics.

[Hardening Accelerator] The hardening accelerator can be used without particular limitation, and it is preferably at least one selected from the group consisting of an amine-based hardening accelerator and a phosphorus-based hardening accelerator. In particular, from the viewpoint of easily obtaining a hardened material having excellent thermal conductivity, from the viewpoint of rich derivatives, and from the viewpoint of easily obtaining a desired active temperature, as the hardening accelerator, an amine-based hardening accelerator is preferred, and more preferably It is at least one selected from the group consisting of an imidazole compound, an aliphatic amine, and an alicyclic amine, and more preferably an imidazole compound. Examples of the imidazole compound include 2-phenyl-4-methylimidazole and 1-benzyl-2-methylimidazole. A hardening accelerator may be used individually by 1 type, and may use 2 or more types together. Examples of commercially available hardening accelerators include "2P4MZ" and "1B2MZ" manufactured by Shikoku Chemical Industry Co., Ltd.

The content of the hardening accelerator is preferably within the following range based on the thermosetting resin (such as epoxy resin) and the hardening agent (such as phenol resin). From the viewpoint of easily obtaining a sufficient hardening promoting effect, the content of the hardening accelerator is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and still more preferably 0.3% by mass or more. From the standpoint that hardening does not easily progress during the steps (such as coating and drying) when manufacturing the sealing film or during storage of the sealing film, and it is easy to prevent cracking of the sealing film and poor molding 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% by mass, more preferably 0.1 to 3% by mass, and still more preferably 0.3 to 1.5% by mass.

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

Surface modification of inorganic fillers. The method for surface modification is not particularly limited. From the viewpoint of easy handling, abundant functional group types, and easy provision of desired characteristics, surface modification using a silane coupling agent is preferred.

Examples of the silane coupling agent include alkyl silane, alkoxy silane, vinyl silane, epoxy silane, amino silane, acryl silane, methacryl silane, thiol silane, thioether silane, isosilane Cyanosilane, thiosilane, styrylsilane, alkylchlorosilane, etc.

Specific examples of the silane coupling agent include methyltrimethoxysilane, dimethyldimethoxysilane, trimethylmethoxysilane, methyltriethoxysilane, and methyltriethoxysilane. , Ethyltrimethoxysilane, n-propyltrimethoxysilane, diisopropyldimethoxysilane, isobutyltrimethoxysilane, diisobutyldimethoxysilane, isobutyltriethoxy Silane, n-hexyltrimethoxysilane, n-hexyltriethoxysilane, cyclohexylmethyldimethoxysilane, n-octyltriethoxysilane, n-decylmethoxysilane, phenyltrimethoxy Silane, diphenyldimethoxysilane, triphenylsilanol, methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, n-octyldimethylchlorosilane, tetraethoxysilane , 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3- (2-aminoethyl) aminopropyltrimethoxysilane, 3- (2-amino group (Ethyl) aminopropylmethyldimethoxysilane, 3-phenylaminopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyl Methyldimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, bis (3- (triethyl disulfide) Oxysilyl) propyl), bis (3- (triethoxysilyl) propyl) tetrasulfide, vinyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane , Vinyltriisopropoxysilane, allyltrimethoxysilane, diallyldimethylsilane, 3-methylpropoxypropyltrimethoxysilane, 3-methylpropoxysilane Propylmethyldimethoxysilane, 3-methylpropanyloxypropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3 -Mercaptopropyltriethoxysilane, N- (1,3-dimethylbutylene) -3-aminopropyltriethoxysilane, aminosilane (phenylaminosilane, etc.), and the like. The silane coupling agent may be used singly or in combination of two or more kinds.

From the standpoint of easily inhibiting the aggregation of the inorganic filler and thereby easily dispersing the inorganic filler, the average particle diameter of the inorganic filler is preferably 0.01 μm or more, more preferably 0.1 μm or more, and still more preferably 0.3 μm or more. It is preferably at least 0.5 μm. The average particle diameter of the inorganic filler is preferably 25 μm or less, more preferably 10 μm or less, and further more preferably, from the viewpoint that it is easy to suppress the precipitation of the inorganic filler in the varnish and it is easy to produce a homogeneous sealing film. 5 μm 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 plurality of inorganic fillers having different average particle diameters in combination. In the combination of inorganic fillers, the maximum average particle diameter is preferably 15 to 25 μm. 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 preferably used in combination.

"Average particle diameter" is a particle diameter equivalent to 50% of the volume when the total volume of the particles is set to 100% and a cumulative frequency distribution curve based on the particle diameter is obtained. The measurement was performed by a distribution measuring device using a laser diffraction scattering method. The average particle diameter of each inorganic filler after combination can be confirmed from the average particle diameter of each inorganic filler at the time of mixing, and can also be confirmed by measuring a particle size distribution.

Examples of commercially available inorganic fillers include "DAW-20" manufactured by Denka Corporation; trade names "SC550O-SXE" and "SC2050-KC" manufactured by Admatechs Corporation.

From the viewpoint of improving the thermal conductivity and easily suppressing the warpage of the sealing structure (such as an electronic component device such as a semiconductor device) from increasing due to a difference in the coefficient of thermal expansion with the sealed body, an inorganic filler The content may be 70% by mass or more, 75% by mass or more, 80% by mass or more, and 84% by mass or more based on the total mass of the sealing film. From the viewpoint that it is easy to suppress cracking of the sealing film in the drying step when producing the sealing film, and from suppressing the decrease in fluidity due to an increase in the melt viscosity of the sealing film, it is easy to sufficiently seal the 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% by mass or less, 91% by mass or less, 90% by mass or less, and 88% by mass or less. . From these viewpoints, the content of the inorganic filler may be 70 to 93% by mass, or 75 to 91% by mass, or 80 to 91% by mass, based on the total mass of the sealing film. It may be 80 to 90% by mass or 84 to 88% by mass. The above-mentioned content is the content of the inorganic filler after excluding the amount of the surface treatment agent.

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

From the viewpoint of suppressing the elastomer from becoming excessively string-like, thereby making it easy to obtain the effect of suppressing the fluidity of the resin composition, the carboxy equivalent of the carboxyl-containing elastomer may be 340 g / eq. Or more. It is 400 g / eq. Or more, 600 g / eq. Or more, or 800 g / eq. Or more. From the viewpoint that the molecular chains of the elastomer become easier to form a tighter three-dimensional network and the hollow non-filling property becomes better, the carboxy equivalent of the carboxyl-containing elastomer may be 4000 g / eq. Or less. 3000 g / eq. Or less, or 2000 g / eq. Or less. From these viewpoints, the carboxy equivalent of the carboxyl-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-derived structural unit represented by the following formula (1) as a structural unit having a carboxyl group.

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

From the viewpoint of suppressing the elastomer from becoming excessively cluster-like, thereby making it easy 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-containing elastomer constitutes a carboxyl group The total amount of the structural units of the elastomer is used as a reference, and may be 2 mol% or more, 4 mol% or more, or 6 mol% or more. From the viewpoint that the molecular chains of the elastomer become easier to form a closer three-dimensional network, and the hollow non-filling property becomes better, the content of the structural unit having a carboxyl group constitutes the total The amount can be 39 mol% or less, or 37 mol% or less, 35 mol% or less, 31 mol% or less, or 29 mol% or less. From these viewpoints, the content of the structural unit having a carboxyl group may be 2 to 35 mole%, 4 to 31 mole%, or 6 to 29 mole%. From the same viewpoint, the content of the structural unit represented by the above formula (1) may be within the above range.

The carboxyl-containing elastomer may be a copolymer composed of a plurality of different structural units (for example, a copolymer such as a random copolymer and a block copolymer). The carboxyl group-containing elastomer may further have a structural unit other than the structural unit having a carboxyl group. Examples of the other structural unit include a structural unit having the following group: an alkyl ester group (-C (= O) -OR (R represents an alkyl group which may have a substituent)), a nitrile group (-C≡N) , Hydroxyl (-OH), allyl and the like. Examples of R in the alkyl ester group include methyl, ethyl, and butyl. The carboxyl group-containing elastomer is preferably a copolymer of (meth) acrylic acid and another monomer ((meth) acrylic copolymer).

Examples of the structural unit having an alkyl ester group include a structural unit derived from an alkyl (meth) acrylate represented by the following formula (2). That is, the carboxyl group-containing elastomer may be a copolymer of a carboxyl group-containing monomer and an (meth) acrylic acid alkyl ester (a carboxyl group-containing (meth) acrylic acid alkyl ester copolymer), preferably (meth) acrylic acid and (Meth) acrylic acid ester copolymer ((meth) acrylic acid- (meth) acrylic acid alkyl ester copolymer).

In the formula (2), R ² represents a hydrogen atom or a methyl group, and R represents an alkyl group which may have a substituent.

From the standpoint that the hollow non-filling property is more excellent and more sufficient Tg is easily obtained after curing, the content of the structural unit represented by the above formula (2) in the carboxyl-containing elastomer constitutes a structure of the carboxyl-containing elastomer. The total amount of the unit as a reference may be 65 mol% or more, 69 mol% or more, or 71 mol%, 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), based on the total amount of the structural units constituting the carboxyl group-containing elastomer, may be, for example, 65 to 98 mole%, or 69 to 96 mole%. It can also be 71-94 mole%.

Examples of the structural unit having a nitrile group include a structural unit derived from (meth) acrylonitrile represented by the following formula (3).

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

From the standpoint that the hollow non-filling is more excellent and it is easy to obtain more sufficient Tg after curing, the content of the structural unit represented by the above formula (3) in the carboxyl-containing elastomer constitutes a structure of the carboxyl-containing elastomer The total amount of units is used as a reference, and may be 65-98 mol%, 69-96 mol%, or 71-94 mol%.

From the standpoint that the hollow non-filling property is more excellent and more sufficient Tg is easily obtained after curing, the carboxyl group-containing elastomer preferably has a structural unit represented by the above formula (1) and the above formula (2) And a 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 more excellent hollow non-filling properties, a viewpoint of obtaining more sufficient Tg after hardening, and a viewpoint of obtaining sufficient embedding properties for a sealed body. , Can be 300,000 or more, 400,000 or more, and 500,000 or more, and can 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 10,000,000, 400,000 to 8,000,000, 500,000 to 7,000,000, or 500,000 to 2,000,000. The weight average molecular weight is a value in terms of polystyrene obtained by gel permeation chromatography (GPC) using a calibration curve based on standard polystyrene.

When the carboxyl group-containing elastomer is particulate, the average particle diameter of the elastomer is not particularly limited. From the viewpoint of excellent embedding properties between the sealed bodies, the average particle diameter of the elastomer may be, for example, 50 μm or less. 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 this embodiment can be obtained by polymerizing a polymerizable monomer having a carboxyl group by a conventionally known method, and can also be obtained by polymerizing a polymerizable monomer having a carboxyl group with a conventionally known method. 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 alkyl (meth) acrylate and / or (meth) acrylonitrile. In this embodiment, a carboxy equivalent can be adjusted to a desired range by adjusting the usage-amount of a polymerizable monomer. In addition, in this embodiment, after the polymer is obtained by the method described above, the carboxyl equivalent can be adjusted by substituting a part of the carboxyl group by a method such as esterification.

During the polymerization, a polymerization initiator may be used. Examples of the polymerization initiator include a thermal radical polymerization initiator, a photo radical polymerization initiator, an anionic polymerization initiator, and a cationic polymerization initiator.

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 this embodiment, by setting the content of the elastomer component within the above range, the sealing film has a sufficient Tg after curing, and a sealed structure excellent in reliability can be obtained. From the viewpoint that the hollow non-filling property becomes better, the content of the carboxyl group-containing elastomer may exceed 0% by mass or 2% by mass based on the total amount of the thermosetting component and the carboxyl group-containing elastomer. The above may be 4% by mass or more, 8% by mass or more, or 12% by mass or more. From the viewpoint that the Tg after curing becomes more sufficient and the viewpoint of obtaining sufficient embedding property to the sealed body, the content of the carboxyl group-containing elastomer is the total amount of the thermosetting component and the carboxyl group-containing elastomer. The reference meter may be 35% by mass or less, 30% by mass or less, and 25% by mass or less. Therefore, the content of the carboxyl group-containing elastomer is based on the total amount of the thermosetting component and the carboxyl group-containing elastomer, and may be, for example, more than 0% by mass and less than 40% by mass, or may be 2% by mass or more and less than 40% by mass. It may be 4 to 35% by mass, 8 to 30% by mass, or 12 to 25% by mass.

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

The elastomer component (such as a carboxyl-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 this embodiment may contain an elastomer other than the carboxyl group-containing elastomer as long as it does not affect the present invention. Examples of other elastomers include polybutadiene particles, styrene butadiene particles, acrylic elastomers, polysiloxane powders, silicone oils, and silicone oligomers.

The content of the elastomer component (including the carboxyl group-containing elastomer) in the sealing film of this embodiment is based on the total amount of the thermosetting component and the elastomer component, and is preferably 2% by mass or more and less than 40% by mass. %. That is, even when the elastomer component contains an elastomer other than a carboxyl group-containing elastomer, the total amount of the elastomer component is based on the total amount of the thermosetting component and the elastomer component, and is preferably 2 Mass% or more and less than 40 mass%. In this case, the sealing film has a more sufficient Tg after hardening, and a more reliable sealing structure can be obtained. From the viewpoint that the hollow non-filling property becomes better, 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. It may be 12% by 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 a more sufficient Tg after curing and a viewpoint of obtaining sufficient embedding property to the sealed body. It may be 35% by mass or less, 30% by mass or less, and 25% by 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. .

From the viewpoint that the hollow non-filling property becomes better, 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. The above may be 95% by mass or more. 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 a carboxyl group-containing elastomer.

(Other components) The sealing film of this embodiment can further contain other additives. Specific examples of such additives include pigments, dyes, release agents, antioxidants, and surface tension adjusters.

The sealing film of the present embodiment may contain a solvent (for example, a solvent used in the production of a sealing film). The solvent may be a conventionally known organic solvent. The organic solvent may be a solvent capable of dissolving components other than the inorganic filler, and examples thereof include aliphatic hydrocarbons, aromatic hydrocarbons, terpene, 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 a viewpoint of easily dissolving a thermosetting component. Among them, when the solvent is a ketone, it is particularly easy to dissolve the thermosetting component. From the viewpoint of less volatilization at room temperature (25 ° C) and easy removal during drying, the solvent may be selected from the group consisting of acetone, methyl ethyl ketone, and methyl isobutyl ketone. At least one.

The content of the solvent (organic solvent, etc.) contained in the sealing film is based on the total mass of the sealing film, and is preferably within the following range. The content of the solvent may be 0.2% by mass or more, from the viewpoints that it is easy to prevent the sealing film from becoming brittle and causing problems such as cracking of the sealing film and the case where the minimum melt viscosity becomes high and the embedding property decreases. It is 0.3 mass% or more, may be 0.5 mass% or more, may be 0.6 mass% or more, and may be 0.7 mass% or more. The content of the solvent is from the viewpoints that it is easy to suppress the disadvantages that the adhesiveness of the sealing film becomes too strong and the operability is reduced, and that the solvent (organic solvent, etc.) is volatilized during the thermal curing of the sealing film, which causes problems such as foaming. It may be 1.5% by mass or less, or 1% by mass or less. From these viewpoints, the content of the solvent may be 0.2 to 1.5% by mass, 0.3 to 1% by mass, 0.5 to 1% by mass, 0.6 to 1% by mass, or 0.7 to 1% by mass. 1% by mass.

The thickness of the sealing film may be 20 μm or more, 30 μm or more, or 50 μm or more, or 100 μm or more from the viewpoint of easily suppressing variations in thickness in the surface 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 level of dryness in the depth direction during coating. From these viewpoints, the thickness of the sealing film 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 several sealing films can be laminated | stacked, and the sealing film whose thickness exceeds 250 micrometers can be manufactured.

From the viewpoint of the reliability (thermal reliability) of the obtained sealing structure, the glass transition temperature Tg after the sealing film is cured may be 80 to 150 ° C, 90 to 140 ° C, or 100. ~ 130 ° C. The glass transition temperature Tg of the sealing film can be adjusted by using the kind and content of the thermosetting component, the kind 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 melt viscosity (minimum melt viscosity) of the sealing film at 60 to 140 ° C may be 1,000 to 20,000 Pa ･ s, or 3,000 to 15,000 Pa ･ s, or it may be 5000 ～ 12000Pa ･ s. The said minimum melt viscosity can be calculated | required by measuring the melt viscosity of the sealing film by implementing the method of description.

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

The sealing film of this embodiment can also be used as a sealing film with a support, for example. The sealing film 10 with a support shown in FIG. 1 includes a support 1 and a sealing film 2 provided on the support 1.

As the support 1, a polymer film, a metal foil, or the like can be used. Examples of the polymer film 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. Examples of the metal foil include copper foil and aluminum foil.

The thickness of the support 1 is not particularly limited, but may be 2 to 200 μm from the viewpoint of excellent workability and dryness. When the thickness of the support 1 is 2 μm or more, it is easy to suppress the failure of the support during coating, the failure of the support to bend due to the weight of the varnish, and the like. When the thickness of the support 1 is 200 μm or less, in the drying step, when hot air is blown from both sides of the coating surface and the back surface, it is easy to suppress a problem that the drying of the solvent in the varnish is prevented.

In this embodiment, the support body 1 may not be used. A protective layer may be disposed on the side of the sealing film 2 opposite to the support 1, and the purpose of the protective layer is to protect the sealing film. By forming a protective layer on the sealing film 2, the operability can be improved, and a trouble such as the sealing film sticking to the back surface of the support when the winding is performed can be avoided.

As the protective layer, a polymer film, a metal foil, or the like can be used. Examples of the polymer film 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. Examples of the metal foil include copper foil and aluminum foil.

<The manufacturing method of the sealing film> Specifically, the sealing film of this embodiment can be 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 this embodiment. . The mixing method is not particularly limited, and a mill, a mixer, or a stirring blade can be used. The solvent (organic solvent) can be used to dissolve and disperse the material of the sealing film, that is, the constituents of the resin composition to prepare a varnish, 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.

The varnish produced in this manner can be applied to a support (a film-shaped support, etc.), and then heated and dried by blowing hot air or the like, whereby a sealing film can be produced. The coating method is not particularly limited, and examples thereof include a corner wheel coater, a bar coater, a kiss coater, a roll coater, and a gravure coater. , Die coating machine and other coating devices.

<Sealed Structure and Manufacturing Method> The sealed structure of this embodiment includes a body to be sealed and a sealing portion for sealing the body to be sealed. The sealing portion is a cured product of the sealing film of the present embodiment and includes a cured product of the resin composition of the present embodiment. The sealed structure may be a hollow sealed structure having a hollow structure. The hollow seal structure includes, for example, a substrate, a sealed body provided on the substrate, a hollow region provided between the substrate and the sealed body, and a sealing portion for sealing the sealed body. The sealed structure of the present embodiment may include a plurality of sealed bodies. The plurality of sealed bodies may be the same type or different types.

The sealed structure is, for example, an electronic component device. The electronic component device includes an electronic component as a sealed body. Examples of the electronic component include semiconductor elements, semiconductor wafers, integrated circuits, semiconductor devices, filters such as SAW filters, and passive components such as sensors. 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, and 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, for example, has a movable portion on the surface of the hollow region side (substrate side) through the bumps. Set on the substrate. Examples of such a sealed body include electronic components such as a SAW device (SAW device) such as a SAW filter, and an acceleration sensor. When the sealed body is a SAW filter, a surface on the side of one side of the piezoelectric substrate on which a pair of comb-shaped electrodes are mounted is an interdigital transducer (IDT) becomes a movable portion.

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

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

Then, 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, and the sealing film 2 in which the SAW element 20 is embedded is cured. To obtain a cured product of the sealing film (a sealed portion including a cured product of a resin composition) 2a ((b) of FIG. 2). Thereby, the electronic component device 100 can be obtained.

The laminator used for lamination is not particularly limited, and examples thereof include a laminator such as a roll type and an air bag type. From the viewpoint of excellent embedding properties, the laminator may be a bladder-type laminator capable of vacuum pressure.

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

The sealing film can be cured, for example, in the atmosphere or under an inert gas. The curing 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 sufficiently progress, and the occurrence of a defective condition tends to be suppressed. When the curing temperature is 280 ° C. or lower, there is a tendency that thermal damage to other materials can be suppressed. The curing 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 curing time is within these ranges, the curing of the sealing film can sufficiently progress, and more favorable production efficiency can be obtained. Moreover, a plurality of conditions can be combined for the hardening conditions.

In the present embodiment, a plurality of electronic component devices 200 can be obtained by singulating the electronic component device 100 using a cutter or the like (see (c) of FIG. 2).

The manufacturing method of the hollow sealing structure of the present embodiment described above can ensure excellent embedding property to a sealed body (for example, SAW element 20), and can sufficiently prevent the sealing material from flowing into the hollow region between the substrate 30 and the sealed body. 50.

In this 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). The hollow seal structure is provided with the SAW element 20 embedded in the hardened body 2a. The seal structure can also be obtained by compression molding using a compression molding device, or by using an hydraulic press. Pressing is performed to obtain a sealed structure. The temperature (sealing temperature) when the sealed body is sealed by compression molding and hydraulic pressing may be the same as the above-mentioned lamination temperature.

As mentioned above, although the preferred embodiment of this invention was described, this invention is not necessarily limited to the said embodiment, A change can be implemented suitably within the range which does not deviate from the meaning. [Example]

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

The following materials were used in the examples and comparative examples. (Thermosetting resin) A1: Bisphenol F-type epoxy resin (manufactured by Mitsubishi Chemical Corporation, trade name "jER806", epoxy equivalent: 160g / eq.) (Hardener) B1: novolac phenol resin (Made by 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-containing elastomer (inorganic filler) E1: Alumina (manufactured by Denka Corporation, trade name "DAW-20", average particle size: 20 μm)

<Synthesis of carboxyl group-containing elastomer> (Synthesis Examples 1 to 7) The carboxyl group-containing elastomers D1 to D7 were synthesized in the following procedure. First, according to the blending amounts shown in Table 1, 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). ) Propane] was dissolved in 500 g of methanol to obtain a mixed solution. Here, the total amount of acrylic acid and methyl acrylate is 500 g. Then, 960 g of deionized water was put into a 3 liter synthesis flask, and the temperature was raised to 90 ° C. while being stirred under a nitrogen atmosphere. After the above mixed solution was poured into the flask over 2 hours, stirring was performed at 90 ° C for 4 to 6 hours. After stirring, the obtained reaction solution was cooled. Then, the product in the reaction solution was washed with deionized water. The water washing was performed 4 times, and the amount of deionized water used each time was set to 3 times the mass of the product. The product after washing with water was dried, whereby a carboxyl group-containing elastomer (acrylic acid-methyl acrylate copolymer) was obtained.

The carboxyl equivalent, weight average molecular weight (Mw), and content of the structural unit derived from acrylic acid of the carboxyl group-containing elastomer are shown in Table 1. The carboxy equivalent is judged by the feeding amount of each monomer. The weight average molecular weight (Mw) is calculated based on a standard polystyrene exchange algorithm using gel permeation chromatography (GPC). The measurement conditions of GPC are shown below.・ Measurement device: High-speed GPC device (HLC-8220GPC manufactured by Tosoh Corporation) ・ Column: TSKguardcolumn SuperHZ-H (made by Tosoh Corporation) ・ Solvent: Tetrahydrofuran

[Table 1]

<Preparation of a film for sealing (film-like epoxy resin composition)> (Example 1) After 100 g of MEK (methyl ethyl ketone) was put into a 1 L (liter) polyethylene container, and 900 g of an inorganic filler E1 was added, 51 g of epoxy resin A1 and 34 g of hardener B1 were added and stirred. Subsequently, 15 g of the elastomer D1 was added and further stirred for 3 hours. 0.3 g of a hardening accelerator C1 was added, and further stirred for 3 hours. The obtained mixed liquid was filtered through a nylon # 150 mesh (opening: 106 μm), and the filtrate was extracted. Thereby, a varnish-like epoxy resin composition was obtained. Using a coater, this varnish-like epoxy resin composition was coated on a PET film under the following conditions. Thereby, a 200 μm-thick sealing film was produced on the support.・ Applying head method: corner 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 (a polyethylene terephthalate film having a thickness of 50 μm) is disposed on the side opposite to the support in the sealing film, thereby protecting the surface of the sealing film. The same applies to the following examples and comparative examples.

(Examples 2 to 5 and Comparative Examples 1 to 2) Except that elastomers D2 to D7 were used instead of elastomer D1 as the elastomer, the same procedure as in Example 1 was performed 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 sealing film of 200 micrometers in thickness on a support body (PET film).

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

(Example 7) A varnish-like epoxy resin composition was obtained in the same manner as in Example 3 except that 39 g of epoxy resin A1, 26 g of hardener B1, and 35 g of elastomer D3 were used. Except having used this varnish-like epoxy resin composition, it carried out similarly to Example 3, and produced the sealing film of 200 micrometers in thickness 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 no elastic component was used. Except having used this varnish-like epoxy resin composition, it carried out similarly to Example 1, and produced the sealing film of 200 micrometers in thickness on a support body (PET film).

(Comparative Example 4) A varnish-like epoxy resin composition was obtained in the same manner as in Example 3 except that 36 g of epoxy resin A1, 24 g of hardener B1, and 41 g of elastomer D3 were used. Except having used this varnish-like epoxy resin composition, it carried out similarly to Example 3, and produced the sealing film of 200 micrometers in thickness on a support body (PET film).

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

(1) Flow rate (flow rate) An evaluation test was made by punching a sealing film having a support and a protective film produced in the examples and comparative examples through a 4 mm diameter circle using a punch. kind. Then, the protective film of the evaluation sample was peeled off, and five evaluation samples (a sealing film with a support body attached, symbol 10 in Fig. 3) were arranged in the arrangement shown in Fig. 3 (a). On a silicon wafer (5 cm x 5 cm, symbol 4 in Fig. 3). At this time, the surface on the side of the sealing film faces the silicon wafer. Then, after the support was removed from the evaluation sample, a glass plate (5 cm × 5 cm, thickness 3.0 mm, symbol 5 in FIG. 3) was placed on the evaluation test as shown in FIG. 3 (b). On a sample, 470 g of an iron plate (5 cm x 5 cm, symbol 6 in Fig. 3) was placed on a glass plate to obtain a laminated body. This laminate was placed in an oven at 70 ° C and held 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 calculated from the following formula. Flow rate = (maximum diameter of sealing film after test / 4 mm) × 100 The average value of the obtained flow rates at 5 points was used as the flow rate in this evaluation.

(2) Embedding property and hollow non-filling property at sealing temperature of 70 ° C The embedding property and hollow non-filling property at sealing temperature of 70 ° C were evaluated by the following methods. First, the produced sealing film (a sealing film including a support and a protective film) was cut into a rectangle of 8 mm × 8 cm to prepare an evaluation sample. In addition, a substrate (5 cm × 5 cm, thickness: 0.2 mm) provided with a through hole (diameter 2 mm) in the center of the main surface was prepared. Then, a PET film (5 cm x 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 above-mentioned substrate provided with a through hole was placed thereon. Then, the protective film of the evaluation sample was peeled off, and the through-hole of the substrate was covered with the sealing film, and the sealing film was directed to the substrate side, and the evaluation sample (the sealing film including the support) was placed on the substrate on. Then, 470 g of an iron plate (5 cm × 5 cm) was placed on the evaluation sample to obtain a laminated body. The obtained laminate was heated in an oven at 70 ° C. (trade name “SAFETY OVEN SPH-201” manufactured by ESPEC Corporation) for 1 hour.

After heating, use a digital microscope to observe whether the resin flows into the glass plate side from the through hole and the amount of resin (the maximum diameter of the resin layer expanded on the glass surface) due to the melting of the sealing film. Assess embedding and hollow non-filling. [Embedding property] A: Resin reaches the substrate B: Resin does not reach the substrate [Hollow non-filling property] A: The maximum diameter of the resin layer flowing ≦ 2.1 mm B: The maximum diameter of the resin layer flowing> 2.1 mm but ≦ 2.3mm C: The maximum diameter of the resin layer flowing in is greater than 2.3mm

(3) The glass transition temperature Tg after the sealing film is cured. The sealing films of Examples and Comparative Examples were laminated on a copper foil under the following conditions to obtain a sealing film with a copper foil.・ Laminator device: MVLP-500, a vacuum pressurizing laminator manufactured by Meiji Seisakusho ・ Laminating temperature: 110 ° C ・ Laminating pressure: 0.5MPa ・ Evacuation time: 30 seconds ・ Laminating time: 40 seconds

A sealing film with a copper foil is adhered to a stainless steel (SUS) plate, and the sealing film is hardened under the following conditions to obtain a cured product of the sealing film with a copper foil (epoxy with copper foil). Resin hardened body) • Oven: SAFETY OVEN SPH-201 manufactured by ESPEC Corporation • Oven temperature: 140 ° C • Time: 120 minutes

After peeling the copper foil from the hardened | cured material of the sealing film with a copper foil attached, the hardened | cured material of the sealing film was cut into 4 mm x 30 mm, and the test piece was produced. The glass transition temperature of the produced test piece was measured under the following conditions. In this evaluation, if the glass transition temperature is 100 ° C or higher, the glass transition temperature is judged to be 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). The content (% by 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

2‧‧‧ Sealing film

2a‧‧‧Hardened film (sealing part)

4‧‧‧ silicon wafer

5‧‧‧ glass plate

6‧‧‧ iron plate

10‧‧‧ Sealing film with support

20‧‧‧Surface acoustic wave element (sealed body)

20a‧‧‧ Surface of surface acoustic wave element on hollow area side (substrate side)

30‧‧‧ substrate

40‧‧‧ bump

50‧‧‧ hollow area

60‧‧‧ hollow structure

100, 200‧‧‧ hollow seal structure (sealed structure)

FIG. 1 is a schematic cross-sectional view showing a sealing film with a support, which includes a sealing film according to an embodiment. FIG. 2 is a schematic cross-sectional view illustrating an embodiment of a method for manufacturing a hollow seal structure. FIG. 3 is a diagram showing a method of evaluating a flow rate in an example.

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Claims (13)

A sealing film comprising a resin composition containing a thermosetting component, an inorganic filler, and a carboxyl group-containing elastomer having a carboxyl equivalent of 270 to 4300 g / eq .; and The content is less than 40% by mass based on the total amount of the thermosetting component and the carboxyl group-containing elastomer. The sealing film according to claim 1, wherein the content of the elastomer component containing the carboxyl group-containing elastomer contained in the resin composition is based on the total amount of the thermosetting component and the elastomer component. It is 2 mass% or more and less than 40 mass%. The sealing film according to claim 1 or 2, wherein the content of the structural unit having a carboxyl group in the carboxyl-containing elastomer is 2 to based on the total amount of the structural unit constituting the carboxyl-containing elastomer. 35 mole%. The sealing film according to any one of claims 1 to 3, wherein the carboxyl group-containing elastomer includes a structural unit derived from (meth) acrylic acid. The sealing film 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 million. The sealing film according to any one of claims 1 to 5, wherein the thermosetting component contains an epoxy resin and a phenol resin. The sealing film according to any one of claims 1 to 6, 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 any one of claims 1 to 7, wherein the film thickness is 20 to 400 μm. The sealing film according to any one of claims 1 to 8, wherein the sealing film is used to seal an object to be sealed, and the object to be sealed is provided on a substrate via a bump. A method for manufacturing a sealed structure, which comprises preparing a hollow structure including a substrate and a sealed body provided on the substrate with a bump interposed therebetween, and providing between the substrate and the sealed body The hollow region; and the sealed body is sealed with the sealing film according to any one of claims 1 to 9. The method for manufacturing a sealed structure according to claim 10, wherein the sealed body is a surface acoustic wave element having an electrode on the hollow region side. A sealed structure including: a substrate; a sealed body provided on the substrate with a bump interposed therebetween; and a hardened body of the sealing film according to any one of claims 1 to 9, which is used for The sealed body is sealed; and a hollow region is provided between the substrate and the sealed body. The sealed structure according to claim 12, wherein the sealed body is a surface acoustic wave element having an electrode on the hollow region side.