JP6980986B2 - Resin compositions for semiconductor encapsulation and semiconductor devices - Google Patents

Description

The present invention relates to a resin composition for encapsulating a semiconductor and a semiconductor device.

So far, various studies have been conducted on encapsulants for encapsulating semiconductor devices. In particular, the filler dispersed in the encapsulant is under particular study. In the encapsulant described in Patent Document 1, black titanium oxide having an α-ray shielding property is used as a filler. It is described that this can reduce the amount of α-ray emission of the encapsulant to 0.1 cph / cm ^2.

JP-A-2015-117302

However, as a result of the study by the inventor of the present application, the required characteristics are increasing as the semiconductor element becomes thinner. Therefore, in the encapsulant described in Patent Document 1, there is room for improvement in the control stability of the semiconductor element. Turned out to have.

After various studies on fillers, the present inventor focused on cristobalite, which can impart rigidity to the encapsulant. On the other hand, we have proceeded with a concrete study on the relationship between the control stability required for thin semiconductor devices in recent years and the α-dose emitted from the encapsulant.
Further diligent research based on these findings revealed that the α-ray dose emitted from the encapsulant can be kept below a predetermined value by appropriately controlling the amount of α-rays emitted from cristobalite and its dispersibility. We have found that it is possible to provide a sealing material having excellent control stability of a thin semiconductor element, and have completed the present invention.

According to the present invention
(A) Epoxy resin and
(B) Hardener and
A resin composition for semiconductor encapsulation containing (C) an inorganic filler containing cristobalite.
_{The linear expansion coefficient α 2} of the cured product of the semiconductor encapsulating resin composition at the glass transition temperature or higher is 30 ppm / K or more and 67 ppm / K or less .
The spiral flow of the semiconductor encapsulating resin composition is 135 cm or more and 230 cm or less.
A semiconductor encapsulating resin composition having an α dose in a cured product of the semiconductor encapsulating resin composition measured using an α-ray counter is 0.000 cf / cm ² or more and 0.005 cf / cm ² or less. Provided.

Further, according to the present invention,
With the board
The semiconductor element mounted on one surface of the substrate and
A semiconductor device comprising a sealing material layer for encapsulating the semiconductor element.
A semiconductor device is provided in which the encapsulant layer is a cured product of the semiconductor encapsulating resin composition.

According to the present invention, it is possible to provide a semiconductor encapsulation resin composition used as a encapsulant having excellent control stability of a semiconductor element, and a semiconductor device using the same.

It is sectional drawing which shows an example of the semiconductor device. It is sectional drawing which shows an example of a structure.

Hereinafter, embodiments will be described with reference to the drawings as appropriate. In all drawings, similar components are designated by the same reference numerals, and description thereof will be omitted as appropriate.

[Resin composition for semiconductor encapsulation]
The resin composition for semiconductor encapsulation of the present embodiment contains (A) an epoxy resin, (B) a curing agent, and (C) an inorganic filler containing cristobalite. In the present embodiment, the α dose in the cured product of the semiconductor encapsulating resin composition measured using the α ray counter ^{can be 0.005 cf / cm 2} or less.

The semiconductor encapsulating resin composition of the present embodiment is used to form a encapsulating resin layer for encapsulating a semiconductor element (semiconductor chip or the like) mounted on a substrate. The encapsulating resin layer is composed of a cured body (encapsulating material) of the semiconductor encapsulating resin composition of the present embodiment.

Here, the required level of control stability is increasing as semiconductor devices become thinner, miniaturized, and highly integrated.
On the other hand, as a result of the study by the present inventor, it has been found that the α dose released from the encapsulant can be controlled to a predetermined value or less by using cristobalite having a reduced impurity content. It was also found that by increasing the dispersibility of the cristobalite, the variation in the amount of α-dose released in the encapsulant is reduced. As described above, it is possible to provide a sealing material having excellent control stability of a thin semiconductor element.

Here, as the semiconductor element becomes finer and more integrated, the amount of electric charge accumulated in the memory element becomes smaller, so that unexpected influences (for example, data change) due to α rays emitted from the outside are likely to occur. It's coming. Similarly, since the magnitude of the current flowing through the semiconductor element is also small, the noise generated by the α-rays becomes relatively large, and malfunctions are likely to occur. On the other hand, according to the semiconductor encapsulating resin composition of the present embodiment, excellent control stability is realized for such a finely divided and highly integrated semiconductor element (particularly a memory element). Can be done.

Further, as the layer of the semiconductor element becomes thinner, the warp of the semiconductor device tends to affect the reliability. On the other hand, the resin composition for encapsulating a semiconductor of the present embodiment can sufficiently suppress the warp of the semiconductor device, as will be described later.
The semiconductor encapsulating resin composition of the present embodiment can also be applied to various electronic components other than semiconductor devices.

The composition of the resin composition for semiconductor encapsulation of the present embodiment will be described.

[(A) Epoxy resin]
As the (A) epoxy resin in the present embodiment, a monomer, an oligomer, or a polymer having two or more epoxy groups in one molecule can be used in general, and the molecular weight and molecular structure thereof are not particularly limited. In the present embodiment, it is particularly preferable to use a non-halogenated epoxy resin as the (A) epoxy resin.

In the present embodiment, the (A) epoxy resin is, for example, a biphenyl type epoxy resin; a bisphenol type epoxy resin such as a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a tetramethyl bisphenol F type epoxy resin; Novolak type epoxy resin such as novolak type epoxy resin and cresol novolak type epoxy resin; Polyfunctional epoxy resin such as triphenol methane type epoxy resin and alkyl modified triphenol methane type epoxy resin; Phenol aralkyl type epoxy resin such as phenol aralkyl type epoxy resin having a skeleton; naphthol type epoxy resin such as epoxy resin obtained by glycidyl etherification of dihydroxynaphthalene type epoxy resin and dihydroxynaphthalene dimer; triglycidyl isocyanurate, mono A triazine nucleus-containing epoxy resin such as allyldiglycidyl isocyanurate; a bridge cyclic hydrocarbon compound such as a dicyclopentadiene-modified phenol-type epoxy resin, or one or more selected from modified phenol-type epoxy resins.
Of these, from the viewpoint of improving the balance between moisture resistance reliability and moldability, among bisphenol type epoxy resin, biphenyl type epoxy resin, novolak type epoxy resin, phenol aralkyl type epoxy resin, and triphenol methane type epoxy resin. It is more preferable to include at least one. Further, from the viewpoint of suppressing warpage of the semiconductor device, it is particularly preferable to contain at least one of a phenol aralkyl type epoxy resin and a novolak type epoxy resin. A biphenyl type epoxy resin is particularly preferable for further improving the fluidity, and a phenol aralkyl type epoxy resin having a biphenylene skeleton is particularly preferable for controlling the elastic modulus at high temperature.

Examples of the epoxy resin (A) include an epoxy resin represented by the following formula (1), an epoxy resin represented by the following formula (2), an epoxy resin represented by the following formula (3), and the following formula (4). A resin containing at least one selected from the group consisting of the epoxy resin represented by the following formula (5) and the epoxy resin represented by the following formula (5) can be used. Among these, one containing one or more selected from the epoxy resin represented by the following formula (1) and the epoxy resin represented by the following formula (4) is mentioned as one of the more preferable embodiments.

（上記式（１）中、Ａｒ^１はフェニレン基またはナフチレン基を表し、Ａｒ^１がナフチレン基の場合、グリシジルエーテル基はα位、β位のいずれに結合していてもよい。Ａｒ^２はフェニレン基、ビフェニレン基またはナフチレン基のうちのいずれか１つの基を表す。Ｒ_ａおよびＲ_ｂは、それぞれ独立に炭素数１〜１０の炭化水素基を表す。ｇは０〜５の整数であり、ｈは０〜８の整数である。ｎ^３は重合度を表し、その平均値は１〜３である。）

(In the above formula (1), Ar ¹ represents a phenylene group or a naphthylene group, and when Ar ¹ is a naphthylene group, the glycidyl ether group may be bonded to either the α-position or the β-position ^{. Ar 2} may be bonded to the phenylene. A group represents any one of a group, a biphenylene group or a naphthylene group. _Ra and R _b each independently represent a hydrocarbon group having 1 to 10 carbon atoms. G is an integer of 0 to 5. h is an integer of 0 to 8. n ³ represents the degree of polymerization, and the average value thereof is 1 to 3).

（式（２）中、複数存在するＲ_ｃは、それぞれ独立に水素原子または炭素数１〜４の炭化水素基を表す。ｎ^５は重合度を表し、その平均値は０〜４である。）

(In the formula (2), a plurality of R _cs independently represent a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms. N ⁵ represents a degree of polymerization, and the average value thereof is 0 to 4. )

（式（３）中、複数存在するＲ_ｄおよびＲ_ｅは、それぞれ独立に水素原子又は炭素数１〜４の炭化水素基を表す。ｎ^６は重合度を表し、その平均値は０〜４である。）

(In the formula (3), a plurality of R _d and _Re each independently represent a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms. N ⁶ represents the degree of polymerization, and the average value thereof is 0 to 4. Is.)

（式（４）中、複数存在するＲ_ｆは、それぞれ独立に水素原子又は炭素数１〜４の炭化水素基を表す。ｎ^７は重合度を表し、その平均値は０〜４である。）

(In the formula (4), a plurality of R _fs independently represent a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms. N ⁷ represents a degree of polymerization, and the average value thereof is 0 to 4. )

（式（５）中、複数存在するＲ_ｇは、それぞれ独立に水素原子又は炭素数１〜４の炭化水素基を表す。ｎ^８は重合度を表し、その平均値は０〜４である。）

(In the formula (5), a plurality of R _g each independently represent a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms. N ⁸ represents the degree of polymerization, and the average value thereof is 0 to 4. )

The lower limit of the content of the (A) epoxy resin in the semiconductor encapsulating resin composition of the present embodiment is preferably, for example, 8% by mass or more with respect to the entire semiconductor encapsulating resin composition. It is more preferably 10% by mass or more, and particularly preferably 15% by mass or more. By setting the content of the epoxy resin (A) to the above lower limit value or more, the fluidity of the semiconductor encapsulating resin composition can be improved and the moldability can be further improved.
On the other hand, the upper limit of the content of the epoxy resin (A) is preferably, for example, 50% by mass or less, more preferably 40% by mass or less, based on the entire semiconductor encapsulating resin composition. .. (A) By setting the content of the epoxy resin to the above upper limit value or less, the moisture resistance reliability and reflow resistance of the semiconductor device provided with the sealing resin formed by using the semiconductor sealing resin composition are improved. be able to.

[(B) Curing agent]
The curing agent (B) in the present embodiment is not particularly limited as long as it is generally used in the resin composition for encapsulating semiconductors, and is, for example, a phenol-based curing agent, an amine-based curing agent, or an acid anhydride-based curing agent. Examples thereof include a curing agent and a mercaptan-based curing agent. Among these, a phenolic curing agent is preferable from the viewpoint of balance of flame resistance, moisture resistance, electrical characteristics, curability, storage stability and the like.

<Phenolic curing agent>
The phenolic curing agent is not particularly limited as long as it is generally used in resin compositions for encapsulating semiconductors. For example, phenols such as phenol novolac resin and cresol novolak resin, cresol, resorcin, and catechol. Novolac resin obtained by condensing or co-condensing phenols such as bisphenol A, bisphenol F, phenylphenol, aminophenol, α-naphthol, β-naphthol, and dihydroxynaphthalene with formaldehyde and ketones under an acidic catalyst. Phenolic aralkyl resin having a biphenylene skeleton synthesized from dimethoxyparaxylene or bis (methoxymethyl) biphenyl, phenol aralkyl resin such as phenol aralkyl resin having a phenylene skeleton, phenol resin having a trisphenylmethane skeleton, etc. These may be used alone or in combination of two or more.

<Amine-based curing agent>
Examples of the amine-based curing agent include aliphatic polyamines such as diethylenetriamine (DETA), triethylenetetramine (TETA) and metaxylylene diamine (MXDA), diaminodiphenylmethane (DDM), m-phenylenediamine (MPDA) and diaminodiphenylsulfone ( In addition to aromatic polyamines such as DDS), polyamine compounds containing dicyandiamide (DICY), organic acid dihydraradide and the like can be mentioned, and these may be used alone or in combination of two or more.

<Acid anhydride-based curing agent>
Examples of the acid anhydride-based curing agent include alicyclic acid anhydrides such as hexahydroanhydride phthalic acid (HHPA), methyltetrahydroanhydride phthalic acid (MTHPA) and maleic anhydride, trimellitic anhydride (TMA) and pyromellitic anhydride. Examples thereof include aromatic acid anhydrides such as (PMDA), benzophenone tetracarboxylic acid (BTDA), and phthalic anhydride, and these may be used alone or in combination of two or more.

<Mercaptan-based curing agent>
Examples of the mercaptan-based curing agent include trimethylolpropane tris (3-mercaptobutyrate) and trimethylolethane ethanetris (3-mercaptobutyrate), and these may be used alone or in combination of two or more. May be good.

<Other curing agents>
Examples of other curing agents include isocyanate compounds such as isocyanate prepolymers and blocked isocyanates, and organic acids such as carboxylic acid-containing polyester resins, which may be used alone or in combination of two or more. ..
Further, two or more of the above-mentioned curing agents of different systems may be used in combination.

When the (B) curing agent is a phenolic curing agent, the equivalent ratio of the (A) epoxy resin to the (B) curing agent, that is, the number of moles of epoxy groups in the epoxy resin / the molar number of phenolic hydroxyl groups in the phenolic curing agent. The ratio of the numbers is not particularly limited, but in order to obtain a resin composition for semiconductor encapsulation having excellent moldability and reflow resistance, for example, the range is preferably 0.5 or more and 2 or less, and 0.6 or more and 1.8. The following range is more preferable, and the range of 0.8 or more and 1.5 or less is most preferable.

[(C) Inorganic filler]
The (C) inorganic filler of the present embodiment contains at least cristobalite.

The cristobalite that can be used in the present embodiment is not particularly limited in shape, and either spherical or crushed cristobalite can be used. Spherical cristobalite may be used from the viewpoint of enhancing the filling property and dispersibility in the semiconductor encapsulating resin composition of the present embodiment.

As the cristobalite of the present embodiment, it is preferable to use one having a reduced content of impurities. Examples of the impurities include uranium, thorium and the like.
In the present embodiment, for cristobalite having a low impurity concentration, the upper limit of the total amount of impurity concentrations of uranium and thorium is preferably, for example, 10 ppb or less, more preferably 8 ppb or less, and 5 ppb or less. It is particularly preferable to have. As a result, the amount of α rays emitted in the cured product made of the resin composition for encapsulating the semiconductor of the present embodiment can be significantly reduced. On the other hand, the lower limit of the total amount of impurity concentrations of uranium and thorium is, for example, larger than 1 ppb.

In the present embodiment, as a method for quantifying the impurity concentration, a method of measuring a residual aqueous solution in which Cristovalite is dissolved and removed using an appropriate treatment liquid such as fluoroacid is measured by ICP-MS (inductively coupled plasma mass spectrometry). May be adopted.
In the present specification, the content of the impurity concentration refers to a value converted by the mass of the metal element.
When (C) cristobalite and silica are used in combination as the inorganic filler, the total amount of these impurity concentrations may be set to a predetermined value or less.

Cristobalite in this embodiment can be obtained, for example, by converting silica particles into cristobalite. Specifically, the predetermined silica particles are heated at a high temperature of 1000 to 1600 ° C., particularly preferably 1200 to 1500 ° C. for 1 to 50 hours, particularly preferably 5 to 40 hours to ensure that the crystals grow, and then slowly. It can be made into cristobalite by cooling with. Further, by using silica particles having reduced impurities, cristobalite having a low impurity concentration as described above can be obtained. Specifically, silica particles may be obtained by adding a purification step, or silica particles may be produced from a silicon compound (raw material) having a low impurity concentration.

Further, for cristobalite in the present embodiment, high-purity amorphous silica is placed in a high-speed mixing device, and while mixing at high speed, an aluminum, titanium or magnesium compound solution is applied by spraying, and the sol or slurry of the compound solution is used. After surface treatment of silica, the surface-treated silica is dried, crushed into primary particles, and the crushed primary particles are heat-treated at, for example, 1,000 to 1,600 ° C. to produce the silica. can do. After the heat treatment, it may be allowed to cool naturally to room temperature. Further, the container to be used is preferably a high-purity container with few impurities.

The upper limit of the specific surface area of the cristobalite, nitrogen adsorption method specific surface area measured by (BET method), for example, may be 1.0 m ² / g or less, more preferably 0.8 m ² / g or less. This results in a relatively high thermal conductivity. Further, the lower limit of the specific surface area of the cristobalite, for example, preferably 0.05m ² / g or more, more preferably 0.1 m ² / g or more and 0.2 m ² / g or more Is even more preferable. As a result, the fluidity of the resin composition for semiconductor encapsulation is good, voids and burrs are less likely to occur in the moldability, and the moldability of the package is excellent.

The upper limit of the average particle size of cristobalite of the present embodiment is, for example, preferably 20 μm or less, more preferably 15 μm or less, further preferably 13 μm or less, still more preferably 10 μm or less. As a result, cristobalite can be dispersed evenly throughout the semiconductor encapsulating resin composition, and thermal conductivity and moisture absorption resistance can be efficiently imparted to the cured product of the semiconductor encapsulating resin composition. Can be done. The lower limit of the average particle size of cristobalite is not particularly limited, but may be, for example, 3 μm or more, or 5 μm or more. Thereby, the fluidity of the resin composition for semiconductor encapsulation can be improved.
In the present specification, the "average particle size" refers to a volume 50% average particle size (D ₅₀ ), and is measured using, for example, a laser diffraction / scattering type particle size distribution meter SALD-7000 manufactured by Shimadzu Corporation. can do.

The lower limit of the cristobalite content is preferably 5% by mass or more, more preferably 10% by mass or more, and 12% by mass or more with respect to the entire semiconductor encapsulating resin composition. Is particularly preferable. By setting the cristobalite content to the above lower limit or higher, the heat resistance and hygroscopicity of the semiconductor device provided with the sealing resin layer formed by using the semiconductor sealing resin composition can be further improved. can.
On the other hand, the upper limit of the content of the cristobalite is preferably 60% by mass or less, more preferably 50% by mass or less, based on the whole resin composition for semiconductor encapsulation. By setting the content of cristobalite to the above upper limit value or less, high fluidity of the resin composition for semiconductor encapsulation can be ensured. In addition, the dispersibility of cristobalite can be enhanced.

Further, in the present embodiment, as the constituent material of the (C) inorganic filler, an inorganic filler other than cristobalite can be used in combination. The types of inorganic fillers that can be used together are not particularly limited, but are, for example, silica such as fused silica, crystalline silica, and fine powder silica, alumina, silicon nitride, aluminum nitride, aluminum hydroxide, magnesium hydroxide, zinc borate, and zinc molybdenate. Etc., and any one or more of these can be used. Among these, silica may be used in combination from the viewpoint of excellent versatility. Further, the (C) inorganic filler may contain a component capable of imparting flame retardancy, such as aluminum hydroxide, magnesium hydroxide, zinc borate, and zinc molybdate.

(C) When silica is used in combination as the inorganic filler, for example, two or more kinds of spherical silica having _{different average particle diameters (D 50) can be used in combination. As a result, the linear expansion coefficients α 1} , α ₂ , and the flexural modulus E ₍₂₅₎ of the cured product of the resin composition for semiconductor encapsulation at 25 ° C., the flexural modulus E _{(260) at} 260 ° C., and the shrinkage coefficient S ₁ Etc. can be further easily adjusted. Therefore, it is possible to contribute to suppressing the warp of the semiconductor device.

Further, in the present embodiment, the inclusion of fine silica (nanosilica) having an average particle size of 1 μm or less as the silica improves the filling property of the resin composition for encapsulating a semiconductor and suppresses the warp of the semiconductor device. From this point of view, it is mentioned as one of the preferable embodiments.

(C) The lower limit of the content of the entire inorganic filler is, for example, preferably 30% by mass or more, more preferably 45% by mass or more, based on the total content of the semiconductor encapsulating resin composition. It is particularly preferable that the content is 50% by mass or more. (C) By setting the content of the inorganic filler to the above lower limit or higher, the low hygroscopicity and low thermal expansion of the sealing material layer formed by using the semiconductor encapsulating resin composition are improved, and the moisture resistance is reliable. The properties and reflow resistance can be improved more effectively. On the other hand, the upper limit of the content of the (C) inorganic filler is, for example, preferably 88% by mass or less, more preferably 85% by mass or less, based on the entire semiconductor encapsulating resin composition. It is preferably 82% by mass or less, and particularly preferably 82% by mass or less. (C) By setting the content of the inorganic filler to the above upper limit or less, the moldability of the semiconductor encapsulating resin composition is lowered due to the lowering of the fluidity, and the bonding wire flow due to the higher viscosity is prevented. It becomes possible to suppress it. In addition, the control stability of the semiconductor device can be improved. The upper limit of the (C) inorganic filler is not limited to the above, and can be appropriately selected according to the physical properties such as the coefficient of linear expansion of the organic substrate and the thickness. From such a viewpoint, the content of the (C) inorganic filler can be 80% by mass or less, or 70% by mass or less, depending on the type of the organic substrate.
Further, (C) by controlling the content of the entire inorganic filler in such a range, the linear expansion coefficients α ₁ , α _{2 of the cured product, the flexural modulus E (25) at} 25 ° C., and the flexural modulus E (25) at 260 ° C. It becomes easier to set the physical property values such as the flexural modulus E ₍₂₆₀₎ and the shrinkage modulus S _{1 within a desired range.} Therefore, it is possible to contribute to suppressing the warp of the semiconductor device.

In the present embodiment, when cristobalite and other inorganic fillers are used in combination as the (C) inorganic filler, the lower limit of the cristobalite content at the time of the combined use is, for example, the lower limit of the cristobalite content with respect to the entire (C) inorganic filler, for example. 5% by mass or more is preferable, 10% by mass or more is more preferable, and 15% by mass or more is further preferable. This makes it possible to improve the thermal elastic modulus while increasing the thermal linear expansion coefficient of the cured product of the resin composition for semiconductor encapsulation. The upper limit of the calcium fluoride content at the time of combined use is, for example, preferably 70% by mass or less, more preferably 60% by mass or less, still more preferably 50% by mass or less, based on the entire (C) inorganic filler. Thereby, for example, the effect of the combined use of silica can be sufficiently obtained. In addition, the control stability of the semiconductor device can be improved.

[(D) Curing accelerator]
The resin composition for semiconductor encapsulation of the present embodiment may further contain, for example, (D) a curing accelerator. The curing accelerator (D) may be any as long as it promotes the cross-linking reaction between the (A) epoxy resin and the (B) curing agent, and the one used in a general semiconductor encapsulation resin composition should be used. Can be done.

In the present embodiment, the (D) curing accelerator contains a phosphorus atom such as an organic phosphine, a tetra-substituted phosphonium compound, a phosphobetaine compound, an adduct of a phosphine compound and a quinone compound, and an adduct of a phosphonium compound and a silane compound. Compounds; 1,8-diazabicyclo (5,4,0) undecene-7, benzyldimethylamine, 2-methylimidazole and the like are exemplified with amidin and tertiary amines, and nitrogen atoms such as the quaternary salt of amidin and amine are contained. It can contain one or more selected from the compounds. Among these, it is more preferable to contain a phosphorus atom-containing compound from the viewpoint of improving curability. Further, from the viewpoint of improving the balance between moldability and curability, it has latent properties such as a tetra-substituted phosphonium compound, a phosphobetaine compound, an adduct of a phosphine compound and a quinone compound, and an adduct of a phosphonium compound and a silane compound. It is more preferable to include one.

Examples of the organic phosphine that can be used in the resin composition for encapsulating semiconductors of the present embodiment include first phosphine such as ethylphosphine and phenylphosphine; second phosphine such as dimethylphosphine and diphenylphosphine; trimethylphosphine and triethylphosphine. Examples thereof include a third phosphine such as tributylphosphine and triphenylphosphine.

Examples of the tetra-substituted phosphonium compound that can be used in the semiconductor encapsulating resin composition of the present embodiment include compounds represented by the following general formula (6).

（上記一般式（６）において、Ｐはリン原子を表す。Ｒ^４、Ｒ^５、Ｒ^６およびＲ^７は芳香族基またはアルキル基を表す。Ａはヒドロキシル基、カルボキシル基、チオール基から選ばれる官能基のいずれかを芳香環に少なくとも１つ有する芳香族有機酸のアニオンを表す。ＡＨはヒドロキシル基、カルボキシル基、チオール基から選ばれる官能基のいずれかを芳香環に少なくとも１つ有する芳香族有機酸を表す。ｘ、ｙは１〜３の数、ｚは０〜３の数であり、かつｘ＝ｙである。）

(In the above general formula (6), P represents a phosphorus atom. R ⁴ , R ⁵ , R ⁶ and R ⁷ represent an aromatic group or an alkyl group. A is selected from a hydroxyl group, a carboxyl group and a thiol group. Represents an anion of an aromatic organic acid having at least one functional group in the aromatic ring. AH is an aromatic having at least one functional group selected from a hydroxyl group, a carboxyl group, and a thiol group in the aromatic ring. Represents an organic acid. X and y are numbers 1 to 3, z is a number 0 to 3, and x = y.)

The compound represented by the general formula (6) can be obtained, for example, as follows, but is not limited thereto. First, a tetra-substituted phosphonium halide, an aromatic organic acid and a base are mixed uniformly with an organic solvent to generate an aromatic organic acid anion in the solution system. Then, water can be added to precipitate the compound represented by the general formula (6). In the compound represented by the general formula (6), R ⁴ , R ⁵ , R ⁶ and R ⁷ bonded to the phosphorus atom are phenyl groups, and AH is a compound having a hydroxyl group in the aromatic ring, that is, phenols. Yes, and A is preferably an anion of the phenols. Examples of the phenols include monocyclic phenols such as phenol, cresol, resorcin, and catechol, condensed polycyclic phenols such as naphthol, dihydroxynaphthalene, and anthraquinol, and bisphenols such as bisphenol A, bisphenol F, and bisphenol S. Examples thereof include polycyclic phenols such as phenylphenol and biphenol.

Examples of the phosphobetaine compound that can be used in the semiconductor encapsulating resin composition of the present embodiment include compounds represented by the following general formula (7).

（上記一般式（７）において、Ｐはリン原子を表す。Ｒ^８は炭素数１〜３のアルキル基、Ｒ^９はヒドロキシル基を表す。ｆは０〜５の数であり、ｇは０〜３の数である。）

(In the above general formula (7), P represents a phosphorus atom. R ⁸ represents an alkyl group having 1 to 3 carbon atoms, R ⁹ represents a hydroxyl group. F is a number from 0 to 5, and g is 0 to 0. It is a number of three.)

The compound represented by the general formula (7) can be obtained, for example, as follows. First, it is obtained through a step of contacting a tri-aromatic substituted phosphine, which is a tertiary phosphine, with a diazonium salt, and substituting the tri-aromatic substituted phosphine with the diazonium group of the diazonium salt. However, it is not limited to this.

Examples of the adduct of the phosphine compound and the quinone compound that can be used in the resin composition for encapsulating a semiconductor of the present embodiment include compounds represented by the following general formula (8).

（上記一般式（８）において、Ｐはリン原子を表す。Ｒ^１０、Ｒ^１１およびＲ^１２は炭素数１〜１２のアルキル基または炭素数６〜１２のアリール基を表し、互いに同一であっても異なっていてもよい。Ｒ^１３、Ｒ^１４およびＲ^１５は水素原子または炭素数１〜１２の炭化水素基を表し、互いに同一であっても異なっていてもよく、Ｒ^１４とＲ^１５が結合して環状構造となっていてもよい。）

(In the above general formula (8), P represents a phosphorus atom. R ¹⁰ , R ¹¹ and R ¹² represent an alkyl group having 1 to 12 carbon atoms or an aryl group having 6 to 12 carbon atoms, and are identical to each other. ^{R 13} , R ¹⁴ and R ¹⁵ represent hydrogen atoms or hydrocarbon groups having 1 to 12 carbon atoms, which may be the ^{same or different from each other, and R 14} and R ¹⁵ are bonded to each other. It may have a annular structure.)

Examples of the phosphin compound used as an adduct between the phosphin compound and the quinone compound include triphenylphosphine, tris (alkylphenyl) phosphin, tris (alkoxyphenyl) phosphin, trinaphthylphosphine, tris (benzyl) phosphine and the like. Substituents or those having a substituent such as an alkyl group or an alkoxyl group are preferable, and examples of the substituent such as an alkyl group and an alkoxyl group include those having 1 to 6 carbon atoms. Triphenylphosphine is preferred from the standpoint of availability.

Examples of the quinone compound used as an adduct of the phosphin compound and the quinone compound include benzoquinone and anthraquinone, and among them, p-benzoquinone is preferable from the viewpoint of storage stability.

As a method for producing an adduct of a phosphine compound and a quinone compound, the adduct can be obtained by contacting and mixing in a solvent in which both organic tertiary phosphine and benzoquinones can be dissolved. As the solvent, ketones such as acetone and methyl ethyl ketone, which have low solubility in adducts, are preferable. However, it is not limited to this.

In the compound represented by the general formula (8), the compounds in which R ¹⁰ , R ¹¹ and R ¹² bonded to the phosphorus atom are phenyl groups and R ¹³ , R ¹⁴ and R ¹⁵ are hydrogen atoms, that is, 1, A compound to which 4-benzoquinone and triphenylphosphine are added is preferable because it lowers the thermal elasticity of the cured product of the resin composition for encapsulating a semiconductor.

Examples of the adduct of the phosphonium compound and the silane compound that can be used in the semiconductor encapsulating resin composition of the present embodiment include compounds represented by the following general formula (9).

（上記一般式（９）において、Ｐはリン原子を表し、Ｓｉは珪素原子を表す。Ｒ^１６、Ｒ^１７、Ｒ^１８およびＲ^１９は、それぞれ、芳香環または複素環を有する有機基、あるいは脂肪族基を表し、互いに同一であっても異なっていてもよい。式中Ｒ^２０は、基Ｙ^２およびＹ^３と結合する有機基である。式中Ｒ^２１は、基Ｙ^４およびＹ^５と結合する有機基である。Ｙ^２およびＹ^３は、プロトン供与性基がプロトンを放出してなる基を表し、同一分子内の基Ｙ^２およびＹ^３が珪素原子と結合してキレート構造を形成するものである。Ｙ^４およびＹ^５はプロトン供与性基がプロトンを放出してなる基を表し、同一分子内の基Ｙ^４およびＹ^５が珪素原子と結合してキレート構造を形成するものである。Ｒ^２０、およびＲ^２１は互いに同一であっても異なっていてもよく、Ｙ^２、Ｙ^３、Ｙ^４およびＹ^５は互いに同一であっても異なっていてもよい。Ｚ^１は芳香環または複素環を有する有機基、あるいは脂肪族基である。）

(In the above general formula (9), P represents a phosphorus atom and Si represents a silicon atom. R ¹⁶ , R ¹⁷ , R ¹⁸ and R ¹⁹ are organic groups or fats having an aromatic ring or a heterocyclic ring, respectively. Represents a group group and may be the same or different from each other. In the formula, R ²⁰ is an organic group bonded to the groups Y ² and Y ^{3. In the formula, R 21} is a group Y ⁴ and Y ⁵ . ^{Y 2} and Y ³ are organic groups to be bonded. Y 2 and Y 3 represent a group formed by a proton donor group releasing a proton, ^{and groups Y 2} and Y ³ in the same molecule are bonded to a silicon atom to form a chelate structure. Y ⁴ and Y ⁵ represent groups formed by the proton donor group releasing a proton, and the groups Y ⁴ and Y ⁵ in the same molecule combine with a silicon atom to form a chelate structure. There, R ²⁰ and R ²¹ may be the same or different from each other ^{, and Y 2} , Y ³ , Y ⁴ and Y ⁵ may be the same or different from each other. Z ¹ is an aromatic ring. Alternatively, it is an organic group having a heterocycle or an aliphatic group.)

In the general formula (9) ^{, examples of R 16} , R ¹⁷ , R ¹⁸ and R ¹⁹ include a phenyl group, a methylphenyl group, a methoxyphenyl group, a hydroxyphenyl group, a naphthyl group, a hydroxynaphthyl group, a benzyl group and a methyl group. , Ethyl group, n-butyl group, n-octyl group, cyclohexyl group, etc. Among these, alkyl group such as phenyl group, methylphenyl group, methoxyphenyl group, hydroxyphenyl group, hydroxynaphthyl group, alkoxy group, etc. , An aromatic group having a substituent such as a hydroxyl group or an unsubstituted aromatic group is more preferable.

Further, in the general formula (9), R ²⁰ is an organic group bonded to ^{Y 2} and Y ^3. Similarly, R ²¹ is an organic group that binds to groups Y ⁴ and Y ^5. Y ² and Y ³ are groups formed by a proton donor group releasing a proton, and the groups Y ² and Y ³ in the same molecule are bonded to a silicon atom to form a chelate structure. Similarly, Y ⁴ and Y ⁵ are groups formed by a proton donor group releasing a proton, and the groups Y ⁴ and Y ⁵ in the same molecule are bonded to a silicon atom to form a chelate structure. The groups R ²⁰ and R ²¹ may be the same or different from each other, and the groups Y ² , Y ³ , Y ⁴ and Y ⁵ may be the same or different from each other. ^{In such a group represented by −Y 2} −R ²⁰ −Y ³ − and Y ⁴ −R ²¹ −Y ⁵ − in the general formula (9), the proton donor releases two protons. As the proton donor, an organic acid having at least two carboxyl groups or hydroxyl groups in the molecule is preferable, and further, a carboxyl group or a hydroxyl group is added to an adjacent carbon constituting an aromatic ring. An aromatic compound having at least two is preferable, and an aromatic compound having at least two hydroxyl groups on adjacent carbons constituting the aromatic ring is more preferable, for example, catechol, pyrogallol, 1,2-dihydroxynaphthalene, 2,3-dihydroxy. Naphthalene, 2,2'-biphenol, 1,1'-bi-2-naphthol, salicylic acid, 1-hydroxy-2-naphthoic acid, 3-hydroxy-2-naphthoic acid, chloranilic acid, tannic acid, 2-hydroxybenzyl Examples thereof include alcohol, 1,2-cyclohexanediol, 1,2-propanediol and glycerin, among which catechol, 1,2-dihydroxynaphthalene and 2,3-dihydroxynaphthalene are more preferable.

^{Further, Z 1} in the general formula (9) represents an organic group or an aliphatic group having an aromatic ring or a heterocyclic ring, and specific examples thereof include a methyl group, an ethyl group, a propyl group and a butyl group. An aliphatic hydrocarbon group such as a hexyl group and an octyl group, an aromatic hydrocarbon group such as a phenyl group, a benzyl group, a naphthyl group and a biphenyl group, a glycidyloxy group such as a glycidyloxypropyl group, a mercaptopropyl group and an aminopropyl group. , A mercapto group, a reactive substituent such as an alkyl group having an amino group and a vinyl group, etc. Among these, a methyl group, an ethyl group, a phenyl group, a naphthyl group and a biphenyl group are selected from the viewpoint of thermal stability. , More preferred.

As a method for producing an adduct of a phosphonium compound and a silane compound, a silane compound such as phenyltrimethoxysilane and a proton donor such as 2,3-dihydroxynaphthalene are added to a flask containing methanol and dissolved, and then at room temperature. The sodium methoxide-methanol solution is added dropwise with stirring. Further, when a solution prepared in advance in which a tetra-substituted phosphonium halide such as tetraphenylphosphonium bromide is dissolved in methanol is added dropwise under room temperature stirring, crystals are precipitated. The precipitated crystals are filtered, washed with water and vacuum dried to obtain an adduct of a phosphonium compound and a silane compound. However, it is not limited to this.

In the present embodiment, the content of the (D) curing accelerator is preferably 0.05% by mass or more, preferably 0.15% by mass or more, based on the total amount of the resin composition for encapsulating the semiconductor. It is more preferably 0.25% by mass or more, and particularly preferably 0.25% by mass or more. (D) By setting the content of the curing accelerator to the above lower limit value or more, the curability at the time of sealing molding can be effectively improved.
On the other hand, the content of the (D) curing accelerator is preferably 2.0% by mass or less, more preferably 1.5% by mass or less, based on the entire semiconductor encapsulating resin composition. .. (D) By setting the content of the curing accelerator to the above upper limit value or less, the fluidity at the time of sealing molding can be improved.

[(E) Coupling agent]
The resin composition for semiconductor encapsulation of the present embodiment may contain, for example, (E) a coupling agent. Examples of the coupling agent include various silane compounds such as epoxysilane, mercaptosilane, aminosilane, alkylsilane, ureidosilane, vinylsilane, and methacrylicsilane, titanium compounds, aluminum chelate compounds, and aluminum / zirconium compounds. Known coupling agents can be used. Examples of these are vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (β-methoxyethoxy) silane, γ-methacryloxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxy. Silane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-methacryloxypropyltriethoxysilane , Vinyl Triacetoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-anilinopropyltrimethoxysilane, γ-anilinopropylmethyldimethoxysilane, γ- [bis (β-hydroxyethyl) ] Aminopropyltriethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropyltriethoxysilane, N-β- (aminoethyl)- γ-Aminopropylmethyldimethoxysilane, phenylaminopropyltrimethoxysilane, γ- (β-aminoethyl) aminopropyldimethoxymethylsilane, N- (trimethoxysilylpropyl) ethylenediamine, N- (dimethoxymethylsilylisopropyl) ethylenediamine, methyl Trimethoxysilane, dimethyldimethoxysilane, methyltriethoxysilane, N-β- (N-vinylbenzylaminoethyl) -γ-aminopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, hexamethyldisilane, vinyltrimethoxysilane , Γ-Mercaptopropylmethyldimethoxysilane, 3-Ixionpropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-triethoxysilyl-N- (1,3-dimethyl-butylidene) propylamine hydrolyzate, etc. Silane-based coupling agent, isopropyltriisostearoyl titanate, isopropyltris (dioctylpyrophosphate) titanate, isopropyltri (N-aminoethyl-aminoethyl) titanate, tetraoctylbis (ditridecylphosphite) titanate, tetra (2, 2-Diallyloxymethyl-1-butyl) bis (ditridecyl) phosphite titanate, bis (dioctylpyrophosph) Eto) oxyacetate titanate, bis (dioctylpyrophosphate) ethylene titanate, isopropyltrioctanoyl titanate, isopropyldimethacrylisostearoyl titanate, isopropyltridodecylbenzenesulfonyl titanate, isopropylisostearoyldiacryl titanate, isopropyltri (dioctylphosphate) titanate, Examples thereof include titanate-based coupling agents such as isopropyltricylphenyl titanate and tetraisopropylbis (dioctylphosphite) titanate. These may be used individually by 1 type and may be used in combination of 2 or more type. Among these, silane compounds such as epoxysilane, mercaptosilane, aminosilane, alkylsilane, ureidosilane and vinylsilane are more preferable. Further, from the viewpoint of more effectively improving the filling property and moldability, it is particularly preferable to use a secondary aminosilane typified by phenylaminopropyltrimethoxysilane.

The content of the coupling agent (E) is preferably 0.1% by mass or more, more preferably 0.15% by mass or more, based on the total amount of the resin composition for encapsulating the semiconductor. By setting the content of the (E) coupling agent to the above lower limit value or more, the dispersibility of the (C) inorganic filler can be improved. On the other hand, the content of the (E) coupling agent is preferably 1% by mass or less, more preferably 0.5% by mass or less, based on the total amount of the resin composition for encapsulating the semiconductor. (E) By setting the content of the coupling agent to the above upper limit value or less, the fluidity of the semiconductor encapsulation resin composition at the time of encapsulation and molding can be improved, and the filling property and moldability can be improved. ..

[(F) Other ingredients]
Further, if necessary, the resin composition for encapsulating the semiconductor of the present embodiment includes an ion trapping agent such as hydrotalcite; a coloring agent such as carbon black and red iron oxide; a natural wax such as carnauba wax, a montanic acid ester wax and the like. Synthetic wax, higher fatty acids such as zinc stearate and mold release agents such as metal salts thereof or paraffin; various additives such as antioxidants may be appropriately blended.

Further, the resin composition for semiconductor encapsulation of the present embodiment may contain, for example, a low stress agent. Low stress agents include, for example, silicone oil, silicone rubber, polyisoprene, 1,2-polybutadiene, polybutadiene such as 1,4-polybutadiene, styrene-butadiene rubber, acrylonitrile-butadiene rubber, polychloroprene, poly (oxypropylene), poly. It can contain one or more selected from thermoplastic elastomers such as (oxytetramethylene) glycol, polyolefin glycol, poly-ε-caprolactone, polysulfide rubber, and fluororubber. Among these, containing at least one of silicone rubber, silicone oil, and acrylonitrile-butadiene rubber controls the flexural modulus and shrinkage to a desired range, and suppresses the occurrence of warpage of the obtained semiconductor package. From the viewpoint, it can be selected as a particularly preferable embodiment.

When this low stress agent is used, the total content of the low stress agent is preferably 0.05% by mass or more, preferably 0.10% by mass or more, based on the total content of the semiconductor encapsulating resin composition. Is more preferable. On the other hand, the content of the low stress agent is preferably 1% by mass or less, more preferably 0.5% by mass or less, based on the whole resin composition for encapsulating the semiconductor. By controlling the content of the low stress agent within such a range, the warpage of the obtained semiconductor package can be suppressed more reliably.

A method for producing the semiconductor encapsulating resin composition of the present embodiment will be described. For example, first, each of the above-mentioned raw material components is mixed by a known means to obtain a mixture. Further, the mixture is melt-kneaded to obtain a kneaded product. As a kneading method, for example, an extrusion kneader such as a single-screw kneading extruder or a twin-screw kneading extruder or a roll-type kneading machine such as a mixing roll can be used, but a twin-screw kneading extruder is used. Is preferable. After cooling, the kneaded product can be in the form of powder, granules, or tablets.

Examples of the method for obtaining the powdery and granular resin composition include a method of pulverizing the kneaded product with a pulverizer. The kneaded product formed into a sheet may be crushed. As the crushing device, for example, a hammer mill, a millstone grinder, a roll crusher, or the like can be used.

As a method for obtaining a granular or powdery resin composition, for example, a die having a small diameter is installed at the outlet of the kneading device, and the melted kneaded material discharged from the die is cut into a predetermined length by a cutter or the like. It is also possible to use a granulation method typified by a hot-cut method of cutting into plastic. In this case, it is preferable to obtain a granular or powdery resin composition by a granulation method such as a hot-cut method, and then degas before the temperature of the resin composition drops so much.

The characteristics of the resin composition for semiconductor encapsulation of the present embodiment will be described.

Dose α in the cured product of the resin composition for semiconductor encapsulation of the present embodiment is 0.005cph / cm ² or less, more preferably 0.003cph / cm ² or less, more preferably 0.001 cph / cm ² or less .. Thereby, the semiconductor device including the semiconductor element sealed with the cured product of the resin composition for semiconductor encapsulation of the present embodiment can suppress the malfunction of the semiconductor element even in long-term use. Therefore, it is possible to realize a semiconductor device having excellent control stability. The α dose in the cured product can be measured using an α ray counter.

Further, in the semiconductor encapsulating resin composition of the present embodiment, the content of cristobalite is 5% by mass or more and 60% by mass or less with respect to the entire semiconductor encapsulating resin composition, and is used for semiconductor encapsulation. The α-dose in the cured product of the resin composition can be 0.001 cph / cm ² or less. As described above, according to the present embodiment, it is possible to achieve both a high content of cristobalite and a reduction in the α dose in the cured product of the resin composition for semiconductor encapsulation. Therefore, while suppressing the warp of the semiconductor device, the influence of malfunction due to α rays can be suppressed. Therefore, the resin composition for semiconductor encapsulation of the present embodiment is particularly preferably used for a thin semiconductor device. can.

In this embodiment, the α dose is measured using an α ray counter. For example, as a measurement method, a test piece (cured product of a resin composition for encapsulating a semiconductor) of 120 mm × 140 mm × 2 mm is measured with an α-ray counter at a predetermined measurement time, and the count number is measured to count per unit time. The amount of change in the number (cph / cm ² ) can be calculated. As the measurement time, for example, 60 hours to 100 hours may be adopted.

In the present embodiment, for example, the cured product (sealing) is obtained by appropriately selecting the type and blending amount of each component contained in the semiconductor encapsulating resin composition, the method for preparing the semiconductor encapsulating resin composition, and the like. It is possible to control the α dose of the material) and its variation. Among these, for example, improving the impurity concentration and particle size of cristobalite, the impurity concentration and particle size of the combined filler, the content and content ratio thereof, and improving the dispersibility of the filler are the above-mentioned α-dose. Is mentioned as an element for setting a desired numerical range.

According to this embodiment, the α dose of the encapsulant can be reduced, and the variation thereof can be suppressed. Therefore, it is possible to realize a semiconductor device having excellent control stability and to improve its manufacturing stability.

Further, by using the semiconductor encapsulating resin composition of the present embodiment, the control stability of the semiconductor element can be improved and the warp of the semiconductor device can be sufficiently suppressed, so that the semiconductor device has a high degree of reliability. Can be realized.

The lower limit _{of the linear expansion coefficient α 2} of the cured product obtained by heat-treating the semiconductor encapsulating resin composition of the present embodiment at 175 ° C. for 3 minutes and then heat-treating at 175 ° C. for 4 hours at a glass transition temperature or higher. The value is, for example, preferably 30 ppm / K or more, more preferably 35 ppm / K or more, further preferably 40 ppm / K or more, and particularly preferably 50 ppm / K or more. This makes it possible to approach the coefficient of linear expansion of the substrate during heat. On the other hand, the upper limit of the linear expansion coefficient α ₂ of the cured product may be, for example, 200 ppm / K or less, preferably 100 ppm / K or less, more preferably 80 ppm / K or less, still more preferably 70 ppm / K or less. .. As a result, it is possible to prevent the difference between the linear expansion coefficient of the substrate and the linear expansion coefficient of the cured product from widening at the time of heat.

As mentioned above, in recent years, there has been an increasing demand for suppressing the occurrence of warpage, especially for thin semiconductor devices. Further, from the viewpoint of expanding the applicable range of semiconductor devices, there is a high demand for suppressing warpage during heat.
As a result of diligent studies by the present inventors in response to such demands, a semiconductor element is mounted on _{a cured product of a semiconductor encapsulating resin composition by adjusting the linear expansion coefficient α 2 to the specific range.} It was found that the difference in the coefficient of thermal expansion from the substrate can be alleviated and the warp of the semiconductor device as a whole can be suppressed.

The lower limit _{of the flexural modulus E (260)} of the cured product obtained by heat-treating the semiconductor encapsulating resin composition of the present embodiment at 175 ° C. for 3 minutes and then heat-treating at 175 ° C. for 4 hours at 260 ° C. The value is, for example, preferably 100 MPa or more, more preferably 200 MPa or more, still more preferably 300 MPa or more. By setting the flexural modulus E ₍₂₆₀₎ at 260 ° C. to the above lower limit value or more, the warp of the semiconductor device can be stably controlled.
On the other hand, _{the upper limit of the flexural modulus E (260)} at 260 ° C. is not particularly limited, but may be, for example, 1 Gpa or less, preferably 950 MPa or less, and more preferably 900 MPa or less. By setting the flexural modulus E ₍₂₆₀₎ at 260 ° C. to the above upper limit or less, it is possible to impart appropriate flexibility as a sealing resin, and effectively relieve external stress and thermal stress. , It is possible to improve the solder resistance reliability at the time of reflow.

In the cured product using the semiconductor encapsulating resin composition of the present embodiment, the linear expansion coefficient α ₂ and the flexural modulus E _{(260) at} 260 ° C. can be satisfied at the same time. This makes it possible to reduce the warp of the entire semiconductor device in a high temperature environment.

_{The linear expansion coefficient α 1 of the} cured product obtained by heat-treating the semiconductor encapsulating resin composition of the present embodiment at, for example, 175 ° C. for 3 minutes and then heat-treating at 175 ° C. for 4 hours at a temperature lower than the glass transition temperature. The lower limit of the above value is, for example, preferably 5 ppm / K or more, more preferably 10 ppm / K or more, and even more preferably 15 ppm / K or more. On the other hand, the upper limit of the linear expansion coefficient α ₁ below the glass transition temperature is, for example, preferably 40 ppm / K or less, more preferably 35 ppm / K or less, and even more preferably 30 ppm / K or less. By setting the coefficient of linear expansion α ₁ within the above numerical range, it is possible to suppress the occurrence of warpage in the semiconductor package due to the difference in the coefficient of linear expansion between the substrate and the encapsulating resin even under relatively low temperature conditions. It becomes.

_{The bending elastic modulus E (25)} of the cured product obtained by heat-treating the semiconductor encapsulating resin composition of the present embodiment at, for example, 175 ° C. for 3 minutes and then heat-treating at 175 ° C. for 4 hours at 25 ° C. The lower limit value is, for example, preferably 1.0 GPa or more, more preferably 3.0 GPa or more, still more preferably 5.0 GPa or more. By setting the flexural modulus E ₍₂₅₎ at 25 ° C. to the above lower limit value or more, it is possible to more effectively suppress the warp of the semiconductor device at room temperature.
_{On the other hand, the upper limit of the flexural modulus E (25)} at 25 ° C. of the cured product is not particularly limited, but is preferably 40 GPa or less, preferably 30 GPa or less, and even more preferably 20 GPa or less. By setting the flexural modulus E ₍₂₅₎ of the cured product at 25 ° C. to the above upper limit value or less, stress from the outside can be effectively relaxed and the reliability of the semiconductor device can be improved.

Further, the lower limit of the glass transition temperature of the cured product obtained by heat-treating the semiconductor encapsulating resin composition of the present embodiment at 175 ° C. for 3 minutes and then heat-treating at 175 ° C. for 4 hours is, for example, 130. ° C. or higher is preferable, 140 ° C. or higher is more preferable, and 150 ° C. or higher is even more preferable. By setting the glass transition temperature to the above temperature or higher, the semiconductor element can be stably sealed even when it is hot. On the other hand, the upper limit of the glass transition temperature of the cured product is not particularly limited, but may be, for example, 250 ° C. or lower, or 230 ° C. or lower.

_{For the linear expansion coefficients α 1} , α ₂ and the glass transition temperature of the cured product obtained by curing the semiconductor encapsulating resin composition of the present embodiment, for example, a thermomechanical analyzer (TMA100 manufactured by Seiko Denshi Kogyo Co., Ltd.) is used. The measurement can be performed under the conditions of a measurement temperature range of 0 ° C. to 320 ° C. and a heating rate of 5 ° C./min. Measurements of flexural modulus at 260 ° C. and 25 ° C. can be performed in accordance with JIS K 6911.

Further, the resin composition for semiconductor encapsulation of the present embodiment, 175 ° C., the lower limit of the shrinkage factor S ₁ when heat treated at 3 minutes, for example, preferably at least 0.1%, 0.2% or more More preferably, 0.3% or more is further preferable. On the other hand, the upper limit of the shrinkage factor _{S 1,} for example, preferably 2.0% or less, more preferably 1.5% or less. By setting the shrinkage rate of the resin composition for semiconductor encapsulation during molding within a specific range in this way, the shrinkage amount of a substrate such as an organic substrate and the shrinkage amount of the resin composition during curing can be matched with each other to achieve a semiconductor. It is possible to stabilize the package in a shape in which warpage is suppressed.

The shrinkage rate S ₁ can be measured, for example, as follows. First, using a transfer molding machine, a semiconductor encapsulation resin composition is injected into a mold cavity under the conditions of a mold temperature of 175 ° C., a molding pressure of 9.8 MPa, and a curing time of 3 minutes, and a disk-shaped test is performed. Make a piece. The test piece is then cooled to 25 ° C. _{Here, the shrinkage rate S 1} (%) is calculated from the inner diameter of the mold cavity at 175 ° C. and the outer diameter of the test piece at 25 ° C. as follows.
S ₁ = {(inner diameter dimension of mold cavity at 175 ° C.)-(outer diameter dimension of test piece at 25 ° C.)} / (inner diameter dimension of mold cavity at 175 ° C.) × 100

In the semiconductor encapsulating resin composition of the present embodiment, the flow length of the spiral flow is, for example, preferably 135 cm or more, more preferably 140 cm or more, and particularly preferably 150 cm or more. Thereby, the filling property at the time of filling the semiconductor encapsulating resin composition between the substrate and the semiconductor element can be more effectively improved. The upper limit of the flow length of the spiral flow is not particularly limited, but may be, for example, 230 cm or less, 210 cm or less, or 200 cm or less. For the measurement of the spiral flow, for example, a low pressure transfer molding machine (“KTS-15” manufactured by Kotaki Seiki Co., Ltd.) is used, and the mold temperature is 175 ° C. It can be carried out by injecting a resin composition for semiconductor encapsulation under the conditions of an injection pressure of 9.8 MPa and a curing time of 3 minutes, and measuring the flow length. In the present embodiment, the spiral flow can be increased by, for example, using fused spherical silica as an inorganic filler, lowering the softening point of the epoxy resin and the curing agent, reducing the amount of the curing accelerator, and the like.

The upper limit of the viscosity of the semiconductor encapsulating resin composition of the present embodiment is, for example, preferably 0.5 MPa or less, more preferably 0.3 MPa or less, and particularly preferably 0.2 MPa or less. preferable. Thereby, the filling property at the time of filling the semiconductor encapsulating resin composition between the substrate and the semiconductor element can be more effectively improved. The lower limit of the viscosity is preferably 0.03 MPa or more, more preferably 0.04 MPa or more, and particularly preferably 0.05 MPa. This makes it possible to prevent resin leakage from the mold gap during molding. In this embodiment, the viscosity can be measured using, for example, rectangular pressure. Specifically, using a low pressure transfer molding machine (NEC Corp. 40t manual press), mold temperature 175 ° C., at a rate of infusion 177cm ³ / sec condition, width 13 mm, thickness 1 mm, length A resin composition for encapsulating a semiconductor is injected into a 175 mm rectangular flow path, and the change over time of pressure is measured by a pressure sensor embedded at a position 25 mm from the upstream tip of the flow path, and the resin composition flows. Measure the minimum pressure in.

The semiconductor device of this embodiment will be described.
The semiconductor device of this embodiment includes a substrate, a semiconductor element, and a sealing resin layer.
In the present embodiment, as the substrate, for example, an organic substrate such as an interposer can be used. The semiconductor element (semiconductor chip) is mounted on one surface of the substrate. The semiconductor element is electrically connected to the substrate by, for example, wire bonding or flip chip connection. A plurality of semiconductor elements may be mounted. For example, the plurality of semiconductor elements may be arranged on the mounting surface of the substrate so as to be separated from each other, or may be arranged so as to be laminated with each other. A plurality of semiconductor elements may use different types.

The semiconductor encapsulating resin composition of the present embodiment is used to form a encapsulating resin layer for encapsulating a semiconductor element mounted on a substrate. The encapsulation molding using the semiconductor encapsulation resin composition is not particularly limited, and examples thereof include a transfer molding method and a compression molding method.

The semiconductor device of the present embodiment is not particularly limited, and is, for example, QFP (Quad Flat Package), SOP (Small Outline Package), BGA (Ball Grid Array), CSP (Chip Size Package), QFN (Quad-Fad). Package), SON (Small Outline Non-led Package), LF-BGA (Lead Flame BGA), and the like. Further, the BGA or CSP may be an overmold type in which the upper surface of the semiconductor element (the top surface opposite to the mounting surface) is covered with the encapsulating resin layer, and the upper surface of the semiconductor element is exposed from the encapsulating resin. It may be an exposed type package.

Further, the resin composition for semiconductor encapsulation according to the present embodiment can also be used for a structure formed by MAP (Mold Array Package) molding, which is often applied to molding of the above packages. The structure can be obtained by collectively encapsulating a plurality of semiconductor elements mounted on a substrate by using the semiconductor encapsulating resin composition of the present embodiment.

The effect of suppressing the warp of the semiconductor device in the present embodiment is that the upper surface of the BGA, CSP, or semiconductor element of the type in which the thickness of the sealing resin is thinner than the thickness of the substrate is exposed from the sealing resin among the BGA and CSP. This is particularly noticeable in packages such as exposed type BGA and CSP in which the sealing resin does not have sufficient force to suppress deformation due to expansion and contraction of the substrate.

The resin composition for semiconductor encapsulation of the present embodiment can be used, for example, as a mold underfill material. The mold underfill material is a material that collectively seals the semiconductor element arranged on the substrate and fills the gap between the substrate and the semiconductor element. This makes it possible to reduce the man-hours in manufacturing the semiconductor device. Further, since the semiconductor encapsulating resin composition according to the present embodiment can be filled between the substrate and the semiconductor element, it is possible to more effectively suppress the warp of the semiconductor device.

In the present embodiment, as an example of a semiconductor device formed by using a semiconductor encapsulating resin composition, a semiconductor package in which a semiconductor element is mounted on one surface of an organic substrate can be mentioned. In this case, the one side of the organic substrate and the semiconductor element are sealed by the semiconductor encapsulating resin composition. That is, it is a single-sided sealed package. Further, on the other surface of the organic substrate opposite to the above one surface, for example, a plurality of solder balls are formed as external connection terminals. In such a semiconductor package, the upper surface of the semiconductor element may be sealed with a sealing resin or may be exposed from the sealing resin.

In such a semiconductor package, for example, the thickness of the sealing resin may be 0.4 mm or less, or may be 0.3 mm or less. This makes it possible to reduce the thickness of the semiconductor package. Further, even with such a thin semiconductor package, it is possible to suppress the occurrence of package warpage by using the semiconductor encapsulating resin composition according to the present embodiment. Here, the thickness of the sealing resin refers to the thickness of the sealing resin with respect to the one side in the normal direction of the one side of the organic substrate. Further, in the present embodiment, for example, the thickness of the sealing resin can be set to be equal to or less than the thickness of the organic substrate. As a result, the semiconductor package can be made thinner more efficiently.

The resin composition for semiconductor encapsulation of the present embodiment is, for example, in the form of powder, granules or tablets. This makes it possible to perform sealing molding using a transfer molding method, a compression molding method, or the like. In the present embodiment, the powder or granular material refers to either powder or granules. Further, the tablet-shaped resin composition for encapsulating a semiconductor may be in a B stage state.

Next, the semiconductor device 100 will be described with reference to FIG.
FIG. 1 is a cross-sectional view showing an example of a semiconductor device 100.

The semiconductor device 100 is a semiconductor including a substrate 10, a semiconductor element 20 mounted on one surface of the substrate 10, and a sealing resin layer 30 for sealing the one surface of the substrate 10 and the semiconductor element 20. It is a package. That is, the semiconductor device 100 is a single-sided sealed semiconductor package in which the other side of the substrate 10 opposite to the one side is not sealed by the sealing resin layer 30. The encapsulating resin layer 30 is composed of a cured product of the semiconductor encapsulating resin composition of the present embodiment. As a result, the coefficient of linear expansion of the sealing resin layer 30 at the time of heat can be increased, so that the difference in the coefficient of linear expansion of the sealing resin layer 30 and the substrate 10 at the time of heat can be reduced. Therefore, it is possible to suppress the warp of the entire semiconductor device 100 when it is used in a high temperature environment.

In the present embodiment, the upper surface of the semiconductor element 20 may be covered with the sealing resin layer 30 (FIG. 1) or may be exposed from the sealing resin layer 30 (not shown).

In the example shown in FIG. 1, an organic substrate is used as the substrate 10. For example, a plurality of solder balls 12 are provided on the back surface of the substrate 10 opposite to the front surface (mounting surface) on which the semiconductor element 20 is mounted. Further, the semiconductor element 20 is flip-chip mounted on the substrate 10, for example. The semiconductor element 20 is electrically connected to the substrate 10 via, for example, a plurality of bumps 22. As a modification, the semiconductor element 20 may be electrically connected to the substrate 10 via a bonding wire.

In the example shown in FIG. 1, the gap between the semiconductor element 20 and the substrate 10 is filled with, for example, an underfill 32. As the underfill 32, for example, a film-like or liquid underfill material can be used. The underfill 32 and the sealing resin layer 30 may be made of different materials, but may be made of the same material. The resin composition for semiconductor encapsulation of the present embodiment can be used as a mold underfill material. Therefore, the underfill 32 and the sealing resin layer 30 can be made of the same material and can be formed in the same process. Specifically, a sealing step of sealing the semiconductor element 20 with the semiconductor encapsulating resin composition, and a filling step of filling the gap between the substrate 10 and the semiconductor element 20 with the semiconductor encapsulating resin composition. Can be carried out in the same process (collective).

In the present embodiment, the thickness of the sealing resin layer 30 is, for example, from the mounting surface of the substrate 10 (one surface opposite to the surface on which the bump 12 for external connection is formed) to the top of the sealing resin layer 30. The shortest distance to the surface. The thickness of the sealing resin layer 30 refers to the thickness of the sealing resin layer 30 with respect to the above one surface in the normal direction of one surface on which the semiconductor element 20 of the substrate 10 is mounted. In this case, the upper limit of the thickness of the sealing resin layer 30 may be, for example, 0.4 mm or less, 0.3 mm or less, or 0.2 mm or less. On the other hand, the lower limit of the thickness of the sealing resin layer 30 is not particularly limited, but may be, for example, 0 mm or more (exposed type) or 0.01 mm or more.
Further, the upper limit of the thickness of the substrate 10 may be, for example, 0.8 mm or less, or 0.4 mm or less. On the other hand, the lower limit of the thickness of the substrate 10 is not particularly limited, but may be, for example, 0.1 mm or more.
According to this embodiment, it is possible to reduce the thickness of the semiconductor package in this way. Further, even in a thin semiconductor package, the warp of the semiconductor device 100 can be suppressed by forming the sealing resin layer 30 by using the semiconductor encapsulating resin composition according to the present embodiment. .. Further, in the present embodiment, for example, the thickness of the sealing resin layer 30 can be set to be equal to or less than the thickness of the substrate 10. As a result, the semiconductor device 100 can be made thinner more efficiently.

Next, the structure 102 will be described.
FIG. 2 is a cross-sectional view showing an example of the structure 102. The structure 102 is a molded product formed by MAP molding. Therefore, by individualizing the structure 102 for each semiconductor element 20, a plurality of semiconductor packages can be obtained.

The structure 102 includes a substrate 10, a plurality of semiconductor elements 20, and a sealing resin layer 30. The plurality of semiconductor elements 20 are arranged on one surface of the substrate 10. FIG. 2 illustrates a case where each semiconductor element 20 is flip-chip mounted on a substrate 10. In this case, each semiconductor element 20 is electrically connected to the substrate 10 via a plurality of bumps 22. On the other hand, each semiconductor element 20 may be electrically connected to the substrate 10 via a bonding wire. As the substrate 10 and the semiconductor element 20, the same ones as those exemplified in the semiconductor device 100 can be used.

In the example shown in FIG. 2, the gap between each semiconductor element 20 and the substrate 10 is filled with, for example, an underfill 32. As the underfill 32, for example, a film-like or liquid underfill material can be used. On the other hand, the above-mentioned resin composition for semiconductor encapsulation can also be used as a mold underfill material. In this case, sealing of the semiconductor element 20 and filling of the gap between the substrate 10 and the semiconductor element 20 are performed collectively.

The sealing resin layer 30 seals a plurality of semiconductor elements 20 and the above-mentioned one surface of the substrate 10. In this case, the other surface of the substrate 10 opposite to the above one surface is not sealed by the sealing resin layer 30. Further, the sealing resin layer 30 is composed of the cured product of the above-mentioned semiconductor sealing resin composition. As a result, it is possible to suppress the warp of the structure 102 and the semiconductor package obtained by separating the structure 102 into individual pieces. The encapsulating resin layer 30 is formed, for example, by encapsulating a semiconductor encapsulating resin composition using a known method such as a transfer molding method or a compression molding method. Further, in the present embodiment, the upper surface of each semiconductor element 20 may be sealed by the sealing resin layer 30 as shown in FIG. 2, or may be exposed from the sealing resin layer 30.

Although the present invention has been described above based on the embodiments, the present invention is not limited to the above-described embodiment, and the configuration thereof can be changed without changing the gist of the present invention.

Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to the description of these examples.

The components used in each example and each comparative example are shown below.
(Preparation of resin composition for semiconductor encapsulation)
First, each of the raw materials blended according to Table 1 was mixed at room temperature using a mixer, and then rolled and kneaded at 70 to 100 ° C. Then, after cooling the obtained kneaded product, it was pulverized to obtain a resin composition for semiconductor encapsulation. The details of each component in Table 1 are as follows. The unit in Table 1 is mass%.

(A) Epoxy resin Epoxy resin 1: Phenolic aralkyl type epoxy resin having a biphenylene skeleton (manufactured by Nippon Kayaku Co., Ltd., NC-3000)
Epoxy resin 2: Triphenylmethane type epoxy resin (manufactured by Mitsubishi Chemical Corporation, JER 1032H-60)

(B) Hardener Hardener 1: Phenol aralkyl resin having a biphenylene skeleton (manufactured by Nippon Kayaku Co., Ltd., GPH-65)
Hardener 2: Phenol resin having a trisphenylmethane skeleton (MEH-7500, manufactured by Meiwa Kasei Co., Ltd.)

(C) Inorganic filler Inorganic filler 1: Spherical molten silica (manufactured by Denka Co., Ltd., trade name "FB560", average particle size (D ₅₀ ) 30 μm)
Inorganic filler 2: Cristobalite (manufactured by Tokai Mineral Co., Ltd., CR-1, average particle size (D ₅₀ ) 5 μm)
Inorganic filler 3: High-purity spherical cristobalite obtained by the following production method (average particle size (D ₅₀ ) 7.5 μm, uranium amount 2.3 ppb, thorium amount less than 1 ppb)
[Inorganic filler 3: Method for producing the above-mentioned high-purity spherical cristobalite]
Silica was placed in a high-speed mixing device, and the aluminum compound solution was spray-applied while mixing at high speed, and the surface treatment of silica was performed for 10 minutes. The surface-treated silica was dried at 100 ° C. for 5 hours and then crushed into primary particles. The crushed primary particles were heated from room temperature to 1,400 ° C over 6 hours, maintained at 1,400 ° C for 6 hours, then from 1,400 ° C to 600 ° C for 6 hours, and from 600 ° C to 200 ° C 4 The temperature was lowered over time. It was allowed to cool naturally from 200 ° C. to room temperature.
Inorganic filler 4: Spherical molten silica (fine powder) (manufactured by Admatex Co., Ltd., SO-C2, average particle size (D ₅₀ ) 0.5 μm)
Inorganic filler 5: Spherical molten silica (manufactured by Admatex Co., Ltd., SO-C5, average particle size (D ₅₀ ) 1.6 μm)
Inorganic filler 6: High-purity spherical molten silica (manufactured by Denka Co., Ltd., FB-105X, average particle size (D ₅₀ ) 10.4 μm, uranium amount less than 1 ppb, thorium amount less than 1 ppb)
Inorganic filler 7: High-purity spherical molten silica (manufactured by Admatex Co., Ltd., SO-E2, average particle size (D ₅₀ ) 0.5 μm, uranium amount less than 1 ppb, thorium amount less than 1 ppb)
Inorganic filler 8: High-purity aluminum hydroxide (manufactured by Nippon Light Metal Co., Ltd., BE043, average particle size (D ₅₀ ) 3.0 μm, uranium amount 1 ppb, thorium amount less than 1 ppb)
The average particle size of the inorganic filler in this example was measured using a laser diffraction / scattering type particle size distribution meter SALD-7000 manufactured by Shimadzu Corporation.

［硬化促進剤１の合成方法］
メタノール１８００ｇを入れたフラスコに、フェニルトリメトキシシラン２４９．５ｇ、２，３−ジヒドロキシナフタレン３８４．０ｇを加えて溶かし、次に室温攪拌下２８％ナトリウムメトキシド−メタノール溶液２３１．５ｇを滴下した。さらにそこへ予め用意したテトラフェニルホスホニウムブロマイド５０３．０ｇをメタノール６００ｇに溶かした溶液を室温攪拌下滴下すると結晶が析出した。析出した結晶を濾過、水洗、真空乾燥し、桃白色結晶の上記硬化促進剤１を得た。 (D) Curing Accelerator Curing Accelerator 1: Curing Accelerator represented by the following formula

[Method for synthesizing Curing Accelerator 1]
To a flask containing 1800 g of methanol, 249.5 g of phenyltrimethoxysilane and 384.0 g of 2,3-dihydroxynaphthalene were added and dissolved, and then 231.5 g of a 28% sodium methoxide-methanol solution was added dropwise under room temperature stirring. Further, a solution prepared in advance in which 503.0 g of tetraphenylphosphonium bromide was dissolved in 600 g of methanol was added dropwise to the solution under stirring at room temperature to precipitate crystals. The precipitated crystals were filtered, washed with water and vacuum dried to obtain the above-mentioned curing accelerator 1 of pinkish white crystals.

Curing accelerator 2: Curing accelerator represented by the following formula

[Method for synthesizing Curing Accelerator 2]
In a separable flask equipped with a stirrer, 37.5 g (0.15 mol) of 4,4'-bisphenol S and 100 ml of methanol are charged, stirred and dissolved at room temperature, and 4.0 g of sodium hydroxide is previously added to 50 ml of methanol while stirring. A solution in which (0.1 mol) was dissolved was added. Then, a solution prepared by dissolving 41.9 g (0.1 mol) of tetraphenylphosphonium bromide in 150 ml of methanol was added in advance. Stirring was continued for a while, 300 ml of methanol was added, and then the solution in the flask was added dropwise to a large amount of water with stirring to obtain a white precipitate. The precipitate was filtered and dried to obtain the above-mentioned curing accelerator 2 as white crystals.

(E) Coupling agent Coupling agent: Phenylaminopropyltrimethoxysilane (manufactured by Toray Dow Corning Co., Ltd., CF4083)

(F) Other synthetic separation type agents: Montanic acid ester wax (WE-4 (manufactured by Clariant Japan Co., Ltd.))
Ion catcher: Hydrotalcite (DHT-4H (manufactured by Kyowa Chemical Industry Co., Ltd.))
Colorant: Carbon black (Carbon # 5 (manufactured by Mitsubishi Chemical Corporation))
Low stress agent 1: Silicone oil (manufactured by Toray Dow Corning Co., Ltd., FZ-3730)
Low stress agent 2: Acrylonitrile-butadiene rubber (manufactured by Ube Industries, Ltd., CTBN1008SP)

[Evaluation item]
(Shrinkage factor)
For each of the Examples and Comparative Examples, the shrinkage ratio of the obtained resin composition for semiconductor encapsulation was measured as follows. First, using a transfer molding machine, a semiconductor encapsulation resin composition is injected into a mold cavity under the conditions of a mold temperature of 175 ° C., a molding pressure of 9.8 MPa, and a curing time of 3 minutes, and a disk-shaped test is performed. Pieces were made. The test piece was then cooled to 25 ° C. _{Here, the shrinkage rate S 1} (%) was calculated from the inner diameter of the mold cavity at 175 ° C. and the outer diameter of the test piece at 25 ° C. as follows.
S ₁ = {(inner diameter dimension of mold cavity at 175 ° C.)-(outer diameter dimension of test piece at 25 ° C.)} / (inner diameter dimension of mold cavity at 175 ° C.) × 100
The results are shown in Table 1.

(Glass transition temperature, coefficient of linear expansion (α ₁ , α ₂ ))
For each Example and each Comparative Example, the glass transition temperature and the coefficient of linear expansion of the cured product of the obtained semiconductor encapsulating resin composition were measured as follows. First, a semiconductor encapsulation resin composition was injection-molded using a transfer molding machine at a mold temperature of 175 ° C., an injection pressure of 9.8 MPa, and a curing time of 3 minutes to obtain a test piece having a size of 15 mm × 4 mm × 4 mm. Next, the obtained test piece was post-cured at 175 ° C. for 4 hours, and then using a thermomechanical analyzer (TMA100 manufactured by Seiko Electronics Inc.), the measurement temperature range was 0 ° C. to 320 ° C., and the temperature rise rate. The measurement was performed under the condition of 5 ° C./min. From this measurement result, the glass transition temperature, the coefficient of linear expansion below the glass transition temperature (α ₁ ), and the coefficient of linear expansion above the glass transition temperature (α ₂ ) were calculated. In Table 1, _{the unit of α 1} and α ₂ is ppm / K, and the unit of the glass transition temperature is ° C. The results are shown in Table 1.

(Bending elastic modulus, bending strength)
For each Example and each Comparative Example, the flexural modulus and bending strength of the obtained cured resin composition for semiconductor encapsulation were measured as follows. First, a semiconductor encapsulation resin composition was injection-molded using a transfer molding machine at a mold temperature of 175 ° C., an injection pressure of 9.8 MPa, and a curing time of 3 minutes, and a test piece having a width of 10 mm, a thickness of 4 mm, and a length of 80 mm was injected. Got Then, the obtained test piece was post-cured at 175 ° C. for 4 hours. Then, the flexural modulus E ₍₂₅₎ at 25 ° C. and the flexural modulus E _{(260) at} 260 ° C. of the test piece were measured according to JIS K 6911. The unit of flexural modulus is MPa. The results are shown in Table 1.

(Α dose of encapsulant)
Using a compression molding machine, the mold temperature was 175 ° C., the molding pressure was 9.8 MPa, and the curing time was 2 minutes. ) Was molded. Six of the obtained test pieces were arranged side by side to form a test sample (total surface area of 1008 cm ² ), and a low-level α-ray measuring device (manufactured by Sumitomo Chemical Industry Co., Ltd., LACS-4000M, applied voltage 1.9 KV) was used using this test sample. , PR-10 gas (argon: methane = 9: 1) 100 m / min, effective counting time 88 h), and the α dose of the test piece was measured. In Table 1, "0.000" cph / cm ² indicates that it was below the detection limit.

(Amount of uranium, amount of thorium)
[Measurement of uranium and thorium in (high-purity) inorganic filler]
(High purity) After dissolving the inorganic filler in hydrogen fluoride to volatilize the main component, the residue is dissolved in nitric acid, and the supernatant liquid treated by the centrifuge is inductively coupled by Seiko Instruments Co., Ltd. Measurements were made using an inductively coupled plasma mass spectrometry (ICP-MS) device SPQ-9000.

(Spiral flow)
Using a low-pressure transfer molding machine (KTS-15 manufactured by Kotaki Seiki Co., Ltd.), a mold for measuring spiral flow according to ANSI / ASTM D 3123-72 was used, and the mold temperature was 175 ° C, injection pressure was 6.9 MPa, and maintenance was performed. Under the condition of a pressure time of 120 seconds, the resin composition for semiconductor encapsulation obtained above was injected, and the flow length was measured. Spiral flow is a parameter of fluidity, and the larger the value, the better the fluidity. The unit is cm.

(Viscosity (rectangular pressure))
Using a low-pressure transfer molding machine (40t manual press manufactured by Nippon Electric Co., Ltd.), a rectangular shape with a width of 13 mm, a thickness of 1 mm, and a length of 175 mm under the conditions of a ^{mold temperature of 175 ° C. and an injection speed of 177 cm 3 / sec.} The semiconductor encapsulation resin composition obtained above is injected into the flow path, and the change with time of pressure is measured by a pressure sensor embedded at a position 25 mm from the upstream tip of the flow path, and the semiconductor encapsulation resin composition is measured. The minimum pressure when the object was flowing was measured. The rectangular pressure is a parameter of the melt viscosity, and the smaller the value, the lower the melt viscosity and the better. If the rectangular pressure value is 6 MPa or less, there is no problem, and if it is 5 MPa or less, a good viscosity can be obtained.

(Warp of semiconductor device)
Using a transfer molding machine for MAP molding (Y series manufactured by TOWA Corporation), the obtained semiconductor encapsulation resin was mounted on a substrate (substrate thickness 0.28 mm) on which a Si chip of 10 × 10 × 0.2 mm was mounted. The composition was molded to a package size of 13 × 13 × 0.68 mm (molding temperature 175 ° C., molding pressure 6.9 MPa, curing time 2 minutes). The package was then post-cured at 175 ° C. for 4 hours to give a sample. Five of the obtained samples were heated from 25 ° C to 260 ° C using a shadow moiré type warp measuring device (manufactured by akrometrix), and the difference between the maximum and minimum values in the package height direction at 25 ° C and 260 ° C. Was measured, and the average value is shown in Table 1. The unit is μm. In Table 1, the smaller the absolute value, the smaller the warp of the semiconductor device.

As shown in Table 1, the semiconductor encapsulating resin compositions of Examples 1 and 2 show a relatively high coefficient of linear expansion α ₂ when cured. From this, it was possible to suppress the warp even when the semiconductor package was manufactured. Moreover, the resin compositions for semiconductor encapsulation of Examples 1 and 2 show a low α-dose in the cured encapsulant. From this, it was found that it can be applied to semiconductor devices that are easily affected by malfunctions due to α rays.

100 Semiconductor device 102 Structure 10 Substrate 12 Solder ball 20 Semiconductor element 22 Bump 30 Encapsulating resin 32 Underfill

Claims (16)

(A) Epoxy resin and
(B) Hardener and
A resin composition for semiconductor encapsulation containing (C) an inorganic filler containing cristobalite.
_{The linear expansion coefficient α 2} of the cured product of the semiconductor encapsulating resin composition at the glass transition temperature or higher is 30 ppm / K or more and 67 ppm / K or less.
The spiral flow of the semiconductor encapsulating resin composition is 135 cm or more and 230 cm or less.
A resin composition for semiconductor encapsulation, wherein the α dose in the cured product of the resin composition for semiconductor encapsulation measured using an α-ray counter is 0.000 cf / cm ² or more and 0.005 cf / cm ² or less. The semiconductor encapsulating resin composition according to claim 1.
The content of the cristobalite is 5% by mass or more and 60% by mass or less with respect to the entire semiconductor encapsulating resin composition, and
A resin composition for encapsulating a semiconductor, wherein the α dose in the cured product is 0.000 cf / cm ² or more and 0.001 cf / cm ^{2 or less.} The semiconductor encapsulating resin composition according to claim 1 or 2.
A resin composition for encapsulating a semiconductor, wherein the average particle size of the cristobalite is 3 μm or more and 20 μm or less. The semiconductor encapsulating resin composition according to any one of claims 1 to 3.
A resin composition for encapsulating a semiconductor, wherein the cristobalite contains spherical cristobalite. The semiconductor encapsulating resin composition according to any one of claims 1 to 4.
A resin composition for semiconductor encapsulation, wherein the cured product of the resin composition for semiconductor encapsulation has a glass transition temperature of 130 ° C. or higher and 250 ° C. or lower. The semiconductor encapsulating resin composition according to any one of claims 1 to 5.
A resin composition for semiconductor encapsulation, wherein the cured product of the resin composition for semiconductor encapsulation has a flexural modulus E _{(260) at} 260 ° C. of 100 MPa or more and 1 GPa or less. The semiconductor encapsulating resin composition according to any one of claims 1 to 6.
The (C) inorganic filler further contains silica, which is a resin composition for encapsulating a semiconductor. The semiconductor encapsulating resin composition according to claim 7.
The silica contains fine silica having an average particle size of more than 0 μm and not more than 1 μm.
Resin composition for semiconductor encapsulation. The semiconductor encapsulating resin composition according to any one of claims 1 to 8.
A resin composition for encapsulating a semiconductor, wherein the (A) epoxy resin contains a biphenyl type epoxy resin. The semiconductor encapsulating resin composition according to any one of claims 1 to 9.
A resin composition for encapsulating a semiconductor, wherein the epoxy resin (A) contains a phenol aralkyl type epoxy resin having a biphenylene skeleton. The semiconductor encapsulating resin composition according to any one of claims 1 to 10.
A resin composition for semiconductor encapsulation further comprising a coupling agent which is a secondary aminosilane. The semiconductor encapsulating resin composition according to any one of claims 1 to 11.
The semiconductor encapsulating resin composition further contains (D) a curing accelerator and contains.
A resin composition for encapsulating a semiconductor, wherein the (D) curing accelerator contains at least one selected from the compounds represented by the following general formulas (6) to (9).

(In the above general formula (6), P represents a phosphorus atom. R ⁴ , R ⁵ , R ⁶ and R ⁷ represent an aromatic group or an alkyl group. A is selected from a hydroxyl group, a carboxyl group and a thiol group. Represents an anion of an aromatic organic acid having at least one functional group in the aromatic ring. AH is an aromatic having at least one functional group selected from a hydroxyl group, a carboxyl group, and a thiol group in the aromatic ring. Represents an organic acid. X and y are numbers 1 to 3, z is a number 0 to 3, and x = y.)

(In the above general formula (7), P represents a phosphorus atom. R ⁸ represents an alkyl group having 1 to 3 carbon atoms, R ⁹ represents a hydroxyl group. F is a number from 0 to 5, and g is 0 to 0. It is a number of three.)

(In the above general formula (8), P represents a phosphorus atom. R ¹⁰ , R ¹¹ and R ¹² represent an alkyl group having 1 to 12 carbon atoms or an aryl group having 6 to 12 carbon atoms, and are identical to each other. ^{R 13} , R ¹⁴ and R ¹⁵ represent hydrogen atoms or hydrocarbon groups having 1 to 12 carbon atoms, which may be the ^{same or different from each other, and R 14} and R ¹⁵ are bonded to each other. It may have a annular structure.)

(In the above general formula (9), P represents a phosphorus atom and Si represents a silicon atom. R ¹⁶ , R ¹⁷ , R ¹⁸ and R ¹⁹ are organic groups or fats having an aromatic ring or a heterocyclic ring, respectively. Represents a group group and may be the same or different from each other. In the formula, R ²⁰ is an organic group bonded to the groups Y ² and Y ^{3. In the formula, R 21} is a group Y ⁴ and Y ⁵ . ^{Y 2} and Y ³ are organic groups to be bonded. Y 2 and Y 3 represent a group formed by a proton donor group releasing a proton, ^{and groups Y 2} and Y ³ in the same molecule are bonded to a silicon atom to form a chelate structure. Y ⁴ and Y ⁵ represent groups formed by the proton donor group releasing a proton, and the groups Y ⁴ and Y ⁵ in the same molecule combine with a silicon atom to form a chelate structure. There, R ²⁰ and R ²¹ may be the same or different from each other ^{, and Y 2} , Y ³ , Y ⁴ and Y ⁵ may be the same or different from each other. Z ¹ is an aromatic ring. Alternatively, it is an organic group having a heterocycle or an aliphatic group.) The semiconductor encapsulating resin composition according to any one of claims 1 to 12.
A resin composition for semiconductor encapsulation used as a mold underfill material. The semiconductor encapsulating resin composition according to any one of claims 1 to 13.
A resin composition for encapsulating semiconductors in the form of powder, granules or tablets. With the board
The semiconductor element mounted on one surface of the substrate and
A semiconductor device comprising a sealing material layer for encapsulating the semiconductor element.
The semiconductor device, wherein the encapsulant layer is a cured product of the resin composition for encapsulating a semiconductor according to any one of claims 1 to 14. The semiconductor device according to claim 15.
The upper surface of the semiconductor element is exposed, or the upper surface of the semiconductor element is sealed in the encapsulant layer, and the encapsulant layer from the one surface of the substrate to the top surface of the encapsulant layer. The thickness of the semiconductor device is 0.01 mm or more and 0.4 mm or less.

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