JP2001114992A - Sealing resin composition and semiconductor device sealed therewith - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sealing resin composition that can give a high-reliability sealed semiconductor device improved in the adhesion of the resin composition and a pre-plated frame, especially, a frame pre-plated with Pd, Pd-Au, or the like and therefore in reflow resistance and made proof against moisture deterioration after reflow. SOLUTION: Provided are a sealing resin composition essentially consisting of (A) an epoxy resin, (B) a novolac phenolic resin, (C) 2,4,6-triazinetrithiol sodium salt, and (D) an inorganic filler and containing 0.004-0.2 wt.%, based on the resin composition, component C and 25-95 wt.%, based on the resin composition, component D, and a sealed semiconductor device prepared by sealing a semiconductor chip with the composition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to Pd, Pd-A
The present invention relates to an epoxy resin composition having excellent reliability such as reflow crack resistance in a semiconductor package using a u-Ag-plated frame, and a semiconductor sealing device.

[0002]

2. Description of the Related Art In recent semiconductor devices, the number of semiconductor packages employing a frame plated with Pd or Pd-Au instead of solder plating is increasing.

[0003] Conventional semiconductor devices employing a pre-plating frame of Pd or Pd-Au sealed with a resin composition comprising an epoxy resin, a novolak-type phenol resin and an inorganic filler, are sealed with the pre-plating frame. There was a drawback that the adhesion to the resin was extremely poor. In particular, when a semiconductor device that has absorbed moisture is surface-mounted by an infrared (IR) reflow method, peeling occurs between the sealing resin and the lead frame or between the sealing resin and the semiconductor chip, causing remarkable moisture resistance deterioration and disconnection due to corrosion of the electrode. Leakage current due to moisture or moisture, and as a result, the semiconductor device has a drawback that long-term reliability cannot be guaranteed. For this reason, there has been a strong demand for the development of a material which has little influence on moisture resistance and has good moldability with little moisture resistance deterioration even if surface mounting of the entire semiconductor device is performed by IR reflow.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned drawbacks and to meet the above-mentioned demands.
d, Pd-Au, Ag, etc., high adhesiveness to a pre-plating frame, particularly excellent in reflow resistance and reliability after reflow, good moldability, sealing resin composition and semiconductor sealing device It is intended to provide.

[0005]

Means for Solving the Problems As a result of intensive studies to achieve the above object, the present inventor has found that by adding a sodium salt of 2,4,6-triazinetrithiol to a resin composition, Significantly improved adhesion with pre-plating frames such as Pd, Pd-Au, Ag, etc.
The inventors have found that the above objects have been achieved and completed the present invention.

That is, the present invention provides (A) an epoxy resin,
(B) Novolak type phenolic resin, (C) 2, 4, 6
Sodium salt of triazinetrithiol and (D)
An inorganic filler is an essential component, and the sodium salt of (C) 2,4,6-triazinetrithiol is 0.004 to 0.2% by weight based on the resin composition, and the (D) inorganic filler is Is contained at a ratio of 25 to 95% by weight. Further, there is provided a semiconductor encapsulating apparatus characterized in that a semiconductor chip is encapsulated with a cured product of the encapsulating resin composition.

Hereinafter, the present invention will be described in detail.

The epoxy resin (A) used in the present invention is not particularly limited in molecular structure, molecular weight, etc., as long as it is a compound having at least two epoxy groups in the molecule, and is generally used as a sealing material. Can be widely encompassed. For example, biphenyl type, bisphenol type aromatic type, aliphatic type such as cyclohexane derivative, and epoxy novolak type epoxy resin represented by the following general formula can be used.

[0009]

Embedded image (Wherein, R ¹ represents a hydrogen atom, a halogen atom or an alkyl group, R ² represents a hydrogen atom or an alkyl group, and n represents an integer of 1 or more.) These epoxy resins may be used alone or in combination of two or more. They can be used in combination.

The (B) novolak-type phenolic resin used in the present invention includes a novolak-type phenolic resin obtained by reacting a phenol such as phenol or alkylphenol with an aldehyde such as formaldehyde or paraformaldehyde, or a modified resin thereof. For example, an epoxidized or butylated novolak type phenol resin is used, and these resins are used alone or in combination of two or more. The mixing ratio of the novolak type phenol resin is such that the equivalent ratio [(a) / (b)] between the epoxy group (a) of the epoxy resin and the phenolic hydroxyl group (b) of the novolak type phenol resin is 0.1 to 10; Is preferably within the range. Equivalent ratio is less than 0.1 or 10
Exceeding the above range deteriorates heat resistance, moisture resistance, molding workability and electrical properties of the cured product.
Therefore, it is better to limit to the above range.

The sodium salt of (C) 2,4,6-triazinetrithiol used in the present invention is represented by the following structural formula.

[0012]

Embedded image The compounding ratio of the sodium salt of 2,4,6-triazinetrithiol is 0.004 to 0.004 to the entire resin composition.
It is desirable to contain 0.2% by weight. This ratio is 0.
If the amount is less than 004% by weight, there is no effect on the improvement of the adhesive strength of Pd, Pd-Au, Ag or the like to the pre-plating frame. Is not suitable for practical use and is not preferred.

The inorganic filler (D) used in the present invention includes silica powder, alumina powder, antimony trioxide, talc, calcium carbonate, titanium white, clay, mica, red iron oxide, glass fiber and the like. Alternatively, two or more kinds can be used in combination. Among these, silica powder and alumina powder are particularly preferable and are often used. The inorganic filler is desirably contained in a proportion of 25 to 95% by weight based on the whole resin composition. If the proportion is less than 25% by weight, heat resistance, moisture resistance, solder heat resistance, mechanical properties and moldability deteriorate, and if it exceeds 95% by weight, burrs increase and the moldability deteriorates, which is not suitable for practical use. .

The encapsulating resin composition of the present invention comprises an epoxy resin, a novolak type phenol resin, a sodium salt of 2,4,6-triazinetrithiol and an inorganic filler as essential components. To the extent not to the contrary, and if necessary, for example, natural waxes, synthetic waxes, metal salts of linear fatty acids, acid amides, esters, release agents such as paraffins, chlorinated paraffins, brominated toluene, Flame retardants such as hexabromobenzene and antimony trioxide, coloring agents such as carbon black and red iron, various curing accelerators and the like can be appropriately added and blended.

The general method for preparing the encapsulating resin composition of the present invention as a molding material includes epoxy resin, novolak type phenol resin, sodium salt of 2,4,6-triazinetrithiol, and inorganic filler. After mixing the components and other components sufficiently and uniformly by using a mixer, etc., the mixture is further subjected to a melt-mixing process using a hot roll or a mixing process using a kneader, etc., then solidified by cooling, pulverized to an appropriate size, and pulverized into a molding material. can do. If the molding material thus obtained is applied to sealing, coating, insulating, etc. of electronic parts or electric parts such as semiconductor devices, excellent properties and reliability can be imparted.

The semiconductor sealing device of the present invention can be easily manufactured by sealing a semiconductor chip using the sealing resin obtained as described above. The most common sealing method is a low-pressure transfer molding method, but sealing by injection molding, compression molding, casting or the like is also possible. The sealing resin composition is heated and cured at the time of sealing, and finally a semiconductor sealing device sealed with a cured product of this composition is obtained. Curing by heating is 150
Desirably, the composition is cured by heating to a temperature of at least ℃. As a semiconductor device for sealing, for example, an integrated circuit, a large-scale integrated circuit, a transistor, a thyristor, a diode, and the like are not particularly limited.

[0017]

According to the sealing resin composition and the semiconductor sealing device of the present invention, desired properties can be obtained by using a sodium salt of 2,4,6-triazinetrithiol as one of the resin components. Things. That is, 2,4,6-
The sodium salt of triazinetrithiol can improve the adhesion of the resin composition to a pre-plating frame of Pd, Pd-Au, Ag, etc., and can improve the reliability of the semiconductor package such as reflow crack resistance.

[0018]

Next, the present invention will be described with reference to examples, but the present invention is not limited to these examples. In the following Examples and Comparative Examples, “%” means “% by weight”.

Example 1 Cresol novolak epoxy resin (epoxy equivalent 21
5) 19%, 9% of novolak type phenol resin (phenol equivalent 107), 0.1% of sodium salt of 2,4,6-triazinetrithiol shown in the following chemical formula 3,

Embedded image 71% of fused silica powder, 0.3% of a curing accelerator and 0.3% of ester waxes are blended, mixed at room temperature, kneaded at 90-95 ° C, and cooled and pulverized to produce a molding material. did. This molding material was transfer-injected into a mold heated to 170 ° C. and cured to produce a molded product (sealed product). About this molded product, Pd and Pd-Au
Was tested for adhesion and moisture resistance to a pre-plating frame, and the results are shown in Table 1. In particular, a remarkable effect of the present invention was observed in adhesive strength.

Example 2 Cresol novolak epoxy resin (epoxy equivalent 21
5) 19%, 9% of novolak type phenol resin (phenol equivalent: 107), and 0.1% of sodium salt of 2,4,6-triazinetrithiol previously mixed with fused silica powder to treat the surface of the silica powder 71 %, A curing accelerator 0.3% and an ester wax 0.3% were mixed, kneaded and pulverized in the same manner as in Example 1 to produce a molding material.
Further, a molded article was prepared in the same manner as in Example 1, and Pd and Pd were formed.
Table 1 shows the results of a characteristic test of d-Au's adhesion to a pre-plating frame and moisture resistance. In particular, a remarkable effect of the present invention was observed in adhesive strength.

Comparative Example Cresol novolak type epoxy resin (epoxy equivalent 2
15) 19%, 9% of novolak type phenol resin (phenol equivalent: 107), 71% of silica powder, 0.3% of curing accelerator and 0.3% of ester waxes were mixed and molded in the same manner as in Example 1. The material was manufactured. A molded article was formed using this molding material, and a test was performed on various characteristics of the molded article in the same manner as in Example 1. The results are shown in Table 1.

[0022]

[Table 1] * 1: A molded article having an adhesion area of 4 mm ² was formed by Pd or Pd-Au pre-plating by transfer molding, left at 175 ° C. for 8 hours, and the shear adhesive strength was determined.

* 2: Using a molding material, a silicon chip (test element) having two or more aluminum wirings was adhered to a Pd pre-plating frame.
Transfer molding at 5 ° C. for 2 minutes, QFP-208
P, a molded product of 2.8 mm ^t was made,
Post-curing was performed for 8 hours. The molded product obtained in this way is
After moisture absorption treatment at 40 ° C., 90% RH and 100 hours, M
a. Passed through an IR reflow furnace at 240 ° C. four times. afterwards,
Perform PCT in saturated steam at 127 ° C and 2.5 atm.
The disconnection due to aluminum corrosion was evaluated as defective.

[0024]

As apparent from the above description and Table 1, the encapsulating resin composition and the semiconductor encapsulating apparatus of the present invention have excellent adhesion to Pd, Pd-Au, and Ag-plated inserts. It does not peel off even after IR reflow, and has excellent moisture resistance. As a result, disconnection due to electrode corrosion and occurrence of leak current due to moisture can be significantly reduced, and reliability can be guaranteed for a long period of time. it can.

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Claims (2)

[Claims] 1. A resin composition comprising (A) an epoxy resin, (B) a novolak-type phenol resin, (C) a sodium salt of 2,4,6-triazinetrithiol and (D) an inorganic filler as essential components. On the other hand, (C) 2, 4,
0.006 sodium salt of triazinetrithiol
4 to 0.2% by weight, and 25% of the inorganic filler (D).
A sealing resin composition, which is contained in a proportion of about 95% by weight. 2. A resin composition comprising (A) an epoxy resin, (B) a novolak-type phenol resin, (C) a sodium salt of 2,4,6-triazinetrithiol and (D) an inorganic filler as essential components. On the other hand, (C) 2, 4,
0.006 sodium salt of triazinetrithiol
4 to 0.2% by weight, and 25% of the inorganic filler (D).
A semiconductor encapsulation device characterized in that a semiconductor chip is encapsulated with a cured product of an encapsulation resin composition contained in a proportion of up to 95% by weight.