WO2018199310A1 - Sealing film, sealed structure, and method for producing sealed structure - Google Patents

Abstract

A sealing film comprising a resin composition which comprises a thermally curable component, an inorganic filler, and a carboxylated elastomer having a carboxy equivalent of 270-4,300 g/eq., wherein the content of the carboxylated elastomer is less than 40 mass% with respect to the total amount of the thermally curable component and the carboxylated elastomer.

Description

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

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

In recent years, along with the development of electronic devices such as smartphones, which are made on the premise of carrying, semiconductor devices are becoming smaller and thinner. Similarly, electronic component devices used there are also becoming smaller. There is an increasing demand for thinning. For this reason, various techniques for packaging electronic components having movable parts such as surface acoustic wave (SAW) devices have been studied. A SAW device is an electronic component in which a regular comb-shaped electrode is formed on a piezoelectric thin film or a piezoelectric substrate, and an electronic device that can extract an electrical signal in a specific frequency band using surface acoustic waves. It is a part.

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

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

Therefore, a method of preparing a hollow structure in which a chip on which comb-shaped electrodes are formed is flip-chip mounted on a substrate via bumps and sealing the chip in a state where a hollow region is provided between the substrate and the chip Has been proposed (for example, Patent Documents 2 and 3).

Japanese Patent Laid-Open No. 2002-16466 Patent No. 4989402 Japanese Unexamined Patent Publication No. 2016-175976

When a hollow sealed structure (eg, an electronic component device) is obtained by sealing a sealed body in a state where a hollow area is provided between the substrate and the sealed body, a sealing material (sealing) for the hollow area is obtained. It is necessary to suppress the inflow of the resin composition constituting the stop film. 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, the elastomer component causes the glass transition temperature (Tg) of the cured product. ) Significantly decreases, and the reliability (particularly thermal reliability) of the hollow sealing structure may be decreased. For example, when the thermosetting component and the elastomer component form a sea-island structure, it is assumed that the Tg derived from the elastomer component exists in the low temperature range, but the thermal expansion coefficient of the resin greatly changes before and after the Tg. For this reason, a high concentration of the elastomer component contributes to a decrease in the reliability of the hollow sealing structure.

Therefore, the present invention can sufficiently suppress the inflow of the sealing material into the hollow region between the substrate and the object to be sealed and can form a cured product having a sufficient glass transition temperature. An object of the present invention is to provide a sealing structure using the sealing film and a method for producing the sealing structure.

From the viewpoint of avoiding a decrease in Tg, the present inventors have studied on the premise that the smaller the amount of the elastomer component added, the better. And the state and effect | action of an ideal elastomer component were considered as follows from a viewpoint of fully suppressing inflow of the sealing material (resin composition which comprises the film for sealing) to a hollow area | region.
(1) From the viewpoint that the elastomer component becomes resistance to flow of the resin composition and the flow of the resin composition can be suppressed, the shape of the elastomer component in the resin composition is linear rather than excessive string shape. Is preferred.
(2) From the viewpoint that the elastomer component constrains the flow of the resin composition, and thus the flow of the resin component can be suppressed, the elastomer component is preferably pseudo-polymerized by intermolecular interaction.

As a result of intensive studies based on the above viewpoints, the present inventors reduced the amount of the elastomer component added while using the elastomer having a specific carboxy group equivalent, while allowing the resin composition to flow into the hollow region. The inventors have found that it can be sufficiently suppressed, and have reached the present invention.

That is, one aspect of the present invention is that the thermosetting component, the inorganic filler, and the carboxy group equivalent are 270 to 4300 g / eq. A carboxy group-containing elastomer, and the content of the carboxy group-containing elastomer is less than 40% by mass based on the total amount of the thermosetting component and the carboxy group-containing elastomer. The present invention relates to a sealing film. According to this sealing film, the inflow of the sealing material into the hollow region between the substrate and the object to be sealed can be sufficiently suppressed. That is, the sealing film is excellent in hollow non-fillability. Moreover, according to the said film for sealing, the hardened | cured material which has sufficient glass transition temperature (Tg) can be formed.

The content of the elastomer component including the carboxy group-containing elastomer contained in the resin composition is 2% by mass or more and less than 40% by mass based on the total amount of the thermosetting component and the elastomer component. Good. In this case, it is excellent in hollow non-filling property, and sufficient Tg is easily obtained after curing.

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

The carboxy group-containing elastomer may contain a structural unit derived from (meth) acrylic acid. In this case, it is excellent in hollow non-filling property, and sufficient Tg is easily obtained after curing.

The weight average molecular weight of the carboxy group-containing elastomer may be 300,000 to 10,000,000. In this case, it is excellent in hollow non-filling property, and sufficient Tg is easily obtained after curing.

The 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 (thermal expansion coefficient)) of the cured film and the reliability of the SAW device 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 excellent embeddability with respect to the sealed object.

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

The above-mentioned sealing film can be suitably used for sealing an object to be sealed provided on a substrate via bumps.

One aspect of the present invention includes a substrate and a sealed body provided on the substrate via a bump, and a hollow region is provided between the substrate and the sealed body. The present invention relates to a method for manufacturing a sealing structure, in which a hollow structure is prepared and the object to be sealed is sealed with the sealing film of the present invention. According to this method, the inflow of the sealing material into the hollow region between the substrate and the object to be sealed can be sufficiently suppressed. Moreover, since a to-be-sealed body can be sealed with the hardened | cured material which has sufficient Tg, the sealing structure excellent in reliability (thermal reliability) is obtained.

In the above manufacturing method, the object to be sealed may be a SAW device having an electrode on the hollow region side. In the said manufacturing method, while being able to fully suppress that a sealing material adheres to the surface which has the electrode of a SAW device, a SAW device can be sealed with the hardened | cured material which has sufficient Tg. Therefore, according to the manufacturing method, the reliability of the SAW device can be improved. For the same reason, in the manufacturing method described above, the yield in manufacturing a sealing structure (hollow sealing structure) including such an object to be sealed can be improved.

One aspect of the present invention is a substrate, a sealed body provided on the substrate via bumps, and a cured product of the sealing film of the present invention that seals the sealed body. And a sealing structure in which a hollow region is provided between the substrate and the object to be sealed. In this sealed structure, the hollow region is sufficiently secured, and the sealed body is sealed with a cured product having a sufficient Tg.

In the above sealing structure, the object to be sealed may be a SAW device having an electrode on the hollow region side. In this sealing structure, adhesion of the sealing material to the surface having the electrode of the SAW device is sufficiently suppressed, and the SAW device is sealed with a cured product having a sufficient Tg. Therefore, the reliability of the SAW device is excellent.

ADVANTAGE OF THE INVENTION According to this invention, while being able to fully suppress the inflow of the sealing material to the hollow area | region between a board | substrate and a to-be-sealed body, the film for sealing which can form the hardened | cured material which has sufficient glass transition temperature A sealing structure using the sealing film and a method for producing the sealing structure can be provided.

FIG. 1: is a schematic cross section which shows the film for sealing with a support provided with the film for sealing of 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 a method for evaluating the fluidity rate in Examples.

In this specification, a numerical range indicated by using “to” indicates a range including the numerical values described before and after “to” as the minimum value and the maximum value, respectively. In the numerical ranges described stepwise in the present specification, the upper limit value or lower limit value of a numerical range of a certain step may be replaced with the upper limit value or lower limit value of the numerical range of another step. In the numerical range described in this specification, the upper limit value or the lower limit value of the numerical range may be replaced with the values shown in the examples. “A or B” only needs to include either A or B, and may include both. Unless otherwise specified, the materials exemplified in the present specification may be used alone or in combination of two or more. In the present specification, the content of each component in the composition is the sum of the plurality of substances present in the composition unless there is a specific indication when there are a plurality of substances corresponding to each component in the composition. Means quantity.

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

<Sealing film>
The sealing film of the present embodiment has a carboxy group equivalent of 270 to 4300 g / eq., Which is a thermosetting component, an inorganic filler, and an elastomer (flexibilizer) component. And a carboxy group-containing elastomer. In this embodiment, the carboxy group equivalent is 270 to 4300 g / eq. The content of the carboxy group-containing elastomer may be less than 40% by mass based on the total amount of the thermosetting component and the carboxy group-containing elastomer. In this embodiment, the content of the elastomer component (including the carboxy group-containing elastomer) contained in the resin composition is 2% by mass or more and 40% by mass or more based on the total amount of the thermosetting component and the elastomer component. It may be less than mass%.

The sealing film of the present embodiment is provided between a substrate, a sealed body (for example, an electronic component such as a SAW device) provided on the substrate, and the substrate and the sealed body. It is preferably used for a hollow structure including a hollow region. According to the sealing film, the inflow of the sealing material into the hollow region between the substrate and the object to be sealed can be sufficiently suppressed. Moreover, according to the said film for sealing, since the hardened | cured material which has sufficient glass transition temperature can be formed, the sealing structure excellent in reliability (thermal reliability) is obtained. The reason why such an effect is obtained is not clear, but the present inventors presume as follows.

That is, first, the carboxy group equivalent of the elastomer is 270 g / eq. When the ratio is less than 1, the polarity of the elastomer increases, and it is assumed that the molecular chain of the elastomer takes a thread-like structure in the sealing film (in the resin composition). As described above, when the elastomer is excessively thread-like, it is considered that the resistance effect for suppressing the fluidity of the resin composition in the sealing film is small. Therefore, in order to sufficiently suppress the inflow of the sealing material into the hollow region, it is assumed that a large amount of the elastomer component needs to be added. On the other hand, the carboxy group equivalent was 4300 g / eq. Is larger, the molecular polarity of the elastomer is presumed to have a nearly linear structure in the sealing film (resin composition), but the polar carboxyl group is Since there are few, it is guessed that the interaction between molecular chains is small. In this case, since there is little interaction between the molecular chains, as an effect of suppressing the fluidity of the resin composition in the sealing film by adding the elastomer component, only an effect commensurate with the addition amount of the elastomer component can be obtained. Conceivable. On the other hand, the sealing film of this embodiment has a carboxy group equivalent of 270 to 4300 g / eq. Which is an elastomer. This elastomer maintains a linear shape in the resin composition, and the molecular chains of the elastomer are pseudo-polymerized by the interaction of carboxy groups (that is, the elastomer's chain). It is inferred that molecular chains form a three-dimensional network). Therefore, in the said sealing film, the addition amount of an elastomer component can be decreased rather than before, and it is guessed that the said effect is acquired as a result.

In addition, when the elastomer component is contained in the sealing film at a high concentration, a change in the thermal expansion amount at the time of mounting the electronic component device increases due to the influence of Tg derived from the elastomer component in the low temperature range, and there is a problem (warping). , Cracks, etc.) are likely to occur. On the other hand, in the sealing film of this embodiment, since the content of the elastomer component is in the above range, problems during mounting can be reduced.

In addition, when the sealing film contains an elastomer component at a high concentration, there may be cases where sufficient embeddability with respect to the object to be sealed cannot be obtained. On the other hand, in the sealing film of this embodiment, since the amount of the elastomer component added can be reduced, sufficient embeddability to the object to be sealed is easily obtained.

(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 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 and the like. As the thermosetting resin, an epoxy resin is preferable from the viewpoint of easily controlling the fluidity and curing reactivity of the resin.

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, bisphenol C type epoxy resin, bisphenol E type epoxy resin, and 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, biphenyl type epoxy resin, naphthalene type epoxy resin Dicyclopentadiene type epoxy resins, bixylenol type epoxy resins (such as bixylenol diglycidyl ether), hydrogenated bisphenol A type epoxy resins (such as hydrogenated bisphenol A glycidyl ether), and dibasic acid-modified diglycidyl ethers of these resins Type epoxy resin, aliphatic epoxy resin and the like. An epoxy resin may be used individually by 1 type, and may use 2 or more types together.

From the viewpoint of easily suppressing the occurrence of cracks and cracks on the film surface, the epoxy resin may be an epoxy resin that is liquid at 25 ° C. (liquid epoxy resin). 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, water-added bisphenol A type glycidyl ether, and ethylene oxide adduct bisphenol A type. Examples thereof include glycidyl ether, propylene oxide adduct bisphenol A-type glycidyl ether, naphthalene resin glycidyl ether, trifunctional or tetrafunctional glycidylamine, and the like. “Liquid at 25 ° C.” means that the viscosity at 25 ° C. measured with an E-type viscometer is 400 Pa · s or less.

As commercially available epoxy resins, for example, trade name “jER825” (bisphenol A type epoxy resin, epoxy equivalent: 175 g / eq.) Manufactured by Mitsubishi Chemical Corporation, trade name “jER806” (bisphenol F manufactured by Mitsubishi Chemical Corporation), and the like. Type epoxy resin, epoxy equivalent: 160 g / eq.), Trade name “HP-4032D” manufactured by DIC Corporation (naphthalene type epoxy resin, epoxy equivalent: 141 g / eq.), Trade name “EXA-” manufactured by DIC Corporation Flexible toughness epoxy resin such as “4850”, trade name “HP-4700” (tetrafunctional naphthalene type epoxy resin) manufactured by DIC Corporation, trade name “HP-4750” (trifunctional naphthalene type epoxy resin), trade name “ HP-4710 ”(tetrafunctional naphthalene type epoxy resin), trade name“ Epicron N-770 ”( Enol novolac epoxy resin), trade name “Epicron N-660” (cresol novolac epoxy resin) and trade name “Epicron HP-7200H” (dicyclopentadiene epoxy resin), trade name “Nippon Kayaku Co., Ltd.” EPPN-502H "(trisphenylmethane type epoxy resin) and trade name" NC-3000 "(biphenylaralkyl type epoxy resin), trade name" ESN-355 "(naphthalene type epoxy resin) manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., Mitsubishi Examples include trade name “YX-8800” (anthracene type epoxy resin) manufactured by Chemical Co., Ltd., and trade name “ESCN-190-2” (o-cresol novolac type epoxy resin) manufactured by Sumitomo Chemical Co., Ltd. These epoxy resins may be used alone or in combination of two or more.

The content of the thermosetting resin is preferably 1% by mass or more, more preferably 3% by mass or more, more preferably 4% by mass or more, based on the total quality of the sealing film, from the viewpoint of easily obtaining excellent fluidity. Is more preferable, 5% by mass or more is particularly preferable, 10% by mass or more is extremely preferable, and 15% by mass or more is very preferable. 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, from the viewpoint of easily suppressing the occurrence of cracks and cracks on the film surface. 20 mass% or less is still more preferable. The above upper limit value and lower limit value can be arbitrarily combined. Therefore, the content of the thermosetting resin is, for example, 1 to 30 mass, 3 to 30 mass, or 4 to 25 mass% based on the total quality of the sealing film. It may be 5 to 25% by mass, 10 to 20% by mass, or 15 to 20% by mass. In addition, also in the following similar description, the individually described upper limit value and lower limit value can 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. 50 mass% or more is preferable, 80 mass% or more is more preferable, and 90 mass% or more is still more preferable. 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. 3% by mass or more is more preferable, 5% by mass or more is particularly preferable, 7% by mass or more is extremely preferable, and 9% by mass or more is very preferable. The content of the liquid epoxy resin is 20% by mass or less based on the total mass of the sealing film from the viewpoint of easily suppressing an excessive increase in the tackiness of the film and from the viewpoint of easily suppressing edge fusion. Preferably, 15 mass% or less is more preferable, and 13 mass% or less is still more preferable. Accordingly, the content of the liquid epoxy resin may be, for example, 0.5 to 20% by mass, 1 to 20% by mass, or 3 to 15% by mass based on the total mass of the sealing film. %, 5 to 15% by mass, 7 to 13% by mass, or 9 to 13% by mass.

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 more than mass%. The content of the liquid epoxy resin is 95% by mass or less based on the total mass of the thermosetting resin, from the viewpoint of easily suppressing an excessive increase in the tackiness of the film and from the viewpoint of easily suppressing edge fusion. Preferably, 90 mass% or less is more preferable, and 80 mass% or less is still more preferable. Accordingly, the content of the liquid epoxy resin may be, for example, 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. There may be. 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 hardening | curing agent, A phenol type hardening | curing agent (for example, phenol resin), an acid anhydride type hardening | curing agent, an active ester type hardening | curing agent, a cyanate ester type hardening | curing agent etc. are mentioned. When the thermosetting resin contains an epoxy resin, the curing agent can be used without particular limitation as long as it is a compound having two or more functional groups that react with an epoxy group in one molecule. Examples of such curing agents include phenol resins and acid anhydrides. As the curing agent, a phenol resin is preferable from the viewpoint of easily obtaining a cured product having excellent thermal conductivity. A hardening | curing agent may be used individually by 1 type, and may use 2 or more types together.

As the phenol resin, any 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 condensation or co-condensation of phenols and / or naphthols and aldehydes under an acidic catalyst, biphenyl skeleton type phenol resins, paraxylylene-modified phenol resins, metaxylylene / paraxylylene-modified phenol resins. Melamine-modified phenol resin, terpene-modified phenol resin, dicyclopentadiene-modified phenol resin, cyclopentadiene-modified phenol resin, polycyclic aromatic ring-modified phenol resin, xylylene-modified naphthol resin, and the like. Examples of phenols include phenol, cresol, xylenol, resorcinol, catechol, bisphenol A, bisphenol F, and the like. Examples of naphthols include α-naphthol, β-naphthol, dihydroxynaphthalene and the like. Examples of aldehydes include formaldehyde, acetaldehyde, propionaldehyde, benzaldehyde, salicylaldehyde and the like.

Commercially available phenol resins include the product name “PAPS-PN2” (Novolac type phenol resin) manufactured by Asahi Organic Materials Co., Ltd., and the product name “SK Resin HE200C-7” (biphenyl aralkyl type phenol) manufactured by Air Water Co., Ltd. Resin), trade name “HE910-10” (trisphenylmethane type phenol resin), trade names “MEH-7000”, “DL-92”, “H-4” and “HF-1M” manufactured by Meiwa Kasei Co., Ltd. Product names “LVR-8210DL”, “ELP” series and “NC” series manufactured by Gunei Chemical Industry Co., Ltd. Product names “SN-100, SN-300, SN-395, SN” manufactured by Nippon Steel & Sumikin Chemical Co., Ltd. -400 "(naphthalene type phenolic resin), and trade name" HP-850N "(Novolac type) manufactured by Hitachi Chemical Co., Ltd. Phenol resins) and the like.

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

When the thermosetting resin contains an epoxy resin, the number of moles M1 of the epoxy group of the epoxy resin and the number of moles M2 of the functional group (such as phenolic hydroxyl group) that reacts with the epoxy group in the curing agent (such as phenolic hydroxyl group equivalent) 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. 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, an unreacted epoxy resin and / or an unreacted hardening | curing agent do not remain easily, and a desired hardened | cured material characteristic is easy to be obtained.

[Curing accelerator]
Although it can use without a restriction | limiting especially as a hardening accelerator, At least 1 sort (s) chosen from the group which consists of an amine type hardening accelerator and a phosphorus type hardening accelerator is preferable. As the curing accelerator, in particular, from the viewpoint of easily obtaining a cured product having excellent thermal conductivity, the viewpoint that a derivative is abundant, and the viewpoint that a desired active temperature is easily obtained, an amine-based curing accelerator is used. Preferably, at least one selected from the group consisting of imidazole compounds, aliphatic amines and alicyclic amines is more preferable, and imidazole compounds are more preferable. 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 curing accelerators include “2P4MZ” and “1B2MZ” manufactured by Shikoku Kasei Kogyo Co., Ltd.

The content of the curing accelerator is preferably in the following range on the basis of a thermosetting resin (such as an epoxy resin) and a curing agent (such as a phenol resin). The content of the curing 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 viewpoint that a sufficient curing acceleration effect can be easily obtained. The content of the curing accelerator is such that curing does not easily proceed during the process (for example, coating and drying) at the time of producing the sealing film, or during the storage of the sealing film, And from a viewpoint of being easy to prevent the molding defect accompanying a raise of melt viscosity, 5 mass% or less is preferable, 3 mass% or less is more preferable, and 1.5 mass% or less is still more preferable. From these viewpoints, the content of the curing 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, conventionally known inorganic fillers can be used and are not particularly limited. Constituent materials 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, boron nitride, barium titanate, strontium titanate, calcium titanate, magnesium titanate, Examples thereof include bismuth titanate, titanium oxide, barium zirconate, and calcium zirconate. From the viewpoint of improving the dispersibility in the resin composition and the effect of suppressing sedimentation in the varnish by surface modification (for example, surface treatment with a silane compound) and the like, and a relatively small coefficient of thermal expansion. From the viewpoint of easily obtaining desired cured film characteristics because of having an inorganic filler, an inorganic filler containing silica is preferable. From the viewpoint of obtaining high thermal conductivity, an inorganic filler containing aluminum oxide is preferable. An inorganic filler may be used individually by 1 type, and may use 2 or more types together.

The surface of the inorganic filler may be modified. The method of surface modification is not particularly limited. Surface modification using a silane coupling agent is preferable from the viewpoint of simple treatment, rich types of functional groups, and easy provision of desired characteristics.

Examples of the silane coupling agent include alkyl silane, alkoxy silane, vinyl silane, epoxy silane, amino silane, acrylic silane, methacryl silane, mercapto silane, sulfide silane, isocyanate silane, sulfur silane, styryl silane, alkyl chlorosilane, and the like.

Specific examples of the silane coupling agent include methyltrimethoxysilane, dimethyldimethoxysilane, trimethylmethoxysilane, methyltriethoxysilane, methyltriphenoxysilane, ethyltrimethoxysilane, n-propyltrimethoxysilane, diisopropyldimethoxysilane, isobutyl. Trimethoxysilane, diisobutyldimethoxysilane, isobutyltriethoxysilane, n-hexyltrimethoxysilane, n-hexyltriethoxysilane, cyclohexylmethyldimethoxysilane, n-octyltriethoxysilane, n-dodecylmethoxysilane, phenyltrimethoxysilane, Diphenyldimethoxysilane, triphenylsilanol, methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, -Octyldimethylchlorosilane, tetraethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3- (2-aminoethyl) aminopropyltrimethoxysilane, 3- (2-aminoethyl) aminopropylmethyl Dimethoxysilane, 3-phenylaminopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldi Ethoxysilane, bis (3- (triethoxysilyl) propyl) disulfide, bis (3- (triethoxysilyl) propyl) tetrasulfide, vinyltriacetoxysilane, vinyltrimethoxysilane, vinyltriet Sisilane, vinyltriisopropoxysilane, allyltrimethoxysilane, diallyldimethylsilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-mercaptopropyltrimethoxy Examples thereof include silane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltriethoxysilane, N- (1,3-dimethylbutylidene) -3-aminopropyltriethoxysilane, aminosilane (phenylaminosilane and the like), and the like. A silane coupling agent may be used individually by 1 type, and may use 2 or more types together.

The average particle diameter of the inorganic filler is preferably 0.01 μm or more, more preferably 0.1 μm or more, and more preferably 0.3 μm or more from the viewpoint of easily suppressing the aggregation of the inorganic filler and easy dispersion of the inorganic filler. Is more preferable, and 0.5 μm or more is particularly preferable. The average particle diameter of the inorganic filler is preferably 25 μm or less, more preferably 10 μm or less, and more preferably 5 μm or less from the viewpoint of easily suppressing the precipitation of the inorganic filler in the varnish and easy to produce a uniform sealing film. Is more preferable. From these viewpoints, the average particle size 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 0 Very preferably 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 different average particle diameters. Among the combinations of inorganic fillers, the largest average particle size is preferably 15 to 25 μm. A combination of 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. It is preferable to use it.

The “average particle size” is the particle size at a point corresponding to a volume of 50% when the cumulative frequency distribution curve by the particle size is obtained with the total volume of the particles being 100%, and the particle size distribution using the laser diffraction scattering method It can be measured with a measuring device or the like. The average particle diameter of each combined inorganic filler 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.

Examples of commercially available inorganic fillers include “DAW-20” manufactured by Denka Co., Ltd., and trade names “SC550O-SXE” and “SC2050-KC” manufactured by Admatechs Co., Ltd.

The content of the inorganic filler increases the warpage of the sealing structure (for example, an electronic component device such as a semiconductor device) due to the viewpoint of improving the thermal conductivity and the difference in thermal expansion coefficient from the sealed body. From the viewpoint of being easily suppressed, it may be 70% by mass or more, 75% by mass or more, 80% by mass or more, and 84% by mass based on the total mass of the sealing film. It may be the above. The content of the inorganic filler is such that the sealing film is easily cracked in the drying step when the sealing film is produced, and the fluidity is increased due to an increase in the melt viscosity of the sealing film. From the viewpoint of suppressing the reduction and easily sealing the object to be sealed (electronic component etc.), it may be 93% by mass or less and 91% by mass or less based on the total mass of the sealing film. It may be 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, 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. In addition, the said content is content of the inorganic filler except the quantity of the surface treating agent.

(Elastomer)
The elastomer component has a carboxy group equivalent of 270 to 4300 g / eq. A carboxy group-containing elastomer. Here, the “carboxy group equivalent” means the mass of the carboxy group-containing elastomer per one equivalent (1 eq.) Of the carboxy group contained in the carboxy group-containing elastomer. The carboxy group equivalent can be determined from the charged amount of the monomer component. The carboxyl group equivalent can be measured by a titration method.

The carboxy group equivalent of the carboxy group-containing elastomer is 340 g / eq. From the viewpoint that the elastomer is suppressed from being excessively thread-stringed and the fluidity suppressing effect of the resin composition is easily obtained. It can be 400 g / eq. Or more, 600 g / eq. It may be 800 g / eq. It may be the above. The carboxy group equivalent of the carboxy group-containing elastomer is 4000 g / eq. From the viewpoint that the molecular chains of the elastomer easily form a denser three-dimensional network and the hollow non-filling property becomes better. Or 3000 g / eq. Or 2000 g / eq. It may be the following. From these viewpoints, the carboxy group equivalent of the carboxy group-containing elastomer is 340 to 4000 g / eq. 400 to 4000 g / eq. It may be 600 to 3000 g / eq. 800-2000 g / eq. It may be.

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

［式（１）中、Ｒ^１は、水素原子又はメチル基を示す。］

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

The content of the structural unit having a carboxy group in the carboxy group-containing elastomer is such that the elastomer is suppressed from being excessively thread-like, and the effect of suppressing the fluidity of the resin composition is easily obtained. Based on the total amount of structural units constituting the elastomer, it may be 2 mol% or more, 4 mol% or more, or 6 mol% or more. The content of the structural unit having a carboxy group is the structural unit constituting the carboxy group-containing elastomer from the viewpoint that the molecular chains of the elastomer are more likely to form a denser three-dimensional network and the hollow non-filling property is better. 39 mol% or less, 37 mol% or less, 35 mol% or less, 31 mol% or less, or 29 mol% or less, based on the total amount of Also good. From these viewpoints, the content of the structural unit having a carboxy 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 formula (1) may be in the above range.

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

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

［式（２）中、Ｒ^２は、水素原子又はメチル基を示し、Ｒは、置換基を有していてもよいアルキル基を示す。］

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

The content of the structural unit represented by the above formula (2) in the carboxy group-containing elastomer is excellent in the hollow non-filling property, and the structure constituting the carboxy group-containing elastomer from the viewpoint of obtaining sufficient Tg after curing. Based on the total amount of the unit, it may be 65 mol% or more, 69 mol% or more, or 71 mol% or more, 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%, and 69 to 96 mol%, based on the total amount of the structural units constituting the carboxy group-containing elastomer. It may be 71 to 94 mol%.

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

［式（３）中、Ｒ^３は、水素原子又はメチル基を示す。］

[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 carboxy group-containing elastomer is excellent in the hollow non-filling property and is a structure constituting the carboxy group-containing elastomer from the viewpoint of obtaining sufficient Tg after curing. Based on the total amount of units, it may be 65 to 98 mol%, 69 to 96 mol%, or 71 to 94 mol%.

The carboxy group-containing elastomer is excellent in hollow non-filling properties and has a structure represented by the structural unit represented by the above formula (1) and a structure represented by the above formula (2) from the viewpoint that sufficient Tg can be easily obtained after curing. It is preferable to have a unit and / or a structural unit represented by the above formula (3).

The weight average molecular weight Mw of the carboxy group-containing elastomer is 300,000 or more from the viewpoint of being excellent in hollow non-fillability, from the viewpoint of obtaining sufficient Tg after curing, and from the viewpoint of obtaining sufficient embeddability in an object to be sealed, It may be 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 carboxy group-containing elastomer may be, for example, 300,000 to 10 million, may be 400,000 to 8 million, may be 500,000 to 7 million, and may be 500,000 to 200,000. It may be 10,000. In addition, a weight average molecular weight is a polystyrene conversion value using the calibration curve by a standard polystyrene by the gel permeation chromatography method (GPC).

When the carboxy group-containing elastomer is in the form of particles, the average particle size 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 excellent embedding between the objects to be sealed. The average particle diameter of the elastomer may be 0.1 μm or more from the viewpoint of excellent dispersibility of the carboxy group-containing elastomer.

The carboxy group-containing elastomer of the present embodiment may be obtained by polymerizing a polymerizable monomer having a carboxyl group by a conventionally known method, a polymerizable monomer having a carboxyl group, and a polymerizable monomer having no carboxyl group; May be obtained by copolymerization by a conventionally known method. For example, a carboxyl group-containing elastomer may be obtained by copolymerizing (meth) acrylic acid with (meth) acrylic alkyl ester and / or (meth) acrylonitrile. In this embodiment, a carboxyl group equivalent can be adjusted to a desired range by adjusting the usage-amount of a polymerizable monomer. Moreover, in this embodiment, after obtaining a polymer by the said method, you may adjust a carboxyl group equivalent by substituting a part of carboxyl group by methods, such as esterification.

In 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 carboxy group-containing elastomer may be less than 40% by mass based on the total amount of the thermosetting component and the carboxy group-containing elastomer. In this embodiment, by making content of an elastomer component into the said range, the sealing film has sufficient Tg after hardening and is excellent in reliability. The content of the carboxy group-containing elastomer may be more than 0% by mass based on the total amount of the thermosetting component and the carboxy group-containing elastomer from the viewpoint of better hollow non-fillability, and 2% by mass. It may be 4% by mass or more, 8% by mass or more, or 12% by mass or more. The content of the carboxy group-containing elastomer is based on the total amount of the thermosetting component and the carboxy group-containing elastomer from the viewpoint that the Tg after curing becomes more sufficient and sufficient embedding property to the sealed body is obtained. 35 mass% or less may be sufficient, 30 mass% or less may be sufficient, and 25 mass% or less may be sufficient. Therefore, the content of the carboxy group-containing elastomer may be, for example, more than 0% by mass and less than 40% by mass based on the total amount of the thermosetting component and the carboxy group-containing elastomer, and 2% by mass or more and 40% by mass. It may be less than 4, may be 4 to 35% by mass, may be 8 to 30% by mass, and may be 12 to 25% by mass.

In the present embodiment, the total amount of the thermosetting component, the inorganic filler, and the carboxy group-containing elastomer in the sealing film may be 80% by mass or more based on the total mass of the sealing film, and 90 It may be not less than mass%, may be not less than 95 mass%, and may be 100 mass%.

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

The sealing film of the present embodiment may contain other elastomers other than the above-mentioned carboxy group-containing elastomer as long as the effects of the present invention are not affected. Examples of other elastomers include polybutadiene particles, styrene butadiene particles, acrylic elastomers, silicone powders, silicone oils, and silicone oligomers.

In the sealing film of the present embodiment, the content of the elastomer component (including the carboxy group-containing elastomer) is 2% by mass or more and less than 40% by mass based on the total amount of the thermosetting component and the elastomer component. It is preferable. That is, even when the elastomer component includes other elastomers other than the carboxy group-containing elastomer, the total amount of the elastomer component is 2% by mass or more and less than 40% by mass based on the total amount of the thermosetting component and the elastomer component. It is preferable. In this case, the sealing film has a more sufficient Tg after curing and a more reliable sealing structure. The content of the elastomer component may be 4% by mass or more and 8% by mass or more based on the total amount of the thermosetting component and the elastomer component from the viewpoint of better hollow non-fillability. It may be 12% by mass or more. The content of the elastomer component is 35 masses on the basis of the total amount of the thermosetting component and the elastomer component from the viewpoint that the Tg after curing becomes more sufficient and sufficient embedding property to the sealed body is obtained. % Or less, 30 mass% or less, or 25 mass% or less. Accordingly, the content of the elastomer component may be, for example, 4 to 35% by mass, 8 to 30% by mass, or 12 to 12% by mass based on the total amount of the thermosetting component and the elastomer component. It may be 25% by mass.

The content of the carboxy group-containing elastomer in the elastomer component may be 80% by mass or more and 90% by mass or more based on the total mass of the elastomer component from the viewpoint of better hollow non-fillability. It may be 95% by mass or more. The content of the carboxy group-containing elastomer in the elastomer component may be 100% by mass or less. Therefore, the content of the carboxy 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 carboxy group-containing elastomer.

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

In addition, the sealing film of the present embodiment may contain a solvent (for example, a solvent used for manufacturing the sealing film). The solvent may be a conventionally known organic solvent. The organic solvent may be a solvent that can dissolve components other than inorganic fillers, such as aliphatic hydrocarbons, aromatic hydrocarbons, terpenes, halogens, esters, ketones, alcohols, aldehydes, etc. Is mentioned. 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 low environmental burden and the ability to easily dissolve the thermosetting component. Among these, when the solvent is a ketone, the thermosetting component is particularly easily dissolved. The solvent may be at least one selected from the group consisting of acetone, methyl ethyl ketone, and methyl isobutyl ketone from the viewpoint of little volatilization at room temperature (25 ° C.) and easy removal during drying.

The content of a solvent (such as an organic solvent) contained in the sealing film is preferably in the following range based on the total mass of the sealing film. The content of the solvent is from the viewpoint of easily suppressing the sealing film from becoming brittle and causing problems such as cracking of the sealing film, and the minimum melt viscosity to be increased and the embedding property to be lowered. It may be 2% by mass or more, 0.3% by mass or more, 0.5% by mass or more, 0.6% by mass or more, 0.7% by mass It may be the above. The content of the solvent is a problem that the adhesiveness of the sealing film becomes too strong and the handleability is lowered, and a problem such as foaming due to the volatilization of the solvent (organic solvent, etc.) during thermal curing of the sealing film. May be 1.5 mass% or less, and may be 1 mass% or less. From these viewpoints, the solvent content may be 0.2 to 1.5% by mass, 0.3 to 1% by mass, or 0.5 to 1% by mass. It may be 0.6 to 1% by mass or 0.7 to 1% by mass.

The thickness (film thickness) of the sealing film may be 20 μm or more, 30 μm or more, or 50 μm or more from the viewpoint of easily suppressing variation in the in-plane thickness during coating. It may be 100 μm or more. The thickness of the sealing film may be 400 μm or less, may be 250 μm or less, may be 200 μm or less, and may be 150 μm from the viewpoint that a constant drying property can be easily obtained in the depth direction during coating. It may be the following. 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, 100 It may be up to 150 μm. Further, a plurality of sealing films can be laminated to produce a sealing film having a thickness exceeding 250 μm.

The glass transition temperature Tg after curing of the sealing film may be 80 to 150 ° C. or 90 to 140 ° C. from the viewpoint of the reliability (thermal reliability) of the resulting sealing structure. 100 to 130 ° C. The glass transition temperature Tg of the sealing film 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.

The minimum melt viscosity at 60 to 140 ° C. (minimum melt viscosity) of the sealing film may be 1000 to 20000 Pa · s, or 3000 to 15000 Pa · s from the viewpoint of forming a hollow structure. It may be 5000 to 12000 Pa · s. The said minimum melt viscosity can be calculated | required by measuring the melt viscosity of the film for sealing by the method as described in an Example.

As described above, the sealing film of the present embodiment is suitably used for sealing the object to be sealed in the hollow structure, but the structure to be sealed does not have a hollow structure. May be. The sealing film of this embodiment can also be used, for example, for sealing semiconductor devices, embedding 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. A support-equipped sealing film 10 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; acetylcellulose films; 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 drying property. When the thickness of the support 1 is 2 μm or more, it is easy to suppress problems such as breakage of the support during coating, deflection of the support due to the weight of the varnish, and the like. When the thickness of the support 1 is 200 μm or less, it is easy to suppress problems that prevent drying of the solvent in the varnish when hot air is blown from both the coated surface and the back surface in the drying step.

In this embodiment, the support 1 may not be used. Moreover, you may arrange | position the protective layer aiming at protection of the film for sealing on the opposite side to the support body 1 of the film 2 for sealing. By forming the protective layer on the sealing film 2, the handling property is improved, and when the film is wound up, the problem that the sealing film sticks to the back surface of the support 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; acetylcellulose films; it can. Examples of the metal foil include copper foil and aluminum foil.

<Method for producing film for sealing>
Specifically, the sealing film of the present embodiment can be produced as follows.

First, the varnish (varnish-like resin composition) is produced by mixing the structural components (thermosetting resin, curing agent, curing accelerator, inorganic filler, elastomer component, solvent, etc.) of the resin composition of this embodiment. To do. The mixing method is not particularly limited, and a mill, a mixer, and a stirring blade can be used. A solvent (such as an organic solvent) can be used to dissolve and disperse the constituents of the resin composition, which is a material for the sealing film, to prepare a varnish, or to assist in preparing the varnish. . Most of the solvent can be removed in the drying step after coating.

The sealing varnish can be produced by applying the varnish thus produced to a support (film-like support etc.) and then drying by heating with hot air blowing or the like. Although it does not specifically limit as a coating (coating) method, For example, coating apparatuses, such as a comma coater, a bar coater, a kiss coater, a roll coater, a gravure coater, a die coater, can be used.

<Sealing structure and manufacturing method thereof>
The sealing structure which concerns on this embodiment is provided with a to-be-sealed body and the sealing part which seals the said to-be-sealed body. The sealing part 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 sealing structure may be a hollow sealing structure having a hollow structure. The hollow sealing structure includes, for example, a substrate, an object to be sealed provided on the substrate, a hollow area provided between the substrate and the object to be sealed, and a seal that seals the object to be sealed. A stop portion. The sealing structure of this embodiment may include a plurality of objects to be sealed. The plurality of objects to be sealed may be of the same type or different types.

The sealing 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 a semiconductor element; a semiconductor wafer; an integrated circuit; a semiconductor device; a filter such as a SAW filter; a passive component such as a sensor. A semiconductor element obtained by separating a semiconductor wafer may 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 sealing structure, the object to be sealed has, for example, a movable portion on the surface of the hollow region side (substrate side), It is provided on the substrate via bumps. Examples of such an object to be sealed include a SAW device such as a SAW filter and an electronic component such as an acceleration sensor. When the object to be sealed is a SAW filter, the surface of the piezoelectric substrate on which the IDT (Inter Digital Transducer) that is a pair of comb electrodes is attached becomes the movable part.

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

FIG. 2 is a schematic cross-sectional view for explaining an embodiment of a method for producing a semiconductor device, which is an electronic component device, as an embodiment of a method for producing a hollow sealing structure. In the manufacturing method of this embodiment, first, a hollow structure including a substrate 30 and a plurality of SAW devices 20 arranged side by side via bumps 40 on the substrate 30 as an object to be sealed (an object to be embedded). Then, the surface on the SAW device 20 side of the substrate 30 and the surface on the sealing film 2 side of the sealing film with support 10 are made to face each other ((a) in FIG. 2). Here, the hollow structure 60 has a hollow region 50, and the SAW device 20 has a movable portion on the surface 20a on the hollow region 50 side (substrate 30 side).

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

The laminator used for laminating is not particularly limited, and examples thereof include a roll type and a balloon type laminator. The laminator may be a balloon type capable of vacuum pressurization from the viewpoint of excellent embeddability.

Lamination is usually performed below the softening point of the support. The laminating temperature (sealing temperature) is preferably near the minimum melt viscosity of the sealing film. The laminating temperature is, for example, 60 to 140 ° C. The pressure at the time of laminating varies depending on the size, density, etc. of an object to be sealed (for example, an electronic component such as a semiconductor element). The pressure during 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, but 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 air 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. If the curing temperature is 80 ° C. or higher, the curing of the sealing film proceeds sufficiently and the occurrence of defects tends to be suppressed. When the curing temperature is 280 ° C. or lower, the occurrence of heat damage to other materials tends to 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, curing of the sealing film proceeds sufficiently, and better production efficiency can be obtained. Moreover, you may combine several conditions for hardening conditions.

In the present embodiment, a plurality of electronic component devices 200 may be obtained by further dividing the electronic component device 100 with a dicing cutter or the like ((c) in FIG. 2).

In the manufacturing method of the hollow sealing structure of the present embodiment, the hollow region 50 between the substrate 30 and the sealed body is secured while ensuring excellent embeddability to the sealed body (for example, the SAW device 20). Inflow of the sealing material can be sufficiently suppressed.

In this embodiment, after sealing the SAW device 20 with the sealing film 2 by the laminating method, the sealing film 2 is thermally cured to provide the hollow sealing including the SAW device 20 embedded in the cured product 2a. Although a structure (electronic component device) is obtained, a sealed structure may be obtained by a compression mold using a compression mold device, or a sealed structure may be obtained by press molding using a hydraulic press. . The temperature (sealing temperature) at which the object to be sealed is sealed with a compression mold and a hydraulic press may be the same as the above-described laminating temperature.

The preferred embodiments of the present invention have been described above, but the present invention is not necessarily limited to the above-described embodiments, and modifications may be made as appropriate without departing from the spirit of the present invention.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.

In the examples and comparative examples, the following materials were used.
(Thermosetting resin)
A1: Bisphenol F type epoxy resin (manufactured by Mitsubishi Chemical Corporation, trade name “jER806”, epoxy group equivalent: 160 g / eq.)
(Curing agent)
B1: Novolac type phenol resin (Madewa Kasei Co., Ltd., trade name “DL-92”, phenolic hydroxyl group equivalent: 107 g / eq.)
(Curing accelerator)
C1: Imidazole (manufactured by Shikoku Kasei Kogyo Co., Ltd., trade name “2P4MZ”)
(Elastomer)
D1 to D7: Carboxy group-containing elastomer (inorganic filler)
E1: Aluminum oxide (Denka Co., Ltd., trade name “DAW-20”, average particle size: 20 μm)

<Synthesis of carboxy group-containing elastomer>
(Synthesis Examples 1 to 7)
Carboxy group-containing elastomers D1 to D7 were synthesized according to the following procedure. First, with the compounding amounts shown in Table 1, acrylic acid (molecular weight: 72) and methyl acrylate (molecular weight: 86) and 2,2′-azobis [2- (2-imidazolin-2-yl) propane] 55 g Were dissolved in 500 g of methanol to obtain a mixed solution. Here, the total amount of acrylic acid and methyl acrylate was 500 g. Next, 960 g of deionized water was put into a 3 liter synthesis flask and heated to 90 ° C. with stirring in a nitrogen gas atmosphere. The above mixed solution was poured into this flask over 2 hours, and then stirred at 90 ° C. for 4 to 6 hours. After stirring, the resulting reaction solution was cooled. The product in the reaction solution was then washed with deionized water. Washing with water was carried out four times, and the amount of deionized water used per time was three times the mass of the product. The product after washing with water was dried to obtain a carboxy group-containing elastomer (acrylic acid-methyl acrylate copolymer).

Table 1 shows the carboxy group equivalent of the carboxy group-containing elastomer, the weight average molecular weight (Mw), and the content of structural units derived from acrylic acid. The carboxy group equivalent was judged by the charged amount of each monomer. The weight average molecular weight (Mw) was calculated by a standard polystyrene conversion method using gel permeation chromatography (GPC). The measurement conditions for GPC are shown below.
・ Measuring device: High-speed GPC device (HLC-8220GPC, manufactured by Tosoh Corporation)
Column: TSK guard column Super HZ-H (manufactured by Tosoh Corporation)
・ Solvent: Tetrahydrofuran

<Preparation of sealing film (film epoxy resin composition)>
Example 1
After adding 100 g of MEK (methyl ethyl ketone) and 900 g of inorganic filler E1 to a 1 L polyethylene container, 51 g of epoxy resin A1 and 34 g of curing agent B1 were added and stirred. Next, 15 g of elastomer D1 was added and stirred for another 3 hours. 0.3 g of the curing accelerator C1 was added and further stirred for 1 hour. The obtained mixture was filtered through nylon # 150 mesh (opening 106 μm), and the filtrate was collected. This obtained the varnish-like epoxy resin composition. This varnish-like epoxy resin composition was apply | coated on the following conditions on PET film using the coating machine. Thus, a sealing film having a thickness of 200 μm was produced on the support (PET film).
・ Coating head method: Comma ・ Coating and drying speed: 0.3 m / min ・ Drying conditions (temperature / furnace length): 80 ° C./1.5 m, 100 ° C./1.5 m
Film support: PET film with a thickness of 38 μm

The surface of the sealing film was protected by disposing a protective layer (polyethylene terephthalate film having a thickness of 50 μm) on the side opposite to the support in the sealing film. The same applies to the following examples and comparative examples.

(Examples 2-5 and Comparative Examples 1-2)
A varnish-like epoxy resin composition was obtained in the same manner as in Example 1 except that the elastomers D2 to D7 were used in place of the elastomer D1. A sealing film having a thickness of 200 μm was produced on a support (PET film) in the same manner as in Example 1 except that this varnish-like epoxy resin composition was used.

(Example 6)
A varnish-like epoxy resin composition was obtained in the same manner as in Example 3, except that 57 g of epoxy resin A1 was used, 38 g of curing agent B1 was used, and 5 g of elastomer D3 was used. A sealing film having a thickness of 200 μm was produced on a support (PET film) in the same manner as in Example 3 except that this varnish-like epoxy resin composition was used.

(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 was used, 26 g of curing agent B1 was used, and 35 g of elastomer D3 was used. A sealing film having a thickness of 200 μm was produced on a support (PET film) in the same manner as in Example 3 except that this varnish-like epoxy resin composition was used.

(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 curing agent B1 was used, and no elastomer component was used. A sealing film having a thickness of 200 μm was produced on a support (PET film) in the same manner as in Example 1 except that this varnish-like epoxy resin composition was used.

(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 was used, 24 g of curing agent B1 was used, and 41 g of elastomer D3 was used. A sealing film having a thickness of 200 μm was produced on a support (PET film) in the same manner as in Example 3 except that this varnish-like epoxy resin composition was used.

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

(1) Flow rate (flow rate)
The sealing film provided with the support body and the protective film prepared in Examples and Comparative Examples was punched into a 4 mm diameter circular shape using a punch to prepare an evaluation sample. Subsequently, the protective film of the evaluation sample is peeled off, and five evaluation samples (sealing film with support, 10 in FIG. 3) are arranged in the arrangement shown in FIG. 3 (a) with a silicon wafer (5 cm × 5 cm, Arranged on 4) in FIG. At this time, the surface on the sealing film side was made to face the silicon wafer. Next, after peeling off the support from the evaluation sample, as shown in FIG. 3B, a glass plate (5 cm × 5 cm, thickness 3.0 mm, in FIG. 3) on the evaluation sample (sealing film). 5) was placed, and a 470 g iron plate (5 cm × 5 cm, 6 in FIG. 3) was placed on the glass plate to obtain a laminate. This laminate was placed in an oven at 70 ° C. and held for 30 minutes. Thereafter, the laminate was taken out of the oven and allowed to stand at room temperature for 30 minutes, and then the maximum diameter of the sealing film on the silicon wafer was measured. The fluidity (flow rate) was calculated from the diameter 4 mm of the initial sealing film and the maximum diameter of the sealing film after the test. The fluidity was calculated from the following formula.
Fluidity = (Maximum diameter of sealing film after test / 4 mm) × 100
The average of the obtained 5 points of fluidity was made into the fluidity in the evaluation.

(2) Embedding property and non-filling property at a sealing temperature of 70 ° C. The embedding property and non-filling property of the sealing film at a sealing temperature of 70 ° C. were evaluated by the following methods. First, the produced sealing film (sealing film provided with a support and a protective film) was cut into an 8 mm × 8 cm rectangular shape to produce an evaluation sample. Moreover, the board | substrate (5 cm x 5 cm, thickness 0.2mm) which provided the through-hole (diameter 2mm) 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 a substrate provided with the through hole was placed thereon. Next, the protective film of the evaluation sample is peeled off, and the sealing film is directed to the substrate side so that the sealing film covers the through hole of the substrate, and the evaluation sample (sealing film having a support) is substrate. Placed on top. Next, 470 g of an iron plate (5 cm × 5 cm) was placed on the evaluation sample to obtain a laminate. 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, observe the presence or absence of resin flowing into the glass plate from the through hole due to melting of the sealing film and the amount of resin flowing (maximum diameter of the resin layer spreading on the glass surface) with a digital microscope. Based on the criteria, embedding property and hollow non-filling property were evaluated.
[Embeddability]
A: Resin reaches the glass substrate B: Resin does not reach the glass substrate [hollow non-fillability]
A: Maximum diameter of the flowed resin layer: ≦ 2.1 mm
B: Maximum diameter of the flowed resin layer:> 2.1 mm, ≦ 2.3 mm
C: Maximum diameter of the resin layer that flowed in:> 2.3 mm

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

The sealing film with copper foil was attached to a SUS plate, and the sealing film was cured under the following conditions to obtain a cured product of the sealing film with copper foil (epoxy resin cured body with copper foil).
・ Oven: SAFETY OVEN SPH-201 manufactured by ESPEC CORP.
・ Oven temperature: 140 ℃
・ Time: 120 minutes

After peeling copper foil from the cured product of the sealing film with copper foil, the cured product of the sealing film was cut into 4 mm × 30 mm to prepare test pieces. The glass transition temperature of the produced test piece was measured under the following conditions. In this evaluation, if the glass transition temperature was 100 ° C. or higher, it was determined that the glass transition temperature was sufficient.
・ Measurement device: DVE (DVE-V4 manufactured by Rheology Co., Ltd.)
・ Measurement temperature: 25-300 ℃
・ Raising 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). Moreover, content (mass%) of an elastomer is content based on the total amount of a thermosetting component (thermosetting resin, a hardening | curing agent, and a hardening accelerator) and an elastomer component.

DESCRIPTION OF SYMBOLS 1 ... Support body, 2 ... Sealing film, 2a ... Hardened | cured material (sealing part) of sealing film, 10 ... Sealing film with a support body, 20 ... SAW device (sealed body), 30 ... Substrate, 40 ... bump, 50 ... hollow region, 60 ... hollow structure, 100, 200 ... hollow sealing structure (sealing structure).

Claims (13)

A thermosetting component, an inorganic filler, and a carboxy group equivalent of 270 to 4300 g / eq. A carboxy group-containing elastomer, and a resin composition containing
Content of the said carboxy group containing elastomer is a film for sealing which is less than 40 mass% on the basis of the total amount of the said thermosetting component and the said carboxy group containing elastomer. The content of the elastomer component including the carboxy group-containing elastomer contained in the resin composition is 2% by mass or more and less than 40% by mass based on the total amount of the thermosetting component and the elastomer component. The sealing film according to claim 1. The sealing according to claim 1 or 2, wherein the content of the structural unit having a carboxy group in the carboxy group-containing elastomer is 2 to 35 mol% based on the total amount of the structural units constituting the carboxy group-containing elastomer. Stop film. The sealing film according to any one of claims 1 to 3, wherein the carboxy group-containing elastomer contains a structural unit derived from (meth) acrylic acid. The sealing film according to any one of claims 1 to 4, wherein the weight average molecular weight of the carboxy group-containing elastomer is 300,000 to 10,000,000. 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, which is used for sealing an object to be sealed provided on a substrate via bumps. A substrate and a sealed body provided on the substrate via bumps, and preparing a hollow structure in which a hollow region is provided between the substrate and the sealed body;
A method for manufacturing a sealing structure, wherein the object to be sealed is sealed with the sealing film according to any one of claims 1 to 9. The method for manufacturing a sealing structure according to claim 10, wherein the object to be sealed is a SAW device having an electrode on the hollow region side. A cured product of the sealing film according to any one of claims 1 to 9, wherein the substrate, a sealed body provided on the substrate via bumps, and the sealed body are sealed. With
A sealing structure in which a hollow region is provided between the substrate and the body to be sealed. The sealing structure according to claim 12, wherein the object to be sealed is a SAW device having an electrode on the hollow region side.

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