JP2000204138A - Sealing resin composition and sealed semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sealing resin composition and a sealed semiconductor device, which are difficultly affected by temperature in a heat cycle test after IR reflowing, enable the disconnection of electrodes or the like to remarkably be reduced and can ensure reliability concerning the surface contamination of a molded article for a long term. SOLUTION: This sealing resin composition includes (A) an epoxy resin, (B) a phenolic novolak resin, (C) a diallyl phthalate resin and (D) an inorganic filler, as essential ingredients. The ingredient C is an aggregate formed by the nonchemical binding of primary particles having <=0.5 μm average size and comprises globoids having <=80 μm average size of the aggregate. The contents of ingredients C and D are 0.1-5.0 wt.% and 25-90 wt.% both based on the weight of the resin composition, respectively. This sealed semiconductor device is produced by sealing a semiconductor chip with the resin composition, followed by curing the resin composition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an encapsulating resin composition and a semiconductor encapsulating apparatus having improved low stress properties and excellent continuous productivity.

[0002]

2. Description of the Related Art In recent years, along with the development of technologies for higher integration and higher reliability in the field of semiconductors and integrated circuits, automation of the mounting process of semiconductor devices has been promoted. For example, when attaching a flat package type semiconductor device to a circuit board, conventionally, soldering was performed for each lead pin.
Recently, a method has been adopted in which the entire semiconductor device is immersed in a solder bath heated to 250 ° C. and immersed in the solder all at once.

[0003] In a conventional semiconductor device sealed with a resin composition comprising an epoxy resin such as a novolak type epoxy resin, a novolak type phenol resin and an inorganic filler, when the entire device is immersed in a solder bath, the moisture resistance is reduced. There is a disadvantage that. In particular, when a semiconductor device that has absorbed moisture is immersed in a solder bath, peeling occurs between the sealing resin and the semiconductor chip, or between the sealing resin and the frame, and internal resin cracks occur, causing significant moisture resistance deterioration and corrosion of the electrodes. Leakage current occurs due to disconnection or moisture, and as a result, the semiconductor device has a disadvantage that long-term reliability cannot be guaranteed. For this reason, there has been a strong demand for the development of a material that has little influence on moisture resistance, has little moisture resistance deterioration even when the entire semiconductor device is subjected to surface mounting by immersion in a solder bath, and has good moldability.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned drawbacks, and has high heat resistance. In particular, moisture resistance and solder heat resistance after surface mounting by immersion in a solder bath, and moldability. It is an object of the present invention to provide an encapsulating fat composition and a semiconductor encapsulating device which are excellent in quality.

[0005]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above-mentioned object, and as a result, have found that the average particle size is not more than 0.1.
The low stress property is improved by blending a diallyl phthalate resin in which the primary particles having a particle size of 5 μm or less are formed by non-chemical bonds and the aggregate has a spherical shape having an average particle size of about 80 μm or less, and The inventors have found that a resin composition having excellent continuous productivity can be obtained, and have completed the present invention.

That is, the present invention provides (A) an epoxy resin,
(B) a novolak-type phenolic resin, and (C) a diallyl phthalate such as an aggregate formed by non-chemical bonding of primary particles having an average particle size of 0.5 μm or less, and having an average particle size of 80 μm or less. A resin and (D) an inorganic filler as essential components, and (C) an aggregate of non-chemical bonds of the primary particles having an average particle size of 0.5 μm or less with respect to the resin composition. A diallyl phthalate resin having a diameter of 80 μm or less and having a diameter of 0.
1 to 5.0% by weight, and 25% of the inorganic filler (D).
A sealing resin composition characterized by being contained in a proportion of about 90% by weight, and wherein a semiconductor pellet is sealed with a cured product of the sealing resin composition. Semiconductor sealing device.

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, bisphenol-type aromatic resins, aliphatic resins such as cyclohexane derivatives, and epoxy novolak resins represented by the following general formulas are exemplified.

[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. These 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,
Epoxidized or butylated novolak-type phenol resins and the like can be mentioned, and these can 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 and the phenolic hydroxyl group (b) of the novolak type phenol resin is 0.1 to 1;
It is desirable to be within the range of 0. If the equivalent ratio is less than 0.1 or exceeds 10, the 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) Average particle size of 0.5 μm used in the present invention
The following formula is an example of a diallyl phthalate resin comprising the following aggregates formed by non-chemical bonds of primary particles and having an average particle size of 80 μm or less.

[0012]

Embedded image (In the formula, a represents an integer of 1 or more, b represents 0 or an integer of 1 or more.) A preferable average particle diameter of the primary particles is 0.1 μm, and a preferable average particle diameter of the aggregate is 30 μm. Is exemplified. These can be used alone or in combination of two or more. Further, other organic or silicone elastomers can be used in combination.

[0013] The compounding ratio of the diallyl phthalate resin (C), which is an aggregate formed by non-chemical bonding of primary particles having an average particle size of 0.5 µm or less and whose aggregate has a spherical shape having an average particle size of 80 µm or less Is 0.1 to the entire resin composition.
Desirably, the content is 1 to 5.0% by weight. If this ratio is less than 0.1% by weight, there is no effect on low stress, and
If the content exceeds 5.0% by weight, moldability and the like and moldability and reflow crack resistance are adversely affected, which is unsuitable for practical use.

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 90% by weight based on the entire resin composition. If the proportion is less than 25% by weight, heat resistance, moisture resistance, soldering heat resistance, mechanical properties and moldability are deteriorated, and if it exceeds 90% by weight, burrs are increased and the moldability is poor and is not suitable for practical use. .

The sealing resin composition of the present invention comprises an epoxy resin, a novolak type phenol resin, and an average particle size of 0.1 μm.
The primary particles are aggregates formed by non-chemical bonds, and the average particle size of the aggregates is a diallyl phthalate resin such as a spherical body having a particle size of about 30 μm and an inorganic filler as essential components.
To the extent not contrary to the object of the present invention, and if necessary, release agents such as natural waxes, synthetic waxes, metal salts of linear fatty acids, acid amides, esters, paraffins, chlorinated paraffins Flame retardants such as brominated toluene, hexabromobenzene and antimony trioxide, coloring agents such as carbon black and red iron oxide, and various curing accelerators can be appropriately added and blended.

A general method for preparing the encapsulating resin composition of the present invention as a molding material includes the above-mentioned epoxy resin, novolak-type phenol resin, and non-primary primary particles having an average particle diameter of 0.1 μm. In an aggregate formed by chemical bonding, a diallyl phthalate resin, an inorganic filler, and other components having an average particle diameter of about 30 μm and consisting of a spherical body are selected and blended in a predetermined composition ratio, and sufficiently mixed with a mixer or the like. After uniform mixing, the mixture is further subjected to a melt-mixing process using a hot roll or a mixing process using a kneader or the like, and then 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 encapsulation device of the present invention can be easily manufactured by encapsulating a semiconductor chip using the above-described molding material. The semiconductor chip to be sealed is not particularly limited to, for example, an integrated circuit, a large-scale integrated circuit, a transistor, a thyristor, a diode, and the like. 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 molding material is heated and cured at the time of sealing, and finally a semiconductor sealing device sealed with the cured product is obtained. Curing by heating is 150
Desirably, the composition is cured by heating to a temperature of at least ℃.

[0018]

The epoxy resin composition and the semiconductor encapsulation device of the present invention have the above-mentioned specific average particle diameter of 0.5 as a resin component.
Aggregates of non-chemical bonds of primary particles of μm or less, the desired properties of which were obtained by using a diallyl phthalate resin having an average particle size of spherical particles of 80 μm or less. It is. Average particle size 0.5μm
The following primary particles are aggregates formed by non-chemical bonds, and the diallyl phthalate resin such that the average particle size of the aggregates is a spherical body having a particle size of 80 μm or less improves the low stress property of the resin composition, Deterioration of the reliability of the pellet due to the aluminum slide etc. could be prevented.

[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 type epoxy resin (epoxy equivalent 2
15) 18%, 9% of novolak type phenol resin (phenol equivalent 107), average particle size 0.1 μm represented by the following formula
1.0% diallyl phthalate resin, which is an aggregate formed by non-chemical bonds of primary particles of m, and has an average particle size of about 30 μm.

[0021]

Embedded image 71% fused silica powder and ester waxes
3% was blended, mixed at room temperature, kneaded at 90-95 ° C., and cooled and pulverized to produce a molding material of Example 1.

Example 2 Cresol novolak type epoxy resin (epoxy equivalent 2
15) 9% of novolak type phenol resin (phenol equivalent: 107) at 19%, aggregates of non-chemical bonds of primary particles having an average particle size of 0.1 μm shown in the above formula 3, and the average of the aggregates 4.0% of diallyl phthalate resin having a particle diameter of about 30 μm, 71% of silica powder
And 0.3% of ester waxes were mixed and pulverized in the same manner as in Example 1 to produce a molding material of Example 2.

Example 3 Cresol novolak type epoxy resin (epoxy equivalent 2
15) 9% of novolak type phenol resin (phenol equivalent: 107) at 19%, aggregates of non-chemical bonds of primary particles having an average particle size of 0.1 μm shown in the above formula 3, and the average of the aggregates 8.0% of diallyl phthalate resin having a particle diameter of about 30 μm, 0.2% of γ-glycidoxypropyltrimethoxysilane, silica powder 71
% And ester waxes were mixed and pulverized in the same manner as in Example 1 to produce a molding material of Example 3.

Comparative Example 1 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, 0.3% of ester wax and 0.4% of silane coupling agent at room temperature The mixture was mixed and pulverized in the same manner as in Example 1 to produce a molding material of Comparative Example 1.

Examples 1 to 3 thus produced and Comparative Example 1
After transfer molding at 175 ° C. for 3 minutes using the molding material described above, after-cure was performed at 180 ° C. for 8 hours to produce a test piece. For these molding materials and test pieces, moldability, spiral flow, melt viscosity using an elevated flow tester, water absorption (PCT), glass transition temperature, bending properties, temperature cycle test (TCT), and surface contamination of molded products by continuous molding And (continuous productivity) were measured. The above results are summarized in Table 1, and a remarkable effect of the present invention could be confirmed.

[0026]

[Table 1] * 1: Measurement temperature of spiral and melt viscosity is 175 ° C. * 2: The molding material was subjected to transfer molding at 175 ° C. for 3 minutes, and after-cured at 180 ° C. for 8 hours to produce a molded product. This was allowed to stand in saturated steam at 127 ° C. and 2 atm for 24 hours, and the weight was increased. * 3: From a molded article similar to the test for water absorption, 2.5 × 2.
A sample having a size of 5 × (15.0 to 20.0) was prepared, and a thermomechanical analyzer DL-1500H (manufactured by Vacuum Riko Co., Ltd.)
(Product name) at a heating rate of 5 ° C./min. * 4: 5.4 x 10 from a molded product similar to the test for water absorption
A sample having a size of × 100 is prepared and a bending tester AG
22 ° C using D1000 (trade name, manufactured by Shimadzu Corporation)
Was measured. * 5: Using a molding material, a silicon chip having two aluminum wirings was bonded to a normal 42 alloy frame and transfer-molded at 175 ° C. for 2 minutes.
Post-curing was performed at 175 ° C. for 8 hours. The molded article thus obtained was previously subjected to a moisture absorption treatment at 40 ° C., 90% RH and 100 hours, and then placed in an IR reflow furnace having a maximum temperature of 240 ° C.
I passed. Then, at -65 ° C for 20 minutes → 25 ° C for 2.
A temperature cycle test (TCT) was performed in which a cycle of 5 minutes → 150 ° C. for 20 minutes was performed, and the time at which a disconnection failure due to resin stress occurred was evaluated. . * 6: The molding material is 15 mm at 175 ° C. for 3 minutes.
The element for evaluation having a size of 15 mm was sealed and after-cured at 180 ° C. for 8 hours. The package is then
After leaving it in an atmosphere of 40 ° C. and a relative humidity of 40% for 168 hours to perform a moisture absorption treatment, it was passed through an IR reflow furnace at a maximum temperature of 240 ° C. three times. At this point, the occurrence of cracks in the package was examined. * 7: Automatic molding machine VPS-80N (TOW)
A (manufactured by A Co., Ltd.), and was continuously molded at 175 ° C. for 120 seconds, and the stain on the molded product surface was evaluated.

[0027]

As is clear from the above description and Table 1, the encapsulating resin composition and the semiconductor encapsulating apparatus of the present invention are hardly affected by the temperature even in the temperature cycle test after IR reflow, Can be significantly reduced, and reliability can be guaranteed for a long period of time. In addition, continuous production can be ensured for a long period of time with respect to surface contamination of a molded product.

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Claims (2)

[Claims] 1. An epoxy resin, (B) a novolak type phenol resin, and (C) a resin having an average particle diameter of 0.5 μm or less.
An aggregate formed by a non-chemical bond of the next particles, and the diallyl phthalate resin and the inorganic filler (D), which are composed of a spherical body having an average particle diameter of 80 μm or less, are essential components. (C) an average particle size of 0.5 μm
m to 0.1 to 5.0% by weight of an aggregate formed by non-chemical bonds of primary particles having an average particle diameter of 80 μm or less. A) a sealing resin composition comprising an inorganic filler in a ratio of 25 to 90% by weight. 2. An epoxy resin, (B) a novolak type phenol resin, and (C) a resin having an average particle size of 0.5 μm or less.
An aggregate formed by non-chemical bonding of the secondary particles, and a diallyl phthalate resin having an average particle diameter of 80 μm or less as a spherical body and (D) an inorganic filler are essential components. (C) Average particle size 0.5 μm
0.1 to 5.0% by weight of a diallyl phthalate resin which is composed of spherical particles having an average particle diameter of 80 μm or less in the following aggregates of non-chemical bonds of primary particles: A semiconductor sealing device, wherein a semiconductor pellet is sealed with a cured product of a sealing resin composition containing an inorganic filler at a ratio of 25 to 90% by weight.