JP3298084B2 - Sealing resin composition and semiconductor sealing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to Pd and Pd-Au
The present invention relates to an encapsulating resin composition and a semiconductor encapsulating apparatus having excellent reliability such as reflow crack resistance in a semiconductor package using a frame on which pre-plating has been performed.

[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] A conventional semiconductor device 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 has a problem in that an insert and a sealing resin are bonded. There was a drawback that the properties were extremely poor. In particular, when the semiconductor device that has absorbed moisture is surface-mounted, peeling occurs between the sealing resin and the lead frame or between the sealing resin and the semiconductor chip, causing significant moisture resistance deterioration, disconnection due to electrode corrosion, and leakage current due to moisture. 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 having excellent reflow resistance, less influence of moisture resistance, and less mold deterioration with good moldability.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned drawbacks and to meet the above-mentioned demands.
The present invention provides a sealing resin composition and a semiconductor sealing device having high adhesiveness to a pre-plating frame such as d or Pd-Au, and particularly having excellent reflow resistance and reliability after reflow, and having good moldability. What you want to do.

[0005]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above object, and as a result, by blending dipentanemethylene thiuram tetrasulfide into a resin composition, Pd, Pd-Au or the like has been obtained. It has been found that the above-mentioned object is achieved by greatly improving the adhesion to the pre-plating frame of the present invention, and the present invention has been completed.

That is, the present invention provides (A) an epoxy resin,
(B) Novolak type phenol resin, (C) dipentanemethylene thiuram tetrasulfide and (D) an inorganic filler are essential components, and the dipentanemethylene thiuram tetrasulfide of (C) is 0.001 to 0.001 to the resin composition. 0.1% by weight, and 25 to 95% by weight of the inorganic filler (D), and a curing resin composition. A semiconductor sealing device characterized by sealing a semiconductor chip mounted on a frame on which Pd or Pd-Au is pre-plated with an object.

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 (In the formula, 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 phenolic resin is such that the equivalent ratio [(a) / (b)] of the epoxy group (a) of the epoxy resin and the phenolic hydroxyl group (b) of the novolak type phenolic resin is 0.1 to 0.1.
It is desirable to be within the range of 10. 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.

The (C) dipentanemethylenethiuram tetrasulfide used in the present invention is represented by the following structural formula.

[0011]

Embedded image

In addition, sulfur and zinc oxide can be used in combination.

The mixing ratio of dipentanemethylenethiuram tetrasulfide is 0.001 to 0.001 to the entire resin composition.
It is desirable to contain 0.1% by weight. This ratio is 0.001
If the amount is less than 0.1% by weight, it has no effect on improving the adhesive strength with a pre-plating frame such as Pd or Pd-Au.
If the content exceeds% by weight, the impurity concentration is adversely affected, such as curing of the sealing resin, which 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, dipentanemethylenethiuram tetrasulfide and an inorganic filler as essential components. If necessary, for example, release agents such as natural waxes, synthetic waxes, metal salts of linear fatty acids, acid amides, esters, paraffins, chlorinated paraffins, brominated toluene, hexabromobenzene, trioxide Flame retardants such as antimony, coloring agents such as carbon black and red iron, various curing accelerators, and the like can be appropriately added and blended.

A general method for preparing the encapsulating resin composition of the present invention as a molding material includes an epoxy resin, a novolak type phenol resin, dipentanemethylenethiuram tetrasulfide, an inorganic filler and other components. After blending and mixing sufficiently uniformly with a mixer or the like, a melt-mixing treatment with a hot roll or a mixing treatment with a kneader or the like is further performed, followed by cooling and solidification, and pulverization into an appropriate size to obtain a molding material. 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 encapsulating apparatus of the present invention can be easily manufactured by encapsulating a semiconductor chip using the encapsulating 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.

[0018]

The resin composition for sealing and the semiconductor encapsulating device of the present invention can obtain desired characteristics by using dipentanemethylenethiuram tetrasulfide as a resin component. That is, it is possible to improve the adhesive strength with a pre-plating frame such as Pd or Pd-Au, prevent deterioration of the adhesiveness between the insert and the sealing resin after surface mounting, and guarantee long-term reliability. I was able to.

[0019]

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: 215
) 19%, 9% of novolak type phenol resin (phenol equivalent 107), 0.03% of dipentanemethylenethiuram tetrasulfide shown in the following chemical formula 3,

[0021]

Embedded image Fused silica powder (71%) and ester waxes (0.3%) were mixed at room temperature, kneaded at 90-95 ° C, and cooled and pulverized to produce a molding material. This molding material was transfer-injected into a mold heated to 170 ° C. and cured to produce a molded product (sealed product). Pd and A
Table 1 shows the results of testing the adhesive strength of u-Pd and the like to a pre-plating frame. 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%, 0.03% of dipentanemethylenethiuram tetrasulfide of the above 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 a characteristic test such as adhesion to a pre-plating frame such as Pd or Au-Pd was conducted. The results are shown in Table 1. 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 resin (phenol equivalent: 107), 0.04% of dipentanemethylenethiuram tetrasulfide of the above formula 3, 0.2% of γ-glycidoxypropyltrimethoxysilane, 71% of silica powder and ester-based Mix 0.3% of wax as in Example 1,
The mixture was kneaded and pulverized to produce a molding material. Further, a molded article was prepared in the same manner as in Example 1, and a characteristic test such as adhesion to a pre-plating frame such as Pd or Au-Pd was conducted. 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) 19%, 9% novolak type phenol resin (phenol equivalent 107), silica powder 71%, curing accelerator 0.3%,
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.

[0025]

[Table 1] * 1: A molded article having an adhesive area of 2 mm ² was prepared by transfer molding, and this was post-cured at 175 ° C. for 8 hours, and 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 subjected to 85 ° C., 40% RH, 168
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.

[0026]

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.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ identification code FI H01L 23/31 (58) Fields investigated (Int.Cl. ⁷ , DB name) C08L 63/00 H01L 23/28-23/31 C08G 59/62 C08K 3/00

Claims (2)

(57) [Claims] 1. An epoxy resin, (B) a novolak-type phenol resin, (C) dipentanemethylenethiuram tetrasulfide and (D) an inorganic filler as essential components. A) dipentane methylene thiuram tetrasulfide of 0.001 to 0.1% by weight; and the inorganic filler of (D) in a ratio of 25 to 95% by weight. 2. An epoxy resin, (B) a novolak-type phenol resin, (C) dipentanemethylenethiuram tetrasulfide and (D) an inorganic filler as essential components. The cured product of the encapsulating resin composition containing 0.001 to 0.1% by weight of dipentanemethylenethiuram tetrasulfide and 25 to 95% by weight of the inorganic filler of (D) described above)
Alternatively, a semiconductor sealing device characterized by sealing a semiconductor chip mounted on a frame on which Pd-Au pre-plating has been performed.