JPH11209573A - Sealing resin composition and semiconductor sealing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor sealing device especially improving an adhesiveness of a pre-plating frame such as Pd or Pd-Au with a resin composition, improving resistance to reflow soldering of a semiconductor sealing device, preventing deterioration by moisture absorption after the reflow and having high reliabilities. SOLUTION: This invention relates to a sealing resin composition containing (A) an epoxy resin, (B) a novolak-type phenolic resin, (C) dibutylthiourea and (D) an inorganic filler as essential components and containing 0.001-0.5 wt.% of the component C and 25-95 wt.% of the component D to the resin compositions, and a semiconductor sealing device in which semiconductor chips are sealed with the sealing resin composition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to Pd, Pd-Au
The present invention relates to an epoxy resin composition for encapsulation and a semiconductor encapsulation device having excellent reliability such as reflow crack resistance in a semiconductor package incorporating a plated frame.

[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 not 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.
Provided are a sealing resin composition and a semiconductor sealing device having high adhesiveness to a pre-plating frame such as d, Pd-Au, etc., and particularly excellent in reflow resistance and reliability after reflow, and having good moldability. What you want to do.

[0005]

Means for Solving the Problems As a result of diligent studies aimed at achieving the above object, the present inventor has found that by adding dibutylthiourea to a resin composition, Pd, Pd-
The present invention has been completed by finding that the above-mentioned object is achieved by greatly improving the adhesion to a pre-plating frame of Au or the like.

That is, the present invention provides (A) an epoxy resin,
(B) Novolak type phenol resin, (C) dibutylthiourea and (D) an inorganic filler are essential components, and the dibutylthiourea of (C) is added to the resin composition in an amount of 0.01%.
To 0.5% by weight, and 25 to 95% by weight of the inorganic filler of (D).
It is a resin composition for encapsulation characterized in that it is contained in a proportion of% 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 and molecular weight, 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. As the novolak type phenol resin (B) used in the present invention, novolak type phenol resins obtained by reacting phenols such as phenol and alkylphenol with aldehydes such as formaldehyde and paraformaldehyde, and modified resins thereof, for example, epoxidation Alternatively, a butylated novolak type phenol resin may be used, and these resins may be 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)] of the epoxy group (a) of the epoxy resin to the phenolic hydroxyl group (b) of the novolak type phenol resin is in the range of 0.1 to 10. It is desirable to be within. If the equivalent ratio is less than 0.1 or more than 10, heat resistance, moisture resistance, molding workability, and electrical properties of the cured product are deteriorated, and any case is not preferable. Therefore, it is better to limit to the above range. (C) Dibutylthiourea used in the present invention is represented by the following structural formula.

[0010]

Embedded image In addition, other vulcanization accelerators and zinc oxide or magnesium oxide can be used in combination with this dibutylthiourea.

The mixing ratio of dibutylthiourea is desirably 0.01 to 0.5% by weight based on the whole resin composition. If this compounding ratio is less than 0.01% by weight, Pd, Pd
-Au has no effect on improving the adhesive strength to the pre-plating frame, and if it exceeds 0.5% by weight, it adversely affects the curing of the sealing resin and is not suitable for practical use and is not preferable.

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, resulting in poor moldability and not suitable for practical use.

The encapsulating resin composition of the present invention contains an epoxy resin, a novolak-type phenol resin, dibutylthiourea and an inorganic filler as essential components, but as far as it does not contradict the object of the present invention, and if necessary. For example, natural waxes, synthetic waxes, metal salts of linear fatty acids, release agents such as acid amides, esters, paraffins, etc., and difficulties such as chlorinated paraffins, brominated toluene, hexabromobenzene, and antimony trioxide Flame retardants, low-stress components such as elastomers, 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 phenol resin, dibutylthiourea,
After blending the inorganic filler and other components and mixing them sufficiently uniformly with a mixer or the like, further perform a melting and mixing treatment with a hot roll or a mixing treatment with a kneader or the like, and then cool and solidify and pulverize to an appropriate size. It can be a molding material. The molding material thus obtained is used for encapsulation of electronic components or electric components including semiconductor devices,
When applied to coating, insulation and the like, excellent characteristics 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. 150 ° C for curing by heating
It is desirable to cure by heating as described above. The semiconductor device for sealing is not particularly limited, for example, with an integrated circuit, a large-scale integrated circuit, a transistor, a thyristor, a diode, and the like.

[0016]

According to the sealing resin composition and the semiconductor sealing device of the present invention, desired characteristics can be obtained by using dibutylthiourea as a resin composition component.
That is, dibutyl thiourea is mixed with Pd and Pd-A
It is possible to improve the adhesive strength with the pre-plating frame such as u, and to improve the reliability of the semiconductor package such as reflow crack resistance.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described specifically 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 215)
) 19%, novolak type phenol resin (phenol equivalent 107) 9%, dibutylthiourea 0.1% as shown in the following chemical formula 3.
05%,

[0019]

Embedded image Fused silica powder 71% and ester waxes 0.3%
Was mixed at room temperature, kneaded at 90-95 ° C., and cooled and pulverized to produce a molding material. This molding material
Transfer was injected into a mold heated to 170 ° C. and cured to form a molded product (sealed product). This molded article was tested for adhesion and moisture resistance of Pd and Pd-Au 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 Biphenyl type epoxy resin (epoxy equivalent: 215) 17%
Novolak type phenol resin (phenol equivalent 107
8), 0.06% of the above-mentioned dibutylthiourea of formula 3, 74% of silica powder and 0.3% of ester waxes 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 was formed.
Table 1 shows the results of a characteristic test of adhesion strength and moisture resistance of Pd and Au to a pre-plating frame. In particular, a remarkable effect of the present invention was observed in adhesive strength.

Example 3 Cresol novolak epoxy resin (epoxy equivalent: 215
19%, 9% of novolak type phenol aralkyl resin (phenol equivalent 107), 0.06% of dibutylthiourea of the above formula 3, 0.2% of γ-glycidoxypropyltrimethoxysilane, 71% of silica powder and 0.3% of ester wax Was 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 the adhesion and moisture resistance of Pd and Pd-Au to the pre-plating frame were tested. The results are shown in Table 1. In particular, a remarkable effect of the present invention was observed in adhesive strength.

Comparative Example Cresol novolak type epoxy resin (epoxy equivalent 21
5) Novolak type phenol resin (phenol equivalent 107) 9%, silica powder 71%, curing accelerator 0.3%, 19%
A molding material was manufactured in the same manner as in Example 1 by mixing 0.3% of the ester wax and 0.4% of the silane coupling agent. 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.

[0023]

[Table 1] * 1: A molded article having an adhesive 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 then the shear adhesive strength was determined. * 2: A molded article was prepared by transfer molding, post-cured at 175 ° C for 8 hours, and measured using a thermal equipment analyzer. * 3: Using a molding material, a silicon chip (test element) having two or more aluminum wirings is adhered to a Pd pre-plating frame, transfer molded at 175 ° C for 2 minutes, and QFP-208P, 2.8 make moldings mm ^t, which 175 ° C., was cured after 8 hours. The molded article thus obtained was previously prepared at 40 ° C., 90% RH, 100
After the moisture absorption treatment for a period of time, the mixture was passed four times through an IR reflow furnace at Max 240 ° C. Thereafter, PCT was performed in saturated steam at 127 ° C. and 2.5 atm, and a 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 adhesiveness with Pd and Pd-Au plated inserts and have an IR reflow. Without exfoliation even after, excellent in moisture resistance, as a result, it is possible to significantly reduce the occurrence of leakage current due to disconnection or moisture due to electrode corrosion,
Moreover, reliability can be guaranteed for a long period of time.

Continued on the front page (51) Int.Cl. ⁶ Identification code FI // (C08K 13/02 5: 405 3:00)

Claims (2)

[Claims] 1. An epoxy resin, (B) a novolak-type phenol resin, (C) dibutylthiourea and (D) an inorganic filler are essential components, and the dibutylthiourea of (C) is added to the resin composition. , And the inorganic filler of (D) in an amount of 25 to 95% by weight. 2. An epoxy resin, (B) a novolak-type phenol resin, (C) dibutylthiourea and (D) an inorganic filler are essential components, and the dibutylthiourea of (C) is added to the resin composition. Wherein the semiconductor chip is sealed with a cured product of a sealing resin composition containing 0.01 to 0.5% by weight and the inorganic filler (D) in a ratio of 25 to 95% by weight. Semiconductor sealing device.