JP7115520B2 - Sealing film and sealing structure - Google Patents

Description

TECHNICAL FIELD The present invention relates to a resin composition, a cured product, a sealing film and a sealing structure.

As electronic devices become lighter, thinner, and smaller, electronic component devices (semiconductor devices, etc.) are becoming smaller and thinner. A form using a semiconductor device of approximately the same size as a semiconductor element (semiconductor chip such as a silicon chip), or a mounting form (package-on-package) in which a semiconductor device is stacked on top of a semiconductor device, are widely used. From now on, it is expected that electronic component devices will be further miniaturized and thinned.

As the miniaturization of semiconductor elements progresses and the number of terminals increases, it becomes difficult to provide all the external connection terminals (terminals for external connection) on the semiconductor element. For example, if external connection terminals are provided forcibly, the pitch between the terminals becomes narrower and the height of the terminals becomes lower, making it difficult to ensure connection reliability after the semiconductor device is mounted. Therefore, many new mounting methods have been proposed in order to reduce the size and thickness of electronic component devices.

For example, semiconductor elements produced by singulating a semiconductor wafer are rearranged so as to have appropriate intervals, and then the semiconductor elements are sealed using a solid or liquid resin (sealing resin) to obtain a semiconductor element. A mounting method capable of providing an external connection terminal on a sealing portion that seals a semiconductor element on the outside of the semiconductor device, and a semiconductor device manufactured using the method have been proposed (for example, Patent Documents 1 to 3 below. reference).

Japanese Patent No. 3616615 Japanese Patent Application Laid-Open No. 2001-244372 JP-A-2001-127095

However, when the thermal conductivity of the sealing portion (cured product of the sealing resin) that seals the object to be sealed is low, heat dissipation is poor. Therefore, low thermal conductivity causes deterioration of the device, ignition of the device, and the like. In this case, it is conceivable that the thickness of the sealing portion (sealing thickness) on the object to be sealed is reduced to improve heat dissipation. However, in a package form such as PoP (Package on Package), for example, stacking the CPU and memory, which are normally mounted separately, has the advantage of reducing the mounting area. As a result, there is a concern that heat dissipation is likely to deteriorate. Therefore, there is a limit to improving heat dissipation by reducing the thickness of the sealing portion.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a resin composition capable of obtaining a cured product having excellent thermal conductivity, and a cured product thereof. Another object of the present invention is to provide a sealing film and a sealing structure using the resin composition.

The thermal conductivity of a cured product of a conventional encapsulating resin composition (such as a film-like epoxy resin composition) is about 1.2 W/m·K. In contrast, the present inventors obtained a cured product having excellent thermal conductivity by using a resin composition containing a thermosetting component and a specific amount of an inorganic filler containing aluminum oxide. The inventors have found that it is possible to achieve the present invention.

The resin composition according to the present invention is a resin composition containing a thermosetting component and an inorganic filler, wherein the inorganic filler contains aluminum oxide, and the content of the inorganic filler is the total mass of the resin composition It is 72% by mass or more based on (excluding the mass of the solvent).

According to the resin composition according to the present invention, it is possible to obtain a cured product having excellent thermal conductivity. A cured product having a thermal conductivity of m·K or more can be obtained. If the thermal conductivity of the cured product of the encapsulating resin composition can be improved, the heat dissipation of an electronic component device (semiconductor device, etc.) provided with a sealing portion containing the cured product of the resin composition can be improved. progress of deterioration, ignition of the device, etc. can be suppressed. In particular, according to the resin composition according to the present invention, it is possible to improve heat dissipation, which is a problem in thicker package forms (such as PoP). According to the resin composition of the present invention, it is possible to obtain a cured product having excellent thermal conductivity while ensuring the embedding properties of the resin composition.

The thermosetting component may contain a thermosetting resin. The thermosetting resin preferably contains an epoxy resin.

The thermosetting component may further contain a curing agent. The curing agent preferably contains a phenolic resin.

The thermosetting component may further contain a curing accelerator. The curing accelerator preferably contains an imidazole compound.

The content of the epoxy resin that is liquid at 25° C. is preferably 5% by mass or more, more preferably 7% by mass or more, based on the total mass of the resin composition (excluding the mass of the solvent).

The content of the inorganic filler is preferably 93% by mass or less, more preferably 85% by mass or less, based on the total mass of the resin composition (excluding the mass of the solvent).

The average particle size of the inorganic filler is preferably 0.01 to 25 μm, more preferably 0.01 to 10 μm.

The content of aluminum oxide in the inorganic filler is preferably 50% by mass or more.

The resin composition according to the present invention may further contain a solvent.

A cured product according to the present invention is a cured product of the resin composition according to the present invention.

By the way, sealing of electronic components such as semiconductor elements (sealing step in packaging method) is usually performed in the final stages of manufacturing electronic component devices such as semiconductor devices. In the mounting method in this case, a step of forming wiring for arranging the external connection terminals and the external connection terminals on the sealing structure (sealed molding) produced by sealing the electronic component is performed. be implemented.

In a conventional mounting method, a plurality of electronic component devices (semiconductor devices, etc.) may be obtained by dicing a sealing structure obtained by sealing a plurality of electronic components (semiconductor elements, etc.). In this case, the more electronic components that are rearranged, the more electronic component devices that can be manufactured in one process. Therefore, studies are being conducted to increase the size of the sealing structure. At present, for example, since a semiconductor manufacturing apparatus is used for wiring formation, the sealing structure is formed in a wafer shape, and there is a tendency for the diameter of the wafer shape to increase. Furthermore, panelization of the sealing structure is also being studied so that a printed wiring board manufacturing apparatus, etc., which can be made larger and which is less expensive than a semiconductor manufacturing apparatus, can be used.

For sealing electronic components, there are cases where molding is used in which a solid or liquid resin sealing material is molded with a mold. For example, transfer molding may be used in which a pellet-shaped resin sealing material is melted and the resin is poured into a mold for sealing. However, in transfer molding, a melted resin is poured into the mold to form the mold, so when sealing a large area, there is a possibility that an unfilled portion may occur. Therefore, in recent years, compression molding, in which molding is performed after supplying a resin sealing material to a mold or an object to be sealed in advance, has begun to be used. In compression molding, since the resin sealing material is directly supplied to the mold or the object to be sealed, there is an advantage that unfilled portions are less likely to occur even when sealing a large area.

Similar to transfer molding, compression molding uses a solid or liquid resin sealing material. However, when the object to be sealed becomes large, the liquid resin sealing material may cause liquid flow or the like, making it difficult to uniformly supply it onto the object to be sealed. In addition, since it is necessary to uniformly supply the resin onto the object to be sealed, as the solid resin sealing material, granules or powder resin sealing material is used instead of the conventional pellet-shaped resin. Sometimes. However, when the resin sealing material is in the form of granules or powder, it is difficult to uniformly supply the resin sealing material onto a mold or an object to be sealed. It becomes a source of dust, and there is concern about contamination of equipment or clean rooms.

Further, in molding, resin is molded in a mold, and therefore, in order to increase the size of the sealing structure, it is essential to increase the size of the mold. However, increasing the size of the mold requires high mold precision, which increases technical difficulty and greatly increases the manufacturing cost of the mold.

On the other hand, the resin composition according to the present invention may be in the form of a film as a sealing film for sealing an object to be sealed. The sealing film according to the present invention contains the resin composition according to the present invention. In this case, it is possible to uniformly supply the resin onto the object to be sealed and to reduce dust generation. In addition, it is possible to obtain an embedding ability that enables sealing not only by molding, but also by a molding method (laminating, pressing, etc.) that does not require a mold (high-pressure mold, etc.).

The solvent content in the sealing film according to the present invention is preferably 0.2 to 1.5% by mass. The minimum melt viscosity of a film-like resin composition, which is important for embedding an object to be sealed (for example, an electronic component such as a semiconductor element), decreases as the content of the solvent (organic solvent, etc.) increases. This is probably because the solvent enhances the fluidity of the film-like resin composition. In addition, an appropriate amount of the solvent imparts stickiness to the film-like resin composition, making it easy to prevent peeling from the film-like support and cracking of the film-like resin composition itself. These effects tend to be maximized without causing other problems when the solvent content is 0.2 to 1.5% by mass.

The thickness of the sealing film according to the present invention is preferably 20-250 μm.

A sealing structure according to the present invention includes an object to be sealed and a sealing portion that seals the object to be sealed, and the sealing portion contains a cured product of the resin composition according to the present invention. include. The object to be sealed may be an electronic component.

ADVANTAGE OF THE INVENTION According to this invention, the resin composition which can obtain the hardened|cured material which has the outstanding thermal conductivity, and its hardened|cured material can be provided. Moreover, according to this invention, the film for sealing and the sealing structure which used the said resin composition can be provided.

It is a schematic cross section for describing one embodiment of the manufacturing method of a sealing structure. FIG. 3 is a diagram showing an example of arrangement of silicon chips used for evaluating embeddability in Examples.

In this specification, a numerical range indicated using "to" indicates a range including the numerical values before and after "to" as the minimum and maximum values, respectively. In the numerical ranges described stepwise in this specification, the upper limit value or lower limit value of the numerical range at one step may be replaced with the upper limit value or lower limit value of the numerical range at another step. In the numerical ranges described herein, the upper or lower limits of the numerical ranges may be replaced with the values shown in the examples. "A or B" may include either A or B, or may include both. 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 is the sum of the multiple substances present in the composition when there are multiple substances corresponding to each component in the composition, unless otherwise specified. means quantity.

A "liquid epoxy resin" is an epoxy resin that is liquid at 25°C. “Liquid at 25° C.” means that the viscosity at 25° C. measured with an E-type viscometer is 400 Pa·s or less.

An embodiment of the present invention will be described below.

<Resin composition and cured product>
The resin composition according to this embodiment is a resin composition containing a thermosetting component and an inorganic filler. Examples of thermosetting components include (A) thermosetting resins (excluding compounds corresponding to curing agents), (B) curing agents, and (C) curing accelerators. The thermosetting component may contain thermosetting resins without curing agents and/or curing accelerators. The resin composition according to the present embodiment contains (D) an inorganic filler in addition to the thermosetting component, and the (D) inorganic filler contains aluminum oxide. The resin composition according to this embodiment may be in the form of a varnish or in the form of a film (sealing film). The cured product according to this embodiment is a cured product of the resin composition according to this embodiment.

(Thermosetting component)
[(A) component: thermosetting resin]
Thermosetting resins include epoxy resins, phenoxy resins, cyanate resins, thermosetting polyimides, melamine resins, urea resins, unsaturated polyesters, alkyd resins, polyurethanes, and the like. As the thermosetting resin, an epoxy resin is preferable from the viewpoint of easily obtaining a cured product having excellent thermal conductivity. As the epoxy resin, at least one selected from the group consisting of an epoxy resin that is liquid at 25°C and an epoxy resin that is not liquid at 25°C can be used.

Epoxy resins can be used without particular limitation as long as they are resins having two or more glycidyl groups in one molecule. Examples of epoxy resins include bisphenol A type epoxy resin, bisphenol AP type epoxy resin, bisphenol AF type epoxy resin, bisphenol B type epoxy resin, bisphenol BP type epoxy resin, bisphenol 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 novolak-type epoxy resin (ortho-cresol novolac-type epoxy resin, etc.), biphenyl-type epoxy resin, naphthalene-type epoxy resin, dicyclopentadiene-type epoxy resin, bixylenol-type epoxy resin (bixylenol diglycidyl ether etc.), hydrogenated bisphenol A epoxy resins (hydrogenated bisphenol A glycidyl ether, etc.), dibasic acid-modified diglycidyl ether epoxy resins of these resins, and aliphatic epoxy resins. Epoxy resins may be used alone or in combination of two or more.

Liquid epoxy resins include bisphenol A type glycidyl ether, bisphenol AD type glycidyl ether, bisphenol S type glycidyl ether, bisphenol F type glycidyl ether, hydrogenated bisphenol A type glycidyl ether, and ethylene oxide adduct bisphenol A type glycidyl ether. Glycidyl ether, glycidyl ether of propylene oxide adduct bisphenol A type, glycidyl ether of naphthalene resin, trifunctional or tetrafunctional glycidylamine, and the like.

Commercially available epoxy resins include "EXA-4700" (tetrafunctional naphthalene epoxy resin), "Epiclon HP-4032" and "EXA-4750" (naphthalene skeleton-containing polyfunctional solid epoxy resin) manufactured by DIC Corporation, Japan. Naphthalene-type epoxy resin such as "NC-7000" (naphthalene skeleton-containing polyfunctional solid epoxy resin) manufactured by Kayaku Co., Ltd.; phenol such as "EPPN-502H" (trisphenol epoxy resin) manufactured by Nippon Kayaku Co., Ltd. and epoxidized products of condensates of aromatic aldehydes having phenolic hydroxyl groups (trisphenol-type epoxy resins); "Epiclon HP-7200H" (dicyclopentadiene skeleton-containing polyfunctional solid epoxy resin) manufactured by DIC Corporation, etc. Dicyclopentadiene aralkyl type epoxy resin; Biphenyl aralkyl type epoxy resin such as "NC-3000H" (biphenyl skeleton-containing polyfunctional solid epoxy resin) manufactured by Nippon Kayaku Co., Ltd.; "Epiclon N-660" manufactured by DIC Corporation , "Epiclon N-690", "Epiclon N-740" (phenol novolac type epoxy resin) and "N500P-1" (ortho cresol novolac type epoxy resin), Nippon Kayaku Co., Ltd. "EOCN-104S" etc. Novolac type epoxy resin; tris (2,3-epoxypropyl) isocyanurate such as "TEPIC" manufactured by Nissan Chemical Industries, Ltd.; 4816" and "Epiclon EXA-4822", "Araldite AER280" manufactured by Asahi Chiba Co., Ltd., "Epotote YD-134", "YD-8125" and "YDF8170" manufactured by Tohto Kasei Co., Ltd. (Nippon Steel & Sumikin Chemical Co., Ltd.) , Japan Epoxy Resin Co., Ltd. (Mitsubishi Chemical Co., Ltd.) "jER834", "jER872", "jER807", "jER815", "jER825", "jER827", "jER828", "jER1001", "jER1004", Bisphenol A type epoxy resins such as "jER1007" and "jER1009", "ELA-134" manufactured by Sumitomo Chemical Co., Ltd., "DER-330" manufactured by Dow Chemical Co., "DER-301" and "DER-361"; Bisphenol F type epoxy resin such as "jER806" manufactured by Japan Epoxy Resin Co., Ltd. (Mitsubishi Chemical Corporation); manufactured by Nagase ChemteX Corporation and aliphatic epoxy resins such as "Nadecol DLC301". These epoxy resins may be used individually by 1 type, and may use 2 or more types together.

The content of the thermosetting resin is preferably 1% by mass or more, more preferably 3% by mass or more, based on the total mass of the resin composition (excluding the mass of the solvent) from the viewpoint of easily obtaining excellent fluidity. Preferably, 4% by mass or more is more preferable, 4% by mass or more is particularly preferable, 5% by mass or more is extremely preferable, 10% by mass or more is very preferable, and 15% by mass or more is even more preferable. The content of the thermosetting resin is preferably 30% by mass or less, and 25% by mass, based on the total mass of the resin composition (excluding the mass of the solvent), from the viewpoint of easily suppressing the occurrence of cracks and cracks on the film surface. % or less is more preferable, and 20% by mass or less is even more preferable.

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. , is preferably 50% by mass or more, more preferably 80% by mass or more, and even more preferably 90% by mass or more. The content of the epoxy resin may be 100% by weight based on the total weight of the thermosetting resin.

The content of the liquid epoxy resin is preferably 0.5% by mass or more based on the total mass of the resin composition (excluding the mass of the solvent) from the viewpoint of easily suppressing the occurrence of cracks and cracks on the film surface. More preferably, it is at least 3% by mass, more preferably at least 3% by mass, particularly preferably at least 5% by mass, extremely preferably at least 7% by mass, and very preferably at least 9% by mass. The content of the liquid epoxy resin is based on the total mass of the resin composition (excluding the mass of the solvent) from the viewpoint of easily suppressing an excessive increase in the tackiness of the film and from the viewpoint of easily suppressing edge fusion. , is preferably 20% by mass or less, more preferably 15% by mass or less, and even more preferably 13% by mass or less.

The content of the liquid epoxy resin is preferably 20% by mass or more, more preferably 30% 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. % or more by mass is more preferable. 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 excessive increase in tackiness of the film and from the viewpoint of easily suppressing edge fusion. It is preferably 90% by mass or less, more preferably 80% by mass or less. The content of the liquid epoxy resin may be 100% by weight based on the total weight of the thermosetting resin.

When the resin composition contains component (A) (epoxy resin, etc.), component (B), component (C) and component (D), the content of the liquid epoxy resin is such that cracks and cracks do not occur on the film surface. From the viewpoint of easy suppression, it is preferably 0.5% by mass or more, more preferably 1% by mass or more, still more preferably 3% by mass or more, and 5% by mass or more, based on the total mass of components (A) to (D). is particularly preferred, 7% by weight or more is very preferred, and 9% by weight or more is very preferred. The content of the liquid epoxy resin is 20 based on the total mass of the components (A) to (D) from the viewpoint of easily suppressing excessive increase in tackiness of the film and from the viewpoint of easily suppressing edge fusion. % by mass or less is preferable, 15% by mass or less is more preferable, and 13% by mass or less is even more preferable.

[(B) component: curing agent]
Examples of the curing agent include, but are not limited to, phenol-based curing agents (phenol resins, etc.), acid anhydride-based curing agents, active ester-based curing agents, cyanate ester-based curing agents, and the like. When the component (A) contains an epoxy resin, the curing agent (B) may be any compound having two or more functional groups that react with glycidyl groups in one molecule without any particular limitation. 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. Curing agents may be used alone or in combination of two or more.

As the phenol resin, any known phenol resin can be used without particular limitation as long as it is a resin having two or more phenolic hydroxyl groups in one molecule. Phenolic resins include resins obtained by condensing or co-condensing phenols and/or naphthols and aldehydes in the presence of an acidic catalyst, biphenyl skeleton-type phenolic resins, paraxylylene-modified phenolic resins, metaxylylene/paraxylylene-modified phenolic resins, and melamine. Examples include modified phenol resins, terpene-modified phenol resins, dicyclopentadiene-modified phenol resins, cyclopentadiene-modified phenol resins, polycyclic aromatic ring-modified phenol resins, and xylylene-modified naphthol resins. Phenols include phenol, cresol, xylenol, resorcinol, catechol, bisphenol A, bisphenol F and the like. Naphthols include α-naphthol, β-naphthol, dihydroxynaphthalene and the like. Aldehydes include formaldehyde, acetaldehyde, propionaldehyde, benzaldehyde, salicylaldehyde and the like.

Commercially available phenolic resins include "Phenolite LF2882", "Phenolite LF2822", "Phenolite TD-2090", "Phenolite TD-2149", "Phenolite VH-4150" and "Phenolite VH-4150" manufactured by DIC Corporation. Light VH4170”, “XLC-LL” and “XLC-4L” manufactured by Mitsui Chemicals Co., Ltd., “SN-100”, “SN-300”, “SN-395” and “SN-” manufactured by Nippon Steel & Sumikin Chemical Co., Ltd. 400”, “SK Resin HE910” manufactured by Air Water Co., Ltd., “PAPS-PN2” (molecular weight distribution-intensive novolac resin) manufactured by Asahi Organic Chemicals Industry Co., Ltd., “ELP40” manufactured by Gun Ei Chemical Industry Co., Ltd., etc. are mentioned.

The content of the curing agent is preferably 1 to 20% by mass, preferably 2 to 15% by mass, based on the total mass of the resin composition (excluding the mass of the solvent) from the viewpoint of excellent curability of the thermosetting resin. More preferably, 3 to 10% by mass is even more preferable.

The blending ratio of the epoxy resin and the curing agent (phenolic resin, etc.) is the equivalent of the glycidyl group in the epoxy resin (epoxy equivalent) and the equivalent of the functional group (phenolic hydroxyl group, etc.) that reacts with the glycidyl group in the curing agent (phenolic The ratio (equivalent of the glycidyl group in the epoxy resin/equivalent of the functional group that reacts with the glycidyl group in the curing agent) is preferably 0.7 to 2.0, more preferably 0.8 to 1.8. Preferably, 0.9 to 1.7 is more preferable. When the ratio is 0.7 or more or 2.0 or less, unreacted epoxy resin and/or unreacted curing agent are less likely to remain, and desired cured product properties are likely to be obtained.

[(C) component: curing accelerator]
The curing accelerator may be used without any particular limitation, but is preferably at least one selected from the group consisting of amine-based curing accelerators and phosphorus-based curing accelerators. As the curing accelerator, an amine-based curing accelerator is used from the viewpoint that a cured product having excellent thermal conductivity can be easily obtained, the derivative is abundant, and the desired activation temperature can be easily obtained. Preferably, at least one selected from the group consisting of imidazole compounds, aliphatic amines and alicyclic amines is more preferable, and imidazole compounds are even more preferable. Examples of imidazole compounds include 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole and the like. 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 within the following ranges based on the total amount of the thermosetting resin (epoxy resin, etc.) and the curing agent (phenol resin, etc.). The content of the curing accelerator is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and even more preferably 0.3% by mass or more, from the viewpoint of easily obtaining a sufficient curing acceleration effect. The content of the curing accelerator is such that curing does not progress easily during the steps of manufacturing the sealing film (for example, coating and drying) or during storage of the sealing film, and cracking of the sealing film, And, from the viewpoint of easily preventing molding defects due to an increase in melt viscosity, it is preferably 5% by mass or less, more preferably 3% by mass or less, and even more preferably 1.5% by mass or less. From these points of view, the content of the curing accelerator is preferably 0.01 to 5% by mass, more preferably 0.1 to 3% by mass, even more preferably 0.3 to 1.5% by mass.

((D) component: inorganic filler)
Inorganic fillers include aluminum oxide (such as aluminum oxide particles). Commercially available inorganic fillers containing aluminum oxide include “AA-1.5” manufactured by Sumitomo Chemical Co., Ltd., “DAW20” manufactured by Denka Co., Ltd., and the like.

The inorganic filler may contain constituent materials other than aluminum oxide (such as aluminum oxide particles). That is, the resin composition according to the present embodiment may contain particles containing aluminum oxide and constituent materials other than aluminum oxide, and contains aluminum oxide particles and particles containing components other than aluminum oxide. You may have

The content of aluminum oxide in the inorganic filler is preferably 50% by mass or more, more preferably 70% by mass or more, more preferably 80% by mass, based on the total mass of the inorganic filler, from the viewpoint of further improving the effect of improving thermal conductivity. % or more is more preferable, and 90% by mass or more is particularly preferable. The content of aluminum oxide may be 100% by weight based on the total weight of the inorganic filler.

As a constituent material other than aluminum oxide, constituent materials contained in conventionally known inorganic fillers can be used, and there is no particular limitation. Constituent materials other than aluminum oxide include barium sulfate, barium titanate, silica, talc, clay, magnesium carbonate, calcium carbonate, aluminum hydroxide, silicon nitride, and aluminum nitride. Inorganic fillers containing silica include amorphous silica, crystalline silica, fused silica, and spherical silica. Constituent materials other than aluminum oxide should have a relatively small coefficient of thermal expansion, from the viewpoint that it is easy to obtain the effect of improving dispersibility in resin and the effect of suppressing sedimentation in varnish by surface modification etc. Silica is preferable from the viewpoint that the desired cured product properties are easily obtained from. Examples of commercially available inorganic fillers containing silica include "SC2500-SXJ", "SC5500-SXE" and "SC2050-KC" manufactured by Admatechs Co., Ltd. Constituent materials other than aluminum oxide may be used alone or in combination of two or more.

The inorganic filler may be surface-modified. The method of surface modification is not particularly limited. Surface modification using a silane coupling agent is preferable from the viewpoints of simple treatment, abundant types of functional groups, and ease of imparting desired properties.

Silane coupling agents include alkylsilanes, alkoxysilanes, vinylsilanes, epoxysilanes, aminosilanes, acrylsilanes, methacrylsilanes, mercaptosilanes, sulfidesilanes, isocyanatesilanes, sulfursilanes, styrylsilanes, and alkylchlorosilanes.

Specific examples of silane coupling agents 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, n-octyldimethylchlorosilane, tetraethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-(2- aminoethyl)aminopropyltrimethoxysilane, 3-(2-aminoethyl)aminopropylmethyldimethoxysilane, 3-phenylaminopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane silane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, bis(3-(triethoxysilyl)propyl)disulfide, bis(3-(triethoxysilyl)propyl)tetrasulfide, vinyltriacetoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriisopropoxysilane, allyltrimethoxysilane, diallyldimethylsilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3- methacryloxypropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltriethoxysilane, N-(1,3-dimethylbutylidene)-3-aminopropyltriethoxysilane , aminosilane (phenylaminosilane, etc.), and the like. Silane coupling agents may be used alone or in combination of two or more.

The average particle size of the inorganic filler is preferably 0.01 μm or more, more preferably 0.1 μm or more, and 0.3 μm or more, from the viewpoint of easily suppressing aggregation of the inorganic filler and facilitating dispersion of the inorganic filler. is more preferable, and 0.5 μm or more is particularly preferable. The average particle size of the inorganic filler is preferably 25 μm or less, more preferably 10 μm or less, and 5 μm or less from the viewpoint of easily suppressing sedimentation of the inorganic filler in the varnish and facilitating the production of a homogeneous sealing film. is more preferred. 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. 0.5 to 5 μm is highly preferred. The average particle size of the inorganic filler may be 10-18 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 sizes. Among combinations of inorganic fillers, it is preferable that the largest average particle size is 15 to 25 μm. A combination of an inorganic filler with an average particle size of 15 to 25 μm, an inorganic filler with an average particle size of 0.5 to 2.5 μm, and an inorganic filler with an average particle size of 0.1 to 1.0 μm It is preferable to use

"Average particle size" is the particle size at the point corresponding to 50% volume when the cumulative frequency distribution curve by 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 size of each inorganic filler combined can be confirmed from the average particle size of each inorganic filler at the time of mixing, and can be confirmed by measuring the particle size distribution.

The content of the inorganic filler (the total amount of the inorganic filler containing aluminum oxide and the inorganic filler not containing aluminum oxide) is determined from the viewpoint of improving the thermal conductivity and the coefficient of thermal expansion with the object to be sealed. 72% by mass based on the total mass of the resin composition (excluding the mass of the solvent) from the viewpoint that the warping of the sealing structure (e.g., electronic component device such as a semiconductor device) is likely to be suppressed due to the difference in That's it. The content of the inorganic filler is the total mass of the resin composition (excluding the mass of the solvent) from the viewpoint of further improving the thermal conductivity and from the viewpoint of further suppressing the increase in warping of the sealing structure. is preferably 72.5% by mass or more, more preferably 73% by mass or more. The content of the inorganic filler is from the viewpoint that the sealing film is easily suppressed from cracking in the drying process during the production of the sealing film, and the fluidity is improved due to the increase in the melt viscosity of the sealing film. From the viewpoint of suppressing the decrease and making it easy to sufficiently seal the object to be sealed (electronic component, etc.), it is preferably 93% by mass or less based on the total mass of the resin composition (excluding the mass of the solvent). 90% by mass or less is more preferable, 85% by mass or less is even more preferable, 84.5% by mass or less is particularly preferable, 81% by mass or less is extremely preferable, and 80% by mass or less is extremely preferable. From these points of view, the content of the inorganic filler is preferably 72 to 93% by mass, more preferably 72 to 90% by mass, based on the total mass of the resin composition (excluding the mass of the solvent), and 72 to 85% by mass. % by weight is more preferred, 72 to 84.5% by weight is particularly preferred, 72.5 to 81% by weight is very preferred, and 73 to 80% by weight is very preferred.

The content of the inorganic filler containing aluminum oxide (aluminum oxide particles, etc.) is preferably within the following range based on the total mass of the resin composition (excluding the mass of the solvent). From the viewpoint of further improving thermal conductivity, the content of the inorganic filler containing aluminum oxide is preferably 50% by mass or more, more preferably 60% by mass or more, and even more preferably 70% by mass or more. The content of the inorganic filler containing aluminum oxide is preferably 85% by mass or less, more preferably 80% by mass or less, and even more preferably 75% by mass or less, from the viewpoint of easily ensuring sufficient embeddability.

((E) component: solvent)
The resin composition according to the present embodiment may contain (E) a solvent, or may not contain (E) a solvent. Conventionally known organic solvents can be used as the solvent. The organic solvent is preferably a 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. be done. A solvent may be used individually by 1 type, and may use 2 or more types together.

The solvent is selected from the group consisting of esters, ketones, and alcohols from the viewpoint of low environmental load and the viewpoint of easily dissolving thermosetting resins (epoxy resins, etc.) and curing agents (phenolic resins, etc.). At least one is preferred. Among these, ketones are preferable from the viewpoint of particularly easy dissolution of thermosetting resins (epoxy resins, etc.) and curing agents (phenolic resins, etc.). As the solvent, at least one selected from the group consisting of acetone, methyl ethyl ketone and methyl isobutyl ketone is preferable from the viewpoint of less volatilization at room temperature (25° C.) and easy removal during drying.

((F) component: elastomer)
The resin composition according to the present embodiment may optionally contain (F) an elastomer (flexible agent). From the viewpoint of excellent dispersibility and solubility, it is preferable to use at least one elastomer selected from the group consisting of polybutadiene particles, styrene-butadiene particles, acrylic elastomers, silicone powders, silicone oils and silicone oligomers. One type of elastomer may be used alone, or two or more types may be used in combination.

When the elastomer is particulate, there is no particular limitation on the average particle size of the elastomer. In eWLB (Embedded Wafer-Level Ball Grid Array) applications, it is necessary to embed between semiconductor elements. Therefore, when the sealing film is used for eWLB applications, the average particle size of the elastomer should be 50 μm or less. preferable. The average particle size of the elastomer is preferably 0.1 μm or more from the viewpoint of excellent dispersibility of the elastomer.

Commercially available elastomers include "HTR280" manufactured by Nagase ChemteX Corporation. Moreover, some commercially available elastomer components are dispersed in a liquid resin (for example, a liquid epoxy resin) in advance instead of an elastomer alone, but they can be used without any problem. Such commercially available products include “MX-136” and “MX-965” manufactured by Kaneka Corporation.

(other ingredients)
The resin composition according to this embodiment can further contain other additives. Specific examples of such additives include pigments, dyes, release agents, antioxidants, surface tension modifiers, and the like.

<Film for sealing>
The sealing film according to this embodiment contains the resin composition according to this embodiment. The sealing film according to the present embodiment may be obtained by molding the resin composition according to the present embodiment into a film, and may be made of the resin composition according to the present embodiment. The encapsulating film according to the present embodiment can be used, for example, for encapsulating semiconductor devices, embedding electronic components arranged on printed wiring boards, and the like.

The thickness (film thickness) of the sealing film is preferably 20 μm or more, more preferably 30 μm or more, still more preferably 50 μm or more, and 100 μm or more, from the viewpoint of easily suppressing in-plane thickness variation during coating. Especially preferred. The thickness of the sealing film is preferably 250 µm or less, more preferably 200 µm or less, and even more preferably 150 µm or less, from the viewpoint of easily obtaining a constant drying property in the depth direction during coating. From these viewpoints, the thickness of the sealing film is preferably 20 to 250 μm, more preferably 30 to 250 μm, still more preferably 50 to 200 μm, and particularly preferably 100 to 150 μm. Also, a sealing film having a thickness exceeding 250 μm can be manufactured by laminating a plurality of sealing films.

The content of the inorganic filler in the sealing film (the total amount of the inorganic filler containing aluminum oxide and the inorganic filler not containing aluminum oxide) is the total weight of the sealing film (excluding the weight of the solvent) is preferably within the following range. The content of the inorganic filler is preferably 72% by mass or more, more preferably 72.5% by mass or more, from the viewpoint of further improving the thermal conductivity and from the viewpoint of easily suppressing the increase in warpage of the sealing structure. More preferably, 73% by mass or more is even more preferable. The content of the inorganic filler is 93% by mass from the viewpoint of suppressing the decrease in fluidity due to the increase in the melt viscosity of the sealing film and making it easy to sufficiently seal the object to be sealed (electronic parts, etc.). The following is preferable, 90% by mass or less is more preferable, 85% by mass or less is even more preferable, 84.5% by mass or less is particularly preferable, 81% by mass or less is extremely preferable, and 80% by mass or less is extremely preferable. From these viewpoints, the content of the inorganic filler is preferably 72 to 93% by mass, more preferably 72 to 90% by mass, still more preferably 72 to 85% by mass, particularly preferably 72 to 84.5% by mass, 72.5 to 81% by weight are highly preferred, and 73 to 80% by weight are very preferred.

The content of the solvent (organic solvent, etc.) contained in the sealing film is preferably within the following range with respect to the total mass of the sealing film (including the mass of the solvent). The content of the solvent is 0.5 from the viewpoint of easily suppressing problems such as cracking of the sealing film due to fragility of the sealing film, and increasing the minimum melt viscosity and reducing the embedding property. 2 mass % or more is preferable, 0.3 mass % or more is more preferable, 0.5 mass % or more is still more preferable, 0.6 mass % or more is particularly preferable, and 0.7 mass % or more is extremely preferable. The content of the solvent is such that the adhesiveness of the sealing film becomes too strong, resulting in poor handling, and problems such as foaming due to volatilization of the solvent (organic solvent, etc.) during the heat curing of the sealing film. is preferably 1.5% by mass or less, more preferably 1% by mass or less, from the viewpoint of easily suppressing the From these viewpoints, the solvent content is preferably 0.2 to 1.5% by mass, more preferably 0.3 to 1% by mass, even more preferably 0.5 to 1% by mass, and 0.6 to 1% by mass. % by weight is particularly preferred, 0.7 to 1% by weight being very particularly preferred.

Specifically, the sealing film according to this embodiment can be produced as follows.

First, the constituent components of the resin composition according to the present embodiment ((A) thermosetting resin, (B) curing agent, (C) curing accelerator, (D) inorganic filler, (E) solvent, etc.) are mixed. By doing so, a varnish (varnish-like resin composition) is produced. A 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 dissolve and disperse the components of the resin composition that is the material of the sealing film to prepare a varnish, or to assist in the preparation of the varnish. . Most of the solvent can be removed in a drying step after coating.

A film for sealing can be produced by coating the varnish thus produced on a support (such as a film-like support) and drying it by heating with hot air blowing or the like. The application (coating) method is not particularly limited, and for example, a coating device such as a comma coater, bar coater, kiss coater, roll coater, gravure coater, and die coater can be used.

A polymer film, a metal foil, or the like can be used as the film-like support. Polymer films include polyolefin films such as polyethylene films and polypropylene films; vinyl films such as polyvinyl chloride films; polyester films such as polyethylene terephthalate films; polycarbonate films; Examples of metal foil include copper foil and aluminum foil.

The thickness of the support is not particularly limited, but is preferably 2 to 200 μm from the viewpoint of excellent workability and drying properties. When the thickness of the support is 2 μm or more, problems such as the support being cut during coating and the support bending under the weight of the varnish can be easily suppressed. When the thickness of the support is 200 μm or less, it is easy to prevent the problem that the drying of the solvent in the varnish is hindered when hot air is blown from both the coated surface and the back surface in the drying process.

A protective layer for protecting the sealing film may be disposed on the sealing film formed on the support. By forming the protective layer, the handleability is improved, and the problem of the sealing film sticking to the back surface of the support when wound up can be avoided.

A polymer film, a metal foil, or the like can be used as the protective layer. Examples of polymer films include polyolefin films such as polyethylene films and polypropylene films; vinyl films such as polyvinyl chloride films; polyester films such as polyethylene terephthalate films; polycarbonate films; can. Examples of metal foil include copper foil and aluminum foil.

The sealing film produced as described above is obtained by the steps of arranging the object to be sealed (object to be embedded) facing the sealing film, heating the sealing film to melt it, and applying pressure to the sealing film. and a step of thermally curing a sealing film having embedding ability by heating to obtain a cured body of the sealing film, thereby forming a sealing structure (e.g., a semiconductor It can be used to manufacture electronic component devices such as devices.

<Sealing structure>
A sealing structure according to the present embodiment includes an object to be sealed and a sealing portion that seals the object to be sealed, and the sealing portion is a cured product of the resin composition according to the present embodiment. (such as a cured product of the resin composition contained in the sealing film according to the present embodiment). Examples of sealing structures include electronic component devices and the like. The electronic component device includes an electronic component and a sealing portion that seals the electronic component, and the sealing portion contains a cured product of the resin composition according to the present embodiment. Examples of electronic components include semiconductor elements; semiconductor wafers; integrated circuits; semiconductor devices; filters such as SAW filters; Semiconductor elements obtained by singulating a semiconductor wafer may also 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. The sealing structure according to 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 of different types.

Next, a method for manufacturing an electronic component device using the sealing film according to this embodiment will be described. Here, a case where the electronic component is a semiconductor element will be described. FIG. 1 is a schematic cross-sectional view for explaining an embodiment of a method of manufacturing a semiconductor device, which is an electronic component device, as an embodiment of a method of manufacturing a sealing structure. The manufacturing method according to the present embodiment includes a step of arranging a plurality of semiconductor elements 20 side by side on a substrate 30 having a temporary fixing material 40 as an object to be sealed (an object to be embedded) (FIG. 1A); After facing the semiconductor element 20 with the support-attached sealing film 10 including the body 1 and the sealing film 2 provided on the support 1, the sealing film 2 is heated to the semiconductor element 20. A step of embedding the semiconductor element 20 in the sealing film 2 by pressing (laminating) below (FIG. 1(b)), and curing the sealing film 2 in which the semiconductor element 20 is embedded to obtain a cured product 2a. and a step of obtaining (FIG. 1(c)). In this embodiment, after the semiconductor element 20 is sealed with the sealing film 2 by a lamination method, the sealing film 2 is thermally cured to obtain the semiconductor element 20 embedded in the cured product 2a. Although the structure (electronic component device) is obtained, the sealed structure may be obtained by compression molding.

The laminator used in the lamination method is not particularly limited, but examples thereof include roll-type and balloon-type laminators. The laminator may be of a balloon type capable of vacuum pressurization from the viewpoint of excellent embedding properties.

Lamination is usually carried out below the softening point of the support. The lamination temperature is preferably near the lowest melt viscosity of the sealing film. The pressure during lamination varies depending on the size, density, and the like of the object to be sealed (for example, an electronic component such as a semiconductor element) to be embedded. The pressure during lamination may range, for example, from 0.2 to 1.5 MPa, or from 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, for example, under the atmosphere or under an inert gas. The curing temperature (heating temperature) is not particularly limited, and may be 80 to 280°C, 100 to 240°C, or 120 to 200°C. If the curing temperature is 80° C. or higher, the curing of the sealing film will proceed sufficiently, and the occurrence of defects can be suppressed. When the curing temperature is 280° C. or less, it tends to be possible to suppress the occurrence of heat damage to other materials. The curing time (heating time) is not particularly limited, and may be 30 to 600 minutes, 45 to 300 minutes, or 60 to 240 minutes. When the curing time is within these ranges, the curing of the sealing film proceeds sufficiently, resulting in better production efficiency. Also, the curing conditions may be a combination of multiple conditions.

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

EXAMPLES The present invention will be described in more detail with reference to examples below, but the present invention is not limited to these examples.

The following components were used as components of a varnish-like epoxy resin composition (varnish) for obtaining a sealing film (film-like epoxy resin composition).

(A) component; thermosetting resin (epoxy resin)
A1: Bisphenol F type epoxy resin (manufactured by Mitsubishi Chemical Corporation, trade name: jER806, epoxy equivalent: 160 g/eq, epoxy resin that exhibits a liquid state at 25°C)
A2: Naphthalene skeleton-containing polyfunctional solid epoxy resin (manufactured by DIC Corporation, trade name: EXA-4750, epoxy equivalent: 182 g/eq, epoxy resin that does not exhibit a liquid state at 25 ° C.)
A3: Bisphenol F type epoxy resin containing polybutadiene elastomer particles (manufactured by Kaneka Corporation, trade name: MX-136, content of liquid epoxy resin: 75% by mass, content of elastomer particles: 25% by mass, epoxy equivalent: 226g/ eq, average particle size of elastomer particles: 0.1 μm, component containing epoxy resin exhibiting liquid state at 25° C.)
A4: Epoxy resin containing silicone elastomer particles (mixture of bisphenol F type liquid epoxy resin and bisphenol A type liquid epoxy resin, manufactured by Kaneka Corporation, trade name: MX-965, content of liquid epoxy resin: 75% by mass, elastomer particles content: 25% by mass, a component containing an epoxy resin that exhibits a liquid state at 25 ° C.)
A5: Ortho-cresol novolac type epoxy resin (manufactured by DIC Corporation, trade name: N500P-1, epoxy equivalent: 201 g/eq, epoxy resin that does not exhibit a liquid state at 25 ° C.)
A6: Flexible skeleton-containing bisphenol A type epoxy resin (manufactured by DIC Corporation, trade name: Epiclon EXA-4816, epoxy equivalent: 403 g/eq, epoxy resin that exhibits a liquid state at 25 ° C.)

(B) component; curing agent (phenolic resin)
B1: Phenol novolac resin (manufactured by Asahi Organic Chemicals Industry Co., Ltd., trade name: PAPS-PN2, phenolic hydroxyl group equivalent: 104 g / eq, phenolic resin that does not exhibit a liquid state at 25 ° C.)
B2: Alkylphenol novolac type resin (manufactured by Gun Ei Chemical Industry Co., Ltd., trade name: ELP40, phenolic hydroxyl group equivalent: 140 g/eq)

(C) component; curing accelerator C1: 2-phenyl-4-methylimidazole (manufactured by Shikoku Kasei Co., Ltd., trade name: 2P4MZ)
C2: 1-benzyl-2-methylimidazole (manufactured by Shikoku Chemical Industry Co., Ltd., trade name: 1B2MZ)

(D) component; inorganic filler D1: aluminum oxide particles (manufactured by Sumitomo Chemical Co., Ltd., trade name: AA-1.5, average particle size: 1.5 μm)
D2: Aluminum oxide particles (manufactured by Denka Co., Ltd., trade name: DAW20, average particle size: 20 µm)
D3: Silica particles (manufactured by Admatechs Co., Ltd., trade name: SC2500-SXJ, phenylaminosilane treatment, average particle size: 0.5 μm)
D4: Silica particles (manufactured by Admatechs Co., Ltd., trade name: SC5500-SXE, phenylaminosilane treatment, average particle size: 1.6 μm)
D5: Silica slurry (manufactured by Admatechs Co., Ltd., trade name: SC2050-KC, silicone oligomer treatment, average particle size: 0.5 μm, methyl isobutyl ketone solvent cut (silica filler content: 70% by mass))

(E) component; solvent E1: methyl ethyl ketone

(F) Component; Elastomer F1: Polymeric elastomer (manufactured by Nagase ChemteX Corporation, trade name: HTR280, epoxy-modified linear elastomer)

<Production of sealing film>
(Example 1)
172 g of the organic solvent E1 was placed in a 10 L polyethylene container. After adding 542 g of the inorganic filler D1 to the container, the inorganic filler D1 was dispersed with a stirring blade to obtain a dispersion. To this dispersion, 48 g of thermosetting resin A1, 12 g of thermosetting resin A2, and 38 g of curing agent B1 were added and stirred. After confirming that the curing agent B1 was dissolved, 0.8 g of the curing accelerator C1 was added, and the mixture was further stirred for 1 hour to obtain a mixed liquid. This mixed solution was filtered through a nylon #200 mesh (75 μm opening), and the filtrate was collected to prepare a varnish-like epoxy resin composition. Using a coating machine, this varnish-like epoxy resin composition was applied onto the following film-like support under the following conditions to form a sealing film (film-like epoxy resin composition) having a film thickness of 100 μm on the support. made above.
・Coating head method: Comma coater ・Coating and drying speed: 1 m/min ・Drying conditions (temperature/furnace length): 110°C/3.3m, 130°C/3.3m, 140°C/3.3m
- Film-like support: polyethylene terephthalate film with a thickness of 38 µm

The surface of the sealing film was protected by placing a protective layer (12 μm thick polyethylene terephthalate film) on the opposite side of the sealing film to the support. In each of the following evaluations, the evaluation was performed after the support and the protective layer were peeled off. The same applies to the following examples and comparative examples.

(Example 2)
141 g of organic solvent E1 was placed in a 10 L polyethylene container. After adding 493 g of the inorganic filler D1 to the container, the inorganic filler D1 was dispersed with a stirring blade to obtain a dispersion liquid. To this dispersion, 88 g of thermosetting resin A1, 22 g of thermosetting resin A2, and 70 g of curing agent B1 were added and stirred. After confirming that the curing agent B1 was dissolved, 1.4 g of curing accelerator C1 was added, and the mixture was further stirred for 1 hour to obtain a mixed liquid. This mixed solution was filtered through a nylon #200 mesh (75 μm opening), and the filtrate was collected to prepare a varnish-like epoxy resin composition. Using a coating machine, this varnish-like epoxy resin composition was applied onto a film-like support in the same manner as in Example 1 to obtain a sealing film (film-like epoxy resin composition) having a film thickness of 100 μm. made.

(Example 3)
114 g of organic solvent E1 was placed in a 10 L polyethylene container. After adding 401 g of the inorganic filler D1 to the container, the inorganic filler D1 was dispersed with a stirring blade to obtain a dispersion liquid. To this dispersion, 48 g of thermosetting resin A1, 12 g of thermosetting resin A2, and 38 g of curing agent B1 were added and stirred. After confirming that the curing agent B1 was dissolved, 0.8 g of the curing accelerator C1 was added, and the mixture was further stirred for 1 hour to obtain a mixed liquid. This mixed solution was filtered through a nylon #200 mesh (75 μm opening), and the filtrate was collected to prepare a varnish-like epoxy resin composition. Using a coating machine, this varnish-like epoxy resin composition was applied onto a film-like support in the same manner as in Example 1 to obtain a sealing film (film-like epoxy resin composition) having a film thickness of 100 μm. made.

(Example 4)
149 g of organic solvent E1 was placed in a 10 L polyethylene container. After adding 423 g of the inorganic filler D1 to the container, 104 g of the inorganic filler D3 was added, and the inorganic fillers D1 and D3 were dispersed with a stirring blade to obtain a dispersion. The average particle size of inorganic fillers D1 and D3 was 1.0 μm. To this dispersion, 48 g of thermosetting resin A1, 12 g of thermosetting resin A2, and 38 g of curing agent B1 were added and stirred. After confirming that the curing agent B1 was dissolved, 0.8 g of the curing accelerator C1 was added, and the mixture was further stirred for 1 hour to obtain a mixed liquid. This mixed solution was filtered through a nylon #200 mesh (75 μm opening), and the filtrate was collected to prepare a varnish-like epoxy resin composition. Using a coating machine, this varnish-like epoxy resin composition was applied onto a film-like support in the same manner as in Example 1 to obtain a sealing film (film-like epoxy resin composition) having a film thickness of 100 μm. made.

(Comparative example 1)
96 g of the organic solvent E1 was placed in a 10 L polyethylene container. After adding 328 g of the inorganic filler D1 to the container, the inorganic filler D1 was dispersed with a stirring blade to obtain a dispersion liquid. To this dispersion, 144 g of thermosetting resin A1, 36 g of thermosetting resin A2, and 114 g of curing agent B1 were added and stirred. After confirming that the curing agent B1 was dissolved, 2.3 g of the curing accelerator C1 was added, and the mixture was further stirred for 1 hour to obtain a mixed liquid. This mixed solution was filtered through a nylon #200 mesh (75 μm opening), and the filtrate was collected to prepare a varnish-like epoxy resin composition. Using a coating machine, this varnish-like epoxy resin composition was applied onto a film-like support in the same manner as in Example 1 to obtain a sealing film (film-like epoxy resin composition) having a film thickness of 100 μm. made.

(Comparative example 2)
4629 g of the organic solvent E1 was placed in a 10 L polyethylene container. After adding 6622 g of the inorganic filler D3 to the container, the inorganic filler D3 was dispersed with a stirring blade to obtain a dispersion liquid. To this dispersion, 680 g of thermosetting resin A1, 240 g of thermosetting resin A2, 202 g of thermosetting resin A3, 78 g of thermosetting resin A4, and 711 g of curing agent B1 were added and stirred. After confirming that the curing agent B1 was dissolved, 15 g of the curing accelerator C1 was added, and the mixture was further stirred for 1 hour to obtain a mixed liquid. This mixed solution was filtered through a nylon #200 mesh (75 μm opening), and the filtrate was collected to prepare a varnish-like epoxy resin composition. Using a coating machine, this varnish-like epoxy resin composition was applied onto a film-like support in the same manner as in Example 1 to obtain a sealing film (film-like epoxy resin composition) having a film thickness of 100 μm. made.

(Comparative Example 3)
A sealing film (film-like epoxy resin composition) having a film thickness of 100 μm was produced in the same manner as in Comparative Example 1, except that the coating and drying speed in Comparative Example 1 was changed from 1 m/min to 0.5 m/min. .

(Example 5)
83 g of the organic solvent E1 was placed in a 10 L polyethylene container. After adding 151 g of the inorganic filler D5 to the container, 660 g of the inorganic filler D2 and 53 g of the inorganic filler D4 are added, and the inorganic fillers D2, D4 and D5 are dispersed with a stirring blade to obtain a dispersion liquid. rice field. The average particle size of inorganic fillers D2, D4 and D5 was 16 μm. To this dispersion, 34 g of thermosetting resin A5, 11 g of thermosetting resin A6, and 28 g of curing agent B2 were added and stirred. After confirming that the curing agent B2 was dissolved, 7 g of the elastomer F1 and 0.5 g of the curing accelerator C2 were added and further stirred for 1 hour to obtain a mixed liquid. This mixed solution was filtered through #150 nylon mesh (opening 106 μm), and the filtrate was collected to prepare a varnish-like epoxy resin composition. Using a coating machine, this varnish-like epoxy resin composition was applied onto a film-like support in the same manner as in Example 1 to obtain a sealing film (film-like epoxy resin composition) having a film thickness of 125 μm. made.

(Example 6)
83 g of the organic solvent E1 was placed in a 10 L polyethylene container. After adding 98 g of the inorganic filler D5 to the container, 430 g of the inorganic filler D2 and 34 g of the inorganic filler D4 are added, and the inorganic fillers D2, D4 and D5 are dispersed with a stirring blade to obtain a dispersion liquid. rice field. The average particle size of inorganic fillers D2, D4 and D5 was 18 μm. To this dispersion, 21 g of thermosetting resin A5, 7 g of thermosetting resin A6, and 17 g of curing agent B2 were added and stirred. After confirming that the curing agent B2 was dissolved, 8 g of the elastomer F1 and 0.14 g of the curing accelerator C1 were added and further stirred for 1 hour to obtain a mixed liquid. This mixed solution was filtered through #150 nylon mesh (opening 106 μm), and the filtrate was collected to prepare a varnish-like epoxy resin composition. Using a coating machine, this varnish-like epoxy resin composition was applied onto a film-like support in the same manner as in Example 1 to obtain a sealing film (film-like epoxy resin composition) having a film thickness of 125 μm. made.

(Example 7)
83 g of the organic solvent E1 was placed in a 10 L polyethylene container. After adding 68.6 g of the inorganic filler D3 to the container, 463 g of the inorganic filler D2 and 34.3 g of the inorganic filler D4 are added, and the inorganic fillers D2, D3 and D4 are dispersed with a stirring blade. A dispersion was obtained. The average particle size of inorganic fillers D2, D3 and D4 was 18 μm. To this dispersion, 18.3 g of thermosetting resin A5, 4.6 g of thermosetting resin A6, and 14.4 g of curing agent B2 were added and stirred. After confirming that the curing agent B2 was dissolved, 5.6 g of the elastomer F1 and 0.11 g of the curing accelerator C1 were added and further stirred for 1 hour to obtain a mixed liquid. This mixed solution was filtered through #150 nylon mesh (opening 106 μm), and the filtrate was collected to prepare a varnish-like epoxy resin composition. Using a coating machine, this varnish-like epoxy resin composition was applied onto a film-like support in the same manner as in Example 1 to obtain a sealing film (film-like epoxy resin composition) having a film thickness of 125 μm. made.

(Example 8)
83 g of the organic solvent E1 was placed in a 10 L polyethylene container. After adding 68.6 g of the inorganic filler D3 to the container, 463 g of the inorganic filler D2 and 34.3 g of the inorganic filler D4 are added, and the inorganic fillers D2, D3 and D4 are dispersed with a stirring blade. A dispersion was obtained. The average particle size of inorganic fillers D2, D3 and D4 was 18 μm. To this dispersion, 17.9 g of thermosetting resin A5, 4.5 g of thermosetting resin A6, and 14 g of curing agent B2 were added and stirred. After confirming that the curing agent B2 was dissolved, 6.4 g of the elastomer F1 and 0.11 g of the curing accelerator C1 were added and further stirred for 1 hour to obtain a mixed liquid. This mixed solution was filtered through #150 nylon mesh (opening 106 μm), and the filtrate was collected to prepare a varnish-like epoxy resin composition. Using a coating machine, this varnish-like epoxy resin composition was applied onto a film-like support in the same manner as in Example 1 to obtain a sealing film (film-like epoxy resin composition) having a film thickness of 125 μm. made.

<Evaluation>
(1) Thermal conductivity A of the cured product of the sealing film
Both sides of the sealing films (thickness: 100 μm or 125 μm) of Examples 1 to 8 and Comparative Examples 1 to 3 were laminated with copper foils under the following conditions to obtain sealing films with copper foils on both sides.
・ Laminator device: Vacuum pressurized laminator manufactured by Meiki Seisakusho Co., Ltd., trade name “MVLP-500”
・Lamination temperature: 90°C
・Lamination pressure: 0.5 MPa
・Evacuation time: 30 seconds ・Lamination time: 40 seconds

The resulting sealing film with copper foil on both sides was cured under the following conditions to produce a cured epoxy resin with copper foil.
・ Oven: Espec Co., Ltd., trade name “SAFETY OVEN SPH-201”
・Oven temperature: 140℃
・Heating time: 120 minutes

The copper foil of the produced cured epoxy resin body with copper foil was removed by etching to obtain a cured epoxy resin body (cured material of sealing film). The obtained epoxy resin cured product was cut into 1 cm squares, and the thermal diffusivity was measured using the following device.
・ Thermal diffusivity measurement device: trade name “LFA447” (xenon flash analyzer) manufactured by NETZSCH

Further, the specific gravity of the obtained cured epoxy resin was measured with the following hydrometer.
・ Hydrometer: Product name “SD200L” manufactured by Alpha Mirage Co., Ltd.

Further, the specific heat of the epoxy resin cured product obtained was determined by differential scanning calorimetry under the following conditions.
・ Differential scanning calorimeter: trade name "Q-200" manufactured by TA Instruments Japan Co., Ltd.
・Test conditions: 25°C, 10 minutes (constant) → 25 to 60°C (10°C/min) → 60°C, 10 minutes (constant)

Using the obtained thermal diffusivity, specific gravity and specific heat, the thermal conductivity was determined by the following formula (1).
Thermal conductivity = thermal diffusivity x specific gravity x specific heat (1)

Then, thermal conductivity was evaluated based on the following evaluation criteria. Table 1 shows the results of Examples 1-4. The thermal conductivity of Examples 5 to 8 was equivalent to that of Examples 1 to 4 (evaluation: A). For example, the thermal conductivity of Example 5 was 2.73 W/m·K.
"A": Thermal conductivity > 2.5 W / m K
"B": thermal conductivity ≤ 2.5 W / m · K

(2) Thermal conductivity B of cured product of sealing film
Four sheets of each sealing film (thickness: 125 μm) of Examples 5 to 8 were stacked, and a laminated film having a thickness of 500 μm was produced using a hand press under the following conditions.
・ Hand press device: Trade name “BIG HEART” manufactured by Imoto Manufacturing Co., Ltd.
・Hand press molding temperature: 140°C
・Hand press molding time: 30 minutes ・Forming load: 20 kN

The resulting laminated film having a thickness of 500 μm was cured under the following conditions to prepare an epoxy resin cured product (cured product of sealing film).
・ Oven: Product name “SAFETY OVEN SPH-201” manufactured by Espec Co., Ltd.
・Oven temperature: 140℃
・Heating time: 90 minutes

The cured epoxy resin body thus obtained was cut into 1 cm squares, and the thermal conductivity of the cured epoxy resin body was measured by the temperature gradient method using a thermal resistivity measuring instrument. Then, thermal conductivity was evaluated based on the following evaluation criteria. Table 2 shows the results.
"A": Thermal conductivity > 2.5 W / m K
"B": thermal conductivity ≤ 2.5 W / m · K

(3) Solvent Content of Sealing Film The obtained sealing film was cut into a 5 cm square sample. This sample was placed in an aluminum cup whose mass had been measured in advance, and the mass of the aluminum cup containing the sample was measured. Next, while the sample was kept in the aluminum cup, it was heated in an oven at 180° C. for 10 minutes, and then left at room temperature (25° C.) for 10 minutes. The aluminum cup containing the sample was then weighed again. Next, the mass of the sealing film before and after heating was obtained by subtracting the mass of the separately measured aluminum cup from the measured mass of the aluminum cup containing the sample (before and after heating). Then, the ratio obtained by dividing the value obtained by subtracting the mass of the sealing film after heating from the mass of the sealing film before heating by the mass of the sealing film before heating was obtained as the solvent content. . The results are shown in Tables 1 and 2.

(4) Embedability Four layers of sealing films each having a thickness of 100 μm or 125 μm were laminated to obtain a laminate film having a thickness of 400 μm or 500 μm. An 8-inch eWLB package was produced using the laminated film in the following procedure. FIG. 2 shows a layout of silicon chips in this measurement. First, as shown in FIG. 2, silicon chips (7.3 mm square silicon chip 60 and 3 mm square silicon chip 70) having a thickness of 350 μm were arranged on the SUS plate 50. As shown in FIG. Then, the laminate film was cut into a circle with a diameter of 20 cm and placed on the silicon chip. Then, using a compression molding machine (manufactured by Apic Yamada Co., Ltd., trade name: WCM-300), the silicon chip was sealed under the following conditions to obtain a sealed body (sealed structure).
・Compression molding temperature: 140°C
・Compression mold pressure: 2.5 MPa
・Compression mold time: 10 minutes

Next, the produced sealed body was cured by heating under the following conditions to produce a cured body. This resulted in an eWLB package.
・ Oven: Product name “SAFETY OVEN SPH-201” manufactured by Espec Co., Ltd.
・Oven temperature: 140℃
・Heating time: 120 minutes

The embeddability of the produced cured product was evaluated based on the following evaluation criteria. The results are shown in Tables 1 and 2.
"A": Can be embedded without voids and has a smooth surface "B": Some voids are seen and the surface is smooth "C": Voids are seen and the surface is inferior in smoothness

<Evaluation results>
As shown in Tables 1 and 2, in the resin composition containing a thermosetting component and an inorganic filler, the inorganic filler contains aluminum oxide, and the content of the inorganic filler is It can be seen that when the amount is 72% by mass or more based on the total mass (excluding the mass of the solvent), excellent effects can be obtained regarding the thermal conductivity of the cured product. From Example 4 shown in Table 1, it can be seen that even when the inorganic filler contains silica, an excellent effect on the thermal conductivity of the cured product can be obtained.

From the above results, in the resin composition containing a thermosetting component and an inorganic filler, the inorganic filler contains aluminum oxide, and the content of the inorganic filler is the total weight of the resin composition (excluding the weight of the solvent ) on the basis of 72% by mass or more, it was found that an excellent effect on the thermal conductivity of the cured product is obtained and the embedding property is excellent.

DESCRIPTION OF SYMBOLS 1... Support body, 2... Film for sealing, 2a... Cured material, 10... Film for sealing with support body, 20... Semiconductor element, 30... Substrate, 40... Temporary fixing material, 50... SUS plate, 60... 7 .3 mm square silicon chip, 70...3 mm square silicon chip.

Claims (13)

A sealing film comprising a resin composition containing a thermosetting component and an inorganic filler,
the inorganic filler comprises aluminum oxide and silica;
The content of the inorganic filler is 72% by mass or more and 85% by mass or less based on the total mass of the resin composition (excluding the mass of the solvent),
The content of aluminum oxide in the inorganic filler is 70% by mass or more,
the thermosetting component comprises an epoxy resin and a curing agent;
A sealing film, wherein the content of an epoxy resin that is liquid at 25°C is 5% by mass or more based on the total mass of the resin composition (excluding the mass of the solvent) . The sealing film according to Claim 1, further comprising a solvent. 3. The sealing film according to claim 2, wherein the solvent content is 0.2 to 1.5% by mass . A sealing film comprising a resin composition containing a thermosetting component , an inorganic filler and a solvent ,
the inorganic filler comprises aluminum oxide and silica;
The content of the inorganic filler is 72% by mass or more and 85% by mass or less based on the total mass of the resin composition (excluding the mass of the solvent),
The content of aluminum oxide in the inorganic filler is 70% by mass or more,
the thermosetting component comprises an epoxy resin and a curing agent;
A film for sealing, wherein the content of the solvent is 0.2 to 1.5% by mass . The sealing film according to any one of Claims 1 to 4 , wherein the curing agent comprises a phenolic resin. The sealing film according to any one of claims 1 to 5, wherein said thermosetting component further comprises a curing accelerator. 7. The sealing film according to claim 6 , wherein said curing accelerator comprises an imidazole compound. The seal according to any one of claims 1 to 7 , wherein the content of the epoxy resin that is liquid at 25°C is 7% by mass or more based on the total mass of the resin composition (excluding the mass of the solvent). stopping film . The sealing film according to any one of claims 1 to 8 , wherein the inorganic filler has an average particle size of 0.01 to 25 µm. The sealing film according to any one of claims 1 to 8 , wherein the inorganic filler has an average particle size of 0.01 to 10 µm. The sealing film according to any one of claims 1 to 10, which has a thickness of 20 to 250 µm. An object to be sealed and a sealing portion that seals the object to be sealed,
A sealing structure, wherein the sealing portion comprises a cured product of the sealing film according to any one of claims 1 to 11 . 13. The sealing structure according to claim 12 , wherein the object to be sealed is an electronic component.

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