JPH1112441A - Sealing resin composition and sealed semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the adhesion between a resin composition and a frame pre-plated particularly with, e.g. Pd or Pd-Au, improve the reflowing resistance of a sealed semiconductor device, prevent the moisture deterioration after reflowing, and provide a highly reliable sealed semiconductor device. SOLUTION: This sealing resin composition comprises essentially an epoxy resin (A), a novolak phenolic resin (B), sulfur (C), and an inorganic filler (D), wherein the contents of component C and component D respectively are 0.001-0.1 wt.% and 25-95 wt.% based on the resin composition. The semiconductor device is made by sealing a semiconductor chip with this composition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to Pd, Au, Ag
The present invention relates to an epoxy resin composition excellent in reliability such as reflow crack resistance in a semiconductor package using a 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 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 (IT) reflow method, peeling occurs between the sealing resin and the lead frame or between the sealing resin and the semiconductor chip, causing significant 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 The inventors of the present invention have made intensive studies to achieve the above object, and as a result, by blending sulfur into a resin composition, it has become possible to prepare Pd, Pd-Au, Ag, etc. The present invention has been completed by finding that the above-mentioned object is achieved by greatly improving the adhesiveness to the bearing frame.

That is, the present invention provides (A) an epoxy resin,
(B) Novolak type phenol resin, (C) sulfur and (D) an inorganic filler are essential components, and 0.0001 to 0.05% by weight of the sulfur of the above (C) to the resin composition; A sealing resin composition comprising an inorganic filler in 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 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 Or butylated novolak type phenolic resin and the like,
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)] 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. Examples of (C) sulfur used in the present invention include S ₈ represented by the following structural formula, regardless of the type of transformation.

[0010]

Embedded image Further, zinc oxide can be used in combination with another vulcanization accelerator.

The content of sulfur is desirably 0.0001 to 0.05% by weight based on the whole resin composition. If this ratio is less than 0.0001% by weight, Pd, Pd-Au, Ag
It has no effect on improving the adhesive strength to the pre-plating frame, and if it exceeds 0.05% 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, sulfur 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,
Release agents such as synthetic waxes, metal salts of linear fatty acids, acid amides, esters, and paraffins; flame retardants such as chlorinated paraffins, brominated toluene, hexabromobenzene, and antimony trioxide; carbon black; And various curing accelerators and the like can be appropriately added and blended.

As a general method for preparing the encapsulating resin composition of the present invention as a molding material, an epoxy resin, a novolak-type phenol resin, sulfur, an inorganic filler and other components are blended, and a mixer or the like is used. After the mixture is sufficiently uniformly mixed, a melt-mixing treatment using a hot roll or a mixing treatment using a kneader or the like is further performed, and then the mixture is cooled and solidified, and pulverized to 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 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]

The sealing resin composition and the semiconductor sealing device of the present invention can obtain desired characteristics by using sulfur as a resin component. That is, the sulfur improves the adhesive strength of the resin composition to the pre-plating frame of Pd, Pd-Au, Ag, etc., and can improve the reliability of the semiconductor package such as reflow crack resistance.

[0017]

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%, novolak type phenol resin (phenol equivalent 107) 9%, α sulfur 0.01% shown in the following chemical formula 3,

[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%, 0.01% of α-sulfur of the above formula 3, silica powder 74
% 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 and Pd-Au
Table 1 shows the results of the tests for the characteristics of adhesion and moisture resistance to the 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 a novolak type phenol aralkyl resin (phenol equivalent 107), 0%
012%, γ-glycidoxypropyltrimethoxysilane
0.2%, silica powder 71% and ester wax 0.3
% 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.
It was shown to. 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 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.

Claims (2)

[Claims] An essential component of (A) an epoxy resin, (B) a novolak type phenol resin, (C) sulfur and (D) an inorganic filler, and 0.0001 of said sulfur of (C) to a resin composition. A resin composition for encapsulation, comprising 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) sulfur and (D) an inorganic filler are essential components, and the sulfur of (C) is 0.0001 relative to the resin composition. A semiconductor chip encapsulated with a cured product of an encapsulating resin composition containing the inorganic filler of (D) at a ratio of 25 to 95% by weight. Sealing device.