JPH10245472A - Epoxy resin composition, and semiconductor sealing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an epoxy resin composition excellent in moisture resistance, reflow resistance, moldability, etc., used for a semiconductor sealing device, etc., and high in reliability, by using a rosin compound having a specific structure. SOLUTION: This epoxy resin composition consists essentially of (A) an epoxy resin, (B) a phenol resin, (C) a rosin compound including a structure of the formula and (D) an inorganic filler (e.g. fused silica powder) and includes 0.05-10.0wt.% component C and 25-93wt.% component D based on the total resin composition. For example, a cresol novolak epoxy resin is used as the component A and a novolak phenol resin, etc., are used as the component B.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an epoxy resin composition excellent in moldability, reflow resistance and reliability, and a semiconductor sealing device.

[0002]

2. Description of the Related Art In recent years, in the field of semiconductor integrated circuits,
At the same time as the development of high integration and high reliability technologies, automation of the mounting process of semiconductor devices has been promoted. For example, when a flat package type semiconductor device is mounted on a circuit board, soldering has conventionally been performed for each lead pin, but recently, the entire semiconductor device has been heated to a maximum temperature of 240 ° C.
A method of soldering through a reflow furnace is employed.

[0003]

A semiconductor device encapsulated with a resin composition comprising a conventional epoxy resin such as a novolak type epoxy resin, a novolak type phenol resin, and an inorganic filler requires surface mounting of the entire device by IR reflow. There is a drawback that the moisture resistance is reduced when performing.
In particular, when the semiconductor device that has absorbed moisture is subjected to IR reflow, peeling between the sealing resin and the semiconductor chip, or between the sealing resin and the lead frame, and cracks in the internal resin occur, causing significant deterioration in moisture resistance, and disconnection due to corrosion of the electrodes. There is a drawback that a long-term reliability cannot be guaranteed due to a leak current caused by moisture or moisture. For this reason, there has been a strong demand for the development of a material having a small influence on moisture resistance and a good moldability with little moisture resistance deterioration even when the entire semiconductor device is surface-mounted by IR reflow.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned disadvantages, and has a small influence of moisture absorption. In particular, it has excellent moisture resistance, reflow resistance, and moldability after surface mounting by IR reflow, and has excellent sealing resin. An epoxy resin composition that can guarantee long-term reliability without peeling between the semiconductor chip or the sealing resin and the lead frame and without generation of internal resin cracks, and also without occurrence of disconnection due to electrode corrosion and generation of leak current due to moisture. It is intended to provide a semiconductor sealing device.

[0005]

Means for Solving the Problems As a result of intensive studies to achieve the above object, the present inventor has found that by using a rosin compound having a specific structure, moisture resistance, reflow resistance, moldability and the like are improved. The inventors have found that an excellent and highly reliable resin composition can be obtained, and have completed the present invention.

That is, the present invention provides (A) an epoxy resin,
(B) a phenolic resin, (C) a rosin compound having the following structure and

[0007]

Embedded image (D) The inorganic filler is an essential component, and the rosin compound of (C) is 0.05 to 10.0% by weight and the inorganic filler of (D) is 25 to 93% by weight based on the whole resin composition. It is an epoxy resin composition characterized by containing. In addition, by the cured product of this epoxy resin composition,
A semiconductor sealing device characterized by a semiconductor chip being sealed.

Hereinafter, the present invention will be described in detail.

As long as the epoxy resin (A) used in the present invention is a compound having at least two epoxy groups in its molecule, there is no particular restriction on its molecular weight, structural formula, etc. What is used as can be widely used. For example, epoxy resins such as bisphenol type aromatics, alicyclics such as cyclohexane derivatives, and epoxy novolaks represented by the following general formulas are exemplified.

[0010]

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. It can be mixed and used.

The phenolic resin (B) used in the present invention includes, for example, phenol novolak resin, cresol novolak resin, tert-butylphenol novolak resin, nonylphenol novolak resin, bisphenol F novolak resin, bisphenol A novolak resin, and naphthol novolak resin. Phenol aralkyl resin such as a condensation polymerization compound of 2,2'-dimethoxy-p-xylene and phenol monomer, or a phenol aralkyl resin such as polyparaoxystyrene such as polyparaoxystyrene; Tris (hydroxyphenyl) alkane-based compounds and the like.

[0012]

Embedded image (Wherein, R ¹ and R ² represent a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, which may be the same or different, and R ³ is a single bond or methylene, ethylene or the like) These represent an alkylene group. These can be used alone or in combination of two or more.

The compounding ratio of the novolak type phenol resin is determined by the molar ratio [(a) / () of the epoxy group (a) of the epoxy resin (A) and the phenolic hydroxyl group (b) of the novolak type phenol resin (B). b)] is preferably in the range of 0.1 to 10. When the molar 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.

In the present invention, a rosin compound having the structure of formula 3 is used. As specific compounds, for example, Pine Crystal KR-85, KR-612, KE-604,
KE-100, KE-359, KE-311N, KE-
No. 601, KE-615-3 (trade name, manufactured by Arakawa Chemical Industries, Ltd.) and the like, and these can be used alone or in combination of two or more. It is desirable to use the rosin compound in a proportion of 0.05 to 10.0% by weight based on the whole resin composition. If the amount is less than 0.05% by weight, the reflow resistance is not affected.
Exceeding the range adversely affects moldability and reliability, and is not suitable for practical use and is not preferred.

As the inorganic filler (D) used in the present invention, an inorganic filler having a low impurity concentration, a maximum particle diameter of 100 μm or less, and an average particle diameter of 30 μm or less is preferably used.
If the average particle size exceeds 30 μm, the moisture resistance and moldability are poor, which is not preferable. Specific examples of the inorganic filler include, for example, silica powder, alumina powder, antimony trioxide, talc, calcium carbonate, titanium white, clay, mica, redwood, glass fiber, and the like. It can be mixed and used. Among these, silica powder and alumina powder are particularly preferable and are often used. It is preferable that the inorganic filler is blended so as to contain 25 to 93% 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,
On the other hand, when the content exceeds 93% by weight, burrs increase and the moldability is poor, which is not suitable for practical use.

In the epoxy resin composition of the present invention,
To the extent not contrary to the object of the present invention, and if necessary, for example, 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, rubber-based and silicone-based low-stress imparting agents, and the like can be appropriately added and blended.

A general method for preparing the epoxy resin composition of the present invention as a molding material is to mix an epoxy resin, a novolak-type phenol resin, a rosin compound having the structure of the above formula (3), an inorganic filler and other components, After sufficiently uniform mixing by a mixer or the like, a melt-mixing process using a hot roll or a mixing process using a kneader or the like is performed, and then the mixture is solidified by cooling and pulverized to an appropriate size to obtain a molding material. The molding material thus obtained is
When applied to sealing, coating, insulating, and the like of electronic components or electric components such as semiconductor devices, excellent characteristics and reliability can be imparted.

Further, the semiconductor sealing device of the present invention can be easily manufactured by sealing a semiconductor chip using the molding material described above. As a semiconductor chip 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. 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. After sealing with a molding material, it is heated and cured, and finally a semiconductor sealing device sealed with the cured product is obtained. Curing by heating is desirably performed by heating at a temperature of 150 ° C. or higher.

[0019]

The epoxy resin composition and the semiconductor encapsulation device of the present invention use an epoxy resin, a phenol resin and a specific rosin compound as a resin component, so that the moldability of the resin composition and the bonding strength with the frame are improved. In particular, the reflow resistance corresponding to each stage of the moldability was significantly improved.

[0020]

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 21
5) 18%, 9% novolak type phenol resin (phenol equivalent 107) 9%, ROS-100 KE-100 (Arakawa Chemical Industries, trade name) 1.0%, triphenylphosphine 0.1%
1%, fused silica powder 71% and ester waxes 1.9% were mixed at room temperature, kneaded and cooled at 90-95 ° C, and pulverized to produce a molding material (A).

Example 2 Cresol novolak epoxy resin (epoxy equivalent 21
5) 19%, novolak type phenol resin (phenol equivalent 107) 8%, rosin compound KE-100 (supra) 3.
0%, triphenylphosphine 0.1%, fused silica powder
71% and 1.9% of ester waxes and the like were mixed at room temperature, kneaded and cooled at 90 to 95 ° C, and then pulverized to produce a molding material (B).

Example 3 Biphenyl type epoxy resin (epoxy equivalent: 193) 7.0
%, Novolak type phenolic resin (phenol equivalent 10
7) 3.7%, rosin compound KE-100 (supra) 3.0
%, Triphenylphosphine 0.1%, fused silica powder 85
% And 1.1% of ester waxes and the like were mixed at room temperature, kneaded and cooled at 90 to 95 ° C., and then pulverized to produce a molding material (C).

Comparative Example 1 Cresol novolak epoxy resin (epoxy equivalent 21
5) 19%, 9% of novolak type phenol resin (phenol equivalent: 107), 71% of fused silica powder, 0.1% of triphenylphosphine, 0.3% of ester-based wax and 0.4% of silane-based coupling agent are mixed at room temperature. 90 ~
After kneading and cooling at 95 ° C., the mixture was pulverized to produce a molding material (D).

Comparative Example 2 Biphenyl type epoxy resin (epoxy equivalent: 193) 8.8
%, Novolak type phenolic resin (phenol equivalent 10
7) 4.9%, fused silica powder 85%, triphenylphosphine 0.1%, and ester waxes etc. 1.1% are mixed at room temperature, kneaded and cooled at 90-95 ° C, and then pulverized to form a molding material (E). Was manufactured.

The molding materials (A) to (D) thus produced
After transfer molding at 175 ° C for 3 minutes, a test piece was prepared by aftercure at 180 ° C for 8 hours. For these molding materials and test pieces, moldability,
Spiral flow, melt viscosity by a Koka type flow tester, water absorption (PCT), glass transition temperature, adhesive strength to 42 alloy and copper alloy as a frame material, PCT and reflow resistance were measured. The above measurement results are summarized in Table 1, and the remarkable effect of the present invention was confirmed.

[0027]

[Table 1] * 1: The temperature for measuring spiral and melt viscosity is 175 ° C. * 2: The molding material was transfer-molded at 175 ° C for 3 minutes, and after-cured at 180 ° C for 8 hours to produce a molded product. This is placed in saturated steam at 127 ° C and 2 atm.
Allowed for time and determined by increased weight. * 3: 2.5 × 2.5 × from the same molded product as in the water absorption test
A sample having a size of 15.0 to 20.0 was prepared, and a thermomechanical analyzer DL-1500H (manufactured by Vacuum Riko Co., Ltd.) was used.
It measured at ° C / min. * 4: Using a molding material, a silicon chip with 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 5 ° 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.
It was immersed in a solder bath at 0 ° C. for 10 seconds. Thereafter, a moisture resistance test was performed in saturated steam at 127 ° C. and 2.5 atm to evaluate the time at which 50% disconnection (defect occurrence) due to aluminum corrosion occurred. * 5: The molding material is 15mm x 15mm at 175 ° C for 3 minutes.
The mm evaluation element was sealed and after-cured at 180 ° C. for 8 hours. Next, the package was left in an atmosphere at 85 ° C. and a relative humidity of 60% for 168 hours to perform a moisture absorption treatment, and then passed through an IR reflow furnace having a maximum temperature of 240 ° C. three times. At this point, the occurrence of cracks in the package was examined. Further, the package after the IR reflow was left in a saturated steam atmosphere at 127 ° C. for 100 to 1000 hours in a pressure cooker, and the occurrence rate of defects was examined.

[0028]

As is clear from the above description and Table 1, the epoxy resin composition and the semiconductor encapsulation device of the present invention have excellent reflow resistance and moisture resistance, and are less affected by moisture absorption even after IR reflow. In addition, disconnection due to electrode corrosion and occurrence of leakage current due to moisture can be significantly reduced, and reliability can be guaranteed for a long period of time.

Claims (2)

[Claims] (A) an epoxy resin, (B) a phenolic resin, (C) a rosin compound having the following structure, and (D) The inorganic filler is an essential component, and the rosin compound of (C) is 0.05 to 10.0% by weight and the inorganic filler of (D) is 25 to 93% by weight based on the whole resin composition. An epoxy resin composition characterized by comprising: (A) an epoxy resin, (B) a phenolic resin, (C) a rosin compound having the following structure, and (D) The inorganic filler is an essential component, and the rosin compound of (C) is 0.05 to 10.0% by weight and the inorganic filler of (D) is 25 to 93% by weight based on the whole resin composition. A semiconductor sealing device wherein a semiconductor chip is sealed with a cured product of an epoxy resin composition contained therein.