JP2001206931A - Epoxy resin composition for semiconductor sealing use and semiconductor device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the subject epoxy resin composition having a short gelling time and reduced dielectric constant responding to the tendency of higher frequency in view of the current situation that the semiconductor device technology is in progress in terms of design compatible with the tendency of higher frequency. SOLUTION: This epoxy resin composition essentially comprises the components (A) to (E) mentioned below; wherein the proportion for the components (A) and (C) is such that the equivalent ratio of the cyanate ester groups including the reacted groups in the component (C) to the epoxy groups in the component (A) is 0.10-2.00: (A) epoxy resin, (B) phenolic resin, (C) triazine resin, (D) curing promoter, and (E) inorganic filler.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a low-dielectric constant epoxy resin composition for semiconductor encapsulation having a significantly reduced relative dielectric constant, and a semiconductor device in which a semiconductor element is resin-encapsulated using the same. .

[0002]

2. Description of the Related Art Conventionally, transistors, IC, LS
A resin-encapsulated semiconductor device in which a semiconductor element such as I is resin-molded by transfer molding using an encapsulating material such as an epoxy resin composition is excellent in terms of reliability, mass productivity, low cost, and the like. Therefore, it is widely used together with a ceramic sealing type semiconductor device.

[0003]

However, in recent years, the functions and performance of semiconductor devices such as microprocessors have been improved and the operating frequency has tended to further increase. In the field of information and communication, small electronic devices such as mobile phones and PHSs have come to use frequency bands close to gigahertz with respect to their frequency bands, and further use gigahertz bands of two digits. At present, communications are also being developed.

As described above, as semiconductors become higher in frequency, semiconductor-encapsulated semiconductor devices having excellent high-frequency characteristics are often used for semiconductor devices that require high reliability. However, on the other hand, in reality, adoption of a low-cost resin-encapsulated semiconductor device excellent in mass productivity and various reliability as described above is being considered. For this reason, development of a low dielectric constant epoxy resin composition for a mold used in a resin-sealed semiconductor device is required.

As a low dielectric constant epoxy resin composition used for encapsulating a semiconductor device, for example, Japanese Patent Application Laid-Open No. 9-52
No. 941 discloses a cured product comprising a specific epoxy resin and a cyanate ester compound. However, this epoxy resin composition has a long gelling time,
It is very complicated to use, for example, requiring long-time low-pressure transfer molding, or the need to precisely mix and disperse a curing accelerator in order to adjust to a desired gel time. Also, JP-A-63-90531
In JP-A No. 2000-209, an epoxy resin and a polyvalent cyanate ester compound and a phenol novolak resin are compounded at a specific ratio, and an epoxy resin composition having a good balance of heat resistance, water resistance and electric properties is disclosed. . However, this epoxy resin composition does not mention anything about the dielectric properties, and it is hard to say that a suitable composition system and formulation for the epoxy resin composition exhibiting a low dielectric constant are clearly shown. Met.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and in a situation where the frequency of a semiconductor device is increasing, the relative dielectric constant corresponding to the increase in the frequency is reduced and the semiconductor encapsulation time is short. It is an object of the present invention to provide an epoxy resin composition for stopping and a semiconductor device resin-sealed using the same.

[0007]

In order to achieve the above object, the present invention provides an epoxy resin composition for semiconductor encapsulation containing the following components (A) to (E) as essential components: The content ratio of the component (A) to the component (C) is such that the cyanate ester group containing the reacted group of the component (C) is 0.10 to 1 equivalent of the epoxy group of the component (A).
A first subject matter is an epoxy resin composition for semiconductor encapsulation in which the equivalent ratio is set to be 2.00 equivalents. (A) Epoxy resin. (B) a phenolic resin. (C) Triazine resin. (D) a curing accelerator. (E) an inorganic filler.

[0008] A second aspect of the present invention is a semiconductor device in which a semiconductor element is encapsulated by using the epoxy resin composition for encapsulating a semiconductor.

The present inventor has already found that the hydroxyl group equivalent of the phenol resin is 1.02 to 1.2 equivalents and the cyanate ester group of the polyvalent cyanate ester compound is 0 to 1 equivalent of the epoxy group of the epoxy resin. .10 to 1.0
It has already been found that an epoxy resin composition having a low dielectric constant can be obtained when each component is used so as to have an equivalent ratio of 0 equivalent.

However, in the above-mentioned epoxy resin composition proposed by the present inventors, when each raw material is melt-kneaded by a hot roll or the like, a phenol novolak resin having a reactive cyanate ester group and active hydrogen is bonded to an imide carbonate. Is formed, and the melt viscosity sharply increases during melt-kneading, which makes kneading extremely difficult or, in some cases, causes gelation or the like.
For melt-kneading at about 5 ° C., short-time kneading of about 2 to 3 minutes has been proposed.

Therefore, the present inventor has conceived that if the reactivity of the cyanate ester group of the polyvalent cyanate ester compound proposed above is reduced, the formability of the imide carbonate bond can be reduced. Further research was conducted to further improve workability at the time. As a result, they have found that it is useful to use a triazine resin having a triazine ring.

The inventor of the present invention firstly formulated a triazine resin, which is an essential component, in order to obtain an epoxy resin composition which is excellent in high-frequency characteristics and has a low dielectric constant and a short gelling time. Focusing on the amount, the research was repeated focusing on the equivalent ratio of the cyanate ester group containing the reacted group to the epoxy group of the component. As a result, when the equivalent ratio of the cyanate ester group containing the reacted group of the triazine resin to the equivalent of 1 epoxy group of the epoxy resin is 0.10 to 2.00 equivalents, the above object is achieved. The inventors have found that the present invention has been achieved.

Further, when the epoxy resin and the phenol resin are used in combination so that the total of the epoxy equivalent of the epoxy resin and the hydroxyl equivalent of the phenol resin becomes a specific value or more, the epoxy resin composition having a further lower dielectric constant can be obtained. Is obtained.

That is, although it is well known that an inexpensive resin encapsulation of a semiconductor element is performed by using an epoxy resin composition, it is not easy to simply use an epoxy resin and a phenol resin which have been conventionally used. It has been found that the dielectric constant is relatively high due to the high polarity of the secondary alcoholic hydroxyl group generated after the curing reaction in the cured product.
The present inventor has found that by reducing the concentration of the secondary alcoholic hydroxyl group generated after the curing reaction, the polarity can be reduced as a result, and the relative dielectric constant of the cured product can be reduced. is there.

In particular, the specific epoxy resin represented by the formula (1) is used as the epoxy resin as the component (A), and the phenol resin as the component (B) is used as the epoxy resin as the component (B). When the specific phenolic resin represented is used in combination, the total value of the epoxy equivalent and the hydroxyl equivalent is particularly high, and the relative permittivity of the obtained cured epoxy resin composition is further reduced, which is particularly preferable.

Further, when a polyethylene wax is used as a release agent, the polyethylene wax has a very low content of active hydrogen which reacts with a cyanate ester group, so that the curing reaction of the epoxy resin composition is inhibited. Is preferred.

[0017]

Next, embodiments of the present invention will be described in detail.

The epoxy resin composition for semiconductor encapsulation of the present invention comprises an epoxy resin (component A), a phenol resin (component B), a triazine resin (component C), and a curing accelerator (D
Component E) and an inorganic filler (Component E), and is usually in the form of a powder or a tablet obtained by compressing the powder. Alternatively, the epoxy resin composition is melt-kneaded and then formed into a substantially columnar granule.

The epoxy resin (component A) is not particularly limited as long as it is a solid at ordinary temperature (25 ° C.), and various conventionally known epoxy resins can be used. For example, cresol novolak type epoxy resin, allylphenol novolak type epoxy resin, phenol novolak type epoxy resin, biphenyl type epoxy resin, naphthalene type epoxy resin, bisphenol A type novolak type epoxy resin, phenol aralkyl type epoxy resin, fluorene type epoxy resin, diene Various epoxy resins such as a cyclopentadiene-based epoxy resin, a biphenyl-based epoxy resin obtained by reacting epichlorohydrin with a reaction product of a phenol and a biphenyl-based condensing agent, and derivatives thereof. These epoxy resins can be used alone or
Used in combination of more than one species. More preferably, it is preferable to use an epoxy resin in which the total value of the epoxy equivalent of the epoxy resin and the hydroxyl equivalent of the phenol resin described below is a specific value or more, and as a result, after the formation reaction of the cured product, The concentration of the formed secondary alcoholic hydroxyl group can be reduced. As such an epoxy resin,
Specifically, an epoxy resin represented by the following formula (1):
Examples include an epoxy resin represented by the following formula (4), an epoxy resin represented by the following formula (5), and an epoxy resin represented by the following formula (6).

[0020]

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[0021]

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[0022]

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[0023]

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The phenol resin (component B) serves as a curing agent for the epoxy resin (component A), and is not particularly limited as long as it is solid at ordinary temperature (25 ° C.). Resin is used. For example, phenol novolak, cresol novolak,
Examples include various phenolic resins such as bisphenol A type novolak, naphthol novolak, phenol aralkyl resin, fluorene novolak, dicyclopentadiene novolak, and novolak composed of a reaction product of a phenol and a biphenyl condensing agent, and derivatives thereof. These phenolic resins may be used alone or
Used in combination of more than one species. More preferably, it is preferable to use a phenol resin such that the total value of the hydroxyl equivalent of the phenol resin and the epoxy equivalent of the above-mentioned epoxy resin is a specific value or more, and as a result, after the formation reaction of the cured product, The concentration of the formed secondary alcoholic hydroxyl group can be reduced. As such a phenol resin, specifically, a phenol resin represented by the following formula (2), a phenol resin represented by the following formula (7), and a phenol resin represented by the following formula (8) Resin, the following formula (9)
A phenolic resin represented by

[0025]

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[0026]

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[0027]

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[0028]

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The mixing ratio of the epoxy resin (component A) and the phenol resin (component B) is such that the hydroxyl equivalent in the phenol resin is 0.1 to 1 equivalent of the epoxy group of the epoxy resin.
It is preferable to set in the range of 6 to 1.4 equivalents. More preferably, it is 0.8 to 1.2. That is, when the ratio of the equivalent of the hydroxyl group of the phenolic resin (component B) is less than 0.6 or more than 1.4, the gelation time suitable for low-pressure transfer molding tends to be long.

The triazine resin (component C) used together with the epoxy resin (component A) and the phenol resin (component B) is a so-called cyanate ester prepolymer having a triazine ring. It is obtained by homopolymerization. As such a polyvalent cyanate ester compound monomer, specifically, bis (3,5-dimethyl-4)
-Cyanate phenyl) methane, bis (4- cyanate phenyl) methane, bis (3-ethyl-4- cyanate phenyl) methane, bis (4- cyanate phenyl)-
1,1-ethane, bis (4-cyanatephenyl)-
2,2-propane, di (4-cyanatephenyl) ether, di (4-cyanatephenyl) thioether,
4,4 '-{1,3-phenylenebis (1-methylethylidene)} biphenyl cyanate, 2,2-bis (4-
A divalent cyanate ester compound such as cyanate phenyl) -1,1,1,3,3,3-hexafluoropropane; tris (4-cyanate phenyl) -1,1,1-
Various polyvalent cyanate ester compound monomers such as trivalent cyanate ester compounds such as ethane and bis (3,5-dimethyl-4-cyanatophenyl) -4-cyanatephenyl-1,1,1-ethane are exemplified. These polyvalent cyanate ester compound monomers may be used alone or
Used in combination of more than one species.

Among the above polyvalent cyanate ester compound monomers, bis (3,5-dimethyl-4-cyanatephenyl) methane represented by the following formula (3) whose structure itself has a low dielectric constant skeleton is used. Is particularly preferred.

[0032]

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The above triazine resin (component C) can be prepared, for example, as follows. That is, by using the above polyvalent cyanate ester compound monomer and heating it at a temperature of 120 to 200 ° C. without a catalyst, or as a reaction catalyst, for example, cobalt octylate, zinc octylate, manganese naphthenate, Metal chelate compounds such as copper naphthenate, zinc naphthenate, lead naphthenate, tin naphthenate, nickel naphthenate, iron naphthenate and other organic metal salts, acetylacetonate such as copper acetylacetonate, cobalt acetylacetonate and the like. By adding and heating to about 1000 ppm, it can be converted to a triazine resin, and a desired triazine resin can be produced.

For example, a cyanate ester prepolymer having a triazine ring when bis (3,5-dimethyl-4-cyanatephenyl) methane represented by the above formula (3) is used has a structure as shown below. Become. The “reacted group” of the “cyanate ester group containing the reacted group of the component (C)” in the present invention means a part corresponding to a cyanate ester group in a cyclized structure formed by a trimerization reaction, For example, in the structural formula (A) shown below, it refers to the following (B) portion.

[0035]

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The triazine resin (component (C)) thus obtained, which is a cyanate ester prepolymer having a triazine ring, is preferably a triazine resin having a trimerization conversion to triazine of 35% or more, more preferably. The trimerization conversion is 40-60%. That is, if the conversion to trimerization is less than 35%, an imide carbonate bond between a reactively active cyanate ester group and a phenol novolak resin having active hydrogen is easily formed, which is not preferable. Further, when it exceeds 60%, gelation occurs, which is not preferable.

The triazine resin preferably has a weight average molecular weight in the range of 1,000 to 5,000, and particularly preferably has a weight average molecular weight of 2,000 to 30,
00 range.

The mixing ratio of the triazine resin (component C) is such that the cyanate ester group containing the reacted group of the triazine resin (component C) is 0.1 equivalent to 1 equivalent of the epoxy group of the epoxy resin (component A). It is necessary to set the equivalent ratio to a ratio of 10 to 2.00 equivalents. Particularly preferably, the equivalent ratio of the cyanate ester group containing the reacted group of the triazine resin (component C) to 0.50 to 1.00 equivalent is set to 1 equivalent of the epoxy group of the epoxy resin (component A). That is. That is, the cyanate ester group containing the already reacted group is out of the above range, for example,
When the amount of the cyanate ester group containing the reacted group is less than 0.10 equivalent, the effect of reducing the relative dielectric constant aimed at by the present invention is not obtained, and the amount of the cyanate ester group containing the reacted group is 2.00.
If the equivalent amount is exceeded, the effect of reducing the relative permittivity, which is the object of the present invention, becomes saturated, which wastes economically and prolongs the gelation time suitable for low-pressure transfer molding.

As described above, by containing a cyanate ester group in the epoxy resin composition, the concentration of hydroxyl groups contained in the cured product of the epoxy resin composition can be reduced, and as a result, low dielectric constant can be obtained. Although the efficiency can be improved, it is difficult to control the curing reactivity as a molding material. The present invention is characterized in that, for example, a triazine is trimerized from a reactively active cyanate ester compound to reduce the activity and facilitate the use, and the range of use of a phenol resin acting as a curing agent for an epoxy resin is broadened. Further, the present invention is characterized in that the melt-kneading time is extended to enhance the workability.

The curing accelerator (component D) used together with the above components A to C is not particularly limited, and is a conventionally known one, specifically, 1,8-diazabicyclo (5,4,0). ) Tertiary amines such as undecene-7 and triethylenediamine; imidazoles such as 2-methylimidazole; and phosphorus-based curing accelerators such as triphenylphosphine and tetraphenylphosphonium tetraphenylborate. On the other hand, organic metal salts such as cobalt octylate, zinc octylate, manganese naphthenate, copper naphthenate, zinc naphthenate, lead naphthenate, tin naphthenate, nickel naphthenate, iron naphthenate, copper acetylacetonate, and cobalt acetyl Metal chelate compounds such as acetylacetonate such as acetonate can also be used. These curing accelerators can be used alone or in combination of two or more.

The content of the curing accelerator (component D) is 0.1 to 100 parts by weight of the phenol resin (component B).
It is preferable to set in the range of 5 to 10 parts by weight.

As the inorganic filler (component E) used together with the above components A to D, various inorganic fillers conventionally used are used. For example, silica powder such as fused silica, alumina, silicon nitride, aluminum nitride,
Examples include boron nitride, magnesia, calcium silicate, magnesium hydroxide, titanium white, and the like. Among them, spherical silica powder, milled silica powder, crushed silica powder and the like are preferably used. In particular, it is preferable to use spherical fused silica powder. And it is preferable to use a thing with a maximum particle diameter of 100 micrometers or less as said inorganic filler. Further, the average particle size is 1 to 20 together with the maximum particle size.
It is preferable to use one in the range of μm. The maximum particle size and the average particle size can be measured using, for example, a laser diffraction / scattering type particle size distribution analyzer.

The content of the inorganic filler (component E) is preferably set in the range of 50 to 90% by weight in the entire epoxy resin composition. More preferably 60 to 8
0% by weight. That is, when the content ratio of the inorganic filler exceeds 90% by weight, the ratio of the relative dielectric constant of the inorganic filler such as silica powder of the cured epoxy resin composition for sealing increases, so that the present invention This is because there is a tendency to be incompatible with the lowering of the dielectric constant which is the object of the above.

The epoxy resin composition for encapsulating a semiconductor of the present invention contains the above-mentioned epoxy resin (component A), phenol resin (component B), triazine resin (component C), curing accelerator (component D) and inorganic material. In addition to the filler (component E), various additives such as a release agent, a stress reducing agent, a pigment, a flame retardant, and a coupling agent can be appropriately compounded as needed.

Examples of the releasing agent include polyethylene wax, carnauba wax, fatty acid salt and the like. Among them, polyethylene waxes are preferable because the content of active hydrogen that reacts with the cyanate ester group is extremely low, and the risk of inhibiting the curing reaction of the epoxy resin composition is low.

Examples of the above-mentioned stress reducing agent include silicone compounds such as side chain ethylene glycol type dimethylsiloxane, acrylonitrile-butadiene rubber and the like.

Examples of the pigment include carbon black and titanium oxide.

The flame retardant includes a halogen-based flame retardant such as a brominated epoxy resin, and a flame retardant auxiliary such as antimony trioxide is used as the flame retardant.

Further, in addition to the halogen-based flame retardant, a polyhedral composite metal hydroxide represented by the following general formula (10) can be used. This composite metal hydroxide has a polyhedral crystal shape and has a conventional hexagonal plate shape, or a so-called thin plate-like crystal shape such as a scale-like shape. Rather, the crystal growth in the thickness direction (c-axis direction) is large both vertically and horizontally. Crystal shape, for example, approximately dodecahedron, approximately octahedron,
A composite metal hydroxide having a shape such as a substantially tetrahedron.

[0050]

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Regarding the composite metal hydroxide represented by the general formula (10), M representing the metal element in the formula (10) is represented by Al, Mg, Ca, Ni, Co, Sn, Zn,
Cu, Fe, Ti, B and the like can be mentioned.

The Q representing another metal element in the composite metal hydroxide represented by the general formula (10) is, for example, Fe, Co, Ni, Pd, Cu, Zn or the like. Selected alone or in combination of two or more.

The composite metal hydroxide having such a polyhedral crystal shape can be obtained, for example, by controlling various conditions in the production process of the composite metal hydroxide.
Obtaining a composite metal hydroxide having a desired polyhedral shape, such as a substantially dodecahedral, a substantially octahedral, or a substantially tetrahedral shape, in which crystal growth in the thickness direction (c-axis direction) is large both vertically and horizontally. And usually consists of these mixtures.

Specific typical examples of the composite metal hydroxide having the polyhedral shape include hydrates of magnesium oxide / nickel oxide, hydrates of magnesium oxide / zinc oxide, and hydrates of magnesium oxide / copper oxide. Japanese products.

The composite metal hydroxide having the above polyhedral shape includes a particle size distribution (α) shown below.
It is preferable to have (γ). In addition, a laser type particle size analyzer is used for the measurement of the particle size distribution shown below.
(Α) 10 to 35% by weight having a particle size of less than 1.3 μm.
(Β) 50 to 65 particles having a particle size of less than 1.3 to 2.0 μm
weight%. (Γ) 10-30 particles having a particle size of 2.0 μm or more
weight%.

The aspect ratio of the composite metal hydroxide having the above-mentioned polyhedral shape is usually 1 to 8, preferably 1 to 8.
To 7, particularly preferably 1 to 4. The term “aspect ratio” as used herein refers to the ratio of the major axis to the minor axis of the composite metal hydroxide. That is, when the aspect ratio exceeds 8, the effect of lowering the viscosity when the epoxy resin composition containing the composite metal hydroxide is melted becomes poor. When used as a component of the epoxy resin composition for semiconductor encapsulation of the present invention, one having an aspect ratio of 1 to 4 is generally used.

Further, as the coupling agent, γ-
Glycidoxypropyltrimethoxysilane, β- (3,
Silane coupling agents such as 4-epoxycyclohexyl) ethyltrimethoxysilane.

In the epoxy resin composition for semiconductor encapsulation of the present invention, the total value (X + Y) of the epoxy equivalent X of the epoxy resin (component A) and the hydroxyl equivalent Y of the phenol resin (component B) is 350 or more. As such, it is preferable to use a combination of an epoxy resin and a phenol resin. In particular, a combination in which the total value (X + Y) of the epoxy equivalent X and the hydroxyl equivalent Y is 400 or more is preferable. The upper limit of the total value (X + Y) of the epoxy equivalent X and the hydroxyl equivalent Y is usually about 2000. That is,
This is because the effect of further reducing the relative dielectric constant of the cured epoxy resin composition can be obtained by using a combination such that the total value (X + Y) becomes 350 or more. In the combination of the epoxy resin (component A) and the phenol resin (component B), the total value of the epoxy equivalent and the hydroxyl equivalent is particularly high, and a sufficient effect of reducing the relative dielectric constant can be obtained. It is preferable to use a combination of the epoxy resin represented by the formula (1) and the phenol resin represented by the formula (2). When two or more epoxy resins as the component A are used in combination, the weight average value of the epoxy equivalents of the plurality of epoxy resins becomes the epoxy equivalent X, and two or more of the phenol resins as the component B are used in combination. In this case, the weight average value of the hydroxyl equivalents of the plurality of phenol resins is the above-mentioned hydroxyl equivalent Y. The epoxy equivalent and the hydroxyl equivalent are each represented by g / eq. In the present invention, the total value (X + Y) of the epoxy equivalent X and the hydroxyl equivalent Y does not include the epoxy equivalent of the epoxy resin used as a flame retardant such as the brominated epoxy resin described above.

The epoxy resin composition for semiconductor encapsulation of the present invention can be produced, for example, as follows. That is, the epoxy resin (component A), the phenol resin (component B), the triazine resin (component C), the curing accelerator (component D), the inorganic filler (component E), and other additives as necessary. The desired amount of the epoxy resin composition is obtained by a series of steps in which a fixed amount is blended, sufficiently mixed by melting and dispersing using a hot roll, an extruder, a kneader, etc., followed by cooling and pulverization, and optionally compression molding into a tablet. Can be manufactured.

The encapsulation of the semiconductor element using the thus obtained epoxy resin composition is not particularly limited, and can be performed by a known molding method such as ordinary low pressure transfer molding.

The semiconductor device obtained in this manner is characterized in that, in the epoxy resin composition used as the sealing resin composition, a cyanate ester group containing a reacted group of the triazine resin is added to one equivalent of the epoxy group of the epoxy resin. Is a specific ratio, so that an epoxy resin composition having a short gelation time is obtained, and the epoxy resin composition has a low dielectric constant in which the relative dielectric constant is significantly reduced,
The semiconductor device has high frequency characteristics.

Next, examples will be described together with comparative examples.

First, the following components were prepared.

[Epoxy resin a] An epoxy resin represented by the following formula (a) (epoxy equivalent: 195 g / eq, softening point: 74 ° C.)

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[Epoxy resin b] An epoxy resin represented by the following formula (b) (epoxy equivalent: 192 g / eq, melting point: 107 ° C.)

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[Epoxy resin c] An epoxy resin represented by the following formula (c) (epoxy equivalent: 273 g / eq, softening point: 61 ° C.)

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[Epoxy resin d] An epoxy resin represented by the following formula (d) (epoxy equivalent: 290 g / eq, softening point: 95 ° C.)

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[Phenol resin a] A phenol resin represented by the following formula (a) (hydroxyl equivalent: 106 g / eq, softening point: 82 ° C.)

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[Phenol resin b] A phenol resin represented by the following formula (b) (hydroxyl equivalent 162 g / eq, softening point 60 ° C.)

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[Phenol resin c] A phenol resin represented by the following formula (c) (hydroxyl equivalent 170 g / eq, softening point 70 ° C.)

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[Phenol resin d] A phenol resin represented by the following formula (d) (hydroxyl equivalent: 208 g / eq, softening point: 69 ° C.)

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[Triazine resin] A cyanate ester compound represented by the following formula (e) (cyanate ester group equivalent: 153;
The reaction was carried out for 0 hour to prepare a prepolymer, a triazine resin as a trimerized cyclocyclized compound [trimerization conversion: 42%, viscosity: 15 dPa · s (at 150 ° C), softening point: 70 ° C, weight average molecular weight: 2500]

[0073]

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[Curing accelerator] Tetraphenylphosphonium tetraphenylborate

[Silica Powder] Spherical fused silica powder (maximum particle size 96 μm, average particle size 15 μm)

[Releasing agent] Polyethylene wax

[Flame retardant] Brominated phenol novolak type epoxy resin (epoxy equivalent: 280)

[Flame retardant aid] Antimony trioxide

[Pigment] Carbon black

[Silane coupling agent] β- (3,4-
Epoxycyclohexyl) ethyltrimethoxysilane

[0081]

Examples 1 to 6 and Comparative Examples 1 to 4 The respective raw materials shown in the following Tables 1 and 2 were simultaneously blended in the proportions shown in the same table, and were melted and kneaded for a short time with a hot roll heated to 95 ° C. The kneading time is shown in Tables 1 and 2 below).
A powdered epoxy resin composition having a mesh pass was obtained.

[0082]

[Table 1]

[0083]

[Table 2]

Using the thus obtained powdered epoxy resin compositions of Examples and Comparative Examples, the gel time, relative dielectric constant and glass transition temperature were measured according to the following methods. The results are shown in Tables 3 and 4 below.

[Gelling time] The gelling time of each of the above powdered epoxy resin compositions was measured as follows. That is, after kneading the above-mentioned powdered epoxy resin composition with a hot roll, cooling and pulverizing the mixture, 0.2 to 0.5 g of the powdered epoxy resin composition having a 10-mesh pass was added at 175 ± 1 ° C.
And then thinly stretched while melting. Then, the measurement by the stopwatch was started when the entire sample was melted, and when the fluidity disappeared, the measurement by the stopwatch was terminated, and the time during that period was read. The above operation was performed at least twice using the same sample, and the measurement was performed. The average value was defined as the gel time.

[Measurement of Relative Dielectric Constant] After transfer molding was performed under the conditions of a molding pressure of 6.9 MPa, a mold temperature of 175 ° C. and a molding time of 2 minutes using each of the above powdered epoxy resin compositions, post-curing was performed at 175 ° C. C. for 5 hours to prepare a disk-shaped cured product having a thickness of 3 mm and a diameter of 50 mm. And the diameter of the main electrode is 30 mm using silver paste,
After preparing a silver electrode having a guard electrode diameter of 32 mm and a counter electrode diameter of 45 mm, a measurement frequency of 1 MHz and a temperature of 25 ° C.
, The capacitance of the cured product was measured, and the relative permittivity was calculated by the following equation.

[0087]

(Equation 1)

[Glass Transition Temperature] A cured product having a length of 20 mm × a width of 3 mm × a thickness of 3 mm was prepared by the same transfer molding as described above using each of the above powdered epoxy resin compositions, and after 5 hours at 175 ° C. The glass transition temperature after curing was measured at a heating rate of 5 ° C./min using a thermomechanical analyzer (TMA device manufactured by Rigaku Corporation, model number: MG800GM).

[0089]

[Table 3]

[0090]

[Table 4]

As a result of the above Tables 3 and 4, all of the products of Examples were short in gelling time and low in dielectric constant so as to be suitable for low-pressure transfer molding even after a sufficient melt-kneading step. Above all, examples in which the total value of the epoxy equivalent and the hydroxyl equivalent is particularly high, the ratio of the equivalent of the cyanate ester group containing the reacted group to the equivalent of the epoxy resin c and the equivalent of the phenol resin d is 1 or more, and the equivalent is within the proper range. In the first and sixth products, the effect of reducing the relative dielectric constant was particularly remarkable. Also, the glass transition temperature was not a remarkably inferior value as a cured product of the epoxy resin composition for semiconductor encapsulation. In contrast, the products of Comparative Examples 1 to 3 had a short gelation time, but had a high relative dielectric constant. Also,
The product of Comparative Example 4 had a low relative dielectric constant but a long gelation time. More specifically, in Example 4 and Comparative Example 2 using the same epoxy resin and phenol resin, Example 4 in which the triazine resin was used to have a specific ratio had a low relative permittivity, and the effect of reducing the relative permittivity was low. It turns out that it is excellent. As described above, in the comparative example, a product satisfying both the achievement of a short gelation time and the low dielectric constant was not obtained.

[0092]

As described above, the present invention sets and contains a cyanate ester group containing a reacted group of a triazine resin in a specific equivalent ratio to one equivalent of an epoxy group of an epoxy resin. Epoxy resin composition for semiconductor encapsulation. Therefore, a material having a low dielectric constant with a reduced relative dielectric constant and a short gelation time can be obtained. Therefore, a semiconductor device encapsulated with the epoxy resin composition for semiconductor encapsulation has excellent high-frequency characteristics corresponding to high frequencies.

Further, by setting the sum of the epoxy equivalent of the epoxy resin and the hydroxyl equivalent of the phenol resin to be a specific value or more, the relative dielectric constant can be further reduced.

Then, when the specific epoxy resin represented by the formula (1) is used as the epoxy resin, and the specific phenol resin represented by the formula (2) is used as the phenol resin in combination. The relative permittivity of the cured epoxy resin composition is further reduced.

When a polyethylene wax is used as a mold release agent, the content of active hydrogen that reacts with a cyanate ester group is remarkably small, so that the curing reaction of the epoxy resin composition is inhibited. Is preferred.

Thus, the semiconductor device of the present invention has the conventional features of being excellent in various kinds of reliability and mass productivity and being inexpensive, and has a resin encapsulation that can handle a high frequency. Semiconductor device, which can be said to be an excellent alternative to the conventional ceramic encapsulated semiconductor device.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01L 23/29 H01L 23/30 R 23/31 F-term (Reference) 4J002 CC04X CD03W CD04W CD05W CD06W CM023 DE077 DE137 DE147 DF017 DJ007 DJ017 EE046 EG046 EN036 EU016 EU116 EW176 EY016 FD090 FD130 FD156 FD160 GQ05 4J036 AA01 AC01 AC02 AC03 DA06 DB05 DC02 DC41 DC45 DC46 DD07 FA03 FA05 FB02 FB08 FB09 GA04 GA06 GA12 GA13 EC03 JA03 EB07 EC07 JA07 4M109 A

Claims (8)

[Claims] 1. An epoxy resin composition for semiconductor encapsulation containing the following components (A) to (E) as essential components, wherein the content ratio of the components (A) and (C) is as follows: The cyanate ester group containing the reacted group of the component (C) is used in an amount of 0.10 to 1 equivalent of the epoxy group of the component (A).
An epoxy resin composition for semiconductor encapsulation, wherein the equivalent ratio is set so as to be 2.00 equivalent. (A) Epoxy resin. (B) a phenolic resin. (C) Triazine resin. (D) a curing accelerator. (E) an inorganic filler. 2. The epoxy resin composition for semiconductor encapsulation according to claim 1, wherein the triazine resin as the component (C) is a cyanate ester prepolymer having a triazine ring. 3. The total value (X + Y) of the epoxy equivalent X of the epoxy resin (A) and the hydroxyl equivalent Y of the phenol resin (B) is set to be 350 or more. 3. The epoxy resin composition for semiconductor encapsulation according to 1 or 2. 4. The epoxy resin as the component (A),
An epoxy resin represented by the following general formula (1), wherein the phenol resin as the component (B) is represented by the following formula (2)
The epoxy resin composition for semiconductor encapsulation according to any one of claims 1 to 3, which is a phenol resin represented by the following formula: Embedded image Embedded image 5. The triazine resin according to claim 1, wherein the triazine resin as the component (C) has a trimerization conversion to triazine obtained by homopolymerizing a cyanate ester compound monomer of 35% or more. The epoxy resin composition for semiconductor encapsulation according to claim 1. 6. The method according to claim 5, wherein the cyanate ester compound monomer is a monomer represented by the following formula (3).
The epoxy resin composition for semiconductor encapsulation according to the above. Embedded image 7. The epoxy resin composition for semiconductor encapsulation according to claim 1, further comprising a polyethylene wax together with the components (A) to (E). 8. A semiconductor device comprising a semiconductor element encapsulated with the epoxy resin composition for semiconductor encapsulation according to claim 1.