JP2003160643A - Semiconductor sealing epoxy resin composition and semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor sealing epoxy resin composition whose adhesiveness to a metal surface such as an interconnection and the like in a semiconductor element or an interconnection-providing member is enhanced, in a one-component solvent free liquid sealing material. <P>SOLUTION: There is provided a semiconductor sealing epoxy resin composition that includes an epoxy resin, a curing agent and a potential accelerator as essential components and is liquid in room temperature. The epoxy resin comprises at least one epoxy resin having either a naphthalene backbone or a bisphenol backbone. The curing agent comprises at least either an organic acid anhydride having a succinic anhydride structure that is liquid in room temperature or a compound having a phenolic novolac structure that is liquid in room temperature. Further, at least either 2,4,6-trimercapto-s-triazine or 2-di-n-butylamino-4,6-dimercapto-s-triazine is included in 0.01-3 mass% relative to the whole quantity of the semiconductor sealing epoxy resin composition. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a semiconductor encapsulating epoxy resin composition used for encapsulating a semiconductor element, and a semiconductor device encapsulated with the semiconductor encapsulating epoxy resin composition, In particular, in order to improve reliability such as moisture resistance and heat cycle resistance after sealing, and also to increase bending resistance, impact resistance, vibration resistance, etc. of card-shaped electronic devices and portable information devices, The present invention relates to an epoxy resin composition for semiconductor encapsulation having improved adhesion to a metal surface forming wiring such as electrodes and circuits.

[0002]

2. Description of the Related Art Conventionally, when a liquid epoxy resin composition is used as an encapsulating material in encapsulating a semiconductor element, a method such as potting encapsulation or underfill encapsulation in which this is ejected from a dispenser, or A method such as pressure contact sealing in which pressure and heating are performed at the same time, or a method using printing using a mask or a screen has been performed. These methods do not require a mold release agent because they are not a method of molding with a mold, and therefore, the liquid encapsulant has essentially no adhesiveness as compared with a molding encapsulant that requires a mold. It can be said to be an expensive material.

However, in recent years, semiconductor elements have become larger due to higher functionality and higher integration, the mounting volume has been minimized due to the lightness, thinness and shortness of equipment, and raw materials used to reduce the load on the global environment. In the trend of becoming extremely small, liquid sealing materials are required to have higher performance than ever before. Specifically, even if a large-sized semiconductor element is encapsulated or the cured product of the encapsulant is extremely thin (several micrometers to several tens of micrometers), it has moisture resistance and heat cycle resistance. Can be sufficiently maintained, and in the case of a card-shaped device that can be easily bent, it does not break down even if it is bent, and it can be used in devices such as mobile phones and other portable information terminals and vehicles. In that case, it is required not to break down due to impact or vibration.

In order to meet the above requirements, it is necessary to increase the adhesiveness between the liquid sealing material and the semiconductor element and the wiring donor member for supplying wiring to the semiconductor element more than ever. Specifically, it is necessary to enhance the adhesiveness of the liquid encapsulating material to the metal surface forming the electrodes and wirings in the semiconductor element and the wiring providing member. Here, the above-mentioned wiring donor generally means a circuit board, but recently, due to the need to realize miniaturization and high speed at low cost, chip-on-chip and A structure called chip-on-wafer, that is, one in which another semiconductor element is connected to the wiring part on the surface of the semiconductor element or one in which a semiconductor element is directly connected to a part of a flat high-frequency antenna or the like has appeared. Therefore, in order to include these things, the circuit board is not called, but the wiring donor is called.

[0005]

As means for enhancing the adhesiveness of the liquid encapsulating material, conventionally, a coupling agent is blended with the encapsulating material to form a chemical bond, or a resin in a resin is used. Attempts have been made to incorporate silicone or an elastomer, which is a rubber-like substance, into the encapsulating material in order to reduce internal stress and reduce defects in the adhesive layer, but the effect is still insufficient.

On the other hand, the liquid encapsulating material is required to be a so-called one-component (one-component) solvent-free material from the viewpoint of ease of use. This one-component solvent-free liquid encapsulant has a small viscosity increase even if a chemical reaction progresses until it is heated for the purpose of curing, that is, when stored at room temperature or low temperature, and immediately before use. It does not need to be mixed and further does not contain a volatile solvent that does not contribute to the curing reaction.

The present invention has been made in view of the above points, and in a one-liquid non-solvent type liquid encapsulating material, a semiconductor having improved adhesion to a metal surface such as a wiring in a semiconductor element or a wiring donating member. It is an object of the present invention to provide an epoxy resin composition for encapsulation and a highly reliable semiconductor device.

[0008]

The epoxy resin composition for semiconductor encapsulation according to claim 1 of the present invention is a semiconductor encapsulation liquid at room temperature which contains an epoxy resin, a curing agent, and a latent curing accelerator as essential components. In the stopping epoxy resin composition, the epoxy resin contains at least one of an epoxy resin having a naphthalene skeleton or a bisphenol skeleton, and as a curing agent, an organic acid anhydride having a succinic anhydride structure that is liquid at room temperature and a room temperature. And containing at least one of compounds having a liquid phenol novolac skeleton, 2,4,6-trimercapto-s-triazine and 2-di-n-butylamino-4,6-dimercapto-s-triazine At least one of them is 0.01 to 3 with respect to the total amount of the epoxy resin composition for semiconductor encapsulation.
It is characterized by containing mass%.

According to a second aspect of the present invention, in the first aspect, at least one of spherical amorphous silica and alumina having a maximum particle size of 0.5 to 20 μm as an inorganic filler is used for encapsulating a semiconductor. It is characterized by containing 20 to 70% by volume in terms of true specific gravity with respect to the total amount of the epoxy resin composition.

According to a third aspect of the invention, in the first aspect, at least one of spherical amorphous silica and alumina having a maximum particle size of 0.5 to 5 μm as an inorganic filler is used for encapsulating a semiconductor. It is characterized by containing 20 to 50% by volume in terms of true specific gravity with respect to the total amount of the epoxy resin composition, and having a maximum particle size of solid content of 5 μm or less in the epoxy resin composition for semiconductor encapsulation. .

According to a fourth aspect of the present invention, in a semiconductor device, at least a wiring portion of a semiconductor element and a wiring donating member for providing wiring to the semiconductor element is formed by the epoxy resin composition for semiconductor encapsulation according to any one of the first to third aspects. It is characterized by being sealed.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below.

The epoxy resin composition for semiconductor encapsulation according to the present invention contains an epoxy resin, a curing agent, and a latent curing accelerator as essential components, and further comprises 2,4,6-trimercapto-
s-Triazine and 2-di-n-butylamino-4,6-
It contains at least one of dimercapto-s-triazine and is liquid at room temperature.
Hereinafter, details of each of the above components will be described in order.

In the present invention, as the epoxy resin, at least one of the epoxy resins having a naphthalene skeleton or a bisphenol skeleton is always used. Specifically, the epoxy resin having a naphthalene skeleton is a compound whose basic structure is represented by the following [Chemical formula 1] to [Chemical formula 3], oligomers thereof, and
These novolac types can be illustrated.

[0015]

[Chemical 1]

[0016]

[Chemical 2]

[0017]

[Chemical 3]

As the epoxy resin having a bisphenol skeleton, bisphenol S type epoxy resin,
Examples thereof include compounds having a basic structure represented by the following [Chemical formula 4] to [Chemical formula 6], oligomers thereof, and novolac types thereof.

[0019]

[Chemical 4]

[0020]

[Chemical 5]

[0021]

[Chemical 6]

By using the above-mentioned epoxy resin having a naphthalene skeleton or a bisphenol skeleton, a low-viscosity epoxy resin composition for semiconductor encapsulation can be prepared and the moisture absorption of the cured product can be suppressed to a low level. Moreover, it is possible to obtain high adhesion to the metal surface.

As epoxy resins other than the above, as long as the epoxy resin composition for semiconductor encapsulation becomes liquid at room temperature and the object of the present invention is not impaired,
A commercially available liquid epoxy resin or solid epoxy resin can be used together. When a solid epoxy resin is used, the liquid epoxy resin composition for semiconductor encapsulation can be prepared by pulverizing and dispersing or dissolving the solid epoxy resin. Specific examples of the epoxy resin include a biphenyl type epoxy resin having a biphenyl skeleton, an alicyclic epoxy resin, a dicyclopentadiene type epoxy resin having a dicyclopentadiene skeleton, a phenol novolac type epoxy resin, a cresol novolac type epoxy resin, triphenyl. Methane type epoxy resin,
Examples thereof include bromine-containing epoxy resin, aliphatic epoxy resin, triglycidyl isocyanurate and the like.

In the present invention, as the curing agent, an organic acid anhydride which has a succinic anhydride structure having a 5-membered ring in the molecule and which is liquid at room temperature (hereinafter also referred to as "organic acid anhydride having a succinic anhydride structure") ) And a compound that has a phenol novolac skeleton having a plurality of phenolic hydroxyl groups in the molecule and is liquid at room temperature (hereinafter, also referred to as “compound having a phenol novolac skeleton”). Specifically, examples of the organic acid anhydride having a succinic anhydride structure include methyltetrahydrophthalic anhydride (MTHPA), methylhexahydrophthalic anhydride (MHHPA), and monoterpenes represented by the molecular formula C ₁₀ H ₁₆ . Diels-Alder is a compound that has three carbon-carbon double bonds in one molecule, and two of these double bonds are conjugated (triene monoterpene) and maleic anhydride. Examples thereof include terpene-based acid anhydrides synthesized by 6-membered cyclization by reaction, nonenylsuccinic anhydride, dodecenylsuccinic anhydride, and the like. By using an organic acid anhydride having such a succinic anhydride structure as a curing agent,
It is possible to prepare a low-viscosity epoxy resin composition for encapsulating a semiconductor, and to obtain a cured product having a low hygroscopicity and good electric insulation properties. In addition,
As a curing agent other than the organic acid anhydride having the above succinic anhydride structure, as long as it does not impair the object of the present invention,
The following can be used together. For example, pyromellitic anhydride, benzophenone tetracarboxylic acid anhydride, methylcyclohexene tetracarboxylic acid anhydride, 5- (2,5-dioxotetrahydro-3-furanyl) -3-methyl-3-cyclohexene-1,2. -Dicarboxylic acid anhydride (commercially available from Dainippon Ink and Co., Ltd. under the trade name "Epiclone B-4400")
And Glycerol Tris Anhydrotomellitate (trade name "Rikacid TMTA-C" from Shin Nippon Rika Co., Ltd.
Are commercially available as) and the like.

As the compound having a phenol novolac skeleton, an allyl phenol novolac (trade name “MEH-8000” from Meiwa Kasei Co., Ltd.) is used.
H ”and“ MEH-8000-4L ”and the like, and phenol novolac containing no polynuclear body, and imide-modified products thereof (trade names“ MEH-8105 ”and“ MEH-from Meiwa Kasei Co., Ltd. ”). 8205 "and the like) and the like. By using such a compound having a phenol novolac skeleton as a curing agent, it is possible to suppress the moisture absorption of the cured product to a low level, obtain high adhesion to a metal surface, and further, in a sealed semiconductor element. Good moisture resistance reliability can be realized. Incidentally, as a curing agent other than the compound having a phenol novolac skeleton, within a range not impairing the object of the present invention,
For example, a compound having a phenolic hydroxyl group that is solid at room temperature and an acid anhydride that is solid at room temperature can be used in combination.

Further, the molar ratio of the stoichiometric reactive groups of the epoxy resin and the curing agent, that is, the ratio (equivalent ratio) of the epoxy equivalent and the curing agent equivalent, is an organic acid anhydride having a succinic anhydride structure. When the product is used as a curing agent, 1
It is preferably 0: 6 to 10:10. It is more preferably 10: 7 to 10: 9. If the curing agent equivalent of the curing agent is less than 6 with respect to the epoxy equivalent of 10 of the epoxy resin, the epoxy resin composition for semiconductor encapsulation becomes difficult to cure, or even if cured, the heat resistance of the cured product decreases. However, the strength of the cured product may decrease. On the contrary, when the curing agent equivalent exceeds 10, unreacted organic acid anhydride remains after the curing reaction, and due to the organic acid group of this organic acid anhydride, corrosion of the semiconductor device during moisture absorption or voltage application There is a risk of adverse effects such as leaks. In the present invention, since an acid anhydride may be used as a curing agent as described above, the curing agent equivalent is also referred to as acid anhydride equivalent.

On the other hand, when a compound having a phenol novolac skeleton is used as a curing agent, the epoxy resin: curing agent (equivalent ratio) is preferably 10: 9 to 9:10. As in the case of acid anhydrides, there is little adverse effect due to unreacted functional groups, so by mixing the stoichiometrically necessary amount, the properties such as heat resistance, hygroscopicity, and adhesion of the cured product can be improved. It can be raised. If the equivalent ratio is out of the above range, the curability may be deteriorated or the strength of the cured product may be decreased.

In the present invention, the curing accelerator is
There is no particular limitation as long as it has potential. Here, the latent means that the reaction is initiated by heating, and that the curing is difficult to proceed at room temperature to such an extent that it is practically impaired even when mixed with an epoxy resin and other components, and the mixture is stored as a composition. Because it is possible, it is also called a one-part type, and is distinguished from a two-part type that starts to cure immediately when mixed. Specifically, fine spherical particles (so-called microcapsules) obtained by coating a compound having an imidazole skeleton as a core and coating the periphery of the core with a coating of a thermosetting resin, and amine adduct particles can be exemplified. .

The above-mentioned microcapsules can be produced by a general method such as emulsion polymerization,
In forming the film, phenol / formaldehyde resin, melamine / formaldehyde resin, or epoxy resin can be preferably used. The size (particle diameter) of the microcapsules is preferably 50 μm or less, and 10
It is more preferably not more than μm, most preferably not more than 5 μm.
The smaller the size is, the more uniformly the microcapsules are dispersed in the epoxy resin composition for semiconductor encapsulation, and the entire cured product obtained can be made uniform. As the microcapsule type curing accelerator having the above-mentioned imidazole-based core, those commercially available from Asahi Kasei Kogyo Co., Ltd. under the trade name “Novacure” can be used.

On the other hand, the amine adduct particles can be synthesized from polyamine and various epoxy resins, and the size (particle diameter) of the amine adduct particles is 50 μm or less as in the case of the above microcapsules. It is preferably 10 μm or less, more preferably 5 μm or less. The smaller the size is, the more uniform the obtained cured product can be, as in the case of the microcapsules. As the curing accelerator for the amine adduct particles, those commercially available from Ajinomoto Co., Inc. under the trade name "Amicure" can be used.

In the present invention, 2,4,6-trimercapto-s-triazine represented by the following [Chemical formula 7] and 2-di-n-butylamino-4 represented by the following [Chemical formula 8] are used as additives. , 6-dimercapto-s-triazine in an amount of 0.01 to 3% by mass based on the total amount of the epoxy resin composition for semiconductor encapsulation.

[0032]

[Chemical 7]

[0033]

[Chemical 8]

By using the above additives, the adhesion of the cured product of the epoxy resin composition for semiconductor encapsulation to metal can be improved. Although the reason is not clear, it is presumed that the mercapto group (-SH) in the molecule strongly coordinates with the metal. However, if the amount of the above-mentioned additive is less than 0.01% by mass based on the total amount of the epoxy resin composition for semiconductor encapsulation, the effect of improving the adhesiveness cannot be sufficiently obtained, and conversely exceeds 3% by mass. As a result, the effect of improving the adhesiveness can be obtained, but in the semiconductor device obtained by encapsulation, it becomes impossible to secure the moisture resistance reliability other than the adhesiveness.

An inorganic filler may be added to the epoxy resin composition for semiconductor encapsulation according to the present invention. The inorganic filler is not particularly limited, but at least one of spherical amorphous silica and alumina having a maximum particle size of 0.5 to 20 μm is used as a semiconductor encapsulating epoxy resin composition 20 to 7 in terms of true specific gravity
It is preferable to contain 0% by volume. The reason why the maximum particle size and the volume% in terms of true specific gravity in the above range are preferable is as follows.

First, in the present invention, the maximum particle size of the inorganic filler means that the inorganic filler is sieved to obtain 99 mass% or more 1
It is defined as the size of the mesh of the sieve when less than 00% by mass passes through the sieve. When the maximum particle size of the inorganic filler is less than 0.5 μm,
As the filler is too fine, the viscosity and thixotropy of the epoxy resin composition for semiconductor encapsulation increase, the workability of the encapsulation work may be reduced, or the encapsulation target may not be encapsulated in the desired shape. Is not preferred. Conversely, the maximum particle size is 20μ
When it exceeds m, it becomes difficult to infiltrate the epoxy resin composition for semiconductor encapsulation into a narrow gap (gaps), it may cause deformation of a thin metal conducting wire such as a bonding wire, or the distance between thin metal conducting wires. May be narrowed, which is not preferable. Further, heating during curing lowers the viscosity of the resin, and the filler having a large specific gravity may settle, which may cause non-uniformity of the filler content in the vertical direction, which is not preferable.

Next, in the present invention, the volume% of the inorganic filler in terms of true specific gravity means the true volume (Vf) of the filler and the true volume (Vf) of the filler obtained by the compounding mass of the filler / the true specific gravity of the filler. Vf ÷ (Vf + Vr) × 100 from the compounded mass of the resin component / the true volume (Vr) other than the filler obtained by its true specific gravity
It means the value calculated by the formula. The purpose of blending the inorganic filler is to enhance the strength and elastic modulus of the cured product by exerting a reinforcing effect, and to increase the thermal expansion coefficient of the sealing target such as a semiconductor element and the thermal expansion coefficient of the cured product. The difference can be reduced. However, if the inorganic filler is less than 20% by volume in terms of true specific gravity, the reinforcing effect by the filler becomes insufficient, or the coefficient of thermal expansion cannot be sufficiently reduced as compared with the case where no filler is added. Therefore, it may be difficult to achieve the above object, which is not preferable. On the contrary, when the inorganic filler exceeds 70% by volume in terms of true specific gravity, the viscosity and thixotropy of the epoxy resin composition for semiconductor encapsulation increase, the workability of encapsulation work decreases, and the encapsulation target It is not preferable because there is a possibility that the desired shape cannot be sealed.

Here, as described above, the spherical amorphous silica and alumina can be mixed and used. However, when such fillers having different specific gravities are used together, the average specific gravity is previously set. The calculated value can be used to determine the volume% in terms of true specific gravity based on the above-mentioned formula. Specifically, the average specific gravity of the n types of fillers is
The compounding mass of each filler is Wi, the true specific gravity di (i = 1 to n)
Can be obtained by ΣWi / Σ (Wi / di) (i = 1 to n).

Among the inorganic fillers, spherical amorphous silica and alumina are preferable for the following reason. That is, spherical amorphous silica is silicon dioxide that is not crystalline, but since it has a very small coefficient of thermal expansion, it has a great effect on reducing the coefficient of thermal expansion of the composite material that is a cured product of the composition.
Further, its particle shape is spherical as the name implies, which allows the viscosity of the epoxy resin composition for semiconductor encapsulation to be lower than that of the crushed particle shape, and the composition is a semiconductor When used on the circuit surface of an element or the like, stress concentration on the circuit surface can be reduced, and malfunctions of the semiconductor device can be reduced and reliability can be improved. On the other hand, since alumina has a high thermal conductivity and a high elastic modulus, it is effective for improving the thermal conductivity and the reinforcing effect of the composite material. Regarding the particle shape, the same effect as spherical amorphous silica can be obtained, and therefore, a spherical or near-polyhedral shape close to a spherical shape is preferable to a plate-like or crushed shape.

As described above, by limiting the maximum particle size of the inorganic filler, the volume% in terms of true specific gravity and the material,
The narrow area filling property of the epoxy resin composition for semiconductor encapsulation can be enhanced. Specifically, for example, in flip-chip mounting, even when a semiconductor element or a wiring donor member forms a narrow gap, the gap can be easily filled with the epoxy resin composition for semiconductor encapsulation. .

When the epoxy resin composition for semiconductor encapsulation is used in contact with the surface of a semiconductor element which may be adversely affected by α rays, the spherical amorphous silica or alumina described above may be Uranium (U) and Thorium (T
It is preferable to use those having a small content of radioisotope such as h). In this case, the content of U or Th in the spherical amorphous silica or alumina is preferably 0.5 p.
It is not more than pb, and more preferably not more than 0.1 ppb.

The maximum particle size is 0.5 to 5 μm,
At least one of spherical amorphous silica and alumina is contained in an amount of 20 to 50% by volume in terms of true specific gravity with respect to the total amount of the epoxy resin composition for semiconductor encapsulation, and is solid in the epoxy resin composition for semiconductor encapsulation. Maximum particle size is 5μ
It is more preferably m or less. In this way, the range of maximum particle size is narrowed from 0.5 to 20 μm to 0.5 to 5 μm, and the range of volume% in terms of true specific gravity is narrowed from 20 to 70% by volume to 20 to 50% by volume, and the solid content is By setting the maximum particle size of 5 μm or less, it is possible to easily infiltrate the epoxy resin composition for semiconductor encapsulation into an extremely narrow gap, and to obtain a reinforcing effect by a filler and to obtain a semiconductor element or the like. The difference in the coefficient of thermal expansion from the cured product can be made significantly smaller than in the case where no filler is added.

If the maximum particle size of the inorganic filler is less than 0.5 μm, as already mentioned, the filler is too fine and the viscosity and thixotropy of the epoxy resin composition for semiconductor encapsulation increase, resulting in a seal. This is not preferable because the workability of the stopping work may be reduced and the object to be sealed may not be sealed in the desired shape. On the contrary, when the maximum particle size exceeds 5 μm, it becomes difficult to infiltrate the epoxy resin composition for semiconductor encapsulation into an extremely narrow gap of 10 μm or less, or the semiconductor element is electrically connected to the wiring donor member through the metal bump. It is not preferable because it may hinder the connection.

If the inorganic filler is less than 20% by volume in terms of true specific gravity, as described above, the reinforcing effect by the filler becomes insufficient, or the coefficient of thermal expansion is not added when the filler is not added. In comparison, there is a risk that it cannot be made sufficiently small, which is not preferable. Conversely, the inorganic filler is 50 in terms of true specific gravity.
If the volume% is exceeded, the viscosity and thixotropy of the epoxy resin composition for semiconductor encapsulation will increase, and the workability of encapsulation for penetrating into extremely narrow gaps such as 10 μm or less will decrease, There is a possibility that it may not be possible to accurately seal the shape as described below, which is not preferable.

Further, the solid content in the epoxy resin composition for semiconductor encapsulation refers to a component existing as a solid including an organic substance and an inorganic substance in the composition. For example, when the above 2,4,6-trimercapto-s-triazine or 2-di-n-butylamino-4,6-dimercapto-s-triazine is used in the solid state, they are solid. Further, when various additives such as pigments described later are used in a solid state, these become solid contents. And the maximum particle size of such solids is 5μ
When it exceeds m, it becomes difficult to infiltrate the epoxy resin composition for semiconductor encapsulation into an extremely narrow gap such as 10 μm or less, or when the semiconductor element is electrically connected to the wiring donor member through the metal bump. It is not preferable because it may cause an obstacle. The maximum particle size around 5 μm is JIS
It can be easily measured by the method using a gauge and a scraper shown in K5600-2-5.

As described above, by narrowing the maximum particle size of the inorganic filler and the range of volume% in terms of true specific gravity to limit the material and also the maximum particle size of the solid content in the composition, the semiconductor It is possible to enhance the super narrow portion filling property of the encapsulating epoxy resin composition. Specifically, for example, in flip-chip mounting, even if a semiconductor element or a wiring donating member forms an extremely narrow gap of 10 μm or less,
The gap can be easily filled with the epoxy resin composition for semiconductor encapsulation.

In the present invention, a silane coupling agent or a titanate coupling agent can be used within the range that does not impair the object of the invention. Here, as the silane coupling agent, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, β- (3,4-epoxycyclohexyl)
Epoxysilanes such as ethyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, N-β
(Aminoethyl) γ-aminopropylmethyldimethoxysilane, γ-aminopropyltrimethoxysilane, γ-
Aminosilanes such as ureidopropyltriethoxysilane, mercaptosilanes such as 3-mercaptopropyltrimethoxysilane, p-styryltrimethoxysilane, vinyltrichlorosilane, vinyltris (β-methoxyethoxy) silane, vinyltrimethoxysilane, vinyltriethoxysilane. , Vinyl silanes such as γ-methacryloxypropyltrimethoxysilane, epoxy-based,
Amino-type and vinyl-type polymer type silanes can be used.

On the other hand, as titanate coupling agents, isopropyl triisostearoyl titanate, isopropyl tri (N-aminoethyl aminoethyl) titanate, diisopropyl bis (dioctyl phosphate) titanate, tetraisopropyl bis (dioctyl phosphite) titanate, tetra Octyl bis (ditridecyl phosphite) titanate, tetra (2,2-
Diallyloxymethyl-1-butyl) bis (ditridecyl) phosphite titanate, bis (dioctyl pyrophosphate) oxyacetate titanate, bis (dioctyl pyrophosphate) ethylene titanate and the like can be used.

These coupling agents may be used alone or in combination of two or more. At this time, the coupling agent is preferably 0.1 to 1% by mass with respect to the total amount of the epoxy resin composition for semiconductor encapsulation, or 0.3 to 2% by mass with respect to the filler. The coupling agent may be used by previously treating the filler by a wet method or a dry method, or by performing an integral blending method of mixing with the resin regardless of whether the filler is mixed or not. You may.

Further, the epoxy resin composition for semiconductor encapsulation according to the present invention may contain other substances, if necessary, as long as the object of the present invention is not impaired. Examples of such substances include pigments used for coloring purposes, dispersants, emulsifiers, flame retardants, low elasticity agents, coloring agents such as carbon black, diluents, defoaming agents, ion trap agents, and the like. Various additives can be illustrated.

In order to prepare a uniform liquid epoxy resin composition for encapsulating a semiconductor, generally, the above-mentioned components are mixed with a stirring type disperser or dispersed with a bead mill. The present invention can be carried out by dispersing and mixing with the present roll, but is not limited to these methods. At this time, if a kneading or dispersing device having a strong shearing action such as a three-roll, kneader, or ball mill is used, the maximum particle size of the solid content in the semiconductor encapsulating epoxy resin composition can be 20 μm or less. However, in order to reduce the maximum particle size of the solid content to 5 μm or less, it is often difficult to efficiently prepare by the above-mentioned method.
It is preferable to use a device called a basket mill.
Since the epoxy resin composition for semiconductor encapsulation according to the present invention contains a latent (one-component) curing accelerator, there is no possibility that the reaction will proceed even if all the components are mixed. ,
Moreover, it is not necessary to mix a solvent.

Using the epoxy resin composition for semiconductor encapsulation obtained as described above, a semiconductor element and a wiring donating member for providing wiring thereto are adhered, and at least the semiconductor element and the wiring donating member are bonded together. The semiconductor device according to the present invention can be manufactured by sealing the wiring portion. Specifically, the following three methods can be exemplified. As described above, the wiring providing member includes not only the circuit board but also an electronic component such as a semiconductor element having a function equivalent to that of the circuit board.

The first method is to electrically connect the electrode of the semiconductor element and the wiring of the wiring providing member with a bonding wire or a gold bump, and then apply or print the epoxy resin composition for semiconductor encapsulation. Alternatively, the semiconductor element and the wiring portion of the wiring donating member are covered and cured by flowing into the gap. This method is generally called potting, print sealing, or capillary flow underfill.

The second method uses an epoxy resin composition for semiconductor encapsulation as a reflow simultaneous curing encapsulant or a no-flow encapsulant when electrically connecting a semiconductor element and a wiring donor by metal bumps. It is a thing. The wiring providing member in this case means a circuit board. Then, the epoxy resin composition for semiconductor encapsulation is applied to at least one of the surface of the semiconductor element on the circuit board side and the surface of the circuit board on the semiconductor element side. Then, the semiconductor element and the circuit board are brought into contact with each other via the epoxy resin composition for semiconductor encapsulation, while being heated to the melting temperature of the metal bump or the electrode of the circuit board, whichever is lower, to thereby form the semiconductor element. It is for metal-bonding to a circuit board for electrical connection, and for curing the epoxy resin composition for semiconductor encapsulation.

The third method is to press the semiconductor element and the wiring donating member under pressure when the semiconductor element and the wiring donating member are electrically connected by the metal bump. Also in this case, the wiring providing member means a circuit board. Then, the epoxy resin composition for semiconductor encapsulation is applied to at least one of the surface of the semiconductor element on the circuit board side and the surface of the circuit board on the semiconductor element side. Then, the semiconductor element and the circuit board are brought into pressure contact with each other via the epoxy resin composition for semiconductor encapsulation, or a metal bump or an electrode of the circuit board, whichever is the lower melting temperature, is heated by using a heater or ultrasonic waves at the time of press contact. By heating to, the semiconductor element and the circuit board are metal-bonded and electrically connected, and the epoxy resin composition for semiconductor encapsulation is cured.

In the epoxy resin composition for semiconductor encapsulation according to the present invention, it is possible to obtain high adhesion to the metal surface forming the wiring such as electrodes or circuits in the semiconductor element or the wiring donating member. The moisture resistance can be improved. Therefore, in a semiconductor device manufactured by using this epoxy resin composition for semiconductor encapsulation, reliability such as moisture resistance and heat cycle resistance is high, and further, bending resistance, impact resistance, and vibration resistance are high. And so on,
Even when the above semiconductor device is used in a card-type electronic device, a portable information device, or the like, extremely high reliability can be obtained.

[0057]

EXAMPLES The present invention will be specifically described below with reference to examples.

(Examples 1 to 10 and Comparative Examples 1 to 3) In Examples 1 to 10, the compounding amounts (parts by mass) shown in Tables 1 and 2 below were used, and in Comparative Examples 1 to 3, The epoxy resin composition for semiconductor encapsulation was prepared with the compounding amount (parts by mass) shown in Table 3 above.

Here, the raw materials used in Tables 1 to 3 are as follows.

(Epoxy resin) Resin A: Epoxy resin containing naphthalene ring (manufactured by Dainippon Ink and Chemicals, Inc., product number "HP-4032", epoxy equivalent 143) Resin B: Bisphenol A type epoxy resin (manufactured by Tohto Kasei Co., Ltd.) , Product number "YD-8125", epoxy equivalent 17
2) Resin C: Bisphenol F type epoxy resin (manufactured by Tohto Kasei Co., Ltd., product number “YDF-8170”, epoxy equivalent 1
60) (Curing agent) Curing agent A: terpene-based acid anhydride (manufactured by Yuka Shell Epoxy Co., Ltd., product number "YH-306", acid anhydride equivalent 23
4) Hardener B: Methylhexahydrophthalic anhydride (MHHP
A, manufactured by Dainippon Ink and Chemicals, Inc., product number “B-65
0 ", acid anhydride equivalent 168) Curing agent C: allylated phenol novolac (manufactured by Meiwa Kasei Co., Ltd., product number" MEH8000H ", hydroxyl equivalent 14
1) (Curing accelerator) Accelerator A: Amine adduct (manufactured by Ajinomoto Co., Inc., product number “Amicure PN23”) Accelerator B: Microcapsules containing imidazole as a core (manufactured by Asahi Chemical Industry Co., Ltd., product number “Nova Cure HX308
8 ”) (Additive) Additive A: 2-di-n-butylamino-4,6-dimercapto-s-triazine when only 2,4,6-trimercapto-s-triazine (reagent) is used When only (reagent) is used, 2,4,6-trimercapto-s-triazine and 2-di-n-butylamino-4,
It was divided into three cases when 6-dimercapto-s-triazine was used in combination (mass ratio 1: 1). That is, the components other than the additive A were not changed, and only the additive A was changed to. In addition, the compounding amount of each component is as shown in Tables 1 to 3 in any of the cases.

Additive B: Inorganic ion exchanger as an ion trap agent (composite oxide having a layered structure, manufactured by Toagosei Co., Ltd., product number "IXE-600") Additive C: carbon black (manufactured by Mitsubishi Chemical Corporation) , Part number "MA100") (Inorganic filler) Filler A: Spherical amorphous silica (manufactured by Denki Kagaku Kogyo Co., Ltd., part number "FB-6D", maximum particle size 45 μm, true specific gravity 2.2) Filler B: Spherical amorphous silica (manufactured by Mitsubishi Rayon Co., Ltd., product number “QS-4”, maximum particle size 14 μm, true specific gravity 2.
2) Filler C: Spherical amorphous silica (manufactured by Admatechs Co., Ltd., product number “SO-E2”, maximum particle size 3 μm, true specific gravity 2.
2) Filler D: rounded granular α-alumina (manufactured by Sumitomo Chemical Co., Ltd., product number “AA-5”, maximum particle size 20 μm,
True specific gravity 3.96) Filler E: Spherical α-alumina (Sumitomo Chemical Co., Ltd.,
Product number “AA-07”, maximum particle size 3 μm, true specific gravity 3.9
6) The manufacturing method adopted for preparing the epoxy resin composition for semiconductor encapsulation is as follows.

(Manufacturing Method A) Components other than the curing accelerator are mixed, and the mixture is mixed with a homomixer manufactured by Tokushu Kika Kogyo Co., Ltd. for 3000 to 500.
After being dispersed and mixed at 0 rpm, a curing accelerator was added, and the epoxy resin composition for semiconductor encapsulation was prepared by dispersing and mixing with a homodisper manufactured by Tokushu Kika Kogyo at 300 to 500 rpm.

(Manufacturing method B) Components other than the curing accelerator are mixed, dispersed and mixed by a three-roll mill, and then the curing accelerator is added, and the mixture is added to a special disperser, Homodisper 300-500.
An epoxy resin composition for semiconductor encapsulation was prepared by dispersing and mixing at rpm.

(Manufacturing method C) Components other than the curing accelerator are mixed, dispersed and mixed by a bead mill manufactured by Getzman, and
An epoxy resin composition for semiconductor encapsulation was prepared by adding a curing accelerator and dispersing and mixing with a homodisper manufactured by Tokushu Kika Kogyo at 300 to 500 rpm.

The manufacturing methods adopted for Examples 1 to 10 and Comparative Examples 1 to 3 are shown in the column of manufacturing methods in Tables 1 to 3.

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[Table 1]

[0067]

[Table 2]

[0068]

[Table 3]

In Tables 1 to 3 above, the equivalent ratio (1
00 :) indicates the curing agent equivalent to 100 epoxy equivalent, the filler volume% indicates the volume% of the inorganic filler in terms of true specific gravity, and the filler mass% indicates the epoxy resin composition for semiconductor encapsulation. The mass% of the inorganic filler in is shown.

In calculating the volume percentage of the inorganic filler converted to true specific gravity, the true specific gravity of the resin components other than the filler is 1.2, and the spherical amorphous silica of the filler C and the alumina of the filler D are For the mixture having a mass ratio of 2: 8 (in the case of Example 5), calculation was performed based on the true specific gravity of each, and the average specific gravity was 3.41.

Then, Examples 1 to 10 and Comparative Examples 1 to 3
The characteristics of the epoxy resin composition for semiconductor encapsulation obtained in 1. were measured by the following methods. The measurement results are shown in Tables 4 to 9 below.

(1) Viscosity of epoxy resin composition for semiconductor encapsulation It was measured at room temperature using a B type viscometer.

(2) Gel Time of Epoxy Resin Composition for Semiconductor Encapsulation About 0.5 g of the epoxy resin composition for semiconductor encapsulation was placed on a hot plate at 150 ° C., and timing was started to make a point. The resin state was observed while stirring with the tip of a Teflon (R) rod. When the resin hardened and became tackless, the time measurement was terminated and the gel time was calculated.

(3) Maximum particle size of epoxy resin composition for semiconductor encapsulation 100 μm at maximum in accordance with JIS K5600-2-5
The maximum particle size of the solid content in the composition was measured using a gauge of No. 3, a maximum of 50 μm, or a maximum of 25 μm.

(4) Adhesion Adhesion was evaluated by a shear tensile test with an adhesion area of 0.7 cm square. Specifically, the FR4 copper-clad double-sided plate with a thickness of 1.6 mm is gold-plated, and this is 0.7 cm width x 7 cm.
It was cut into a length, and a portion 1 cm from the end was thoroughly degreased with acetone. Using the plate thus obtained, two degreased ends were adhered to each other with an epoxy resin composition for semiconductor encapsulation, fixed with clips and cured. At this time, after reacting at 120 ° C. for 1 hour, further at 150 ° C. for 3 hours.
It was allowed to react for a period of time to cure. The specimen thus obtained was subjected to a shear tensile test to measure the adhesive force.

(5) PCT reliability FR5 circuit board with 12 mm square C as a semiconductor element
MOS (Complementary Metal-Oxide Semiconductor)
An evaluation IC in which the gate array IC was flip-chip connected by solder bumps was used. The distance between the circuit board and the semiconductor element is 150 μm. The evaluation IC is placed on a hot plate at 70 ° C. and heated, and the epoxy resin composition for semiconductor encapsulation of each of Examples and Comparative Examples is dispensed with a dispenser in one side of a gap formed between the semiconductor element and the circuit board. About 0.
1 cm ^{3 was} applied and the space between the semiconductor element and the circuit board was filled. Then, curing treatment was performed at 120 ° C. for 1 hour and subsequently at 150 ° C. for 3 hours. Then, the probe was applied to the gold-plated electrode of the circuit board to confirm the electrical operation, and the initial operation was confirmed. For each epoxy resin composition for semiconductor encapsulation, 10 good products were obtained and used as test samples. Then, for these test samples, a pressure cooker test at 121 ° C. at 2 atm (P
CT) was performed, and the operation of the sample under test was confirmed every 50 hours up to 1000 hours, and the quality was judged. The total processing time was calculated when the number of defects in 10 test samples reached more than half.

(6) 30 μm Infiltrating 10 μm on a slide glass so that the gap is 30 μm.
An evaluation element is manufactured by mounting a mm-square silicon chip.
This was used for the penetration test. Specifically, silver paste for die bonding is applied to the gold bumps of the silicon chip on which gold bumps are formed, and the load is controlled and mounted on a slide glass with a flip chip bonder, and the silver paste is dried and cured to evaluate the evaluation element. Got Then, this element was placed on a hot plate at 70 ° C. and heated, and about 0.1 c of the epoxy resin composition for semiconductor encapsulation was placed on one side of the gap between the chip and the glass.
m ^{3 was} applied. The time from this point until reaching the side opposite to the side coated with the epoxy resin composition for semiconductor encapsulation was measured. If this time is 30 seconds or less, it is “A”, if it exceeds 30 seconds and is 60 seconds or less, it is “A”, 6
Those exceeding 0 seconds and not more than 2 minutes were judged as “Δ”, and those exceeding 2 minutes were judged as “x”.

(7) Penetrability of 10 μm Using the evaluation element of the same glass substrate as in (6) prepared so that the gap was 10 μm, the infiltration property was evaluated by the same method and standard as in (6).

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[Table 4]

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[Table 5]

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[Table 6]

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[Table 7]

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[Table 8]

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[Table 9]

As can be seen in Tables 4-6, Examples 1-1
Comparing No. 0 with those of Comparative Examples 1 to 3, it is confirmed that all of the Examples have good adhesion and PCT reliability and can be used without problems in actual use.

Further, as shown in Tables 7 to 9, when the examples 4 to 10 are compared with the examples 1 to 3,
It is confirmed that they can be used without problems in applications where narrow area filling properties such as flip-chip mounting are required, since they all have the characteristic of having excellent penetration of 30 μm.

Further, each of Examples 8 to 10 has a feature that it has an excellent penetration property of 10 μm as compared with those of Examples 1 to 7, and is typified by flip chip mounting with an ultra-narrow gap. It has been confirmed that it can be used without problems in applications that require high ultra-narrow part filling properties.

On the other hand, it is confirmed that Comparative Examples 1 and 2 have extremely poor adhesion and PCT reliability and are not put to practical use. Further, the adhesiveness of Comparative Example 3 is not so bad as that of Comparative Examples 1 and 2, but it is confirmed that the PCT reliability is worse than that of each Example and is not put to practical use.

[0089]

As described above, the epoxy resin composition for semiconductor encapsulation according to claim 1 of the present invention is a semiconductor encapsulation liquid at room temperature which contains an epoxy resin, a curing agent and a latent curing accelerator as essential components. In the epoxy resin composition for stopping, as an epoxy resin, at least one of an epoxy resin having a naphthalene skeleton or a bisphenol skeleton is contained, and as a curing agent, an organic acid anhydride having a succinic anhydride structure that is liquid at room temperature and a room temperature. And containing at least one of compounds having a liquid phenol novolac skeleton, 2,4,6-trimercapto-s-triazine and 2-di-n-butylamino-4,6-dimercapto-s-triazine At least one of them is 0.01 to 3 with respect to the total amount of the epoxy resin composition for semiconductor encapsulation.
Since it contains mass%, before curing, it can be easily used as a one-component solventless liquid encapsulating material, and after curing, it is possible to obtain high adhesion to the metal surface, The moisture absorption rate can be kept low.

In the invention of claim 2, the total amount of the epoxy resin composition for semiconductor encapsulation is at least one of spherical amorphous silica and alumina having a maximum particle size of 0.5 to 20 μm as an inorganic filler. 20% in terms of true specific gravity
Since it contains 70% by volume, it can be preferably used even in applications where narrow portion filling properties such as flip chip mounting are required.

According to a third aspect of the present invention, the total amount of the epoxy resin composition for semiconductor encapsulation is at least one of spherical amorphous silica and alumina having a maximum particle size of 0.5 to 5 μm as an inorganic filler. 20 to 5 in terms of true specific gravity
Since the maximum particle size of the solid content in the epoxy resin composition for semiconductor encapsulation is 5 μm or less,
It can be preferably used even in applications requiring ultra-narrow portion filling property, as represented by flip-chip mounting with an ultra-narrow gap of 10 μm or less.

Further, in a semiconductor device according to a fourth aspect, at least a wiring portion of a semiconductor element and a wiring donating member for supplying wiring to the semiconductor element is formed by the epoxy resin composition for semiconductor encapsulation according to any one of the first to third aspects. Because it is sealed,
It has high reliability such as moisture resistance and heat cycle resistance, and is also excellent in bending resistance, shock resistance, vibration resistance, etc., and is used for the above-mentioned semiconductor device in card-shaped electronic devices and portable information devices. Also, it is possible to obtain extremely high reliability.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Shinji Hashimoto             1048, Kadoma, Kadoma-shi, Osaka Matsushita Electric Works Co., Ltd.             Inside the company (72) Inventor Hirohisa Hino             1048, Kadoma, Kadoma-shi, Osaka Matsushita Electric Works Co., Ltd.             Inside the company (72) Inventor Taro Fukui             1048, Kadoma, Kadoma-shi, Osaka Matsushita Electric Works Co., Ltd.             Inside the company F-term (reference) 4J036 AC01 AC05 AD08 AF15 DA04                       DA10 DB18 DC45 FB08 JA07                 4M109 AA01 BA05 CA04 EA02 EB02                       EC09

Claims (4)

[Claims] 1. An epoxy resin composition for semiconductor encapsulation, which is liquid at room temperature and contains an epoxy resin, a curing agent, and a latent curing accelerator as essential components, wherein the epoxy resin comprises an epoxy resin having a naphthalene skeleton or a bisphenol skeleton. At least one of them, and as a curing agent, at least one of an organic acid anhydride having a succinic anhydride structure which is liquid at room temperature and a compound having a phenol novolac skeleton which is liquid at room temperature, and 2,4 , 6
-Trimercapto-s-triazine and 2-di-n-butylamino-4,6-dimercapto-s-triazine in an amount of 0.01 to 3 relative to the total amount of the epoxy resin composition for semiconductor encapsulation. An epoxy resin composition for semiconductor encapsulation, characterized in that the epoxy resin composition contains 100 mass%. 2. The maximum particle size of the inorganic filler is 0.5 to 2
The spherical amorphous silica and / or alumina having a particle size of 0 μm is contained in an amount of 20 to 70% by volume in terms of true specific gravity with respect to the total amount of the epoxy resin composition for semiconductor encapsulation. Epoxy resin composition for semiconductor encapsulation. 3. The maximum particle size of the inorganic filler is 0.5-5.
20 to 50% by volume in terms of true specific gravity of the total amount of the epoxy resin composition for semiconductor encapsulation, containing at least one of spherical amorphous silica and alumina, which is μm, and
The epoxy resin composition for semiconductor encapsulation according to claim 1, wherein the maximum particle diameter of the solid content in the epoxy resin composition for semiconductor encapsulation is 5 μm or less. 4. A semiconductor element and at least a wiring portion of a wiring donating member for supplying wiring to the semiconductor element are sealed with the epoxy resin composition for semiconductor encapsulation according to any one of claims 1 to 3. Semiconductor device.