KR102505321B1 - Encapsulation film, encapsulation structure, and manufacturing method of the encapsulation structure - Google Patents

Abstract

[식(1) 중, X¹은 반응성 관능기를 나타내고, R¹은 탄소수 2∼25의 탄화수소기를 나타냄]A film for sealing comprising a resin composition containing a thermosetting resin having a structural unit represented by the following formula (1) and an inorganic filler.

[In formula (1), X ¹ represents a reactive functional group, and R ¹ represents a hydrocarbon group having 2 to 25 carbon atoms]

Description

Encapsulation film, encapsulation structure, and manufacturing method of the encapsulation structure

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

BACKGROUND ART In recent years, with the development of electronic devices made on the premise of being carried, represented by smartphones and the like, miniaturization and thinning of semiconductor devices are progressing. Similarly, demand for miniaturization and thinning of electronic component devices used therein is increasing. For that reason, a technique for packaging an electronic component having a movable part such as a surface acoustic wave (SAW) device is often examined. A SAW device is an electronic component in which regular comb-shaped electrodes are formed on a piezoelectric thin film or a piezoelectric substrate, and is an electronic component capable of extracting an electrical signal in a specific frequency band using a surface acoustic wave.

When packaging an electronic component having such a movable part, it is necessary to provide a space for securing the movability of the movable part. For example, in a SAW device, since desired frequency characteristics cannot be obtained if other substances adhere to the surface on which the comb-shaped electrode is formed, formation of a hollow structure is essential.

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

Accordingly, a method of preparing a hollow structure in which a chip on which a comb-type electrode is formed is flip-chip mounted on a substrate via a bump, and sealing the chip in a state in which a hollow region is formed between the substrate and the chip has been proposed (for example, Patent Document 2 and Patent Document 3).

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

In the case of sealing the encapsulated body in a state in which a hollow region is formed between the substrate and the encapsulated body, the sealing material (sealing It is difficult to sufficiently suppress the inflow of the resin composition constituting the film). For example, in the techniques of Patent Literature 2 and Patent Literature 3, when an attempt is made to ensure sufficient embeddability, the sealing material may enter the hollow region between the substrate and the body to be sealed.

Therefore, the present invention is excellent in embedding into an object to be sealed and can sufficiently suppress the inflow of the sealing material into the hollow region between the substrate and the object to be sealed, a sealing structure using the film for sealing, and It is an object of the present invention to provide a method for manufacturing the encapsulation structure.

The present inventors first considered adjusting the melt viscosity of the resin composition constituting the sealing film to a desired range, and studied adding an elastomer component to the resin composition, adjusting the amount of inorganic filler, and the like. However, it was difficult to solve the above problems only by adjusting the melt viscosity to a desired range by these methods. The present inventors paid attention to thermosetting resins and further examined them. By introducing a specific side chain group into the main skeleton of a specific thermosetting resin, the fluidity control of the sealing film becomes easy, and while ensuring excellent embedding property in the sealed body, , It was discovered that the inflow of the sealing material (resin composition constituting the film for sealing) into the hollow region between the substrate and the body to be sealed could be sufficiently suppressed, and the present invention was reached.

That is, one aspect of the present invention relates to a film for sealing comprising a resin composition containing a thermosetting resin having a structural unit represented by the following formula (1) and an inorganic filler.

[In formula (1), X ¹ represents a reactive functional group, and R ¹ represents a hydrocarbon group having 2 to 25 carbon atoms]

According to the above sealing film, inflow of the sealing material into the hollow region between the substrate and the object to be sealed can be sufficiently suppressed while ensuring excellent embedding in the object to be sealed. That is, according to the said sealing film, embedding property and hollow non-filling property are compatible. Moreover, according to the said sealing film, the glass transition temperature (Tg) after hardening becomes sufficient easily, and it is easy to improve the reliability (thermal reliability) of the sealing structure.

The thermosetting resin may further contain a structural unit represented by the following formula (2). In this case, the embeddability to the object to be sealed can be further improved while sufficiently maintaining the hollow non-filling property.

[In Formula (2), X ² represents a reactive functional group, and R ² represents a hydrogen atom or a phenyl group]

The above X ¹ may be a hydroxyl group. In this case, heat resistance and flame retardancy are excellent. In addition, such a thermosetting resin can be produced at low cost.

The resin composition may further contain an epoxy resin. In this case, the mechanical strength is excellent, the shrinkage during curing is small, and the dimensional stability is excellent. In addition, it is excellent in heat resistance, water resistance and chemical resistance, and is excellent in electrical insulation.

The content of the structural unit represented by the formula (1) in the thermosetting resin may be 20 mol% or more based on the total amount of the structural units constituting the thermosetting resin. In this case, embedding property and hollow non-filling property can be compatible at a higher level.

500 or more may be sufficient as the weight average molecular weight of the said thermosetting resin. In this case, it is possible to achieve both the embeddability and hollow non-filling properties to the encapsulation body at a higher level.

The film thickness of the said sealing film should just be 20-250 micrometers.

The sealing film can be preferably used for sealing an object to be sealed installed on a substrate through bumps.

One aspect of the present invention is to prepare a hollow structure comprising a substrate and an encapsulated body installed on the substrate through bumps, wherein a hollow region is formed between the substrate and the encapsulated body, and It is related with the manufacturing method of the sealing structure which seals the said to-be-enclosed body with a film for use. According to this method, it is possible to obtain an encapsulation structure in which the encapsulated body is sufficiently embedded and the hollow region is sufficiently secured.

In the above manufacturing method, the sealed body may be a SAW device having electrodes on the side of the hollow region. In the above manufacturing method, the SAW device can be sufficiently embedded, and the adhesion of the sealing material to the electrode-bearing surface of the SAW device can be sufficiently suppressed. Therefore, according to the manufacturing method, the reliability of the SAW device can be improved. Further, for the same reason, in the manufacturing method described above, the yield in manufacturing the sealing structure (hollow sealing structure) provided with such an encapsulated body can be improved.

One aspect of the present invention includes a substrate, an encapsulation body installed on the substrate through bumps, and a cured product of the sealing film of the present invention for sealing the encapsulation body, and between the substrate and the encapsulation body. It relates to an encapsulation structure in which a hollow region is formed. In the above sealing structure, the object to be sealed is sufficiently embedded, and the hollow region is sufficiently secured.

In the above encapsulation structure, the encapsulated body may be a SAW having electrodes on the hollow region side. In this sealing structure, the SAW device is sufficiently embedded, and the adhesion of the sealing material to the surface having the electrode of the SAW device is sufficiently suppressed. Therefore, the reliability of the SAW device is excellent.

According to the present invention, the encapsulation film is excellent in embedding into the encapsulation body and can sufficiently suppress the inflow of the encapsulation material into the hollow region between the substrate and the encapsulation body, the encapsulation structure using the encapsulation film, and the above A method for manufacturing an encapsulation structure can be provided.

[Brief Description of Drawings] Fig. 1 is a schematic cross-sectional view showing a film for sealing with a support containing a film for sealing of an embodiment.
[Fig. 2] A schematic cross-sectional view for explaining one embodiment of a method for manufacturing a hollow encapsulation structure.

In this specification, a numerical range expressed using “to” indicates a range including the numerical values described before and after “to” as the minimum and maximum values, respectively. In the numerical ranges described step by step in this specification, the upper limit or lower limit of the numerical range of a certain stage may be replaced with the upper limit or lower limit of the numerical range of another stage. In the numerical range described in this specification, the upper limit value or lower limit value of the numerical range may be replaced with the value shown in the Example. With "A or B", either one of A and B may be included, and both may be included. The materials exemplified in this specification may be used singly or in combination of two or more, unless otherwise specified. In this specification, the content of each component in the composition means the total amount of the plurality of substances present in the composition when there are a plurality of substances corresponding to each component in the composition, unless otherwise specified.

EMBODIMENT OF THE INVENTION Hereinafter, preferred embodiment of this invention is described, referring drawings.

<Film for Encapsulation>

The film for sealing of this embodiment is a film-shaped resin composition containing a thermosetting component and an inorganic filler. The sealing film of the present embodiment contains a thermosetting resin having a structural unit represented by the following formula (1) as a thermosetting component.

[In formula (1), X ¹ represents a reactive functional group, and R ¹ represents a hydrocarbon group having 2 to 25 carbon atoms]

The sealing film of the present embodiment is a hollow structure including a substrate, an encapsulated body (for example, an electronic component such as a SAW device) provided on the substrate, and a hollow region formed between the substrate and the encapsulated body. can be preferably used for According to the sealing film of this embodiment, the embedding property with respect to a to-be-sealed body and hollow non-filling property are compatible. The reason why such an effect is obtained is not clear, but the present inventors speculate as follows. That is, in the sealing film of the present embodiment, when R ¹ in the structural unit represented by the formula (1) is sterically hindered, the flow of the thermosetting resin in the sealing film is suppressed, and the inflow of the resin composition into the hollow region is suppressed. this is suppressed On the other hand, since R ¹ is of an appropriate size and the steric hindrance is alleviated by the shear stress at the time of encapsulation, the embeddability in the encapsulated body is not impaired. From such a reason, according to the sealant film of this embodiment, it is estimated that the said effect is acquired.

By the way, it is also considered to prevent the inflow of the sealing material (particularly the thermosetting resin) into the hollow region by adding an excessive amount of elastomer to the sealing film, but in this method, not only the embeddability may decrease, but also , the Tg after curing may decrease, and it may be difficult to secure the reliability (thermal reliability) of the encapsulation structure. On the other hand, since the film for sealing of this embodiment does not need to use an excessive amount of elastomer and has the structural unit represented by the above formula (1), it is possible to sufficiently secure Tg after curing.

(thermosetting component)

Examples of the thermosetting component include thermosetting resins, curing agents, and curing accelerators. The thermosetting component may contain a thermosetting resin without containing a curing agent and/or a curing accelerator. In addition, the thermosetting component contains at least a thermosetting resin having a structural unit represented by the above formula (1) (hereinafter also referred to as "first thermosetting resin"), but a thermosetting resin other than the first thermosetting resin (hereinafter referred to as "first thermosetting resin"). 2 thermosetting resin”) may be further contained.

[First thermosetting resin]

The first thermosetting resin has at least a structural unit represented by the above formula (1).

The reactive functional group represented by X ¹ may be a functional group capable of reacting with other reactive functional groups and heat. In this embodiment, a tertiary crosslinked structure is formed and the film for sealing is hardened, for example when the reactive functional group which a 1st thermosetting resin has reacts with another reactive functional group by a heat|fever. A hydroxyl group, an epoxy group, a carboxyl group, an isocyanate group etc. are mentioned as a reactive functional group. Among these, it is preferable that it is a hydroxyl group (phenolic hydroxyl group) from a viewpoint that it can manufacture at low cost, and a viewpoint excellent in heat resistance and a flame retardance. In other words, it is preferable that the first thermosetting resin contains a phenol resin. The other reactive functional group that reacts with the reactive functional group may be a reactive functional group possessed by the first thermosetting resin, a reactive functional group possessed by the second thermosetting resin, or a reactive functional group possessed by the curing agent.

The hydrocarbon group represented by R ¹ may be straight-chain or branched. In addition, either saturated or unsaturated may be sufficient as a hydrocarbon group. When the hydrocarbon group is an unsaturated hydrocarbon group, the unsaturated hydrocarbon group may have two or more unsaturated bonds.

The number of carbon atoms in the hydrocarbon group is preferably 4 or more, more preferably 8 or more, still more preferably 10 or more, and particularly preferably 15 or more, from the viewpoint of improving hollow non-filling properties. In particular, when the number of carbon atoms in the hydrocarbon group is 15 or more, the modulus of elasticity can be reduced, and crackability and bendability can be improved. The number of carbon atoms in the hydrocarbon group may be 22 or less, 20 or less, or 18 or less from the viewpoint of better embedding property. The above upper and lower limit values can be arbitrarily combined. Therefore, the number of carbon atoms in the hydrocarbon group may be, for example, 4 to 22, 8 to 20, 10 to 18, or 15 to 18. In addition, also in the following description, the upper limit value and the lower limit value described individually can be combined arbitrarily.

In the present embodiment, the longer the main chain of the hydrocarbon group, the better the hollow non-filling property tends to be, and the Tg after curing tends to be sufficient. From such a point of view, when the hydrocarbon group is branched, the number of carbon atoms in the main chain of the branched hydrocarbon group may be 2 or more, 4 or more, or 6 or more. The number of carbon atoms in the main chain of the branched hydrocarbon group may be 22 or less, 20 or less, or 18 or less from the viewpoint of better embeddingability.

Examples of the straight-chain hydrocarbon group include -(CH ₂ ) ₁₄ CH ₃ , -(CH ₂ ) ₇ CH=CH(CH ₂ ) ₅ CH ₃ , -(CH ₂ ) ₇ CH=CHCH ₂ CH=CH( CH ₂ ) ₂ CH ₃ , -(CH ₂ ) ₇ CH=CHCH ₂ CH=CHCH=CHCH ₃ , -(CH ₂ ) ₇ CH=CHCH ₂ CH=CHCH ₂ CH=CH ₂ and the like.

Examples of the branched hydrocarbon group include -C(CH ₃ ) ₂ CH ₃ , -C(CH ₃ ) ₂ CH ₂ C(CH ₃ ) ₂ CH ₃ and the like.

The position of R ¹ in the above formula (1) may be ortho, meta, or para position with respect to -X ¹ . From the standpoint of less steric hindrance and excellent reactivity, the position of R ¹ is preferably para to -X ¹ .

The positions of the bonds (-* and -CH ₂ -*) may be ortho, meta, or para positions with respect to -X ¹ . From the viewpoint of extending the range of R ¹ , the position of the bonding hand is preferably ortho to X ¹ . For example, the structural unit represented by formula (1) may contain the structural unit represented by following formula (1a).

[In formula (1a), X ¹ is the same as X ¹ in the formula (1), and R ¹ is the same as R ¹ in the formula (1)]

The first thermosetting resin may consist only of the structural unit represented by the formula (1). In this case, the number of structural units represented by the formula (1) may be plural. When there are a plurality of structural units represented by the formula (1), the plurality of X ^{1 '} s may be the same or different, and the plurality of R ^{1 '} s may be the same or different. The first thermosetting resin may be, for example, a random copolymer composed of a plurality of different structural units, or may be a block copolymer.

When there are a plurality of structural units represented by the formula (1), the first thermosetting resin includes a structural unit (1A) in which R ¹ is a hydrocarbon group having 6 or more carbon atoms, and a structural unit (1B) in which R ¹ is a hydrocarbon group having 5 or less carbon atoms. It is preferable to include.

[In formula (1A), X ¹ is the same as X ¹ in formula (1), and R ^1A represents a hydrocarbon group having 6 or more carbon atoms]

[In Formula (1B), X ¹ is the same as X ¹ in Formula (1), and R ^1B represents a hydrocarbon group having 5 or less carbon atoms]

Among the structural units represented by the above formula (1) in the first thermosetting resin, the content of the structural unit (1A) is based on the total amount of the structural units constituting the thermosetting resin from the viewpoint of improving the hollow non-filling property. Thus, it may be 20 mol% or more, 30 mol% or more, or 40 mol% or more. The content of the structural unit (1A) may be 100 mol% or less, may be 90 mol% or less, and may be 80 mol% or less, based on the total amount of structural units constituting the thermosetting resin, from the viewpoint of improving the embedding property. may be From these points of view, the content of the structural unit (1A) may be 20 to 100 mol%, 30 to 90 mol%, or 40 to 80 mol% based on the total amount of the structural units constituting the thermosetting resin. do.

Among the structural units represented by the above formula (1) in the first thermosetting resin, the content of the structural unit (1B) is based on the total amount of the structural units constituting the thermosetting resin, from the viewpoint of improving the embedding property. , It may be more than 0 mol%, 10 mol% or more may be sufficient, and 20 mol% or more may be sufficient. The content of the structural unit (1B) may be 80 mol% or less, may be 70 mol% or less, or 60 mol%, based on the total amount of the structural units constituting the thermosetting resin, from the viewpoint of improving the hollow non-filling property. may be below. From these points of view, the content of the structural unit (1B) may be more than 0 mol% and 80 mol% or less, may be 10 to 70 mol%, or 20 to 60 mol%, based on the total amount of the structural units constituting the thermosetting resin. It may be mol%.

The molar ratio of the structural unit (1A) to the structural unit (1B) should just be 0.5 or more, and 3.0 or less, from the viewpoint of being able to achieve both the embedding property and hollow non-filling property at a higher level in the encapsulated body. Therefore, the molar ratio of the structural unit (1A) to the structural unit (1B) may be, for example, 0.5 to 3.0.

The first thermosetting resin may further have other structural units other than the structural unit represented by the formula (1). As another structural unit, the structural unit represented by following formula (2) is mentioned, for example.

[In formula (2), X ² represents a reactive functional group, R ² represents a hydrogen atom or a phenyl group, and when there are a plurality of structural units represented by formula (2), a plurality of X ² may be the same or different And, a plurality of R ² may be the same or different.]

Examples of the reactive functional group represented by X ² include the same as those of X ¹ , and preferred examples are also the same.

The position of R ² in the above formula (2) may be ortho, meta, or para position with respect to -X ² . From the standpoint of less steric hindrance and excellent reactivity, the position of R ² is preferably para with -X ² .

The positions of the bonds (-* and -CH ₂ -*) may be ortho, meta, or para positions with respect to -X ² . From the viewpoint of reducing the volume of the thermosetting resin and improving the reactivity, the position of the bonding hand is preferably ortho to -X ² . For example, the structural unit represented by formula (2) may contain the structural unit represented by following formula (2b).

[In formula (2b), X ² is the same as X ² in the formula (2), and R ² is the same as R ² in the formula (2)]

The content of the structural unit represented by the above formula (1) in the first thermosetting resin is 20 mol% or more based on the total amount of structural units constituting the thermosetting resin from the viewpoint of improving the hollow non-filling property It may be 30 mol% or more, or 40 mol% or more. The content of the structural unit represented by the above formula (1) in the first thermosetting resin is 100 mol% or less based on the total amount of structural units constituting the thermosetting resin, from the viewpoint of better embedding property. , 90 mol% or less may be sufficient, and 80 mol% or less may be sufficient. From these points of view, the content of the structural unit represented by the formula (1) in the first thermosetting resin may be 20 to 100 mol%, based on the total amount of the structural units constituting the thermosetting resin, and 30 to 90 mol% may be sufficient, and 40 to 80 mol% may be sufficient.

The content of the structural unit represented by the formula (2) in the first thermosetting resin may be more than 0 mol% based on the total amount of structural units constituting the thermosetting resin from the viewpoint of better embedding property. , 10 mol% or more may be sufficient, and 20 mol% or more may be sufficient. The content of the structural unit represented by the formula (2) in the first thermosetting resin is 80 mol% or less based on the total amount of structural units constituting the thermosetting resin from the viewpoint of improving the hollow non-filling property It may be 70 mol% or less, or 60 mol% or less may be sufficient. From these points of view, the content of the structural unit represented by the formula (2) in the first thermosetting resin is 0 mol% to 80 mol% or less based on the total amount of structural units constituting the thermosetting resin. , 10 to 70 mol% may be sufficient, and 20 to 60 mol% may be sufficient.

The molar ratio of the structural unit represented by the above formula (1) to the structural unit represented by the above formula (2) in the first thermosetting resin is compatible with the embedding property and hollow non-filling property for the encapsulated body at a higher level. From a viewpoint, it should just be 0.5 or more, and should just be 3.0 or less. Therefore, the molar ratio of the structural unit represented by the above formula (1) to the structural unit represented by the above formula (2) may be, for example, 0.5 to 3.0.

The weight average molecular weight of the first thermosetting resin may be 500 to 1,000,000, may be 500 to 500,000, or may be 500 to 300,000 from the viewpoint of achieving both the embedding property and hollow non-filling property to a sealed body at a higher level. In addition, a weight average molecular weight is a polystyrene conversion value using the calibration curve by the standard polystyrene by the gel permeation chromatography method (GPC).

The reactive functional group equivalent of the first thermosetting resin is 100 g/eq. or more, 110g/eq. or more, 120g/eq. or more than 130g/eq. It should just be more than 250 g/eq. or less, 240 g/eq. or less, 210 g/eq. or less than 200 g/eq. It should be below. Therefore, the reactive functional group equivalent of the first thermosetting resin may be, for example, 100 to 250 g/eq., 110 to 240 g/eq., 120 to 210 g/eq., or 130 to 200 g/eq. may be continued In addition, "reactive functional group equivalent" means the mass (g/eq.) of the thermosetting resin per 1 equivalent (1 eq.) of the reactive functional group of the thermosetting resin. The reactive functional group equivalent is, for example, when the reactive functional group is an epoxy group, after dissolving the thermosetting resin in chloroform, adding acetic acid and tetraethylammonium bromide acetic acid solution to the resulting solution, potentiometric titration with perchloric acid acetic acid standard solution It is measured by detecting the end point at which all epoxy groups reacted. In addition, when the reactive functional group equivalent is a hydroxyl group, it is measured by adding an acetylation reagent to a thermosetting resin, heating in a glycerin bath, cooling, adding a phenolphthalein solution as an indicator, and titrating with a potassium hydroxide ethanol solution.

The first thermosetting resin may be in a liquid state at 25°C from the viewpoint of easily suppressing cracks and cracks on the surface of the film. And "liquid at 25 degreeC" refers to the thing whose viscosity at 25 degreeC measured with the E-type viscometer is 400 Pa.s or less.

The resin having the structural unit represented by the above formula (1) can be obtained by, for example, polymerizing a compound represented by the following formula (3) by a conventionally known method. In addition, the resin having the structural unit represented by the formula (1) and the structural unit represented by the formula (2) is a compound represented by the following formula (3) and a compound represented by the following formula (4) It can be obtained by copolymerization by a conventionally well-known method.

[In Formula (3), X ¹ is the same as X ¹ in Formula (1), R ¹ is the same as R ¹ in Formula (1), and the position of R ¹ is ortho to -X ¹ , which may be metawi or parawi]

[In Formula (4), X ² is the same as X ² in Formula (2), R ² is the same as R ² in Formula (2), and the position of R ² is ortho to -X ² , which may be metawi or parawi]

For example, when X ¹ is a hydroxyl group, the first thermosetting resin reacts a substituent-containing phenol represented by the following formula (3a), formaldehyde, and optionally a substituent-containing phenol represented by the following formula (4a) can be obtained by doing In the present embodiment, the content of each structural unit of the first thermosetting resin can be adjusted by adjusting the amount of the substituent-containing phenol represented by formula (3a) and the substituent-containing phenol represented by formula (4a), etc. .

[In formula (3a), R ¹ is the same as R ¹ in formula (1), and the position of R ¹ may be ortho, meta, or para with -OH]

[In formula (4a), R ² is the same as R ² in formula (2), and the position of R ² may be ortho, meta, or para with -OH]

Further, for example, when X ¹ is an epoxy group, the first thermosetting resin can be obtained by reacting the substituent-containing phenol represented by the formula (3a) with epichlorohydrin in a 30% NaOH solution. In the present embodiment, the content of each structural unit of the first thermosetting resin can be adjusted by adjusting the amount of the substituent-containing phenol represented by formula (3a) and the substituent-containing phenol represented by formula (4a), etc. .

The content of the first thermosetting resin may be 1 mass% or more, 3 mass% or more, or 5 mass% or more based on the total mass of the sealing film from the viewpoint of better hollow non-filling properties. The content of the first thermosetting resin may be 50 mass% or less, 30 mass% or less, or 10 mass% or less based on the total mass of the sealing film from the viewpoint of better embedding property. Therefore, the content of the first thermosetting resin may be, for example, 1 to 50% by mass, 3 to 30% by mass, or 5 to 10% by mass based on the total mass of the sealing film.

[Second thermosetting resin]

Examples of the second thermosetting resin include epoxy resins, phenol resins, phenoxy resins, cyanate resins, thermosetting polyimides, melamine resins, urea resins, unsaturated polyesters, alkyd resins, and polyurethanes. It is preferable that the reactive functional group of the second thermosetting resin is a functional group that reacts with the reactive functional group of the first thermosetting resin by heat. For example, when the reactive functional group of the first thermosetting resin is a hydroxyl group (phenolic hydroxyl group), the reactive functional group of the second thermosetting resin is preferably an epoxy group. In other words, when the first thermosetting resin is a phenol resin, the second thermosetting resin is preferably an epoxy resin. In this case, the mechanical strength is excellent, the shrinkage during curing is small, and the dimensional stability is excellent. In addition, it is excellent in heat resistance, water resistance and chemical resistance, and is excellent in electrical insulation. The reactive functional group of the second thermosetting resin may be the same as the reactive functional group of the first thermosetting resin. For example, when the reactive functional group of the first thermosetting resin is a hydroxyl group (phenolic hydroxyl group), the reactive functional group of the second thermosetting resin may be a hydroxyl group (phenolic hydroxyl group). In this case, a curing agent can be used as the thermosetting component.

As the epoxy resin, any resin having two or more epoxy groups in one molecule can be used without particular limitation. As an epoxy resin, for example, 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, 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 resin, bixylenol type epoxy resin (bixylenol diglycidyl ether, etc.) , hydrogenated bisphenol A type epoxy resins (such as hydrogenated bisphenol A glycidyl ether), and dibasic acid-modified diglycidyl ether type epoxy resins and aliphatic epoxy resins of these resins. An epoxy resin may be used individually by 1 type, and may use 2 or more types together.

From the standpoint of easily suppressing cracks and cracks on the surface of the film, the epoxy resin may be a liquid epoxy resin (liquid epoxy resin) at 25°C. As the liquid epoxy resin, bisphenol A type glycidyl ether, bisphenol AD type glycidyl ether, bisphenol S type glycidyl ether, bisphenol F type glycidyl ether, hydrogenated bisphenol A type glycidyl ether , glycidyl ether of ethylene oxide adduct bisphenol A type, glycidyl ether of propylene oxide adduct bisphenol A type, glycidyl ether of naphthalene resin, trifunctional or tetrafunctional glycidylamine, etc. can

As an epoxy resin marketed, for example, Mitsubishi Chemical Corporation trade name "jER825" (bisphenol A type epoxy resin, epoxy equivalent: 175 g/eq.), Mitsubishi Chemical Corporation trade name "jER806" (Bisphenol F type epoxy resin, epoxy equivalent: 160 g/eq.), trade name manufactured by DIC Corporation "HP-4032D" (naphthalene type epoxy resin, epoxy equivalent weight: 141 g/eq.), trade name manufactured by DIC Corporation Flexible toughness epoxy resins such as "EXA-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 "Epiclon N-770" (phenol novolak type epoxy resin), trade name "Epiclon N-660" (cresol novolak type epoxy resin), and trade name "Epiclon N-770" (phenol novolak type epoxy resin) Clone HP-7200H" (dicyclopentadiene type epoxy resin), trade name "EPPN-502H" (trisphenylmethane type epoxy resin) and trade name "NC-3000" (biphenylaralkyl type epoxy) manufactured by Nippon Kayaku Co., Ltd. resin), trade name "ESN-355" (naphthalene type epoxy resin) manufactured by Nippon Steel Sumikin Chemical Co., Ltd., trade name "YX-8800" (anthracene type epoxy resin) manufactured by Mitsubishi Chemical Corporation, Sumitomo Kaga The product name "ESCN-190-2" (o-cresol novolak-type epoxy resin) etc. by the Ku Co., Ltd. are mentioned. These epoxy resins may be used individually, respectively, and may be used in combination of 2 or more type.

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 the phenol resin include a resin obtained by condensation or co-condensation of phenols and/or naphthols and aldehydes in the presence of an acidic catalyst, biphenyl backbone type phenol resins, para-xylylene-modified phenol resins, and metaxylylene parach. Silylene-modified phenolic resins, melamine-modified phenolic resins, terpene-modified phenolic resins, dicyclopentadiene-modified phenolic resins, cyclopentadiene-modified phenolic resins, polycyclic aromatic ring-modified phenolic resins, and xylylene-modified naphthol resins. 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 aldehydes include formaldehyde, acetaldehyde, propionaldehyde, benzaldehyde, salicylaldehyde and the like.

Commercially available phenolic resins include "PAPS-PN2" (novolak-type phenolic resin) manufactured by Asahi Yukizai Kogyo Co., Ltd. and "SK Resin HE200C-7" (biphenyl aral) manufactured by Air Water Co., Ltd. Keel type phenol resin), trade name "HE910-10" (trisphenylmethane type phenol resin), trade names "MEH-7000", "DL-92", "H-4" and "HF- 1M", trade names "LVR-8210DL", "ELP" series and "NC" series manufactured by Kunei Chemical Kogyo Co., Ltd., trade names "SN-100, SN-300 manufactured by Nippon Steel Sumikin Chemical Co., Ltd. , SN-395, SN-400" (naphthalene type phenol resin), and Hitachi Chemical Co., Ltd. trade name "HP-850N" (novolac type phenol resin).

The reactive functional group equivalent of the second thermosetting resin is 100 g/eq. or more, 120g/eq. or more than 140g/eq. What is necessary is more than 500 g/eq. or less, 400 g/eq. or less or 300 g/eq. It should be below. Therefore, the reactive functional group equivalent of the second thermosetting resin may be, for example, 100 to 500 g/eq., 120 to 400 g/eq., or 140 to 300 g/eq.

When the second thermosetting resin contains an epoxy resin, the content of the epoxy resin may be 1% by mass or more, and may be 3% by mass or more, based on the total mass of the sealing film, from the viewpoint of better embedding property It may be 5% by mass or more. The content of the epoxy resin may be 50% by mass or less, 30% by mass or less, or 10% by mass or less based on the total mass of the sealing film from the viewpoint of improving the hollow non-filling property. Therefore, the content of the epoxy resin may be, for example, 1 to 50% by mass, 3 to 30% by mass, or 5 to 10% by mass based on the total mass of the sealing film.

When the second thermosetting resin contains a liquid epoxy resin, the content of the liquid epoxy resin is 0.5% by mass or more based on the total mass of the sealing film from the viewpoint of easily suppressing cracks and cracks on the surface of the film. is preferred, 1% by mass or more is more preferred, 3% by mass or more is still more preferred, 5% by mass or more is particularly preferred, 7% by mass or more is extremely preferred, and 9% by mass or more is extremely preferred. 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 the excessively high tackiness of the film and the viewpoint of easily suppressing edge fusion It is preferable, 15 mass % or less is more preferable, and 13 mass % or less is still more preferable. From these viewpoints, the content of the liquid epoxy resin is preferably 0.5 to 20% by mass, more preferably 1 to 20% by mass, and still more preferably 3 to 20% by mass, based on the total mass of the sealing film. 5 to 20% by mass is particularly preferred, 7 to 15% by mass is extremely preferred, and 9 to 13% by mass is extremely preferred.

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 second thermosetting resin, from the viewpoint of easily suppressing the occurrence of cracks and cracks on the surface of the film, , 50% by mass or more is more preferred. The content of the liquid epoxy resin is preferably 95% by mass or less, based on the total mass of the second thermosetting resin, from the viewpoint of easily suppressing excessive increase in the tackiness of the film and the viewpoint of easily suppressing edge fusion, 90 mass % or less is more preferable, and 80 mass % or less is still more preferable. From these viewpoints, the content of the liquid epoxy resin is preferably 20 to 95% by mass, more preferably 30 to 90% by mass, and further 50 to 80% by mass based on the total mass of the second thermosetting resin. desirable. The content of the liquid epoxy resin may be 100% by mass based on the total mass of the second thermosetting resin.

When the second thermosetting resin contains a phenol resin, the content of the phenol resin may be 1% by mass or more, and may be 3% by mass or more, based on the total mass of the film for sealing, from the viewpoint of better embedding property It may be 5% by mass or more. The content of the phenol resin may be 50% by mass or less, 30% by mass or less, or 10% by mass or less based on the total mass of the sealing film from the viewpoint of better hollow non-filling properties. Therefore, the content of the phenol resin may be, for example, 1 to 50% by mass, 3 to 30% by mass, or 5 to 10% by mass based on the total mass of the sealing film.

In this embodiment, it is preferable that the thermosetting component contains an epoxy resin and a phenol resin, and the first thermosetting resin contains a phenol resin In addition, it is preferable that the second thermosetting resin contains an epoxy resin. In this case, the content of all the epoxy resins and the content of the phenol resin contained in the resin composition can be set based on the ratio of the number of moles M2 of epoxy groups to the number of moles M1 of phenolic hydroxyl groups in the resin composition.

The ratio (M2/M1) of the number of moles M2 of epoxy groups to the number of moles M1 of phenolic hydroxyl groups in the resin composition 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 (M2/M1) may be, for example, 0.7 to 2.0, 0.8 to 1.8, or 0.9 to 1.7.

[curing agent]

The curing agent (excluding components corresponding to thermosetting resins) is not particularly limited, and examples thereof include phenol-based curing agents, acid anhydride-based curing agents, active ester-based curing agents, and cyanate ester-based curing agents. A hardening|curing agent may be used individually by 1 type, and may use 2 or more types together.

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

[Curing accelerator]

As the curing accelerator, it can be used without particular limitation, but at least one selected from the group consisting of amine-based curing accelerators and phosphorus-based curing accelerators is preferred. As the curing accelerator, an amine-based curing accelerator is particularly preferred from the standpoint of easy to obtain a cured product having excellent thermal conductivity, rich in derivatives, and easy to obtain a desired activation temperature, and imidazole compounds, aliphatic amines, and alicyclics. At least one selected from the group consisting of amines is more preferred, and an imidazole compound is still more preferred. 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. As a commercial item of a hardening accelerator, "2P4MZ" by Shikoku Chemical Industry Co., Ltd., "1B2MZ", etc. are mentioned.

The content of the curing accelerator is preferably in the following range based on the total amount of the thermosetting 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 of easy to obtain sufficient curing accelerating effect. The content of the curing accelerator is such that curing does not proceed easily during the process of manufacturing the sealing film (eg, coating and drying) or during storage of the sealing film, resulting in cracking of the sealing film, And from the viewpoint of easily preventing molding defects accompanying an increase in melt viscosity, the content 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 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. As constituent materials of the inorganic filler, 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, bismuth titanate, titanium oxide, barium zirconate, zirconic acid Calcium etc. are mentioned. Characteristics of a cured film desired by surface modification (for example, surface treatment with a silane compound) or the like, since it has a viewpoint of being easy to obtain the effect of improving the dispersibility in the resin composition and the effect of inhibiting sedimentation in the varnish, and having a relatively small coefficient of thermal expansion. From the viewpoint of easy obtaining, an inorganic filler containing silica is preferred. 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 inorganic filler may be surface modified. The method of surface modification is not specifically limited. Surface modification using a silane coupling agent is preferable from the viewpoints of simple treatment, abundant functional groups, and easy imparting of desired properties.

Examples of the silane coupling agent include alkylsilane, alkoxysilane, vinylsilane, epoxysilane, aminosilane, acrylsilane, methacrylsilane, mercaptosilane, sulfidesilane, isocyanatesilane, sulfursilane, styrylsilane, and alkylchlorosilane. can

Specific examples of the silane coupling agent include methyltrimethoxysilane, dimethyldimethoxysilane, trimethylmethoxysilane, methyltriethoxysilane, methyltriphenoxysilane, ethyltrimethoxysilane, n-propyltrimethoxysilane, and diiso. Propyldimethoxysilane, isobutyltrimethoxysilane, diisobutyldimethoxysilane, isobutyltriethoxysilane, n-hexyltrimethoxysilane, n-hexyltriethoxysilane, cyclohexylmethyldimethoxysilane, n- octyltriethoxysilane, n-dodecylmethoxysilane, phenyltrimethoxysilane, diphenyldimethoxysilane, triphenylsilanol, methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, n-octyldimethylchlorosilane, Tetraethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-(2-aminoethyl)aminopropyltrimethoxysilane, 3-(2-aminoethyl)aminopropylmethyldimethyne Toxysilane, 3-phenylaminopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycy Doxypropylmethyldiethoxysilane, bis(3-(triethoxysilyl)propyl)disulfide, bis(3-(triethoxysilyl)propyl)tetrasulfide, vinyltriacetoxysilane, vinyltrimethoxysilane, Vinyltriethoxysilane, vinyltriisopropoxysilane, allyltrimethoxysilane, diallyldimethylsilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacrylic Oxypropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltriethoxysilane, N-(1,3-dimethylbutylidene)- 3-aminopropyltriethoxysilane, aminosilane (phenylaminosilane etc.), etc. are mentioned. 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 still more preferably 0.3 μm or more, from the viewpoint of easily suppressing the aggregation of the inorganic filler and facilitating the dispersion of the inorganic filler, 0.5 μm or more is particularly preferred. The average particle diameter of the inorganic filler is preferably 25 μm or less, more preferably 10 μm or less, and 5 μm The following is more preferable. 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 0.5 to 5 μm. 5 μm is extremely preferred. 10-18 micrometers may be sufficient as the average particle diameter of an inorganic filler.

From the viewpoint of excellent flowability of the resin composition, it is preferable to use a plurality of inorganic fillers having mutually different average particle diameters in combination. Among the combinations of inorganic fillers, a combination in which the average particle size of the inorganic filler having the largest average particle size is 15 to 25 μm is preferable. It is preferable to use a combination of an inorganic filler having an average particle size of 15 to 25 µm, an inorganic filler having an average particle size of 0.5 to 2.5 µm, and an inorganic filler having an average particle size of 0.1 to 1.0 µm.

"Average particle diameter" is the particle diameter at the point corresponding to 50% of the volume when the cumulative frequency distribution curve by the particle diameter is obtained with the total volume of the particles as 100%, and the particle size distribution measuring device using the laser diffraction scattering method etc. can be measured. The average particle diameter of each inorganic filler combined can be confirmed from the average particle diameter of each inorganic filler at the time of mixing, and also can be confirmed by measuring the particle size distribution.

As a commercial item of an inorganic filler, "DAW20" by Denka Co., Ltd., brand name "SC550O-SXE" by Adma Techs Co., Ltd., and "SC2050-KC", etc. are mentioned.

The content of the inorganic filler is determined from the viewpoint of improving the thermal conductivity and from the viewpoint of easily suppressing the increase in warpage of the sealing structure (e.g., electronic component device such as a semiconductor device) due to a difference in thermal expansion coefficient from the sealed body. It may be 70% by mass or more, may be 75% by mass or more, may be 80% by mass or more, or may be 84% by mass or more based on the total mass of the dragon film. The content of the inorganic filler is from the viewpoint that the sealing film is easily suppressed from being broken in the drying step at the time of production of the sealing film, and the decrease in fluidity due to the increase in the melt viscosity of the sealing film is suppressed, and the to-be-sealed body From the standpoint of making it easy to sufficiently seal (electronic components, etc.), it may be 93% by mass or less, 91% by mass or less, or 88% by mass or less based on the total mass of the sealing film. From these points of view, the content of the inorganic filler may be 70 to 93% by mass, may be 75 to 91% by mass, may be 80 to 91% by mass, and may be 84 to 91% by mass based on the total mass of the sealing film %, and may be 84 to 88% by mass. In addition, the said content is content of an inorganic filler excluding the quantity of a surface treatment agent.

(elastomer)

The film for sealing of this embodiment may contain an elastomer (flexible agent) as needed. As the elastomer, it is preferable to use at least one selected from the group consisting of polybutadiene particles, styrene-butadiene particles, acrylic elastomers, silicone powders, silicone oils, and silicone oligomers from the standpoint of excellent dispersibility and solubility. An elastomer may be used individually by 1 type, and may use 2 or more types together.

When the elastomer is in particulate form, the average particle diameter of the elastomer is not particularly limited. In eWLB (Embedded Wafer-Level Ball Grid Array) applications, it is necessary to embed semiconductor elements, so when using the sealing film for eWLB applications, the average particle diameter of the elastomer is preferably 50 μm or less. The average particle diameter of the elastomer is preferably 0.1 μm or more from the viewpoint of excellent dispersibility of the elastomer.

As a commercial item of an elastomer, "SG-280 EK23", "SG-70L", "WS-023 EK30" etc. which are acrylic elastomers by Nagase ChemteX Co., Ltd. are mentioned. In addition, among commercially available elastomer components, there are some that are not elastomer alone, but previously dispersed in a liquid resin (eg, liquid epoxy resin), but they can be used without problems. As such a commercial item, "MX-136" and "MX-965" by Kaneka Corporation are mentioned.

The content of the elastomer may be 1% by mass or more, may be 5% by mass or more, or may be 10% by mass or more based on the total amount of the thermosetting component and the elastomer from the viewpoint of improving the hollow non-filling property. The content of the elastomer is 30 mass, based on the total amount of the thermosetting component and the elastomer, from the viewpoint of improving the embedding property and easy to obtain sufficient Tg after curing and easy to improve the reliability (thermal reliability) of the encapsulating structure. % or less, may be 25% by mass or less, may be 20% by mass or less. From the above, the content of the elastomer may be 1 to 30% by mass, 5 to 25% by mass, or 10 to 20% by mass or less based on the total amount of the thermosetting component and the elastomer.

(other ingredients)

The film for sealing of this embodiment may further contain other additives. Specific examples of such additives include pigments, dyes, release agents, antioxidants, and surface tension regulators.

Moreover, the sealing film of this embodiment may contain a solvent (for example, the solvent used for manufacture of the sealing film). The solvent may be a conventionally known organic solvent. The organic solvent may be any solvent capable of dissolving components other than the inorganic filler, and examples thereof include aliphatic hydrocarbons, aromatic hydrocarbons, terpenes, halogens, esters, ketones, alcohols, and aldehydes. 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 impact and easy dissolution of thermosetting components. Especially, when a solvent is ketones, it is easy to melt|dissolve a thermosetting component especially. 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 less volatilization at room temperature (25°C) and easy removal during drying.

It is preferable that content of the solvent (organic solvent etc.) contained in the sealing film is the following range on the basis of the total mass of the sealing film. The content of the solvent should be 0.2% by mass or more, from the viewpoint of easily suppressing problems such as cracking of the sealing film due to brittleness of the sealing film and a decrease in the embedding property due to an increase in the minimum melt viscosity, and 0.3 It may be mass % or more, 0.5 mass % or more may be sufficient, 0.6 mass % or more may be sufficient, and 0.7 mass % or more may be sufficient. The content of the solvent is determined from the viewpoint of easily suppressing problems such as the problem that the adhesiveness of the film for sealing is too strong and the handleability is lowered, and the problems such as foaming accompanying volatilization of the solvent (organic solvent, etc.) during thermal curing of the film for sealing. , 1.5% by mass or less, and may be 1% by mass or less. From these viewpoints, the content of the solvent may be 0.2 to 1.5 mass%, 0.3 to 1 mass%, 0.5 to 1 mass%, 0.6 to 1 mass%, or 0.7 to 1 mass%.

The thickness (film thickness) of the sealing film may be 20 μm or more, may be 30 μm or more, may be 50 μm or more, or may be 100 μm or more from the viewpoint of easily suppressing in-plane thickness unevenness during coating. do. The thickness of the sealing film may be 250 μm or less, may be 200 μm or less, or may be 150 μm or less from the viewpoint of easy to obtain constant drying property in the depth direction during coating. From these viewpoints, the thickness of the sealing film may be 20 to 250 μm, may be 30 to 250 μm, may be 50 to 200 μm, or may be 100 to 150 μm. In addition, a plurality of sealing films may be laminated to produce a sealing film having a thickness of more than 250 µm.

The glass transition temperature Tg after curing of the sealing film may be 80 to 180°C, 80 to 165°C, or 80 to 150°C from the viewpoint of reliability (thermal reliability) of the resulting sealing structure. The glass transition temperature Tg after curing 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 Examples.

The minimum melt viscosity (minimum melt viscosity) of the sealing film at 35 to 200°C may be 100 to 10000 Pa·s, may be 250 to 8500 Pa·s, or may be 500 to 7000 Pa·s from the viewpoint of better embedding property. may be s. The maximum value of the melt viscosity (maximum melt viscosity) of the encapsulating film at 70 to 90°C may be 500 to 25000 Pa·s, may be 4000 to 20000 Pa·s, and may be 6000 to 25000 Pa·s from the viewpoint of improving the hollow non-filling property. It may be 15000 Pa·s. The minimum melt viscosity and the maximum melt viscosity can be obtained by measuring the melt viscosity of the sealing film by the method described in Examples.

As described above, the sealing film of the present embodiment is preferably used for sealing the object to be sealed in a hollow structure, but the structure to be sealed does not have to have a hollow structure. The film for sealing of this embodiment can also be used, for example, for sealing of a semiconductor device, embedding of an electronic component arranged on a printed wiring board, and the like.

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

As the support 1, a polymer film, metal foil, or the like can be used. As a polymer film, Polyolefin films, such as a polyethylene film and a polypropylene film; vinyl films such as polyvinyl chloride films; polyester films such as polyethylene terephthalate films; polycarbonate films; Acetylcellulose film; A tetrafluoroethylene film etc. are mentioned. As metal foil, copper foil, aluminum foil, etc. are mentioned.

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 properties. When the thickness of the support 1 is 2 μm or more, it is easy to suppress problems such as breaking the support during coating and bending due to the weight of the varnish. When the thickness of the support 1 is 200 μm or less, it is easy to suppress the problem that solvent drying in the varnish is hindered when hot air is blown from both sides of the coated surface and the back surface in the drying step.

In this embodiment, it is not necessary to use the support body 1. Moreover, you may arrange|position the protective layer for the purpose of protecting the sealing film on the side opposite to the support body 1 of the sealing film 2. By providing a protective layer on the sealing film 2, the handleability is improved, and the problem that the sealing film sticks to the back surface of the support body when wound up can be avoided.

As a protective layer, a polymer film, metal foil, etc. can be used. As a polymer film, Polyolefin films, such as a polyethylene film and a polypropylene film; vinyl films such as polyvinyl chloride films; polyester films such as polyethylene terephthalate films; polycarbonate film; Acetylcellulose film; A tetrafluoroethylene film etc. can be illustrated. As metal foil, copper foil, aluminum foil, etc. can be illustrated.

<Method of manufacturing film for sealing>

The film for sealing of this embodiment can be specifically produced as follows.

First, a varnish (varnish-like resin composition) is prepared by mixing constituent components (thermosetting resin, curing agent, curing accelerator, inorganic filler, solvent, etc.) of the resin composition of the present embodiment. The mixing method is not particularly limited, and a mill, mixer, or stirring blade can be used. A solvent (such as an organic solvent) can be used to prepare a varnish by dissolving and dispersing constituents of the resin composition, which is a material of the sealing film, or to assist in preparing the varnish. Most of the solvent can be removed in the drying process after coating.

After the varnish produced in this way is applied to a support (such as a film-like support), a film for sealing can be produced by heating and drying the varnish by hot air spraying or the like. Although it does not specifically limit as an application|coating (coating) method, For example, a coating apparatus, such as a comma coater, a bar coater, a kiss coater, a roll coater, a gravure coater, and a die coater, can be used.

<Encapsulation structure and manufacturing method thereof>

The sealing structure according to the present embodiment includes an encapsulated body and a sealing portion that seals the encapsulated body. The sealing portion is a cured product of the sealing film of the present embodiment, and contains a cured product of the resin composition of the present embodiment. The encapsulation structure may be a hollow encapsulation structure having a hollow structure. The hollow encapsulation structure includes, for example, a substrate, an encapsulation object provided on the substrate, a hollow region formed between the substrate and the encapsulation object, and an encapsulation portion for sealing the encapsulation object. The sealing structure of this embodiment may contain a plurality of objects to be sealed. A plurality of sealed bodies may be of the same type as each other or may be of different types from each other.

The sealing structure is, for example, an electronic component device. An electronic component device contains an electronic component as an object to be sealed. As an electronic component, it is a semiconductor element; semiconductor wafer; integrated circuit; semiconductor devices; filters such as SAW filters; Passive parts, such as a sensor, etc. are mentioned. A semiconductor element obtained by cutting a semiconductor wafer into pieces may be used. An electronic component device includes a semiconductor device including a semiconductor element or a semiconductor wafer as an electronic component; A printed wiring board or the like may be used. When the electronic component device has a hollow structure, that is, when the electronic component device is a hollow encapsulation structure, the encapsulated body is installed on the substrate through bumps so as to have a movable part on the surface on the hollow region side (substrate side), for example. has been As such a sealed body, electronic parts, such as SAW devices, such as a SAW filter, are mentioned, for example. When the encapsulation object is a SAW filter, among the surfaces of the piezoelectric substrate, the surface on the side where electrodes (for example, inter digital transducers (IDTs), which are a pair of comb-shaped electrodes) are mounted, serves as a movable part.

Next, the manufacturing method of the hollow encapsulation structure using the encapsulation film of this embodiment is demonstrated. Here, a case where the hollow encapsulation structure is an electronic component device and the encapsulated object is a SAW device will be described.

2 is a schematic cross-sectional view for explaining one embodiment of a method of manufacturing a semiconductor device which is an electronic component device as an embodiment of a method of manufacturing a hollow encapsulation structure. In the manufacturing method of the present embodiment, first, as an encapsulated body (embedded target), a substrate 30 and a plurality of SAW devices 20 arranged side by side on the substrate 30 via bumps 40 are included. After preparing the hollow structure, the surface of the substrate 30 on the SAW device 20 side and the surface of the film 10 for sealing with a support attached on the side of the film 2 for sealing are opposed (Fig. 2(a) )]. Here, the hollow structure 60 has a hollow region 50, and the SAW device 20 has a movable part on the surface 20a on the hollow region 50 side (substrate 30 side).

Next, the SAW device 20 is embedded in the sealing film 2 by pressing (laminating) the sealing film 2 to the SAW device 20 under heating, and then sealing the SAW device 20 embedded therein. The film 2 is cured to obtain a cured product of the film for sealing (encapsulation portion containing a cured product of a resin composition) 2a (Fig. 2(b)). In this way, the electronic component device 100 can be obtained.

Although it does not specifically limit as a laminator used for lamination, For example, laminator, such as a roll type and a balloon type, is mentioned. From the standpoint of excellent embedding properties, the laminator may be of a balloon type capable of vacuum pressurization.

Lamination is usually performed 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 during lamination differs depending on the size, density, and the like of the encapsulated body to be embedded (e.g., electronic parts such as semiconductor elements). 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.

Curing of the sealing film can be performed under air or under an inert gas, for example. 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, curing of the sealing film proceeds sufficiently, and occurrence of problems can be suppressed. When the curing temperature is 280° C. or less, there is a tendency that occurrence of 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, curing of the sealing film proceeds sufficiently, and better production efficiency is obtained. In addition, the curing conditions may combine a plurality of conditions.

In this embodiment, a plurality of electronic component devices 200 may be obtained by further dividing the electronic component device 100 into pieces using a dicing cutter or the like (Fig. 2(c)).

In the manufacturing method of the hollow encapsulation structure of the present embodiment described above, the hollow region 50 between the substrate 30 and the encapsulated body is formed while ensuring excellent embedding property in the encapsulated body (for example, the SAW device 20). The inflow of the sealing material can be sufficiently suppressed.

In this embodiment, after sealing the SAW device 20 with the film 2 for sealing by the lamination method, the film 2 for sealing 2 is thermally cured, so that the SAW device 20 embedded in the cured product 2a ) is obtained, but the sealing structure may be obtained by compression mold using a compression molding apparatus, or by press molding using a hydraulic press. The temperature (sealing temperature) at the time of sealing the to-be-sealed body with a compression mold and a hydraulic press may be the same as the above-mentioned lamination temperature.

As mentioned above, although the preferable embodiment of this invention was described, this invention is not necessarily limited to the above-mentioned embodiment, You may make a change suitably within the range which does not deviate from the meaning.

[Example]

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

In 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.)

B1: hydrocarbon group-containing phenolic resin (phenolic hydroxyl group equivalent: 140 g/eq., weight average molecular weight: 120,000)

B2: hydrocarbon group-containing phenol resin (phenolic hydroxyl group equivalent: 185 g/eq., weight average molecular weight: 120,000)

B3: hydrocarbon group-containing phenolic resin (phenolic hydroxyl group equivalent: 243 g/eq., weight average molecular weight: 120,000)

B4: hydrocarbon group-containing phenolic resin (phenolic hydroxyl group equivalent: 205 g/eq., weight average molecular weight: 120,000)

B5: novolak-type phenolic resin (manufactured by Maywa Kasei Co., Ltd., trade name "DL-92", phenolic hydroxyl equivalent: 103 g/eq., weight average molecular weight: 50,000)

(curing accelerator)

C1: imidazole (manufactured by Shikoku Kasei Koyo Co., Ltd., trade name "2P4MZ")

(elastomer)

D1: Acrylic acid ester polymer (manufactured by Nagase ChemteX Co., Ltd., trade name "SG-280 EK23", molecular weight: 900,000)

(inorganic filler)

E1: Silica (manufactured by Admatex Co., Ltd., trade name "5 μm SX-E2", phenylaminosilane treatment, average particle diameter: 5.8 μm)

B1 to B4 were prepared by the method described in Japanese Unexamined Patent Publication No. 2015-89949. Specifically, it was prepared by the following method.

(Synthesis Example 1)

First, cardanol, methanol, and 50% formaldehyde aqueous solution were mixed to obtain a mixed solution. Subsequently, 30% sodium hydroxide aqueous solution was added dropwise to the obtained mixture to react, and then sodium hydroxide was neutralized by adding 35% hydrochloric acid to the obtained reaction mixture. Subsequently, after adding phenol to the reaction solution, oxalic acid was further added. Next, after washing the reaction liquid with water, excess phenol was distilled off. As a result, Resin B1 composed of 40 mol% of the structural unit represented by the following formula (5) and 60 mol% of the structural unit represented by the following formula (6) was obtained.

(Synthesis Example 2)

First, 4-tert-butylphenol, methanol, and 50% formaldehyde aqueous solution were mixed to obtain a mixed solution. Subsequently, 30% sodium hydroxide aqueous solution was added dropwise to the obtained mixture to react, and then sodium hydroxide was neutralized by adding 35% hydrochloric acid to the obtained reaction mixture. Subsequently, after adding 4-phenylphenol to the reaction solution, oxalic acid was further added. Next, after washing the reaction solution with water, excess 4-phenylphenol was distilled off. As a result, Resin B2 composed of 50 mol% of the structural unit represented by the following formula (7) and 50 mol% of the structural unit represented by the following formula (8) was obtained.

(Synthesis Example 3)

First, 4-(1,1,3,3-tetramethylbutyl)phenol, methanol, and 50% formaldehyde aqueous solution were mixed to obtain a liquid mixture. Subsequently, a 30% sodium hydroxide aqueous solution was added dropwise to the obtained mixture and reacted. As a result, Resin B3 comprising a structural unit represented by the following formula (9) was obtained.

(Synthesis Example 4)

First, cardanol, methanol, and 50% formaldehyde aqueous solution were mixed to obtain a mixed solution. Subsequently, 30% sodium hydroxide aqueous solution was added dropwise to the obtained mixture to react, and then sodium hydroxide was neutralized by adding 35% hydrochloric acid to the obtained reaction mixture. Then, after adding pentylphenol to the reaction solution, oxalic acid was further added. Next, after washing the reaction liquid with water, excess pentylphenol was distilled off. As a result, Resin B4 composed of 75 mol% of the structural unit represented by the above formula (5) and 25 mol% of the structural unit represented by the following formula (10) was obtained.

<Production of sealing film (film-type epoxy resin composition)>

(Example 1)

To a 0.5 L polyethylene container, A1, B1, D1, and E1 in amounts (parts by mass) shown in Table 1 were added, and stirred with a stirring blade to disperse the inorganic filler E1. Then, C1 of the quantity (mass part) shown in Table 1 was added, and it stirred for another 30 minutes. The resulting mixture was filtered through a nylon #150 mesh (opening: 106 μm), and the filtrate was collected. Thus, a varnish-like epoxy resin composition was obtained. This varnish-like epoxy resin composition was applied onto a PET film using a coater under the following conditions. In this way, a film for sealing having a thickness of 110 μm was produced on the support (PET film).

・Applying head method: comma

·Application and drying speed: 1m/min

Drying conditions (temperature/furnace length): 80℃/1.5m, 100℃/1.5m

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 opposite side of the support in the sealing film. In each of the following evaluations, evaluation was performed after the support and the protective layer were peeled off. The same applies to the following Examples and Comparative Examples.

(Examples 2 to 4 and Comparative Examples 1 to 2)

Examples 2 to 4 and Comparative Example 1 in the same manner as in Example 1, except that the types and blending amounts of the materials used (A1, B1, C1, D1, and E1) were changed as shown in Table 1. -The varnish-like epoxy resin composition of Comparative Example 2 was obtained. Subsequently, in the same manner as in Example 1 except that the varnish-like epoxy resin compositions of Examples 2 to 4 and Comparative Examples 1 to 2 were used instead of the varnish-like epoxy resin of Example 1, Sealing films (thickness: 110 μm) of Examples 2 to 4 and Comparative Examples 1 to 2 were obtained.

<Evaluation method>

The melt viscosity, embeddability and hollow non-filling property of the sealing film, and the elastic modulus after curing and the glass transition temperature of the sealing film were evaluated by the following methods.

(1) Evaluation A: Melt viscosity of sealing film (film type epoxy resin composition)

0.6 g of film for encapsulation was measured and molded into a tablet with a diameter of 2 cm by a compression molding machine. The obtained molding was used as a sample for evaluation, and the melt viscosity of the sealing film was measured under the following conditions. The measurement was performed by raising the temperature from 40°C to 200°C.

Measuring device: Rheometer Product name: ARES-G2 manufactured by TA Instruments Japan Co., Ltd.

Measurement Mode: Dynamic Temperature Ramp

Frequency: 1.0Hz

Temperature range: 40°C to 200°C

Heating rate: 5°C/min

(2) Evaluation B: Embedability and hollow non-fillability at a bag temperature of 70 ° C.

The embeddability and hollow non-filling property of the film for sealing at the sealing temperature of 70 degreeC were evaluated by the following method. First, a substrate (5 cm x 5 cm) in which a through hole (diameter 1 mm) was formed in the center of the main surface was prepared. Subsequently, double-sided tape was attached to a position 2 cm away from the edge of the through hole on one main surface of the substrate, and a glass plate was adhered to the substrate through the double-sided tape. The obtained layered product was placed with the glass plate side facing down, and a sealing film having a 1 cm square size was placed on the surface of the substrate on the opposite side to the glass plate so as to close the through hole. Subsequently, after mounting a 100 g weight on the sealing film, it was heated for 1 hour within a 70°C oven (manufactured by ESPEC Co., Ltd., trade name "SAFETY OVEN SPH-201").

After heating, the presence or absence of resin flowing into the glass plate side from the through hole by melting of the sealing film and the inflow amount (inflow area) of the resin were visually observed, and embeddability and hollow non-filling property were evaluated based on the following criteria.

[Purchasability]

A: The resin reached the glass substrate

B: The resin does not sufficiently reach the glass substrate

[Hollow non-filling]

A: inflow area ≤ 2.5 mm2

B: inflow area ≤5㎟, >2.5㎟

C: inflow area > 5 mm2

(3) Evaluation C: Embedability and hollow non-fillability at a melt viscosity of 7000 Pa s

Based on the measurement results of the melt viscosity of Evaluation A, embedding properties and hollow non-filling properties were evaluated in the same manner as Evaluation B except that the sealing was performed at a temperature at which the melt viscosity of the sealing film was 7000 Pa·s.

(4) Evaluation D: Elastic modulus and glass transition temperature Tg after curing of encapsulation film

Under the following conditions, the sealing films of Examples and Comparative Examples were laminated with copper foil to obtain a copper foil-attached sealing film.

Laminator device: vacuum pressure laminator MVLP-500 manufactured by Meiki Seisakusho

Laminate temperature: 110°C

Laminate pressure: 0.5 MPa

·Vacuum release time: 30 seconds

Laminate time: 40 seconds

The sealing film with copper foil was pasted on a SUS board, and the sealing film was cured under the following conditions to obtain a cured product (cured epoxy resin with copper foil) of the sealing film with copper foil.

Oven: SAFETY OVEN SPH-201 manufactured by Espek Co., Ltd.

・Oven temperature: 140℃

・Time: 120 minutes

After peeling the 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 a test piece. Under the following conditions, the elastic modulus and glass transition temperature of the produced test piece were measured.

・Measurement device: DVE (DVE-V4 manufactured by Rheology Co., Ltd.)

・Measurement temperature: 25 to 300°C

・Temperature increase rate: 5℃/min

When the modulus of elasticity is high, bending and cracking easily occur in the encapsulant structure, so the modulus of elasticity was evaluated according to the following criteria.

A: modulus of elasticity (30 ° C) ≤ 15 GPa

B: modulus of elasticity (30 ° C) > 15 GPa

When the glass transition temperature Tg is low, the thermal reliability of the encapsulation structure deteriorates, so the glass transition temperature was evaluated according to the following criteria.

A: glass transition temperature (° C.) ≥ 100

B: glass transition temperature (° C.) <100

<Evaluation result>

The results are shown in Table 1. And the compounding quantity of each component in Table 1 is a solid content amount (quantity excluding the quantity of a solvent).

[Table 1]

As shown in Table 1, in the examples, embedding property and hollow non-filling property were compatible at a sealing temperature of 70°C. In addition, even when sealing was performed at a temperature at which the melt viscosity was 7000 Pa·s, embedding property and hollow non-filling property were compatible. On the other hand, in Comparative Example 1, the desired embeddability was not obtained at a sealing temperature of 70°C, and the desired hollow non-filling property was not obtained even at a temperature at which the melt viscosity was 7000 Pa·s. In Comparative Example 2, desired hollow non-filling properties were not obtained either in Evaluation A (encapsulation temperature: 70°C) or Evaluation B (melt viscosity: 7000 Pa·s).

1: support
2: film for encapsulation
2a: Cured product of sealing film (encapsulation part)
10: Encapsulation film with support attached
20: SAW device (encapsulated body)
30: Substrate
40 : bump
50: hollow area
60: hollow structure
100, 200: hollow encapsulation structure (encapsulation structure)

Claims (12)

It consists of a resin composition containing a thermosetting resin having a structural unit represented by the following formula (1) and an inorganic filler,
The resin composition further contains an epoxy resin,
Encapsulation film used to encapsulate an encapsulated body installed on a substrate through bumps:

[In Formula (1), X ¹ represents a hydroxyl group and R ¹ represents a hydrocarbon group having 2 to 25 carbon atoms]. According to claim 1,
The thermosetting resin further comprises a structural unit represented by the following formula (2), a film for sealing:

[In Formula (2), X ² represents a reactive functional group, and R ² represents a hydrogen atom or a phenyl group]. According to claim 1 or 2,
The content of the structural unit represented by the formula (1) in the thermosetting resin is 20 mol% or more based on the total amount of structural units constituting the thermosetting resin. According to claim 1 or 2,
The weight average molecular weight of the thermosetting resin is 500 or more, the film for sealing. According to claim 1 or 2,
A film for sealing having a film thickness of 20 to 250 µm. Preparing a hollow structure comprising a substrate and an encapsulated body installed on the substrate through bumps, wherein a hollow region is formed between the substrate and the encapsulated body;
Sealing the to-be-enclosed body with the sealing film according to claim 1 or 2,
A method for manufacturing an encapsulation structure. According to claim 6,
The method of manufacturing an encapsulation structure, wherein the encapsulated body is a SAW device having an electrode on the side of the hollow region. A substrate, an encapsulated body installed on the substrate through bumps, and a cured product of the sealing film according to claim 1 or 2 for sealing the encapsulated body,
A hollow region is formed between the substrate and the encapsulated body,
encapsulation structure. According to claim 8,
The encapsulated body is a SAW device having an electrode on the side of the hollow region. delete delete delete

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