JP4254265B2 - Epoxy resin composition and semiconductor device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an epoxy resin composition for semiconductor encapsulation and a semiconductor device using the same.
[0002]
[Prior art]
As a sealing method for semiconductor elements such as IC and LSI, transfer molding of an epoxy resin composition is suitable for mass production at low cost and has been adopted for a long time, and a phenol resin that is an epoxy resin or a curing agent in terms of reliability. Improvements have been made to improve the characteristics. However, due to the recent trend toward smaller, lighter, and higher performance electronic devices, semiconductors have been increasingly integrated and the surface mounting of semiconductor devices has been promoted. The demand for compositions has become increasingly severe. For this reason, the problem which cannot be solved with the conventional epoxy resin composition has also come out.
The biggest problem is that by adopting surface mounting, the semiconductor device is suddenly exposed to a high temperature of 200 ° C. or higher in the solder dipping or solder reflow process, and the moisture when moisture absorbed explosively evaporates. In particular, a phenomenon in which reliability is remarkably reduced due to peeling at the interface between various plated joints such as gold plating and silver plating on semiconductor elements, lead frames, and inner leads and the cured product of the epoxy resin composition. It is.
[0003]
In order to improve reliability degradation due to solder processing, increase the amount of inorganic filler in the epoxy resin composition to achieve low moisture absorption, high strength, low thermal expansion, improve solder resistance, There is a technique of using a low melt viscosity resin to maintain a high fluidity at a low viscosity during molding (see, for example, Patent Document 1). Although solder resistance is considerably improved by using this method, there is a drawback that fluidity is sacrificed and voids are easily generated in the package as the filling ratio of the inorganic filler increases. In addition, in order to prevent peeling at the interface between the plated portion and the epoxy resin composition, a method has been proposed in which various coupling agents such as aminosilane and mercaptosilane are added to achieve both fluidity and solder resistance (for example, However, even with this method, a sufficiently good epoxy resin composition for encapsulating a semiconductor could not be obtained.
[0004]
[Patent Document 1]
JP-A 64-65116 (pages 2 to 7)
[Patent Document 2]
Japanese Patent Laid-Open No. 9-255852 (pages 2 to 7)
[0005]
[Problems to be solved by the invention]
The present invention provides an epoxy resin composition for semiconductor encapsulation excellent in fluidity and solder resistance, and a semiconductor device using the same.
[0006]
[Means for Solving the Problems]
The present invention
[1] (A) epoxy resin, (B) phenol resin, (C) curing accelerator, (D) inorganic filler, (E) silane coupling agent represented by general formula (1), and (F) An epoxy resin composition for semiconductor encapsulation, comprising a thiazoline compound as an essential component;
[Chemical 3]
[0007]
[2] (E) Epoxy resin for semiconductor encapsulation according to item [1 ] , wherein the structure of the silane coupling agent represented by the general formula (1) is a silane coupling agent represented by the general formula (2) Composition,
[Formula 4]
[3] A semiconductor device comprising a semiconductor element sealed using the epoxy resin composition for semiconductor sealing according to the item [1] or [2] ,
It is.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
The epoxy resin used in the present invention refers to monomers, oligomers, and polymers in general having two or more epoxy groups in one molecule, and the molecular weight and molecular structure are not particularly limited. For example, biphenyl type epoxy resin, bisphenol Type epoxy resin, stilbene type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, triphenolmethane type epoxy resin, alkyl-modified triphenolmethane type epoxy resin, triazine nucleus-containing epoxy resin, dicyclopentadiene modified phenol type epoxy Examples thereof include resins, phenol aralkyl type epoxy resins (having a phenylene skeleton, a biphenylene skeleton, etc.), and these may be used alone or in combination.
[0009]
The phenol resin used in the present invention includes monomers, oligomers, and polymers 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 Examples include novolak resins, dicyclopentadiene-modified phenol resins, terpene-modified phenol resins, triphenolmethane type resins, phenol aralkyl resins (having a phenylene skeleton, biphenylene skeleton, etc.), and these may be used alone or in combination. Absent.
[0010]
As a compounding quantity of an epoxy resin and a phenol resin, it is preferable that the ratio of the number of epoxy groups of all epoxy resins and the number of phenolic hydroxyl groups of all phenol resins is 0.8 to 1.3. There is a possibility that the curability of the composition is lowered, the glass transition temperature of the cured product is lowered, and the moisture resistance reliability is lowered.
[0011]
As a hardening accelerator used for this invention, what is necessary is just to accelerate | stimulate the hardening reaction of an epoxy group and a phenolic hydroxyl group, and what is generally used for a sealing material can be used. Examples thereof include 1,8-diazabicyclo (5,4,0) undecene-7, triphenylphosphine, 2-methylimidazole, tetraphenylphosphonium / tetraphenylborate and the like, and these may be used alone or in combination. Absent.
[0012]
As an inorganic filler used for this invention, what is generally used for the epoxy resin composition for semiconductor sealing can be used. Examples thereof include fused silica, crystalline silica, talc, alumina, silicon nitride and the like, and the most preferably used is spherical fused silica. These inorganic fillers may be used alone or in combination. Although the compounding quantity of an inorganic filler is not specifically limited, 78 to 96 weight% is preferable in all the epoxy resin compositions. If the lower limit is not reached, sufficient solder resistance may not be obtained, and if the upper limit is exceeded, sufficient fluidity may not be obtained.
[0013]
In the present invention, the silane coupling agent represented by the general formula (1) is essential, and when the silane coupling agent represented by the general formula (2) is used, fluidity and solder resistance are improved. The effect is large and preferable. The silane coupling agent represented by the general formula (1) may be used alone or in combination of two or more. Moreover, although a compounding quantity is not specifically limited, 0.01 to 3 weight% is desirable in all the epoxy resin compositions, More preferably, it is 0.05 to 1 weight%. If the lower limit is not reached, sufficient fluidity may not be obtained, and if the upper limit is exceeded, curability may be reduced.
[0014]
In the present invention, a compound containing at least one S atom and one N atom in each molecule is essential, and the molecular weight and molecular structure are not particularly limited, but the compound has a S—C—N structure in the compound. It is preferable because the effect of adhesion with the plated portion is increased. Examples of such compounds include thiazoline and thiazole. Among these compounds, thiazoline compounds are more preferable because of their high adhesion strength. A compound containing one or more each of S and N atoms in one molecule may be used alone or in combination of two or more. Moreover, the compounding quantity of the compound which contains one or more each of S atom and N atom in 1 molecule is not specifically limited, However, 0.01-3 weight% is desirable in all the epoxy resin compositions, More preferably, it is 0.05-. 1% by weight. If the lower limit is not reached, sufficient adhesion to the plated portion may not be obtained, and if the upper limit is exceeded, the curability may be lowered.
[0015]
In the present invention, it is essential to use the silane coupling agent represented by the general formula (1) and the compound containing one or more S atoms and N atoms in one molecule, and only one of them is blended. However, fluidity and solder resistance are not sufficient.
[0016]
(A) epoxy resin, (B) phenol resin, (C) curing accelerator, (D) inorganic filler, (E) silane coupling agent represented by general formula (1), and (F) in one molecule The epoxy resin composition of the present invention comprising a compound containing at least one S atom and at least one N atom as an essential component is represented by an epoxy resin, a phenol resin, a curing accelerator, an inorganic filler, and the general formula (1). A silane coupling agent and a compound containing at least one S atom and one N atom in the molecule are essential components, and in addition to this, aminosilanes and epoxysilanes other than those represented by the general formula (1) as necessary Silane coupling agents such as mercaptosilane, alkyl silane, ureido silane, vinyl silane, titanate coupling agent, aluminum coupling agent, aluminum / zirconium coupling agent, etc. Coloring agents such as pulling agents, carbon black, release agents such as natural wax and synthetic wax, and low stress additives such as rubber, brominated epoxy resins and antimony trioxide, aluminum hydroxide, magnesium hydroxide, zinc borate, Additives such as flame retardants such as zinc molybdate and phosphazene may be appropriately blended.
[0017]
The epoxy resin composition of the present invention can be obtained by mixing the raw materials sufficiently uniformly using a mixer or the like, then melt-kneading with a hot roll or a kneader, cooling and pulverizing.
The epoxy resin composition of the present invention is used to encapsulate various electronic components such as semiconductor elements, and to manufacture semiconductor devices by conventional molding methods such as transfer molding, compression molding, and injection molding. do it.
[0018]
【Example】
Examples of the present invention are shown below, but the present invention is not limited thereto. The blending ratio is parts by weight.
In addition, it shows below about the coupling agent used by the Example and the comparative example, and the compound which each contains one or more S atoms and N atoms in 1 molecule.
Coupling agent 1: Coupling agent represented by formula (3) (manufactured by Shin-Etsu Chemical Co., Ltd., KBM-573)
[Chemical formula 5]
[0019]
Coupling agent 2: Coupling agent represented by formula (4) (Shin-Etsu Chemical Co., Ltd., X12-806)
[Chemical 6]
[0020]
Coupling agent 3: Coupling agent represented by formula (5) (manufactured by Shin-Etsu Chemical Co., Ltd., KBM-403)
[Chemical 7]
[0021]
Coupling agent 4: Coupling agent represented by formula (6) (manufactured by Shin-Etsu Chemical Co., Ltd., KBM-803)
[Chemical 8]
[0022]
Coupling agent 5: Coupling agent represented by formula (7) (manufactured by Shin-Etsu Chemical Co., Ltd., KBE-903)
[Chemical 9]
[0023]
S, N-containing compound 1: compound represented by formula (8) (Kanto Chemical Co., Ltd., primary reagent)
[Chemical Formula 10]
[0024]
S, N-containing compound 2: Compound represented by formula (9) (Kanto Chemical, first grade reagent)
Embedded image
[0026]
Example 1
Epoxy resin 1: Epoxy resin mainly composed of formula (11) (manufactured by Japan Epoxy Resin Co., Ltd., YX-4000, epoxy equivalent 190 g / eq, melting point 105 ° C., hereinafter referred to as E-1) 49 parts by weight 13]
[0027]
Phenolic resin 2: phenolic resin represented by formula (12) (Mitsui Chemicals, XLC-LL, hydroxyl group equivalent 165 g / eq, softening point 79 ° C., hereinafter referred to as H-1) 42 parts by weight
[0028]
1,8-diazabicyclo (5,4,0) undecene-7 (hereinafter referred to as DBU) 5 parts by weight fused spherical silica (average particle size 21 μm) 890 parts by weight coupling agent 1 3 parts by weight S, N-containing compound 1 3 Part by weight Carbon black 3 parts by weight Carnauba wax 5 parts by weight were mixed in a mixer, kneaded at 95 ° C. for 8 minutes using a hot roll, cooled and ground to obtain an epoxy resin composition. The obtained epoxy resin composition was evaluated by the following methods. The results are shown in Table 1.
[0029]
Evaluation Method Spiral Flow: Using a mold for spiral flow measurement according to EMMI-1-66, measurement was performed at a mold temperature of 175 ° C., a pressure of 6.9 MPa, and a curing time of 120 seconds. The unit is cm.
Adhesion strength: Using a transfer molding machine, a 2 mm × 2 mm × 2 mm adhesion strength test piece was molded on a lead frame under conditions of a mold temperature of 175 ° C., an injection pressure of 9.8 MPa, and a curing time of 120 seconds. Two types of lead frames were used: a silver plated copper frame (frame 1) and a gold plated NiPd alloy frame (frame 2). Thereafter, the shear strength between the cured product of the epoxy resin composition and the frame was measured using an automatic shear strength measuring apparatus (manufactured by DAGE, PC2400). The unit is N / mm ² .
Solder crack resistance: Molding 80pQFP (NiPd alloy frame gold-plated, chip size 6.0mm x 6.0mm) at a molding temperature of 175 ° C, a pressure of 8.3MPa, and a curing time of 120 seconds using a low-pressure transfer molding machine. Then, after heat treatment at 175 ° C. for 8 hours as an after bake, a humidification treatment was performed at 85 ° C. and a relative humidity of 85% for 120 hours, followed by an IR reflow treatment at 260 ° C. Peeling and cracks inside the package were confirmed with an ultrasonic flaw detector. The number of defective packages among the 10 packages is shown.
[0030]
Example 2-6, Comparative Examples 1-5
According to the composition of Table 1, an epoxy 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 Table 1.
The raw materials used other than Example 1 are shown below.
Epoxy resin 2: Epoxy resin represented by formula (13) (manufactured by Nippon Kayaku Co., Ltd., NC3000P, softening point 58 ° C., epoxy equivalent 273, hereinafter referred to as E-2)
Embedded image
[0031]
Phenol resin 2: Phenol resin represented by formula (14) (Maywa Kasei Co., Ltd., MEH-7851SS, softening point 107 ° C., hydroxyl equivalent 204, hereinafter referred to as H-2)
Embedded image
[0032]
[Table 1]
[0033]
【The invention's effect】
According to the present invention, an epoxy resin composition for semiconductor encapsulation and a semiconductor device excellent in fluidity and solder resistance can be obtained.

Claims (3)

(A) epoxy resin, (B) phenol resin, (C) curing accelerator, (D) inorganic filler, (E) silane coupling agent represented by general formula (1), and (F) thiazoline compound An epoxy resin composition for semiconductor encapsulation, which is an essential component.
(E) the formula (1) the structure of the silane coupling agent represented by the general formula (2) is a silane coupling agent represented by claim 1 Symbol mounting semiconductor encapsulating epoxy resin composition.
Wherein a obtained by encapsulating a semiconductor element using the epoxy resin composition for semiconductor encapsulation according to claim 1 or 2.