JPH11121658A - Sealing resin composition and semiconductor sealing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To significantly reduce disconnection due to corrosion of an electrode and occurrence of leak current due to water content, etc., while excellent in anti-reflow characteristics and moisture resistance, by, using a specific epoxy resin and phenol resin, comprising an inorganic filler at specific wt.% against the entire resin composition. SOLUTION: A material expressed by an equation I is used as epoxy resin and a material expressed by an equation II is used as phenol resin. Here, n is an integer equal to 0 or 1, or above. As an inorganic filler, that of low impurity concentration, maximum particle size 100 μm or less, and average particle size 30 μm or less is used. Related to a blend-percentage of the inorganic filler, it should be comprises by 25-95 wt.% against the entire resin composition. Then, epoxy resin, phenol resin, and inorganic filler, etc., are blended, which is sufficiently mixed uniformly using a blender, etc., and then melt-mixing by hot roll and mixing process by kneader, etc., are performed, and then cooled for solidification and crushed to an appropriate size, thus a molding material provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to moldability, workability,
The present invention relates to a sealing resin composition having excellent 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 The inventors of the present invention have conducted intensive studies to achieve the above-mentioned object, and as a result, by using a specific epoxy resin and a specific phenol resin, it has become possible to obtain moisture resistance, reflow resistance and molding resistance. It has been found that a highly reliable resin composition having excellent properties and workability can be obtained, and the present invention has been completed.

That is, the present invention provides: (A) an epoxy resin represented by the following formula:

[0007]

Embedded image (B) a phenolic resin represented by the following general formula:

[0008]

Embedded image (Where n represents 0 or an integer of 1 or more) (C)
An encapsulating resin composition comprising an inorganic filler as an essential component and containing the inorganic filler (C) in a ratio of 25 to 95% by weight based on the entire resin composition. .
Further, there is provided a semiconductor sealing device wherein a semiconductor chip is sealed with a cured product of the sealing resin composition.

Hereinafter, the present invention will be described in detail.

As the epoxy resin (A) used in the present invention, those represented by the above formula (5) are used.

The phenol resin (B) used in the present invention is represented by the above formula (6) or n of formula (6).
Are used as a suitable mixture of zero and one or more.

As the inorganic filler (C) 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, silicon nitride 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. It is preferable to mix the inorganic filler so that the inorganic filler is contained in an amount of 25 to 95% by weight based on the entire 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 and moldability deteriorates, 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 encapsulating resin composition of the present invention as a molding material is to mix an epoxy resin of the above formula (5), a phenol resin of the above formula (6), an inorganic filler, and other components with a mixer. After the mixture is sufficiently homogeneously mixed by a method such as the above, a melt-mixing treatment using a hot roll or a mixing treatment 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. When the molding material thus obtained is applied to sealing, covering, insulating, etc. of electronic parts or electric parts including semiconductor devices, excellent properties 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.

[0016]

According to the epoxy resin composition and the semiconductor encapsulation device of the present invention, the use of a specific epoxy resin or a specific phenol resin as the resin component improves the moldability of the resin composition and the bonding strength with the frame. In particular, the reflow resistance corresponding to each stage of the moldability was significantly improved.

[0017]

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 6.2% of an epoxy resin of the above formula (epoxy equivalent: 175),
The phenol resin of the above formula (phenol equivalent: 196) 6.8
%, Triphenylphosphine 0.1%, fused silica powder 85
% 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 (A).

Example 2 4.8% of the epoxy resin of the above formula (epoxy equivalent: 175),
Phenol resin of the above formula (phenol equivalent: 196) 5.2
%, Triphenylphosphine 0.1%, fused silica powder 88
% 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).

Comparative Example 1 o-cresol novolak epoxy resin (epoxy equivalent
195) 8.4%, novolak-type phenol resin (phenol equivalent 107) 4.6%, fused silica powder 88%, triphenylphosphine 0.1%, ester wax 0.3% and silane coupling agent 0.4% were mixed at room temperature. After kneading and cooling at 90-95 ° C, pulverize to form a molding material (C)
Was manufactured.

Comparative Example 2 Biphenyl type epoxy resin (epoxy equivalent 193) 5.3
%, Aralkylphenol resin (phenol equivalent 175)
4.7%, fused silica powder 88%, triphenylphosphine
0.1% 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 (D).

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.

[0023]

[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.) 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.

[0024]

As apparent from the above description and Table 1, the encapsulating resin composition and the semiconductor encapsulating apparatus of the present invention are excellent in reflow resistance and moisture resistance, and are affected by moisture absorption even after IR reflow. In addition, disconnection due to corrosion of the electrode, generation of leakage current due to moisture, and the like can be significantly reduced, and reliability can be guaranteed for a long period of time.

Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08L 63/00

Claims (2)

[Claims] (A) an epoxy resin represented by the following formula: (B) a phenolic resin represented by the following general formula: (In the formula, n represents 0 or an integer of 1 or more.) (C) An inorganic filler is an essential component, and the inorganic filler of (C) is 25 to 95% by weight based on the whole resin composition. The resin composition for sealing characterized by containing in the ratio of. (A) an epoxy resin represented by the following formula: (B) a phenolic resin represented by the following general formula: (In the formula, n represents 0 or an integer of 1 or more.) (C) An inorganic filler is an essential component, and the inorganic filler of (C) is 25 to 95% by weight based on the whole resin composition. Wherein the semiconductor chip is sealed with a cured product of the sealing resin composition contained at a ratio of: