JP2000212401A - Epoxy resin composition and semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor epoxy resin composition which causes no delamination from the semiconductor element during molding and has excellent moisture-resistance reliability, in the case where an island minimizing frame such as a window-pad frame is used. SOLUTION: The composition comprises, as essential ingredients, a dicyclopentadiene-modified epoxy resin, a phenolic resin, a curing accelerator, an inorganic filler, and silane coupling agents of formulae I, II and III, the ratio (a)/(b) of the number (a) of epoxy groups in the total epoxy resin to the number (b) of phenolic hydroxy groups in the total phenolic resin being 1.10-1.20, the content of the inorganic filler being 80-90 wt.% in the total resin composition, the content of the whole silane coupling agents being 0.3-1.3 wt.% in the total resin composition, the weight ratio I/(II+III) of the compounds of formulae I, II and III being 0.5-3.0.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an epoxy resin composition for semiconductor encapsulation excellent in moldability and humidity resistance, and to a semiconductor device obtained by encapsulating a semiconductor element using the same.

[0002]

2. Description of the Related Art As a method for encapsulating semiconductor elements such as ICs and LSIs, a method by transfer molding of an epoxy resin composition (hereinafter referred to as a resin composition) has been adopted as a method suitable for low cost and mass production. In terms of reliability, improvements have been made by improving epoxy resins and phenol resins as curing agents. However, in recent years, semiconductors have been diversified year by year in the market trend of miniaturization, weight reduction, and high performance of electronic devices, and demands for resin compositions have become increasingly severe. For this reason, a problem which cannot be solved by the conventional resin composition has come out. One is that, with the diversification of semiconductor packages, the thickness of the cured product of the resin composition occupying the packages has been significantly different in each package. For example, in the case of a TSOP having a thickness of 1 mm, the thickness of the cured product of the resin composition formed on the upper surface of the semiconductor element is 0.2 to 0.3 m.
m. On the other hand, in the case of a thick package such as a 4 mm-thick SOJ, the cured product of the resin composition formed on the upper surface of the semiconductor element has a thickness of 1 mm or more. Therefore, it is clear that there is a difference between the moldability, the moisture resistance reliability, and the heat resistance reliability. For this reason, various additives have been added to improve the adhesion between the resin composition and the lead frame or the semiconductor element. However, none of them has been a complete solution, and further improvement is desired. ing. A second problem is that the shape of the lead frame, especially the shape of the island bonded to the semiconductor element, has changed.
For example, a window / pad frame corresponds to this. The window / pad frame was developed for the purpose of improving the humidity resistance and the heat resistance. However, by using this, the poor adhesion between the resin composition and the back surface of the semiconductor element when sealing is used. The problem of peeling of the back surface of the semiconductor element resulting from the above has arisen. For this reason, various improvements have been made with the aim of improving the adhesion, but none of them is a complete solution, and further improvements are desired.

[0003]

SUMMARY OF THE INVENTION The present invention relates to a semiconductor encapsulation having excellent moldability, adhesion to the back surface of a semiconductor element, and excellent moisture resistance reliability, particularly when an island miniaturized frame such as a window / pad frame is used. The present invention provides an epoxy resin composition for use and a semiconductor device obtained by sealing a semiconductor element using the same.

[0004]

The present invention provides (A) an epoxy resin, (B) a phenolic resin, (C) a curing accelerator,
(D) an inorganic filler, and (E) Formula (E-1), Formula (E)
-2) and the silane coupling agent of the formula (E-3) as an essential component, and the ratio (a) / () of the number of epoxy groups (a) of all epoxy resins to the number of phenolic hydroxyl groups (b) of all phenol resins. b) is 1.10 to 1.20, the content of the inorganic filler is 80 to 90% by weight in the whole resin composition, and the content of the whole silane coupling agent is the whole resin composition. 0.3 to 1.3% by weight in the product, and the weight ratio (E-1) / ｛of the compounds of the formulas (E-1), (E-2) and (E-3). (E-2) + (E-3)} is
0.5 to 3.0, wherein a particularly preferred epoxy resin is a dicyclopentadiene-modified epoxy resin of the formula (1), and an epoxy resin composition for semiconductor encapsulation, and a semiconductor element is encapsulated using the same. The semiconductor device is stopped. H ₂ NCH ₂ CH ₂ CH ₂ Si (OCH ₂ CH ₃ ) ₃ (E-1)

[0005]

Embedded image HSCH ₂ CH ₂ CH ₂ Si (OCH ₃ ) ₃ (E-3)

[0006]

Embedded image (Where n = 0 to 10)

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The epoxy resin used in the present invention is:
It refers to all monomers, oligomers, and polymers having two or more epoxy groups in one molecule. For example, brominated epoxy resin, biphenyl type epoxy resin, bisphenol type epoxy resin, stilbene type epoxy resin, phenol novolak type epoxy resin, cresol novolak type epoxy resin, cycloaliphatic epoxy resin, glycidyl ester type epoxy resin, glycidyl amine type epoxy resin Resins, heterocyclic epoxy resins, trifunctional epoxy resins, trishydroxyphenylmethane type epoxy resins, and the like. These epoxy resins can be used without any limitation on the molecular weight, melting point or softening point, hydroxyl equivalent, etc., but the chlorine content in the epoxy resin is preferably low. These may be used alone or as a mixture. Among them, a dicyclopentadiene-modified epoxy resin represented by the formula (A-1) is particularly preferable. This epoxy resin has a larger number of reaction starting points and higher adhesion than a novolak epoxy resin or the like, and has the same adhesion as a crystalline epoxy resin such as a biphenyl epoxy resin. In addition, since the viscosity is low, the content of the inorganic filler can be increased, and the curability is improved. Furthermore, n = 1
~ 2 are preferred.

[0008] The phenolic resin used in the present invention refers to all monomers, oligomers and polymers having two or more phenolic hydroxyl groups in one molecule. The phenol resin is not particularly limited, and examples thereof include phenol novolak resin, cresol novolak resin, phenol aralkyl resin, naphthol aralkyl resin, terpene-modified phenol resin, and dicyclopentadiene-modified phenol resin. These phenolic resins can be used without limitation on molecular weight, softening point, hydroxyl equivalent, etc.
It is preferable that the chlorine content in the phenol resin is as low as possible. These may be used alone or as a mixture. The ratio (a) / (b) of the number of epoxy groups (a) of all epoxy resins to the number of phenolic hydroxyl groups (b) of all phenol resins is 1.
10-1.20 is preferred. If it is less than 1.10, the resin composition and the back surface of the semiconductor element may peel off.
When the ratio exceeds 1.20, the releasability from the mold is deteriorated, and the moldability is disadvantageously increased.

Examples of the curing accelerator used in the present invention include amine compounds such as tributylamine, organic phosphorus compounds such as triphenylphosphine and tetraphenylphosphonium tetraphenylborate, and 2-methylimidazole and the like. Examples thereof include, but are not limited to, an imidazole compound and 1,8-diazabicyclo (5,4,0) undecene-7. These may be used alone or as a mixture.

[0010] The inorganic filler used in the present invention is not particularly limited, and a known inorganic filler can be used. Examples of such an inorganic filler include alumina, fused silica, spherical silica, crystalline silica, and secondary aggregated silica. From the viewpoint of improving fluidity, fused spherical silica is particularly preferred. As the shape of the fused spherical silica particles, it is desirable that the particles be infinitely spherical and have a broad particle size distribution in order to improve fluidity. The content of the inorganic filler in the total resin composition is 80 to
90% by weight is preferred. If it is less than 80% by weight, the reinforcing effect of the inorganic filler may not be sufficiently exerted, and if it is more than 90% by weight, the fluidity of the resin composition may be reduced, and poor filling may occur during molding.

The silane coupling agent used in the present invention comprises γ-aminopropyltriethoxysilane of the formula (E-1), γ-glycidoxypropyltrimethoxysilane of the formula (E-2), and -3) γ-mercaptopropyltrimethoxysilane. (E-1) / {(E-2) + (E-3)} is 0.5
It is preferably from 3.0 to 3.0. If the ratio is out of the range of 0.5 to 3.0, the resin composition and the back surface of the semiconductor element may be separated. Of the three types of silane coupling agents,
It is not preferable that even one kind is missing because the adhesiveness is reduced. The addition amount of each of the three types of silane coupling agents is preferably 0.1% by weight or more in the entire resin composition.
Further, within the range not impairing the properties of the silane coupling agents of formulas (E-1) to (E-3) of the present invention, 2- (3,4-
Other silane coupling agents such as epoxycyclohexyl) ethyltrimethoxysilane may be used in combination. The total weight of all the silane coupling agents is preferably 0.3 to 1.3% by weight in the whole resin composition. If it is less than 0.3% by weight, the resin composition may peel off from the back surface of the semiconductor element. If it exceeds 1.3% by weight, the releasability at the time of molding may be deteriorated.

The resin composition of the present invention may further comprise, if necessary, a coloring agent such as carbon black, in addition to the components (A) to (E).
Flame retardants such as brominated epoxy resin, antimony oxide and phosphorus compounds, low stress components such as silicone oil and silicone rubber, release agents such as natural wax, synthetic wax, higher fatty acids and their metal salts or paraffin, antioxidants, etc. Can be blended. The resin composition of the present invention is obtained by mixing the components (A) to (E) and other additives at room temperature using a mixer, melt-kneading the mixture with a kneading machine such as a roll, kneader, extruder, etc., and then pulverizing after cooling. Is obtained. In order to manufacture a semiconductor device by encapsulating an electronic component such as a semiconductor element using the resin composition of the present invention, it is sufficient to cure and mold by a molding method such as a transfer mold, a compression mold, and an injection mold.

[0013]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples. The mixing ratio is by weight. Example 1 Epoxy resin of formula (1) (HP-7200, manufactured by Dainippon Ink and Chemicals, Inc., softening point 65 ° C., epoxy equivalent 265 g / eq) 10.0 parts by weight

Embedded image

Phenol novolak resin (softening point 80 ° C., hydroxyl equivalent 105 g / eq) 4.2 parts by weight 1,8-diazabicyclo (5,4,0) undecene-7 (hereinafter referred to as DBU) 0.2 parts by weight Melting Spherical silica (average particle size 15 μm, specific surface area 4.0 m ² / g) 100 parts by weight Formula (E-1) 0.50 parts by weight Formula (E-2) 0.20 parts by weight Formula (E-3) 30 parts by weight Brominated epoxy resin (epoxy equivalent: 273 g / eq) 2.1 parts by weight Carbon black 0.4 parts by weight Carnauba wax 0.7 parts by weight is mixed with a mixer, kneaded at 70 to 100 ° C., and cooled and ground. Thus, a resin composition was obtained. The obtained resin composition was evaluated by the following method. Table 1 shows the results.

Evaluation method Spiral flow: Measurement was performed using a mold for measuring spiral flow according to EMMI-I-66 at a mold temperature of 175 ° C., an injection pressure of 70 kg / cm ² , and a curing time of 2 minutes. Spiral flow is a parameter of fluidity, and the larger the value, the better the fluidity. The unit is cm. Adhesion after molding: using a low-pressure transfer molding machine, a mold temperature of 175 ° C., a pressure of 75 kg / cm ² , and a curing time of 2 minutes, a 9 × 9 mm semiconductor element having a 9.5 × 9.9 mm island and 80 pQFP. And then post-cured at 175 ° C. for 8 hours. 1
Eight packages were observed for the adhesiveness between the cured product of the resin composition inside the molded article and the semiconductor element by using an ultrasonic probe imager. Moisture resistance: The 80pQFP was molded using a low-pressure transfer molding machine at a mold temperature of 175 ° C, a pressure of 75 kg / cm ² , and a curing time of 2 minutes, and post-cured at 175 ° C for 8 hours. Eighteen packages were treated in an environment of 85 ° C. and 85% relative humidity for 72 hours, and the adhesion between the cured product of the resin composition inside the molded article and the semiconductor element was observed using an ultrasonic probe.

Examples 2 to 10 and Comparative Examples 1 to 11 According to the formulations shown in Tables 1 and 2, a resin composition was obtained in the same manner as in Example 1, and evaluated in the same manner as in Example 1. The results are shown in Tables 1 and 2. In Examples 9 and 10, an ortho-cresol novolak type epoxy resin (softening point: 55 ° C., epoxy equivalent: 196 g / eq) was used.

[0017]

[Table 1]

[0018]

[Table 2]

[0019]

According to the present invention, a semiconductor device having excellent moisture resistance reliability can be obtained without peeling from a semiconductor element at the time of molding, particularly when an island miniaturized frame such as a window / pad frame is used. .

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08K 5/544 C08K 5/54 F 5/5435 E 5/548 L H01L 23/29 H01L 23/30 R 23 / 31 F-term (reference) 4J002 CC04X CC05X CD02W CD03W CD05W CD06W CD07W CD08W CD12W CD13W CE00X DE147 DJ017 EN026 EU116 EU136 EW016 EW176 EX068 EX078 EX088 FA087 FD017 FD090 FD130 FD14X FD156 AD01 AD07 AD02 AD01 AD07 AD07 DC06 DC41 DC46 DD07 DD09 FA03 FA05 FB07 FB08 JA07 4M109 AA01 BA01 CA21 EA02 EA03 EB03 EB04 EB06 EB07 EB08 EB09 EB12 EB13 EB19 EC01 EC09

Claims (3)

[Claims] 1. An epoxy resin (A), a phenolic resin (B), a curing accelerator (C), an inorganic filler (D), and (E) formulas (E-1), (E-2), Formula (E-3)
And the ratio (a) / (b) of the number of epoxy groups (a) of all epoxy resins to the number of phenolic hydroxyl groups (b) of all phenolic resins is 1.10 to 10%.
1.20, and the content of the inorganic filler is 80 to 90% by weight in the whole resin composition, and the content of the whole silane coupling agent is 0.3 to 0.3% in the whole resin composition. 1.
3% by weight, and formula (E-1), formula (E-2),
And the weight ratio of the compound of the formula (E-3) (E-1) / ｛(E
-2) + (E-3)｝ is 0.5 to 3.0, wherein the epoxy resin composition for semiconductor encapsulation is characterized in that: H ₂ NCH ₂ CH ₂ CH ₂ Si (OCH ₂ CH ₃ ) ₃ (E-1) HSCH ₂ CH ₂ CH ₂ Si (OCH ₃ ) ₃ (E-3) 2. The epoxy resin composition for semiconductor encapsulation according to claim 1, wherein the epoxy resin is a dicyclopentadiene-modified epoxy resin represented by the formula (1). Embedded image (Where n = 0 to 10) 3. A semiconductor device comprising a semiconductor element encapsulated with the epoxy resin composition for semiconductor encapsulation according to claim 1 or 2.