JP2003261747A - Epoxy resin composition for sealing semiconductor and semiconductor device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an epoxy resin composition for sealing semiconductors that has all of high flame retardancy, excellent humidity resistance and excellent fluidity. <P>SOLUTION: The epoxy resin composition for semiconductors comprises the following components (A) through (D): (A) an epoxy resin, (B) a phenolic resin, (C) an inorganic filler and (D) an organic phosphorus compound represented by general formula (1) (wherein R is an alkyl). <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor encapsulating epoxy resin composition having not only flame retardancy but also excellent moisture resistance reliability and fluidity, and a semiconductor device using the same.

[0002]

2. Description of the Related Art Conventionally, transistors, ICs, LSs
A semiconductor element such as I is sealed with an epoxy resin composition to be an electronic component. Since it is essential that the electronic parts comply with UL-94V-0, which is a standard of flame retardancy, a method of imparting flame retardancy by adding a brominated epoxy resin and antimony oxide has hitherto been available. It has been taken. However, in recent years, from the viewpoint of environmental protection, a method of imparting flame retardancy without using the above halogen-based flame retardant or antimony compound has been required.

To meet the above requirements, it has been studied to use a metal hydroxide, a boron compound, a red phosphorus compound or the like for the purpose of imparting flame retardancy. However, most of the above compounds are fluidized by using them. There is a problem that the moldability is poor due to the deterioration of the properties and the moisture resistance is deteriorated due to the large content of impurities.

[0004]

For example, in the above compounds, metal hydroxides and the like have a plate-like shape, so that there is a drawback that the fluidity of the epoxy resin composition for sealing is lowered. It was Further, the red phosphorus compound and the like are easily dissolved in water, so that there is a drawback that impurity ions such as phosphoric acid are more likely to be deposited under high temperature and high humidity, and the moisture resistance reliability is deteriorated. Further, although it is considered that ordinary organic phosphorus compounds can also impart flame retardancy, they have a drawback that the moisture resistance reliability is lowered, like the red phosphorus compounds.

The present invention has been made in view of such circumstances, and is obtained by using an epoxy resin composition for semiconductor encapsulation having not only high flame retardancy but also excellent moisture resistance and fluidity, and the same. It is an object of the present invention to provide a semiconductor device having high reliability.

[0006]

To achieve the above object, the present invention has a first gist of an epoxy resin composition for semiconductor encapsulation containing the following components (A) to (D). (A) Epoxy resin. (B) Phenolic resin. (C) Inorganic filler. (D) An organic phosphorus compound represented by the following general formula (1).

[Chemical 3]

A second aspect of the present invention is a semiconductor device obtained by encapsulating a semiconductor element with the above epoxy resin composition for encapsulating a semiconductor.

The present inventors have made flame retardancy a necessary condition,
In addition to this, a series of studies were conducted for the purpose of obtaining an epoxy resin composition which can be an encapsulant excellent in moisture resistance reliability and fluidity. As a result, when the specific organic phosphorus compound represented by the general formula (1) is used, not only excellent flame retardancy is imparted, but also the moisture resistance reliability is excellent, and the metal hydroxide described above is used. The inventors have found that the intended purpose can be achieved without lowering the fluidity as in the case of products, and have reached the present invention.

When the inorganic filler which is the component (C) is used so as to have a content within a specific range, the flame retardancy and the fluidity are particularly well balanced, and a more excellent sealing material is obtained. Will be able to.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Next, embodiments of the present invention will be described in detail.

The semiconductor encapsulating epoxy resin composition of the present invention comprises an epoxy resin (component A), a phenol resin (component B), an inorganic filler (component C), and a specific organic phosphorus compound (component D). Which is obtained by using
It is in the form of powder or tablets that are tableted.

The epoxy resin (component A) is not particularly limited, and various epoxy resins such as dicyclopentadiene type, cresol novolac type, phenol novolac type, bisphenol type and biphenyl type can be used. These epoxy resins may be used alone or in combination of two or more. Among these epoxy resins, it is particularly preferable that the melting point or softening point exceeds room temperature. For example, the cresol novolac type epoxy resin has an epoxy equivalent of 180 to 2
10, those having a softening point of 60 to 110 ° C. are preferably used. Moreover, as the above-mentioned biphenyl type epoxy resin, those having an epoxy equivalent of 180 to 210 and a melting point of 80 to 120 ° C. are preferably used.

The above-mentioned phenol resin (component B) acts as a curing agent for the above-mentioned epoxy resin (component A) and is not particularly limited, but it is a dicyclopentadiene type phenol resin, phenol novolac resin, cresol novolac resin. , Phenol aralkyl resin and the like. These phenol resins may be used alone or in combination of two or more kinds. And as these phenolic resins, the hydroxyl equivalent is 70 to 250 and the softening point is 5
It is preferable to use one having a temperature of 0 to 110 ° C. And
A suitable combination of the epoxy resin (component A) and the phenol resin (component B) is an epoxy resin (A
When a cresol novolac type epoxy resin is used as the component), a phenol novolac resin is preferably used, and when a biphenyl type epoxy resin is used as the epoxy resin (Component A), a phenol aralkyl resin is preferably used.

The mixing ratio of the epoxy resin (component A) and the phenol resin (component B) is preferably set to an amount sufficient to cure the epoxy resin. Generally, the total of hydroxyl groups of the phenol resin (component B) is 0. 1 with respect to 1 equivalent of the epoxy group in the epoxy resin (component A).
It is preferable to add 7 to 1.5 equivalents.
It is more preferably 0.9 to 1.2 equivalents.

The inorganic filler (C component) used together with the above-mentioned A component and B component is not particularly limited and various conventionally known fillers can be mentioned, for example, quartz glass powder, talc, silica powder (melted Silica powder, crystalline silica powder, etc.), alumina powder, aluminum nitride powder, silicon nitride powder and the like. These may be used alone or in combination of two or more. Among them, it is preferable to use the silica powder from the viewpoint that the linear expansion coefficient of the obtained cured product can be reduced, and among the silica powder, it is particularly preferable to use the fused silica powder from the viewpoint of high filling and high fluidity. . Examples of the fused silica powder include spherical fused silica powder and crushed fused silica powder. From the viewpoint of fluidity, it is preferable to use spherical fused silica powder. In particular, the average particle size is 10-60μ
It is preferable to use a resin having a particle size of m, particularly preferably 25 to 45 μm. The average particle diameter can be measured using, for example, a laser diffraction / scattering particle size distribution measuring device.

The content of the above-mentioned inorganic filler (component C) is
It is preferably set within the range of 50 to 95% by weight, particularly preferably 70 to 90% by weight, based on the whole epoxy resin composition. That is, if the amount is too small, such as less than 50% by weight, the proportion of the organic component in the epoxy resin composition increases, and the flame retardant effect of the cured product becomes poor. If the amount exceeds 95% by weight, the epoxy resin composition increases. This is because the fluidity of the product tends to be significantly reduced.

The specific organic phosphorus compound (D component) used together with the above components A to C is an organic phosphorus compound represented by the following general formula (1).

[0018]

[Chemical 4]

In the above formula (1), R represents an alkyl group, and among them, an alkyl group having 1 to 8 carbon atoms is preferable. In particular, R is tert from the viewpoint of reliability and flame retardancy.
It is preferable to use an organophosphorus compound represented by the following chemical formula (2), which is a -butyl group.

[0020]

[Chemical 5]

Further, as the above-mentioned specific organic phosphorus compound (component D), it is preferable to use one having an average particle size of 5 to 70 μm. That is, when the average particle diameter is out of the above range, the dispersibility is deteriorated, and as a result, the flame retardancy tends to be poor.

The content of the above specific organic phosphorus compound (component D) is 0.5 to 20% by weight based on the whole epoxy resin composition.
It is preferable to set in the range of, and particularly preferably 2 to
It is in the range of 10% by weight. That is, the organic phosphorus compound (D
If the content of (ingredient) is too small, such as less than 0.5% by weight, the flame retardant effect, which is an essential condition, is poor, and conversely, if it exceeds 20% by weight and the moisture resistance reliability tends to decrease. Is.

In the epoxy resin composition for semiconductor encapsulation of the present invention, a curing accelerator, a flame retardant other than the organic phosphorus compound which is the D component, may be added, if necessary, in addition to the A to D components.
Flame retardant aids, release agents, pigments and colorants such as carbon black, γ-glycidoxypropyltrimethoxysilane, γ
Other additives such as a silane coupling agent such as mercaptopropyltrimethoxysilane and γ-aminoethylaminopropyltrimethoxysilane and a stress reducing agent can be appropriately added.

As the above-mentioned curing accelerator, conventionally known ones are used. Specifically, tetraphenylphosphonium / tetraphenylborate, organic phosphorus compounds such as triphenylphosphine, 1,8-diazabicyclo [5,4,0] undecene-7,1,5-diazabicyclo [4,3] , 0] Nonene-5 and other diazabicycloalkene compounds. These alone or 2
Used in combination with more than one species.

Examples of the flame retardant other than the organic phosphorus compound which is the above-mentioned component D include various conventionally known organic flame retardants and inorganic flame retardants such as metal hydroxides. These flame retardants have the effects of the present invention. Must be used within a range that does not interfere with.

Examples of the releasing agent include higher fatty acids, higher fatty acid esters, higher fatty acid calcium and the like. For example, carnauba wax and polyethylene wax are used, and these are used alone or in combination of two or more kinds. To be

Examples of the stress reducing agent include butadiene rubber such as methyl acrylate-butadiene-styrene copolymer and methyl methacrylate-butadiene-styrene copolymer, and silicone compounds. Further, an ion trap agent such as hydrotalcites or bismuth hydroxide may be blended for the purpose of improving reliability in the moisture resistance reliability test.

The epoxy resin composition for semiconductor encapsulation used in the present invention can be manufactured, for example, as follows. That is, the epoxy resin (A component), the phenol resin (B component), the inorganic filler (C component) and the specific organic phosphorus compound (D component) and, if necessary, other additives are appropriately added in accordance with a conventional method. After blending and melt-kneading in a heated state using a kneader such as a mixing roll, this is cooled and solidified at room temperature. After that, the desired epoxy resin composition can be produced by a series of steps of pulverizing by known means and tableting if necessary.

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

In the semiconductor device thus obtained, since the epoxy resin composition used as the encapsulating resin composition contains the above specific organic phosphorus compound (D component), the flame retardancy is high. In addition to having high reliability and excellent moisture resistance reliability and fluidity, the semiconductor device has high reliability.

Next, examples will be described together with comparative examples.

First, the following components were prepared.

[Epoxy resin a] Cresol novolac type epoxy resin (epoxy equivalent 1
95, softening point 70 ° C)

[Epoxy Resin b] Biphenyl type epoxy resin represented by the following formula (b) (epoxy equivalent 192,
(Melting point 107 ° C)

[Chemical 6]

[Phenol Resin c] Phenol novolac resin (hydroxyl group equivalent 107, softening point 85 ° C.)

[Phenol resin d] A phenol resin represented by the following formula (d) (hydroxyl group equivalent: 174, softening point: 70)
℃)

[Chemical 7]

[Inorganic filler] Spherical fused silica powder (average particle size 30 μm)

[Curing accelerator] Triphenylphosphine

[Coupling agent] γ-mercaptopropyltrimethoxysilane

[Ester wax] Carnauba wax

[Olefin wax] Polyethylene wax

[Organophosphorus compound] An organophosphorus compound represented by the following structural formula (e) (average particle size: 25 μm)

[Chemical 8]

[Red Phosphorus Flame Retardant] Red phosphorus content of 93% by weight,
Average particle size 30μm (Nova Excel made by Rin Kagaku Kogyo Co., Ltd.)

[Metallic Hydroxide] Zinc-based composite metal hydroxide (manufactured by Tateho Chemical Industry Co., Ltd., Echo Mag Z-10)

[0045]

Examples 1 to 6 and Comparative Examples 1 and 2 The respective raw materials shown in Tables 1 and 2 below were simultaneously blended in the proportions shown in the same table, and melt-kneaded for 3 minutes with a mixing roll machine (temperature 100 ° C.). Next, this melt was cooled and then pulverized to obtain a desired epoxy resin composition for semiconductor encapsulation.

[0046]

[Table 1]

[0047]

[Table 2]

Using the epoxy resin compositions of Examples and Comparative Examples thus obtained, the impurity ion concentration was measured by the following method. Further, a test piece having a thickness of 1/16 inch was molded using each of the above epoxy resin compositions, and the flame retardancy was evaluated according to the method of UL-94V-0 standard. In addition, "passing" means passing UL-94V-0.

[Impurity Ion Concentration] Each epoxy resin composition
A cured product was produced under the following conditions. And got
After crushing the cured product, the extraction strip at 160 ℃ for 20 hours
In some cases, phosphate ion (HPO ₃ ^2-, PO_Four ^-)
The amount of ions was measured by ion chromatography analysis. (Cured product preparation conditions) Temperature: 175 ° C Time: 120 seconds

Using the epoxy resin compositions obtained in the above Examples and Comparative Examples, semiconductor elements (chip size: 7.5 × 7.5 mm) were transfer molded (conditions: 175 ° C. × 120 seconds), A semiconductor package was obtained by post-curing at 175 ° C. for 5 hours. This package is an 80-pin QFP (quad flat package, size: 20 mm × 14 mm × thickness 2 mm), and the die pad size is 8 × 8 mm.

Using the semiconductor package thus manufactured, a pressure cooker bias test (PCB
T) was performed (conditions: 130 ° C./85% RH, 30V bias). In the failure mode, leak failure and open failure were measured, and the time until failure occurred in 50% of the 40 failures was measured to evaluate the moisture resistance reliability.

Further, the fluidity was evaluated by measuring the spiral flow shown in the following method.

[Measurement of Spiral Flow] Using a mold for spiral flow measurement, EMMI 1 at 175 ± 5 ° C.
The spiral flow (SF) value was measured according to -66.

The results of these measurements and evaluations are also shown in Tables 3 to 4 below.

[0055]

[Table 3]

[0056]

[Table 4]

From the results shown in Tables 3 to 4 above, all of the products of Examples showed good flame retardancy and had a small amount of phosphate ions.
Excellent results were also obtained in the moisture resistance reliability evaluation test and the fluidity evaluation test.

On the other hand, the product of Comparative Example 1 using the red phosphorus flame retardant had no problem in flame retardancy, but the amount of phosphate ion was large and the moisture resistance test result was poor. In addition, the product of Comparative Example 2 in which the metal hydroxide was used as the flame retardant without using the red phosphorus flame retardant had good results in the flame retardancy test and the moisture resistance test, but had a short spiral flow value and fluidity. However, there is a problem in using it as a molding material.

[0059]

INDUSTRIAL APPLICABILITY As described above, the present invention provides an epoxy resin composition for semiconductor encapsulation containing the specific organic phosphorus compound (D component) represented by the general formula (1) together with the A to C components. Is. Therefore, in addition to high flame retardance, impurities under high temperature and high humidity conditions are less likely to deposit than in the past, and deterioration of insulation is not observed, resulting in excellent moisture resistance reliability and fluidity. Therefore, by encapsulating a semiconductor element with this epoxy resin composition for encapsulating a semiconductor, a semiconductor device having excellent reliability can be obtained.

When the inorganic filler which is the C component is used so as to have a content within a specific range, the flame retardancy and the fluidity are particularly well balanced, and a more excellent sealing material can be obtained. it can.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H01L 23/31 (72) Inventor Takuya Eto 1-2-1, Shimohozumi, Ibaraki-shi, Osaka Nitto Denko Corporation In-house F-term (reference) 4J002 CC042 CC052 CD021 CD051 CD061 CE002 DE146 DF016 DJ016 DJ046 EW147 FA086 FD016 FD137 FD142 FD150 FD160 GQ05 4J036 AA01 AD07 AF08 DA02 DA04 DC46 DD07 FA03 FA04 FA05 FA12 FB07 A04 JA07 JA04 JA07 JA07 JA04 JA07

Claims (4)

[Claims] 1. An epoxy resin composition for semiconductor encapsulation comprising the following components (A) to (D). (A) Epoxy resin. (B) Phenolic resin. (C) Inorganic filler. (D) An organic phosphorus compound represented by the following general formula (1). [Chemical 1] 2. The organic phosphorus compound which is the component (D),
The epoxy resin composition for semiconductor encapsulation according to claim 1, which is an organic phosphorus compound represented by the following chemical formula (2). [Chemical 2] 3. The epoxy for semiconductor encapsulation according to claim 1, wherein the content of the inorganic filler as the component (C) is set in the range of 50 to 95% by weight in the whole epoxy resin composition. Resin composition. 4. A semiconductor device obtained by encapsulating a semiconductor element with the epoxy resin composition for encapsulating a semiconductor according to claim 1.