JP5320714B2 - Epoxy resin composition for semiconductor encapsulation and semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an epoxy resin composition for sealing a semiconductor, which is excellent in productivity of continuous production in the sealing process of the semiconductor and also having good reliability. <P>SOLUTION: This epoxy resin composition for sealing the semiconductor comprises (A) an epoxy resin, (B) a compound containing &ge;2 phenolic hydroxy groups, (C) an inorganic filler and (D) a curing accelerator, wherein, the epoxy resin (A) contains (A1) an epoxy resin having a structure expressed by formula (1) by the ratio of &ge;20 wt.% based on the total epoxy resin, and the inorganic filler (C) is contained in the ratio of &ge;86 and &le;92 wt.% based on the whole composition. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to an epoxy resin composition for semiconductor encapsulation and a semiconductor device.

  In recent years, as electronic components such as integrated circuits (ICs), large scale integrated circuits (LSIs), and very large scale integrated circuits (VLSIs) and semiconductor devices have been increased in density and integration, their mounting methods have been changed from insertion mounting. It is changing to surface mounting. Along with this, there is a demand for a multi-pin lead frame and a narrow lead pitch. Surface mount type QFP (Quad Flat Package), which is small, light, and compatible with multi-pin use, is used in various semiconductor devices. It has been. And since the semiconductor device is excellent in balance of productivity, cost, reliability, etc., it is mainstream to seal using an epoxy resin composition.

In addition, as the surface mounting of semiconductor devices is promoted in response to further increase in pin count and speed, the level of reliability has become stricter as the temperature of solder mounting becomes higher with lead-free. . On the other hand, from the viewpoint of productivity improvement and cost reduction, continuous moldability is an important issue for sealing molding of semiconductor devices in order to prevent shortening of the molding die cleaning and yield reduction due to molding defects. In order to improve the continuous formability, it is already known that the following characteristics improvement is necessary.
That is,
1) Improvement of curability 2) Addition of effective release agent 3) Increasing shrinkage during molding.

  Regarding 1), there are a method of combining a highly curable epoxy resin and a curing agent and a method of adding an effective curing accelerator (see, for example, Patent Document 1). The reliability of semiconductor devices has been increased due to problems such as poor storage stability during storage of the resin composition, and difficulty in controlling curing during sealing molding, resulting in poor filling, voids, stress at the interface, etc. There was a problem of causing a decline in sex.

  As for 2), it is possible to improve the continuity formation by selecting an appropriate wax and adjusting the amount added (see, for example, Patent Document 2). There was a problem such as lowering.

  With regard to 3), as the shrinkage rate at the time of molding is increased, the releasability from the mold is improved, and the effect of improving the continuous moldability is obtained. The shrinkage rate at the time of molding is a combination of the reaction shrinkage of the resin component during cooling from the mold temperature to room temperature and the thermal shrinkage related to the linear expansion of the cured resin, and increases the shrinkage rate at the time of molding. One way to achieve this is to increase the reaction shrinkage of the resin component, but the combination of epoxy resin and phenolic resin curing agent, which are known as semiconductor encapsulating materials, is a combination that greatly increases the reaction shrinkage. Has not been found. In addition, there is a method of increasing the reaction shrinkage and the heat shrinkage by reducing the content of the inorganic filler, and there is a document disclosing such a point (for example, see Patent Document 3). With the increase of the coefficient of linear expansion and the increase of internal stress, there is a fear that the reliability as a semiconductor device is lowered. Furthermore, a method of increasing the reaction shrinkage by shifting the equivalent ratio between the epoxy group of the epoxy resin and the phenolic hydroxyl group of the phenol resin-based curing agent is also conceivable, but to the extent that the desired reaction shrinkage can be obtained in the conventional resin system. When the equivalence ratio is shifted, the sticking property is increased as the cross-linking density is lowered as a reciprocal event, which is not preferable because the mold release becomes worse. From the above points, it has been difficult to achieve both reliability and continuous formability.

JP 2003-128757 A JP 2002-220434 A JP 2003-002954 A

  The present invention provides an epoxy resin composition for semiconductor encapsulation excellent in continuous productivity and good reliability in a semiconductor encapsulation process, and a semiconductor device obtained by encapsulating a semiconductor element using the same. .

  The epoxy resin composition for semiconductor encapsulation of the present invention comprises (A) an epoxy resin, (B) a compound containing two or more phenolic hydroxyl groups, (C) an inorganic filler, and (D) a curing accelerator. It is the epoxy resin composition for semiconductor sealing containing, Comprising: The ratio of 20 weight% or more in the epoxy resin (A1) in which the said (A) epoxy resin has a structure represented by following General formula (1) in all epoxy resins (C) Inorganic filler is contained in the entire composition in a proportion of 86% by weight or more and 92% by weight or less, and the resin composition is molded at a mold temperature of 175 ° C., a molding pressure of 9.8 MPa, and cured. A shrinkage rate calculated by the following formula (a) in a disk-shaped cured product having a diameter of 100 mm and a thickness of 3 mm molded under a time of 120 seconds is 0.40% or more and less than 0.65%. To do.

(In the above general formula (1), Ar is an aromatic group having 6 to 20 carbon atoms, R1 is a hydrocarbon group having 1 to 6 carbon atoms, R3 is hydrogen, a hydrocarbon group having 1 to 4 carbon atoms, or carbon. R2 is a hydrocarbon group having 1 to 4 carbon atoms, W1 is an oxygen atom or a sulfur atom, and a is 0 to 0. 10 is an integer of 10 and b is an integer of 1 to 3. m and n are molar ratios, 0 <m <1, 0 <n <1, m + n = 1, and m / n is 1 /. 10 to 1/1.)
Shrinkage (%) = {(inner diameter dimension of mold cavity at 175 ° C.) − (Outer diameter dimension of disk-shaped cured product at 25 ° C.)} / (Inner diameter dimension of mold cavity at 175 ° C.) × 100 (%)
(I)

The epoxy resin composition for semiconductor encapsulation of the present invention is obtained by molding the epoxy resin composition for semiconductor encapsulation at 175 ° C. after molding under the conditions of a mold temperature of 175 ° C., a molding pressure of 9.8 MPa, and a curing time of 120 seconds. From the glass transition temperature of the cured product after molding and post-curing, measured by thermo-mechanical analysis (TMA) for the length direction of a test piece having a width of 4 mm, a thickness of 3 mm, and a length of 15 mm that was post-cured for 4 hours. The linear expansion coefficient in the low region may be 0.6 × 10 ⁻⁵ / ° C. or more and 1.2 × 10 ⁻⁵ / ° C. or less.

  The epoxy resin composition for semiconductor encapsulation of the present invention is obtained by molding the epoxy resin composition for semiconductor encapsulation under the conditions of a mold temperature of 175 ° C., a molding pressure of 9.8 MPa, and a curing time of 120 seconds. The glass transition temperature of the cured product after molding, measured by thermomechanical analysis (TMA) in the length direction of the test piece having a length of 3 mm and a length of 15 mm, shall be 100 ° C. or higher and 125 ° C. or lower. it can.

The epoxy resin composition for semiconductor encapsulation of the present invention is obtained by molding the epoxy resin composition for semiconductor encapsulation under the conditions of a mold temperature of 175 ° C., a molding pressure of 9.8 MPa, and a curing time of 120 seconds. The linear expansion coefficient in the region exceeding the glass transition temperature of the cured product after molding, measured by thermomechanical analysis (TMA), in the length direction of the test piece having a length of 3 mm and a length of 15 mm is 2.2 × 10 ^−5. / ° C. or higher and 4.0 × 10 ⁻⁵ / ° C. or lower.

  The epoxy resin composition for semiconductor encapsulation of the present invention is obtained by molding the epoxy resin composition for semiconductor encapsulation at 175 ° C. after molding under the conditions of a mold temperature of 175 ° C., a molding pressure of 9.8 MPa, and a curing time of 120 seconds. The glass transition temperature of the cured product after molding and post-curing was measured by thermomechanical analysis (TMA) for the length direction of a test piece having a width of 4 mm, a thickness of 3 mm, and a length of 15 mm, which was cured after 4 hours. It can be set to 110 ° C. or higher and 140 ° C. or lower.

  In the epoxy resin composition for semiconductor encapsulation of the present invention, the epoxy resin (A1) having the structure represented by the general formula (1) is a phenolic hydroxyl group-containing aromatic, aldehyde, the following general formula (2) The epoxy resin obtained by co-condensing the compound (J) represented by glycidyl ether with epichlorohydrin can be used.

(However, in the said General formula (2), Ar is a C6-C20 aromatic group, R1 is a C1-C6 hydrocarbon group, and may mutually be same or different. R2 Is a hydrocarbon group having 1 to 4 carbon atoms, W1 is an oxygen atom or a sulfur atom, a is an integer of 0 to 10, and b is an integer of 1 to 3).

  In the epoxy resin composition for semiconductor encapsulation of the present invention, the epoxy resin (A1) having a structure represented by the general formula (1) is an epoxy resin having a structure represented by the following general formula (3). Can be.

(However, in the said General formula (3), R1 is a C1-C6 hydrocarbon group and may mutually be same or different. R2 is a C1-C4 hydrocarbon group, W1 is an oxygen atom or a sulfur atom, c is an integer of 0 to 5, d is an integer of 0 to 3, m and n represent a molar ratio, and 0 <m <1, 0 <n <1 M + n = 1 and m / n is 1/10 to 1/1.)

  In the epoxy resin composition for semiconductor encapsulation of the present invention, the epoxy resin having a structure represented by the general formula (3) is an epoxy resin having a structure represented by the following general formula (4). be able to.

(However, in the said General formula (4), R1 is a C1-C6 hydrocarbon group, and may mutually be same or different. C is an integer of 0-5, d is 0. M and n represent molar ratios, 0 <m <1, 0 <n <1, m + n = 1, and m / n is 1/10 to 1/1.)

  The semiconductor device of the present invention is characterized in that a semiconductor element is sealed with a cured product of the above-described epoxy resin composition for semiconductor sealing.

  According to the present invention, it is possible to obtain an epoxy resin composition for semiconductor encapsulation and a semiconductor device that have excellent continuous moldability and good reliability.

  The present invention relates to an epoxy resin composition for semiconductor encapsulation, comprising (A) an epoxy resin, (B) a compound containing two or more phenolic hydroxyl groups, (C) an inorganic filler, and (D) a curing accelerator. And (A) the epoxy resin contains an epoxy resin (A1) having a structure represented by the general formula (1) in a proportion of 20% by weight or more in the total epoxy resin, and (C) the inorganic filler is all It is contained in the composition at a ratio of 86% by weight or more and 92% by weight or less, and the resin composition is molded at a mold temperature of 175 ° C., a molding pressure of 9.8 MPa, a curing time of 120 seconds, and a diameter of 100 mm, Shrinkage ratio (%) in disk-shaped cured product having a thickness of 3 mm = {(inner diameter dimension of mold cavity at 175 ° C.) − (Outer diameter dimension of disk-shaped cured product at 25 ° C.)} / (At 175 ° C. The inner diameter dimension of the mold cavity) x 100 (%) is 0.40. Above, by less than 0.65%, excellent continuous moldability, but a good epoxy resin composition reliability. Hereinafter, an embodiment of the present invention will be described in detail.

  In this embodiment, an epoxy resin (A1) having a structure represented by the following general formula (1) is used as the epoxy resin (A). When the epoxy resin is used, a cured product having a large shrinkage ratio at the time of molding can be obtained in comparison with a conventional epoxy resin in a resin composition having the same inorganic filler content. For this reason, by using the epoxy resin (A1) having a structure represented by the following general formula (1) as the epoxy resin (A) and setting the blending ratio of the inorganic filler to a specific range described later, sealing molding is performed. Excellent continuous formability at the time and good reliability in the semiconductor device can be obtained. In addition, the epoxy resin (A1) having the structure represented by the following general formula (1) has a large amount of aromatic ring carbon in the molecule, and the cured product of the epoxy resin composition using this has excellent flame resistance and water absorption. Another characteristic is that the rate is low.

(In the above general formula (1), Ar is an aromatic group having 6 to 20 carbon atoms, R1 is a hydrocarbon group having 1 to 6 carbon atoms, R3 is hydrogen, a hydrocarbon group having 1 to 4 carbon atoms, or carbon. R2 is a hydrocarbon group having 1 to 4 carbon atoms, W1 is an oxygen atom or a sulfur atom, and a is 0 to 0. 10 is an integer of 10 and b is an integer of 1 to 3. m and n are molar ratios, 0 <m <1, 0 <n <1, m + n = 1, and m / n is 1 /. 10 to 1/1.)

  The ratio m / n between m and n in the epoxy resin (A1) having the structure represented by the general formula (1) is preferably 1/10 to 1/1, and 1/9 to 1/2. It is more preferable that The smaller the m / n value, the greater the reaction shrinkage due to the increase in the crosslink density of the epoxy resin, but conversely, the glass transition temperature becomes higher and the thermal expansion shrinks due to the lower coefficient of linear expansion. As a result, the overall shrinkage during molding is reduced. For this reason, it is difficult to obtain the effect of improving the continuous formability as the value of m / n is smaller. Conversely, as the value of m / n is larger, the effect is reversed and the shrinkage rate during molding increases, but the plastic structure in the molecule increases, so that sticking to the mold occurs during molding. It is easy and easy. When m / n is within the above range, a cured product having a large shrinkage rate during molding can be obtained without causing problems such as sticking, and thus excellent continuous moldability can be obtained. Further, when m / n is within the above range, an effect of improving flame resistance can be obtained. Moreover, if it is in the said range, there is little possibility of causing the fall of the fluidity | liquidity of the resin composition by resin viscosity becoming high.

  Although it does not specifically limit as an epoxy resin (A1) which has a structure represented by General formula (1) used by this embodiment, For example, the epoxy which has a structure represented by following General formula (4) Resin, epoxy resin having a structure represented by the following general formula (5), epoxy resin having a structure represented by the following general formula (6), epoxy resin having a structure represented by the following general formula (7), etc. Is mentioned. From the viewpoint of flame resistance, an epoxy resin having a structure represented by the following general formula (4) and an epoxy resin having a structure represented by the following general formula (6) are more preferable.

(However, in the said General formula (4), R1 is a C1-C6 hydrocarbon group, and may mutually be same or different. R2 is a C1-C4 hydrocarbon group. C is an integer of 0 to 5 and d is an integer of 0 to 3. m and n represent molar ratios, 0 <m <1, 0 <n <1, m + n = 1, and m / N is 1/10 to 1/1.)

(However, in the said General formula (5), R1 is a C1-C6 hydrocarbon group, and may mutually be same or different. R2 is a C1-C4 hydrocarbon group. D is an integer of 0 to 3. m and n represent molar ratios, 0 <m <1, 0 <n <1, m + n = 1, and m / n is 1/10 to 1/1. .)

(However, in the said General formula (6), R1 is a C1-C6 hydrocarbon group, and may mutually be same or different. R2 is a C1-C4 hydrocarbon group. C is an integer of 0 to 5 and d is an integer of 0 to 3. m and n represent molar ratios, 0 <m <1, 0 <n <1, m + n = 1, and m / N is 1/10 to 1/1.)

(However, in the said General formula (7), R1 is a C1-C6 hydrocarbon group and may mutually be same or different. R2 is a C1-C4 hydrocarbon group. D is an integer of 0 to 3. m and n represent molar ratios, 0 <m <1, 0 <n <1, m + n = 1, and m / n is 1/10 to 1/1. .)

  The epoxy resin (A1) having a structure represented by the general formula (1) used in the present embodiment includes a phenolic hydroxyl group-containing aromatic, an aldehyde, and a compound (J) represented by the following general formula (2). Can be obtained by glycidyl etherification with epichlorohydrin. Compound (J) represented by the following general formula (2) has an aromatic ring to which a glycidyl ether group is not bonded, W1R2 (W1 is an oxygen atom or a sulfur atom, and R2 is a hydrocarbon group having 1 to 4 carbon atoms. ) Are connected to each other. Since W1R2 is bonded, the compound (J) represented by the following general formula (2) has polarity, and this improves the reactivity. Therefore, a novolak comprising a phenolic hydroxyl group-containing aromatic or aldehyde The structure of the compound (J) can be introduced into the resin structure. The epoxy resin (A1) has the advantage that the raw material cost is lower than that of the phenol aralkyl type epoxy resin having a biphenylene skeleton having excellent flame resistance and low water absorption, and the raw material is easily available. It can be manufactured or obtained.

(However, in the said General formula (2), Ar is a C6-C20 aromatic group, R1 is a C1-C6 hydrocarbon group, and may mutually be same or different. R2 Is a hydrocarbon group having 1 to 4 carbon atoms, W1 is an oxygen atom or a sulfur atom, a is an integer of 0 to 10, and b is an integer of 1 to 3).

  Although it does not specifically limit as phenolic hydroxyl group containing aromatics used for manufacture of an epoxy resin (A1), For example, phenol, catechol, resorcinol, hydroquinone, o-cresol, p-cresol, m-cresol , Phenylphenol, ethylphenol, n-propylphenol, iso-propylphenol, t-butylphenol, xylenol, methylpropylphenol, methylbutylphenol, dipropylphenol, dibutylphenol, nonylphenol, mesitol, 2,3,5-trimethylphenol, Examples include phenols such as 2,3,6-trimethylphenol, and naphthols such as 1-naphthol, 2-naphthol, and methylnaphthol. Among these, phenol, o-cresol, 1-naphthol and 2-naphthol are preferable, and o-cresol is more preferable. These may be used alone or in combination of two or more.

  Although it does not specifically limit as aldehydes used for manufacture of an epoxy resin (A1), For example, aliphatic aldehydes, such as formaldehyde, acetaldehyde, propionaldehyde, benzaldehyde, 4-methylbenzaldehyde, 3,4- Aromatic aldehydes such as dimethylbenzaldehyde, 4-biphenylaldehyde, naphthylaldehyde, salicylaldehyde and the like can be mentioned. Among these, formaldehyde, benzaldehyde, and naphthylaldehyde are preferable, and formaldehyde is more preferable. These may be used alone or in combination of two or more.

  The compound (J) represented by the general formula (2) used for the production of the epoxy resin (A1) is not particularly limited as long as it is a structure of the general formula (2). For example, methoxybenzene, Ethoxybenzene, methylphenyl sulfide, ethylphenyl sulfide, 1-methoxynaphthalene, 2-methoxynaphthalene, 1-methyl-2-methoxynaphthalene, 1-methoxy-2-methylnaphthalene, 1,3,5-trimethyl-2-methoxy Naphthalene, 1-ethoxynaphthalene, 2-ethoxynaphthalene, 1-t-butoxynaphthalene, methyl naphthyl sulfide, ethyl naphthyl sulfide, 1,4-dimethoxynaphthalene, 2,6-dimethoxynaphthalene, 2,7-dimethoxynaphthalene, 1- And methoxyanthracene. Among these, considering flame resistance and low water absorption as other necessary characteristics, a compound represented by the following formula (8) is preferable, and a methoxynaphthalene compound represented by the following formula (9) is more preferable.

(However, in the said General formula (8), R1 is a C1-C6 hydrocarbon group, and may mutually be same or different. R2 is a C1-C4 hydrocarbon group, W1 is an oxygen atom or a sulfur atom, and c is an integer of 0 to 5.)

(However, in the said General formula (9), R1 is a C1-C6 hydrocarbon group, and may mutually be same or different. C is an integer of 0-5.)

  The method for synthesizing the phenol resin that is a precursor of the epoxy resin (A1) used in the present embodiment is not particularly limited. For example, the phenolic hydroxyl group-containing aromatics and aldehydes are represented by the general formula (2). And a method of co-condensing the compound (J) with an acidic catalyst in the coexistence.

  The method for synthesizing the epoxy resin (A1) having the structure represented by the general formula (1) used in the present embodiment is not particularly limited. For example, an excess of phenol resins that are precursors of the epoxy resin (A1) is used. And a method of reacting at 50 to 150 ° C., preferably 60 to 120 ° C. for 1 to 10 hours in the presence of an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide. After completion of the reaction, excess epichlorohydrin is distilled off, the residue is dissolved in a solvent such as toluene, methyl isobutyl ketone, filtered, washed with water to remove inorganic salts, and then the target epoxy is removed by distilling off the solvent. Resin (A1) can be obtained.

  In the present embodiment, other epoxy resins can be used in combination as long as the effect of using the epoxy resin (A1) having the structure represented by the general formula (1) is not impaired. Examples of epoxy resins that can be used in combination include biphenyl type epoxy resins, bisphenol type epoxy resins, stilbene type epoxy resins, phenol novolac type epoxy resins, cresol novolac type epoxy resins, triphenolmethane type epoxy resins, and phenol aralkyl type epoxy resins having a phenylene skeleton. Resin, phenol aralkyl type epoxy resin having biphenylene skeleton, naphthol type epoxy resin, alkyl modified triphenol methane type epoxy resin, triazine nucleus-containing epoxy resin, dicyclopentadiene modified phenol type epoxy resin, anthracene or hydrogenated product skeleton And epoxy resins having a hydroquinone type. In consideration of moisture resistance reliability as an epoxy resin composition for semiconductor encapsulation, it is preferable that Na ions and Cl ions, which are ionic impurities, be as small as possible. From the viewpoint of curability, the epoxy equivalent is 100 g / eq or more and 500 g / eq. The following is preferred.

  The blending ratio of the epoxy resin (A1) having the structure represented by the general formula (1) when other epoxy resins are used in combination is preferably 20% by weight or more and 40% by weight in all epoxy resins. More preferably. Within the above range, an effect of becoming a cured product having a large shrinkage at the time of molding is obtained, and (C) combined with the blending ratio of the inorganic filler being in a specific range, exhibits excellent continuous moldability. can do.

  In the present embodiment, as the curing agent, a compound (B) containing two or more phenolic hydroxyl groups is used from the viewpoints of flame resistance, moisture resistance, electrical properties, curability, storage stability, and the like. The compound (B) containing two or more phenolic hydroxyl groups is a monomer, oligomer or polymer in general having two or more phenolic hydroxyl groups in one molecule, and its molecular weight and molecular structure are not particularly limited. For example, phenol novolak resin, cresol novolak resin, triphenolmethane type phenol resin, terpene modified phenol resin, dicyclopentadiene modified phenol resin, phenol aralkyl resin having phenylene skeleton and / or biphenylene skeleton, phenylene and / or biphenylene skeleton, etc. A naphthol aralkyl resin, a bisphenol compound, and the like, which may be used, may be used alone or in combination of two or more. Of these, the hydroxyl equivalent is preferably 90 g / eq or more and 250 g / eq or less from the viewpoint of curability. Among them, the phenol aralkyl resin having a phenylene skeleton and / or a biphenylene skeleton, and the naphthol aralkyl resin having a phenylene and / or a biphenylene skeleton, etc. are appropriately separated from each other at a crosslinking point, and in the balance with the sticking property, This is preferable because the shrinkage rate can be increased stably.

  The composition ratio of the epoxy resin (A) and the compound (B) containing two or more phenolic hydroxyl groups is the number of epoxy groups (Ep) in the entire epoxy resin (A) and the number of phenolic hydroxyl groups (Ph) in the entire compound (B). The equivalent ratio (Ep / Ph) is preferably 0.9 or more and 1.3 or less, and more preferably 0.9 or more and 1.2 or less. Within this range, there may be a decrease in curability during sealing molding of the resin composition, deterioration of sticking, a decrease in glass transition temperature in the resin cured product, and a decrease in moisture resistance reliability in the semiconductor device. The nature is low.

  As the inorganic filler (C) used in the present embodiment, those generally used for semiconductor sealing resin compositions can be used, for example, fused silica, spherical silica, crystalline silica, alumina, silicon nitride. And aluminum nitride. The particle size of the inorganic filler (C) is preferably 0.01 μm or more and 150 μm or less in consideration of the filling property to the mold. In addition, the content of the inorganic filler (C) is preferably 86% by weight or more and 92% by weight or less, more preferably 86% by weight or more and 90% by weight or less of the entire epoxy resin composition. . When the content of the inorganic filler (C) is not less than the above lower limit value, the epoxy resin (A1) having a structure represented by the general formula (1) having an effect of giving a cured product having a large shrinkage at the time of molding described above. ) In combination with the use, troubles such as sticking hardly occur and excellent continuous formability can be obtained without using a release agent having a strong release effect that affects reliability. Further, when the content of the inorganic filler (C) is less than or equal to the above upper limit value, there is little possibility of causing problems on the molding surface such as poor filling and void formation due to impaired fluidity. Furthermore, when the content of the inorganic filler (C) is within the above range, the reliability of the semiconductor device can be satisfied. In order to improve the reliability of the inorganic filler (C), the surface can be previously surface-treated with a coupling agent or the like.

  The curing accelerator (D) used in the present embodiment may be anything that promotes the reaction between the epoxy group of the epoxy resin (A) and the phenolic hydroxyl group of the compound (B) containing two or more phenolic hydroxyl groups, What is used for the general epoxy resin composition for semiconductor sealing can be utilized. Specific examples include organic phosphines, tetra-substituted phosphonium compounds, phosphobetaine compounds, phosphorus atom-containing compounds such as adducts of phosphine compounds and quinone compounds, 1,8-diazabicyclo (5,4,0) undecene-7, benzyl Nitrogen atom-containing compounds such as dimethylamine and 2-methylimidazole can be mentioned. Among these, a phosphorus atom-containing compound is preferable, and a tetra-substituted phosphonium compound is particularly preferable in consideration of fluidity, and a phosphobetaine compound and a phosphine compound in consideration of a low elastic modulus when cured of an epoxy resin composition. An adduct of phosphonium compound and silane compound is preferable in view of latent curing property.

  Examples of the organic phosphine that can be used in the present embodiment include a first phosphine such as ethylphosphine and phenylphosphine, a second phosphine such as dimethylphosphine and diphenylphosphine, trimethylphosphine, triethylphosphine, tributylphosphine, and triphenylphosphine. Of the third phosphine.

  Examples of the tetra-substituted phosphonium compound that can be used in the present embodiment include compounds represented by the following general formula (10).

(However, in the said General formula (10), P represents a phosphorus atom. R4, R5, R6, and R7 represent an aromatic group or an alkyl group. A is a functional group chosen from a hydroxyl group, a carboxyl group, and a thiol group. Represents an anion of an aromatic organic acid having at least one of the following: AH is an aromatic organic acid having at least one functional group selected from a hydroxyl group, a carboxyl group, and a thiol group in the aromatic ring X and y are integers of 1 to 3, z is an integer of 0 to 3, and x = y.

  Although the compound represented by General formula (10) is obtained as follows, for example, it is not limited to this. First, a tetra-substituted phosphonium halide, an aromatic organic acid and a base are mixed in an organic solvent and mixed uniformly to generate an aromatic organic acid anion in the solution system. Then, when water is added, the compound represented by the general formula (10) can be precipitated. In the compound represented by the general formula (10), R4, R5, R6 and R7 bonded to the phosphorus atom are phenyl groups, and AH is a compound having a hydroxyl group in an aromatic ring, that is, phenols, and A Is preferably an anion of the phenol.

  Examples of the phosphobetaine compound that can be used in the present embodiment include compounds represented by the following general formula (11).

(However, in the said General formula (11), X1 represents a C1-C3 alkyl group, Y1 represents a hydroxyl group. F is an integer of 0-5, g is an integer of 0-3.)

  The compound represented by the general formula (11) is obtained, for example, as follows. First, it is obtained through a step of bringing a triaromatic substituted phosphine, which is a third phosphine, into contact with a diazonium salt and replacing the triaromatic substituted phosphine with a diazonium group of the diazonium salt. However, the present invention is not limited to this.

Examples of the adduct of a phosphine compound and a quinone compound that can be used in this embodiment include compounds represented by the following general formula (12).
(However, in the said General formula (12), P represents a phosphorus atom. R8, R9, and R10 represent a C1-C12 alkyl group or a C6-C12 aryl group, and they are mutually the same. R11, R12 and R13 each represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms and may be the same or different from each other, and R11 and R12 are bonded to form a cyclic structure. May be.)

  The phosphine compound used as an adduct of a phosphine compound and a quinone compound has no substitution on aromatic rings such as triphenylphosphine, tris (alkylphenyl) phosphine, tris (alkoxyphenyl) phosphine, trinaphthylphosphine, tris (benzyl) phosphine, etc. Or what has substituents, such as an alkyl group and an alkoxyl group, is preferable, and what has 1-6 carbon atoms is mentioned as an organic group of an alkyl group and an alkoxyl group. From the viewpoint of availability, triphenylphosphine is preferable.

  In addition, examples of the quinone compound used for the adduct of the phosphine compound and the quinone compound include o-benzoquinone, p-benzoquinone, and anthraquinones. 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 capable of dissolving both organic tertiary phosphine and benzoquinone. The solvent is preferably a ketone such as acetone or methyl ethyl ketone, which has low solubility in the adduct. However, the present invention is not limited to this.
In the compound represented by the general formula (12), R8, R9 and R10 bonded to the phosphorus atom are phenyl groups, and R11, R12 and R13 are hydrogen atoms, that is, 1,4-benzoquinone and triphenyl A compound to which phosphine has been added is preferable in that it reduces the elastic modulus of the cured epoxy resin composition when heated.

Examples of the adduct of a phosphonium compound and a silane compound that can be used in the present embodiment include compounds represented by the following general formula (13).
(In the general formula (13), P represents a phosphorus atom and Si represents a silicon atom. R14, R15, R16 and R17 are each an organic group having an aromatic ring or a heterocyclic ring, or an aliphatic group. X2 is an organic group bonded to the groups Y2 and Y3, where X3 is an organic group bonded to the groups Y4 and Y5. And Y3 represent a group formed by releasing a proton from a proton donating group, and groups Y2 and Y3 in the same molecule are bonded to a silicon atom to form a chelate structure, and Y4 and Y5 are proton donating groups. The group represents a group formed by releasing a proton, and groups Y4 and Y5 in the same molecule are bonded to a silicon atom to form a chelate structure.X2 and X3 may be the same or different from each other, Y2 Y3, Y4, and Y5 is .Z1 which may be the same or different from each other is an organic group or an aliphatic group, an aromatic ring or a heterocyclic ring.)

  In the general formula (13), as R14, R15, R16 and R17, for example, phenyl group, methylphenyl group, methoxyphenyl group, hydroxyphenyl group, naphthyl group, hydroxynaphthyl group, benzyl group, methyl group, ethyl group, n-butyl group, n-octyl group, cyclohexyl group, and the like. Among these, an aromatic group having a substituent such as phenyl group, methylphenyl group, methoxyphenyl group, hydroxyphenyl group, hydroxynaphthyl group, or the like. A substituted aromatic group is more preferred.

  Moreover, in General formula (13), X2 is an organic group couple | bonded with Y2 and Y3. Similarly, X3 is an organic group bonded to the groups Y4 and Y5. Y2 and Y3 are groups formed by proton-donating groups releasing protons, and groups Y2 and Y3 in the same molecule are combined with a silicon atom to form a chelate structure. Similarly, Y4 and Y5 are groups formed by proton-donating groups releasing protons, and groups Y4 and Y5 in the same molecule are combined with a silicon atom to form a chelate structure. The groups Y2 and Y3 may be the same or different from each other, and the groups Y2, Y3, Y4, and Y5 may be the same or different from each other. The groups represented by -Y2-X2-Y3- and -Y4-X3-Y5- in general formula (13) are formed by releasing two protons from a bivalent or higher proton donor. Examples of divalent or higher proton donors include catechol, pyrogallol, 1,2-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 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 alcohol, 1,2-cyclohexanediol, 1,2- Propanediol, glycerin, etc. are mentioned, among these, catechol, 1,2-dihydroxynaphthalene, 2,3-dihydroxynaphtha Emissions is more preferable.

  Z1 in the general formula (13) represents an organic group or an aliphatic group having an aromatic ring or a heterocyclic ring. Specific examples thereof include a methyl group, an ethyl group, a propyl group, a butyl group, and a hexyl group. Reactions such as aliphatic hydrocarbon groups such as octyl group and aromatic hydrocarbon groups such as phenyl group, benzyl group, naphthyl group and biphenyl group, glycidyloxypropyl group, mercaptopropyl group, aminopropyl group and vinyl group Among them, a methyl group, an ethyl group, a phenyl group, a naphthyl group, and a biphenyl group are more preferable from the viewpoint of thermal stability.

  As a method for producing an adduct of a phosphonium compound and a silane compound, a silane compound such as phenyltrimethoxysilane and a bivalent or higher proton donor such as 2,3-dihydroxynaphthalene are added to a flask containing methanol and dissolved. Then, a sodium methoxide-methanol solution is added dropwise with stirring at room temperature. Furthermore, when a solution prepared by dissolving a tetra-substituted phosphonium halide such as tetraphenylphosphonium bromide in methanol in methanol is added dropwise with stirring at room temperature, 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.

  As for the compounding quantity of the hardening accelerator (D) used for this embodiment, 0.1 to 1 weight% is preferable in all the epoxy resin compositions. There is little possibility of causing curability fall that the compounding quantity of a hardening accelerator (D) exists in the said range. Moreover, there is little possibility of causing a fluid fall as the compounding quantity of a hardening accelerator (D) exists in the said range.

In this embodiment, at the time of sealing molding, in order to express excellent continuous formability without causing problems such as sticking, filling defects, voids, etc., and to obtain good reliability in a semiconductor device, While the inorganic filler (C) is highly filled in the entire composition at a ratio of 86% by weight or more and 92% by weight or less, the shrinkage ratio during molding of the resin composition is 0.40% or more and 0.65%. It is preferable to make the range less than and a high value. The lower limit value of the shrinkage rate at the time of molding is more preferably 0.42% or more. If the shrinkage rate during molding is within this range, excellent continuous moldability and reliability can be maintained. FIG. 1 shows the relationship between the blending ratio of the inorganic filler and the shrinkage rate at the time of molding in the prior art and in the examples and comparative examples of this embodiment. As shown in FIG. 1, while the inorganic filler (C) is highly filled in the whole composition at a ratio of 86% by weight or more and 92% by weight or less, the shrinkage ratio during molding of the resin composition is 0.40%. As described above, there has never been a technique for achieving a high range of less than 0.65%, and the epoxy resin (A1) having a structure represented by the general formula (1) in the epoxy resin (A) The composition ratio of the epoxy resin (A) and the composition ratio of the compound (B) containing two or more phenolic hydroxyl groups can be appropriately adjusted within the scope of the present embodiment. In addition, in this embodiment, the shrinkage rate at the time of shaping | molding of a resin composition is measured as follows. That is, using a transfer molding machine, a disk-shaped cured product having a diameter of 100 mm and a thickness of 3 mm was molded under the conditions of a mold temperature of 175 ° C., a molding pressure of 9.8 MPa, and a curing time of 120 seconds. The inner diameter dimension of the mold cavity and the outer diameter dimension of the disk-shaped cured product at room temperature (25 ° C.) are measured and calculated by the following equation (A).
Shrinkage rate (%) = {(inner diameter dimension of mold cavity at 175 ° C.) − (Outer diameter dimension of cured product of disk at 25 ° C.)} / (Inner diameter dimension of mold cavity at 175 ° C.) × 100 (%)
(I)

In a preferred embodiment of the present invention, the cured product has a glass transition temperature of 100 ° C. or higher and 125 ° C. or lower, more preferably a linear expansion coefficient of 2.2 × 10 in a region exceeding the glass transition temperature. ^{It is -5} / ° C or higher and 4.0 × ^10-5 / ° C or lower. The physical properties of the cured product after molding are important as an index indicating moldability. With respect to the glass transition temperature of the cured product after molding, sticking of the cured product hardly occurs at the above lower limit or less, and below the above upper limit, it becomes easy to adjust the shrinkage ratio at the time of molding to a preferable range. Moreover, regarding the linear expansion coefficient in the region exceeding the glass transition temperature of the cured product after molding, it is easy to adjust the shrinkage rate during molding of the present embodiment to a preferable range by controlling the coefficient within this range. In addition, in this embodiment, the linear expansion coefficient in the area | region exceeding the glass transition temperature and glass transition temperature of the hardened | cured material after shaping | molding is measured as follows. That is, with respect to the length direction of a test piece having a width of 4 mm, a thickness of 3 mm, and a length of 15 mm, which was molded using a transfer molding machine under conditions of a mold temperature of 175 ° C., a molding pressure of 9.8 MPa, and a curing time of 120 seconds. Measured by thermomechanical analysis (TMA) under the conditions of a compression load of 5 g, a heating rate of 10 ° C./min, and a measurement range of −65 ° C. to 300 ° C. As the thermomechanical analyzer, for example, TMA-120 / SSC6200 manufactured by Seiko Instruments Inc. can be used. The coefficient of linear expansion in the region exceeding the glass transition temperature has an average value in the portion where the slope is almost constant in the region exceeding the glass transition temperature in the graph of the temperature obtained by measurement and the sample size. That value is used.

In the present embodiment, as a more preferable aspect as the cured material property, the glass transition temperature of the cured product after molding and post-curing is 110 ° C. or higher and 140 ° C. or lower, and the linear expansion coefficient in the region lower than the glass transition temperature is 0.6 It is not less than × 10 ⁻⁵ / ° C. and not more than 1.2 × 10 ⁻⁵ / ° C. The physical properties of the cured product after being molded and further post-cured to obtain a state close to complete curing is important as an index indicating the reliability of the semiconductor device. As long as the glass transition temperature of the cured product after molding and post-curing and the linear expansion coefficient in the region lower than the glass transition temperature are within the above ranges, excellent reliability as a semiconductor device can be obtained. In the present embodiment, the glass transition temperature of the cured product after molding and post-curing and the linear expansion coefficient in the region lower than the glass transition temperature are measured as follows. That is, using a transfer molding machine, after molding under conditions of a mold temperature of 175 ° C., a molding pressure of 9.8 MPa, a curing time of 120 seconds, and post-cured at 175 ° C. for 4 hours, a width of 4 mm, a thickness of 3 mm, About the length direction of the test piece of length 15mm, it measures by the thermomechanical analysis method (TMA) on condition of compression load 5g, temperature increase rate 10 degree-C / min, and measurement range -65 degreeC-300 degreeC. As the thermomechanical analyzer, for example, TMA-120 / SSC6200 manufactured by Seiko Instruments Inc. can be used. Note that the linear expansion coefficient in the region lower than the glass transition temperature has an average value in a portion where the slope is almost constant in the region lower than the glass transition temperature in the graph of the temperature obtained by measurement and the sample size. That value is used.

In the epoxy resin composition of the present embodiment, the inorganic filler (C) is highly filled at a ratio of 86% by weight or more and 92% by weight or less in the entire composition, but the shrinkage ratio at the time of molding is 0.40%. As mentioned above, it becomes a high value with the range of less than 0.65%, preferably the glass transition temperature of the cured product after molding is 100 ° C. or more and 125 ° C. or less, preferably in the region exceeding the glass transition temperature of the cured product after molding. The linear expansion coefficient is 2.2 × 10 ⁻⁵ / ° C. or higher and 4.0 × 10 ⁻⁵ / ° C. or lower. Preferably, the glass transition temperature of the cured product after molding and post-curing is 110 ° C. or higher and 140 ° C. or lower. In order to achieve a linear expansion coefficient of 0.6 × 10 ⁻⁵ / ° C. or higher and 1.2 × 10 ⁻⁵ / ° C. or lower, preferably in a region lower than the glass transition temperature, the epoxy resin (A) And two or more phenolic hydroxyl groups This can be achieved by adjusting the types and mixing ratios of the compound (B), the inorganic filler (C), and the curing accelerator (D) included above. In particular, selection of the blending ratio of the epoxy resin (A1) having the structure represented by the general formula (1) in the epoxy resin (A) and the blending ratio of the inorganic filler (C) in the entire composition is important. . Moreover, the said characteristic can be further improved by selecting and using the mold release agent and various additives which are mentioned later suitably.

  In this embodiment, a mold release agent can be added as appropriate in order to exhibit continuous formability. Examples thereof include natural waxes such as carnauba wax, synthetic waxes such as polyethylene wax and polyethylene oxide, higher fatty acids such as stearic acid and zinc stearate and metal salts thereof or paraffin, higher fatty acid esters and the like, One or a plurality of them can be added.

  The blending ratio of the release agent that can be used in this embodiment is preferably 0.01% by weight or more and 1% by weight or less, more preferably 0.03% by weight or more and 0.5% in the total resin composition. % By weight or less. It is excellent in the mold release property of the resin cured material from a metal mold | die within the said range. Moreover, when it is within the above range, adhesion between the cured resin and the interface is not impaired, and peeling between the cured resin and the lead frame member during the soldering process can be suppressed. Moreover, when it is in the above-mentioned range, it is also possible to suppress deterioration of mold stains and resin cured product appearance.

Moreover, in this embodiment, regarding continuous moldability, the additive which suppresses progress of the stain | pollution | contamination of the metal mold | die surface at the time of shaping | molding, and the stain | pollution | contamination of the resin cured material surface, and can improve continuous moldability can be included. Examples of such additives include butadiene-acrylonitrile copolymer having a carboxyl group and / or reaction product of butadiene-acrylonitrile copolymer having a carboxyl group and an epoxy resin, organopolysiloxane having a carboxyl group. And a reaction product of an organopolysiloxane having a carboxyl group and an epoxy resin. By adding these compounds having a carboxyl group, the compatibility of each component of the epoxy resin composition contained as a raw material of the epoxy resin composition for sealing and the release agent, specifically, the epoxy resin and the release agent It is preferable that the compatibility of the resin is in an appropriate state, and the progress of the mold surface stain and the resin cured product surface during molding can be suppressed, and the continuous moldability is improved.

  The total amount of these additives that can be used in the present embodiment is preferably 0.01% by weight or more and 1% by weight or less, and 0.05% by weight or more and 0.5% by weight in the total epoxy resin composition. % Or less is more preferable, and 0.1% by weight or more and 0.3% by weight or less are particularly preferable. By setting it as the said range, generation | occurrence | production of malfunctions, such as generation | occurrence | production of the filling failure at the time of shaping | molding by fall of fluidity | liquidity, and the wire flow by high viscosity can be suppressed.

  In the present embodiment, an adhesion assistant such as a silane coupling agent can be added in order to improve the adhesion between the epoxy resin and the inorganic filler. Examples thereof include, but are not limited to, epoxy silane, amino silane, ureido silane, mercapto silane, etc., which react between the epoxy resin and the inorganic filler to improve the interfacial strength between the epoxy resin and the inorganic filler. More specifically, as the epoxy silane, for example, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, β- (3,4 epoxy cyclohexyl) ethyltrimethoxysilane and the like. Examples of the aminosilane include γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, and N-β (aminoethyl) γ-aminopropyl. Methyldimethoxysilane, N-phenylγ-aminopropyltriethoxysilane, N-phenylγ-aminopropyltrimethoxysilane, N-β (aminoethyl) γ-aminopropyltriethoxysilane, N-6- (aminohexyl) 3 -Aminopropyltrimethoxysilane, N- (3- (trimethoxysilylpropyl) -1,3-benzenedimethanane, etc. In addition, examples of ureidosilane include γ-ureidopropyltriethoxysilane, hexa Methyl disilazane, etc. In addition, mercap Examples of tosilane include γ-mercaptopropyltrimethoxysilane, etc. These silane coupling agents may be used alone or in combination of two or more.

  As a compounding quantity of the silane coupling agent which can be used for this embodiment, 0.01 weight% or more and 1 weight% or less are preferable in all the epoxy resin compositions, More preferably, 0.05 weight% or more, 0.0. It is 8% by weight or less, particularly preferably 0.1% by weight or more and 0.6% by weight or less. If the blending amount of the silane coupling agent is within the above range, there is little possibility of causing a decrease in solder crack resistance in the semiconductor device due to a decrease in the interface strength between the epoxy resin and the inorganic filler. Moreover, if the compounding quantity of a silane coupling agent exists in the said range, there is little possibility of causing the fall of solder crack resistance by the water absorption of the hardened | cured material of an epoxy resin composition increasing.

  In this embodiment, in addition to the components described above, colorants such as carbon black, bengara and titanium oxide; low-stress additives such as silicone oil and silicone rubber; inorganic ion exchangers such as hydrotalcite; aluminum hydroxide, water Additives such as metal hydroxides such as magnesium oxide, flame retardants such as zinc borate, zinc molybdate, and phosphazene may be appropriately blended.

  The epoxy resin composition for semiconductor encapsulation of this embodiment is obtained by uniformly mixing the constituent components of this embodiment and other additives at room temperature using, for example, a mixer, and then heating roll, kneader Or what knead | mixed and kneaded using kneading machines, such as an extruder, and cooled and grind | pulverized subsequently, etc., what adjusted dispersion degree, fluidity | liquidity, etc. suitably can be used as needed.

  To manufacture a semiconductor device by sealing a semiconductor element with a cured product of the epoxy resin composition for semiconductor sealing according to the present embodiment, for example, a lead frame, a circuit board, etc. mounted with the semiconductor element are placed in a mold cavity. Then, the epoxy resin composition for semiconductor encapsulation may be molded and cured by a molding method such as a transfer mold, a compression mold, or an injection mold.

  The semiconductor element that performs sealing in the present embodiment is not particularly limited, and examples thereof include an integrated circuit, a large-scale integrated circuit, a transistor, a thyristor, a diode, and a solid-state imaging element.

  The form of the semiconductor device of the present embodiment is not particularly limited. For example, dual in-line package (DIP), plastic leaded chip carrier (PLCC), quad flat package (QFP), low profile・ Quad Flat Package (LQFP), Small Outline Package (SOP), Small Outline J Lead Package (SOJ), Thin Small Outline Package (TSOP), Thin Quad Flat Package (TQFP) Tape carrier package (TCP), ball grid array (BGA), chip size package (CSP), and the like.

  The semiconductor device of this embodiment sealed by a molding method such as the transfer mold is completely cured as it is or at a temperature of about 80 ° C. to 200 ° C. for about 10 minutes to 10 hours. Installed in equipment.

  FIG. 2 is a view showing a cross-sectional structure of an example of a semiconductor device using the epoxy resin composition according to the present embodiment. The semiconductor element 1 is fixed on the die pad 3 via the die bond material cured body 2. The electrode pad of the semiconductor element 1 and the lead frame 5 are connected by a gold wire 4. The semiconductor element 1 is sealed with a cured body 6 of a sealing resin composition.

EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited at all by these Examples. Hereinafter, the blending ratio is parts by weight.
The components used in Examples and Comparative Examples are shown below.

(Epoxy resin)
Epoxy resin 1: an epoxy resin having a structure represented by the following formula (14) (an epoxy resin obtained by glycidyl etherification of a phenol resin obtained by co-condensing o-cresol, formaldehyde, and 2-methoxynaphthalene with epichlorohydrin) Equivalent 251 and softening point 58 ° C. In the following general formula (14), m / n = 1/4.)
Epoxy resin 2: an epoxy resin having a structure represented by the following formula (14) (an epoxy resin obtained by glycidyl etherification of a phenol resin obtained by co-condensing o-cresol, formaldehyde, and 2-methoxynaphthalene with epichlorohydrin) Equivalent 220, softening point 52 ° C. In the following general formula (14), m / n = 1/9.)
Epoxy resin 3: epoxy resin having a structure represented by the following formula (14) (an epoxy resin obtained by glycidyl etherification of a phenol resin obtained by co-condensing o-cresol, formaldehyde, and 2-methoxynaphthalene with epichlorohydrin) Equivalent 270, softening point 63 ° C. In the following general formula (14), m / n = 3/7.)

  Epoxy resin 4: an epoxy resin having a structure represented by the following formula (15) (an epoxy resin obtained by glycidyl etherification of a phenol resin obtained by cocondensation of phenol, formaldehyde and methylphenyl sulfide with epichlorohydrin; epoxy equivalent 196; (Softening point 54 ° C. In the following general formula (15), m / n = 1/4.)

  Epoxy resin 5: epoxy resin having a structure represented by the following formula (16) (an epoxy resin obtained by glycidyl etherification of a phenol resin obtained by cocondensation of phenol, benzaldehyde and methylphenyl sulfide with epichlorohydrin; epoxy equivalent 285; (Softening point 74 ° C. In the following general formula (16), m / n = 1/4.)

  Epoxy resin 6: An epoxy resin having a structure represented by the following formula (17) (an epoxy resin obtained by glycidyl etherification of a phenol resin obtained by co-condensing o-cresol, formaldehyde, and methylnaphthyl sulfide with epichlorohydrin. Epoxy equivalent) 255, softening point 60 ° C. In the following general formula (17), m / n = 1/4.)

Epoxy resin 7: A phenol aralkyl type epoxy resin having a phenylene skeleton (an epoxy resin obtained by glycidyl etherification of a phenol aralkyl resin having a phenylene skeleton with epichlorohydrin. Epoxy equivalent 238, softening point 60 ° C.)
Epoxy resin 8: Orthocresol novolac type epoxy resin (Dainippon Ink & Chemicals, N660, epoxy equivalent 196, softening point 62 ° C.)
Epoxy resin 9: Triphenolmethane type epoxy resin (manufactured by Japan Epoxy Resin Co., Ltd., E-1032H60. Epoxy equivalent 169, softening point 58 ° C.)
Epoxy resin 10: 4,4′-dihydroxy-3,3 ′, 5,5′-tetramethylbiphenyl glycidyl ether (manufactured by Japan Epoxy Resin Co., Ltd., YX-4000HK. Epoxy equivalent 192, melting point 107 ° C.)

(Compounds containing two or more phenolic hydroxyl groups)
Phenol resin 1: Phenol novolak resin (manufactured by Sumitomo Bakelite Co., Ltd., PR-HF-3. Hydroxyl equivalent weight 104, softening point 80 ° C.)
Phenol resin 2: Phenol aralkyl resin having a phenylene skeleton (manufactured by Mitsui Chemicals, Inc., XLC-4L, hydroxyl equivalent 165, softening point 65 ° C.)
Phenol resin 3: biphenyl aralkyl resin having a biphenylene skeleton (manufactured by Nippon Kayaku Co., Ltd., GPH-65, hydroxyl group equivalent 196, softening point 65 ° C.)

(Inorganic filler)
Fused spherical silica (average particle size 30μm)

(Curing accelerator)
Curing accelerator 1: Curing accelerator represented by the following formula (18)

  Curing accelerator 2: Triphenylphosphine

Curing accelerator 3: Curing accelerator represented by the following formula (19)

Curing accelerator 4: Curing accelerator represented by the following formula (20)
Curing accelerator 5: Curing accelerator represented by the following formula (21)

(Release agent)
Mold release agent 1: Carnauba wax (Nikko Rica Co., Ltd., Nikko Carnauba)
Release agent 2: Polyethylene oxide (drop point 120 ° C., acid value 20 mg KOH / g, number average molecular weight 2000, density 0.98 g / cm ³ , average particle size 45 μm, content of particles of 106 μm or more 0.0% by weight. High density polyethylene oxide.)

(Silane coupling agent)
Silane coupling agent 1: γ-glycidoxypropyltrimethoxysilane Silane coupling agent 2: γ-mercaptopropyltrimethoxysilane

(Coloring agent)
Carbon black

Example 1
Epoxy resin 1 8.36 parts by weight Phenol resin 1 2.27 parts by weight Phenol resin 2 2.27 parts by weight Fused spherical silica 86.00 parts by weight Curing accelerator 1 0.30 parts by weight Mold release agent 1 0.20 parts by weight Silane coupling agent 1 0.15 parts by weight Silane coupling agent 2 0.15 parts by weight Carbon black 0.30 parts by weight is mixed at room temperature with a mixer, melt-kneaded with a heating roll at 80 to 100 ° C., cooled and pulverized. An epoxy resin composition was obtained. It evaluated by the following method using the obtained epoxy resin composition. The evaluation results are shown in Table 1.

  Spiral flow: Using a low-pressure transfer molding machine (KTS-15, manufactured by Kotaki Seiki Co., Ltd.), a spiral flow measurement mold according to EMMI-1-66 was applied at 175 ° C., injection pressure 6.9 MPa, holding pressure The epoxy resin composition was injected under the condition of time 120 seconds, and the flow length was measured. The spiral flow is a fluidity parameter, and the larger the value, the better the fluidity. The unit is cm.

Shrinkage during molding: epoxy resin using a transfer molding machine (Tep-50-30, manufactured by Fujiwa Seiki Co., Ltd.) under conditions of a mold temperature of 175 ° C., a molding pressure of 9.8 MPa, and a curing time of 120 seconds. The composition was injection-molded to produce a test piece having a diameter of 100 mm and a thickness of 3 mm. The inner diameter dimension of the mold cavity at 175 ° C. and the outer diameter dimension of the test piece at room temperature (25 ° C.) were measured, and the shrinkage rate was calculated by the following equation (A).
Shrinkage rate (%) = {(inner diameter dimension of mold cavity at 175 ° C.) − (Outer diameter dimension of cured product of disk at 25 ° C.)} / (Inner diameter dimension of mold cavity at 175 ° C.) × 100 (%)
(I)

  The glass transition temperature of the cured product after molding and the linear expansion coefficient in the region exceeding the glass transition temperature: using a transfer molding machine (manufactured by Towa Seiki Co., Ltd., TEP-50-30), a mold temperature of 175 ° C., molding pressure Under conditions of 9.8 MPa and curing time of 120 seconds, the resin composition was injection molded to prepare a test piece having a width of 4 mm, a thickness of 3 mm, and a length of 15 mm. With respect to the length direction of the obtained test piece, a thermomechanical analysis method (TMA, Seiko Inn as a thermomechanical analysis device) under the conditions of a compression load of 5 g, a heating rate of 5 ° C / min, and a measurement range of -65 ° C to 300 ° C. Measured by using TMA-120 / SSC6200 manufactured by Stur Co., Ltd.). The coefficient of linear expansion in the region exceeding the glass transition temperature has an average value in the portion where the slope is almost constant in the region exceeding the glass transition temperature in the graph of the temperature obtained by measurement and the sample size. That value is used.

  Molding, linear expansion coefficient in a region lower than the glass transition temperature and glass transition temperature of the cured product after post-curing: mold temperature 175 ° C. using a transfer molding machine (TEP-50-30, manufactured by Towa Seiki Co., Ltd.) The resin composition was injection molded under conditions of a molding pressure of 9.8 MPa and a curing time of 120 seconds to produce a test piece having a width of 4 mm, a thickness of 3 mm, and a length of 15 mm. Heat treatment was performed for a time. Thermomechanical analysis method (TMA, thermomechanical analyzer) under conditions of compression load 5g, heating rate 5 ° C / min, measurement range -65 ° C to 300 ° C in the length direction of the test piece after molding and post-curing As TMA-120 / SSC6200 manufactured by Seiko Instruments Inc.). Note that the linear expansion coefficient in the region lower than the glass transition temperature has an average value in a portion where the slope is almost constant in the region lower than the glass transition temperature in the graph of the temperature obtained by measurement and the sample size. That value is used.

  Continuous moldability: epoxy resin composition using a low-pressure transfer automatic molding machine (Daiichi Seiko Co., Ltd., GP-ELF) under conditions of a mold temperature of 175 ° C., a molding pressure of 9.8 MPa, and a curing time of 120 seconds. 80 chip QFP (Cu lead frame, package outer dimension: 14 mm × 20 mm × 2.0 mm thickness, pad size: 8.0 mm × 8.0 mm, chip size 7.0 mm × 7. Molding to obtain a thickness of 0 mm × 0.35 mm was continuously performed up to 700 shots. Judgment criteria were ◎ for those that could be continuously molded up to 600 shots without any problems such as unfilled, ◯ for those that could be continuously molded up to 450 shots without any problems such as unfilled, and x otherwise.

  Package appearance and mold stain resistance: In the evaluation of the continuous moldability, the package surface and mold surface after 450 and 600 shot molding were visually evaluated for stain. The package appearance judgment and the mold contamination standard are indicated by ◎ for those that are not dirty up to 600 shots, ◯ for those that are not dirty up to 450 shots, and × that are dirty. Moreover, in the above-mentioned continuous formability, those that could not be formed without any problem up to 450 shots were judged based on the package appearance and the mold contamination status when the continuous forming was abandoned.

  Solder resistance: The package formed in the above-described evaluation of continuous formability is post-cured at 175 ° C. for 8 hours, and the resulting package is humidified at 85 ° C. and 60% relative humidity for 168 hours, followed by IR reflow treatment at 260 ° C. Did. For 20 packages, the adhesion state of the interface between the semiconductor element and the cured product of the epoxy resin composition was observed with an ultrasonic flaw detector, and the peeling occurrence rate [(number of peeling occurrence packages) / (total number of packages) × 100] Calculated. Units%. The criteria for determining solder resistance were ◯ when no peeling occurred, Δ when the peeling rate was less than 20%, and x when the peeling rate was 20% or more.

Examples 2 to 17, 19 and Comparative Examples 1 to 6
According to the composition of Table 1, Table 2, and Table 3, an epoxy resin composition was produced in the same manner as in Example 1 and evaluated in the same manner as in Example 1. The evaluation results are shown in Table 1, Table 2, and Table 3.

  Examples 1 to 19 are an epoxy resin (A) containing 20% by weight or more of an epoxy resin (A1) having a structure represented by the general formula (1), a compound (B) containing two or more phenolic hydroxyl groups, and a resin. It contains 86 wt% or more and 92 wt% or less of the inorganic filler (C) and the curing accelerator (D) with respect to the whole composition, the type and blending ratio of the epoxy resin (A1), and the phenolic hydroxyl group. Although it contains what changed the kind of compound (B) which contains 2 or more, the mixture ratio of an inorganic filler (C), the kind of hardening accelerator (D), etc., all have the shrinkage | contraction rate of a resin composition 0 The result is excellent in the balance between fluidity (spiral flow), continuous formability, package appearance, mold stain resistance, and solder resistance.

  On the other hand, in Comparative Examples 1 to 3 in which the epoxy resin (A1) having the structure represented by the general formula (1) is not used, the shrinkage rate of the resin composition is not a sufficiently large value. As a result, the continuous formability, the package appearance, and the mold contamination were inferior. Moreover, in Comparative Examples 4 and 5 in which the blending ratio of the inorganic filler (C) with respect to the entire resin composition is less than 86% by weight, the resin component is large, so that sticking is facilitated and the releasability is lowered, and the continuous moldability is reduced. As a result, the package appearance and mold soiling were inferior. On the contrary, in Comparative Example 6 in which the blending ratio of the inorganic filler (C) with respect to the entire resin composition exceeds 92% by weight, the fluidity decreases due to the small amount of the resin component, and molding defects such as poor filling and voids occur. As a result, the continuous formability, the package appearance, and the mold contamination were inferior.

  According to the present invention, since an epoxy resin composition for semiconductor encapsulation having excellent continuous moldability and good reliability can be obtained, it is suitable for semiconductor device encapsulation.

It is a figure which shows the relationship between the shrinkage rate at the time of shaping | molding and the inorganic filler compounding ratio in the prior art, and the Example and comparative example of this invention. It is the figure which showed the cross-section about an example of the semiconductor device using the epoxy resin composition which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Semiconductor element 2 Die-bonding material hardening body 3 Die pad 4 Gold wire 5 Lead frame 6 Hardening body of resin composition for sealing

Claims (9)

(A) an epoxy resin;
(B) a compound containing two or more phenolic hydroxyl groups;
(C) an inorganic filler;
(D) a curing accelerator and a release agent;
An epoxy resin composition for semiconductor encapsulation containing
The (A) epoxy resin contains an epoxy resin (A1) having a structure represented by the following general formula (1) in a proportion of 20% by weight or more in the total epoxy resin, and the (C) inorganic filler has a total composition. Contained in the product at a ratio of 86% by weight or more and 92% by weight or less,
(B) the compound containing two or more phenolic hydroxyl groups includes a phenol aralkyl resin having a phenylene skeleton and / or a biphenylene skeleton, or a naphthol aralkyl resin having a phenylene and / or a biphenylene skeleton,
The release agent is contained in the total resin composition in a proportion of 0.03% by weight or more and 1.0% by weight or less,
The curing accelerator is a tetra-substituted phosphonium compound, a phosphobetaine compound, an adduct of a phosphine compound and a quinone compound, 1,8-diazabicyclo (5,4,0) undecene-7, an adduct of a phosphonium compound and a silane compound In addition, the resin composition is molded at a mold temperature of 175 ° C., a molding pressure of 9.8 MPa, and a curing time of 120 seconds. An epoxy resin composition for encapsulating a semiconductor, wherein the shrinkage rate calculated by the following formula (a) in the product is 0.40% or more and less than 0.65%.

(In the above general formula (1), Ar is an aromatic group having 6 to 20 carbon atoms, R1 is a hydrocarbon group having 1 to 6 carbon atoms, R3 is hydrogen, a hydrocarbon group having 1 to 4 carbon atoms, or carbon. R2 is a hydrocarbon group having 1 to 4 carbon atoms, W1 is an oxygen atom or a sulfur atom, and a is 0 to 0. 10 is an integer of 10 and b is an integer of 1 to 3. m and n are molar ratios, 0 <m <1, 0 <n <1, m + n = 1, and m / n is 1 /. 10 to 1/1.)

Shrinkage (%) = {(inner diameter dimension of mold cavity at 175 ° C.) − (Outer diameter dimension of disk-shaped cured product at 25 ° C.)} / (Inner diameter dimension of mold cavity at 175 ° C.) × 100 (%)
(I)
The epoxy resin composition for semiconductor encapsulation was molded under conditions of a mold temperature of 175 ° C., a molding pressure of 9.8 MPa, and a curing time of 120 seconds, and then post-cured at 175 ° C. for 4 hours. The linear expansion coefficient in the region lower than the glass transition temperature of the cured product after molding and post-curing measured by thermomechanical analysis (TMA) in the length direction of the test piece of 3 mm and 15 mm in length is 0.6 × 10. ^The epoxy resin composition for semiconductor encapsulation according to claim 1, wherein the epoxy resin composition is ⁻⁵ / ° C. or higher and 1.2 × 10 ⁻⁵ / ° C. or lower.   The length of a test piece having a width of 4 mm, a thickness of 3 mm and a length of 15 mm, which was molded from the epoxy resin composition for semiconductor encapsulation under the conditions of a mold temperature of 175 ° C., a molding pressure of 9.8 MPa, and a curing time of 120 seconds. 3. The epoxy resin for semiconductor encapsulation according to claim 2, wherein the glass transition temperature of the cured product after molding is 100 ° C. or more and 125 ° C. or less as measured by thermomechanical analysis (TMA). Composition. The length of a test piece having a width of 4 mm, a thickness of 3 mm and a length of 15 mm, which was molded from the epoxy resin composition for semiconductor encapsulation under the conditions of a mold temperature of 175 ° C., a molding pressure of 9.8 MPa and a curing time of 120 seconds. Regarding the direction, the linear expansion coefficient in the region exceeding the glass transition temperature of the cured product after molding, measured by thermomechanical analysis (TMA), is 2.2 × 10 ⁻⁵ / ° C. or more, 4.0 × 10 ⁻⁵ / The epoxy resin composition for semiconductor encapsulation according to claim 3, wherein the epoxy resin composition is for semiconductor encapsulation.   The epoxy resin composition for semiconductor encapsulation was molded under conditions of a mold temperature of 175 ° C., a molding pressure of 9.8 MPa, and a curing time of 120 seconds, and then post-cured at 175 ° C. for 4 hours. The glass transition temperature of the cured product after molding and post-curing is 110 ° C. or higher and 140 ° C. or lower as measured by a thermomechanical analysis method (TMA) in the length direction of a 3 mm long and 15 mm long test piece. The epoxy resin composition for semiconductor encapsulation according to claim 4. The epoxy resin (A1) having the structure represented by the general formula (1) co-condenses the phenolic hydroxyl group-containing aromatics, aldehydes, and the compound (J) represented by the following general formula (2). 6. The epoxy resin composition for semiconductor encapsulation according to claim 5, which is an epoxy resin obtained by glycidyl etherification of the phenol resin obtained in this way with epichlorohydrin.

(However, in the said General formula (2), Ar is a C6-C20 aromatic group, R1 is a C1-C6 hydrocarbon group, and may mutually be same or different. R2 Is a hydrocarbon group having 1 to 4 carbon atoms, W1 is an oxygen atom or a sulfur atom, a is an integer of 0 to 10, and b is an integer of 1 to 3). The epoxy resin (A1) having a structure represented by the general formula (1) is an epoxy resin having a structure represented by the following general formula (3). The epoxy resin composition for semiconductor encapsulation as described.

(However, in the said General formula (3), R1 is a C1-C6 hydrocarbon group and may mutually be same or different. R2 is a C1-C4 hydrocarbon group, W1 is an oxygen atom or a sulfur atom, c is an integer of 0 to 5, d is an integer of 0 to 3, m and n represent a molar ratio, and 0 <m <1, 0 <n <1 M + n = 1 and m / n is 1/10 to 1/1.) The epoxy resin for semiconductor encapsulation according to claim 7, wherein the epoxy resin having a structure represented by the general formula (3) is an epoxy resin having a structure represented by the following general formula (4): Resin composition.

(However, in the said General formula (4), R1 is a C1-C6 hydrocarbon group, and may mutually be same or different. C is an integer of 0-5, d is 0. M and n represent molar ratios, 0 <m <1, 0 <n <1, m + n = 1, and m / n is 1/10 to 1/1.) A semiconductor device comprising a semiconductor element sealed with a cured product of the epoxy resin composition for semiconductor sealing according to claim 1.