JP3145687B2 - Epoxy resin composition and semiconductor encapsulation device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an epoxy resin composition having excellent moldability and a semiconductor encapsulation device.

[0002]

2. Description of the Related Art In a semiconductor integrated circuit, the power consumption of transistors constituting the integrated circuit during its operation causes
Heat is generated around the element. Designing a semiconductor device and designing a system in order to keep the temperature around the element below an allowable temperature is extremely important in terms of performance and reliability of the semiconductor element.

[0003]

In order to efficiently release the heat generated in the peripheral portion of the element to the outside of the semiconductor device, the thickness of the resin in the vicinity of the heat generating portion of the sealing resin is reduced, and particularly the thickness of the resin is reduced to the rear surface portion. Designs such as reducing the thickness of the resin have been made. This causes an extreme deviation in the thickness of the resin inside the semiconductor device. On the other hand, in the sealing resin material,
In order to improve thermal conductivity, an inorganic filler is highly filled, or a crystalline silica filler having high thermal conductivity is used. However, with this, the fluidity of the sealing resin in a molten state has been significantly reduced.

[0004] For these reasons, there have been problems such as a reduction in moldability such as the occurrence of external cavities and unfilled portions during resin casting, and a reduction in yield accompanying this.

According to the present invention, in order to solve the above-mentioned drawbacks, even when the thickness of the resin of the semiconductor sealing device is thin and the thickness is extremely uneven, the sealing is performed while maintaining the thermal conductivity. The purpose is to improve the moldability of the resin composition for use.

[0006]

Means for Solving the Problems The present inventors have conducted intensive studies to achieve the above object, and as a result, have used a specific epoxy resin of a sealing resin composition and a specific urea resin as a curing accelerator. As a result, they have found that a resin composition having excellent moldability and dimensional stability can be obtained while maintaining thermal conductivity, thereby completing the present invention.

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

Embedded image (Wherein, R1 to R4 represent a hydrogen atom or an alkyl group, and n represents an integer of 1 or more) (B) a phenolic resin, (C) a urea-based curing accelerator represented by the following structural formula:

Embedded image (D) A crystalline silica powder or a fused silica powder having a maximum particle diameter of 100 μm or less is an essential component, and the silica powder of (D) is contained in a proportion of 30 to 90% by weight based on the whole resin composition. Epoxy resin composition. In addition, by the cured product of this epoxy resin composition,
A semiconductor sealing device, wherein a semiconductor element is sealed.

Hereinafter, the present invention will be described in detail.

As the epoxy resin (A) used in the present invention, those represented by the following formula (5) are used. Examples of the epoxy resin include an o-cresol novolak type epoxy resin, a biphenyl type epoxy resin, and a dicyclo epoxy resin. Pentadiene-based resins and other generally known epoxy resins can be used in combination.

The phenolic resin (B) used in the present invention is not particularly limited as long as it has two or more phenolic hydroxyl groups in the molecule that can react with the epoxy group of the epoxy resin (A). As specific compounds, for example,

Embedded image (Where n represents an integer of 1 or more)

Embedded image (Where n represents an integer of 1 or more)

Embedded image (Where n represents an integer of 1 or more)

Embedded image (Wherein, n represents 0 or an integer of 1 or more), and these can be used alone or in combination of two or more.

The urea-based curing accelerator (C) used in the present invention is represented by Chemical Formula 6, which can be used alone or as a mixture. Known phosphorus-based curing accelerators, imidazole-based curing accelerators, and DBU-based curing accelerators can be used in combination with (C) a urea-based curing accelerator.

In the present invention, (D) a crystalline silica powder or a fused silica powder having a maximum particle diameter of 100 μm or less has a low impurity concentration and a median diameter of 30 μm or less. If the median diameter exceeds 30 μm, the moldability is remarkably deteriorated, which is not preferable. Crystalline silica powder and fused silica powder can be used alone or in combination,
The mixing ratio is preferably such that the weight of the silica powder is 25 to 90% by weight based on the entire resin composition. If the proportion is less than 25% by weight, the thermal conductivity of the resin composition is low and the hygroscopicity is high, so that the heat dissipation and humidity resistance of the semiconductor device are inferior. 90% by weight
If it exceeds, the moldability is extremely poor, which is not preferable.

The epoxy resin composition of the present invention contains the above-mentioned specific epoxy resin, phenol resin, specific urea-based curing accelerator, crystalline silica powder having a maximum particle diameter of 100 μm or less or fused silica powder as essential components. A release agent such as a natural wax and a synthetic wax, a flame retardant such as antimony trioxide and a brominated epoxy resin, and a coloring agent such as carbon black. A low stress imparting agent such as a rubber-based or silicone-based polymer, a coupling agent such as an amine-modified or epoxy-modified silicone oil, or 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 the above-mentioned epoxy resin, phenol resin, a specific urea-based curing accelerator and crystalline silica powder having a maximum diameter of 100 μm or less. Fused silica powder and other components are blended and mixed sufficiently uniformly with a mixer, etc., and further heated and mixed with a hot roll or kneader, and then solidified by cooling and pulverized to an appropriate size to form a molding material. be able to. If the molding material thus obtained is applied to sealing, covering, insulating, etc. of electronic parts or electric parts including semiconductor devices, it is possible to impart excellent properties such as moldability and reliability.

The semiconductor sealing device of the present invention can be easily manufactured by sealing a semiconductor element using the above molding material. The semiconductor element to be sealed is not particularly limited, for example, with an integrated circuit, a large-scale integrated circuit, a transistor, a thyristor, a diode, and the like. The most common method of sealing is transfer molding, but sealing by injection molding, compression molding or the like is also possible. When the resin is sealed and heated to cure the resin after the sealing, the temperature is preferably set to 150 ° C. or higher.

[0016]

The epoxy resin composition and the semiconductor device of the present invention are characterized in that the epoxy resin composition described above uses a specific other functional epoxy resin and a specific urea-based curing accelerator having a low activity to form a curing reaction. By controlling the speed and maintaining the reactivity at the molding temperature, it is possible to maintain a state in which the melt viscosity of the entire epoxy resin composition is low below that temperature. Thereby, the moldability can be improved while maintaining the heat dissipation of the semiconductor device.

[0017]

Next, the present invention will be described by way of examples. The present invention is not limited by these examples.
In the following Examples and Comparative Examples, “%” means “% by weight”.

Example 1 A total of 82.0% of a fused silica powder and a crystalline silica powder having a maximum particle size of 100 μm or less, epoxy resin (EOCN-102, manufactured by Nippon Kayaku Co., trade name, n =
8.75% of the phenol novolak resin of the above formula (H-4, Meiwa Kasei Co., Ltd.)
Ltd., trade name, n = 2.3~2.7) 2.90%, the chemical formula 6 in the urea-based curing accelerator (U-CAT3503N, Sa
N'apuro trade name) 0.124%, 1.30% tetrabromobisphenol A type epoxy resin, 0.23% carnauba wax, carbon black 0.150%,
And 1.00% of antimony trioxide and 3.55% of a silicone oil such as a coupling agent and a low stress additive are mixed at room temperature, melt-kneaded at 90 to 110 ° C., then cooled and pulverized to form a molding material. Was manufactured.

Example 2 A total of 82.0% of a fused silica powder and a crystalline silica powder having a maximum particle diameter of 100 μm or less, an epoxy resin (EOCN-102, manufactured by Nippon Kayaku Co., trade name, n =
8.70%, phenol novolak resin of the above formula (H-4, Meiwa Kasei Co., Ltd.)
Ltd., trade name, n = 2.3~2.7) 2.88%, the chemical formula 6 in the urea-based curing accelerator (U-CAT3503N, Sa
0.745 %, tetrabromobisphenol A type epoxy resin 1.29%, carnauba wax 0.229%, carbon black 0.149
%, And antimony trioxide 0.994%, other silicone oils such as coupling agents and low stress additives 3.5
3% was mixed at room temperature, melt-kneaded at 90 to 110 ° C., and then cooled and pulverized to produce a molding material.

Comparative Example 1 A total of 81.5% of a fused silica powder and a crystalline silica powder having a maximum particle size of 100 μm or less, 8.85% of the epoxy resin shown in Chemical formula 5, and 2.97 of the phenol novolak resin of Chemical formula 7 above %, Phosphorus-based curing accelerator 0.120%, tetrabromobisphenol A type epoxy resin 1.80%, carnauba wax 0.120%, carbon black 0.1%.
210%, 1.10% of antimony trioxide, 3.33% of a silicone oil such as a coupling agent and a low stress additive are mixed at room temperature, melt-kneaded at 90 to 110 ° C., and then cooled and pulverized. To produce a molding material.

Comparative Example 2 A total of 82.0% of a fused silica powder and a crystalline silica powder having a maximum particle size of 100 μm or less, 8.35% of the epoxy resin shown in Chemical formula 5, and 2.95 of the phenol novolak resin of Chemical formula 7 above %, Imidazole-based curing accelerator 0.205
%, Tetrabromobisphenol A type epoxy resin
30%, carnauba wax 0.150%, carbon black 0.150%, and antimony trioxide 1.00
%, 3.90% of a silicone oil such as a coupling agent and a low-stress additive, and the like at room temperature.
After melt-kneading at 0 ° C., the mixture was cooled and pulverized to produce a molding material.

Using the molding material thus produced,
Various tests were conducted on the fluidity, curability, and heat dissipation at 75 ° C., and the results are shown in Table 1. In order to compare the time for maintaining a low-viscosity molten state at a molding temperature of 175 ° C. or lower, 165 was used for Example 1 and Comparative Example 1.
FIG. 1 shows the time dependence of the viscosity at ° C. In addition, in order to compare the moldability, transfer molding is performed on the transistor semiconductor device TO-3PH in which the ratio of the resin thickness between the upper part and the lower part of the element is extremely changed in order to improve the heat radiation property. Table 1 shows the comparison of the numbers.

[0023]

[Table 1] * 1: The spiral flow at 175 ° C. was measured according to EMMI-I-66.

* 2: When a certain amount of molding material is spread in a circle having a diameter of 4 to 5 cm on a hot plate kept at 175 ° C. and kneaded at a constant speed, the sample thickens and finally becomes viscous. The missing time was measured.

* 3: Koka flow viscosity was measured at 175 ° C.

* 4: Transfer molded at 175 ° C., a molded product having a thickness of φ100 and a thickness of 25 mm was prepared, and measured by using a rapid thermal conductivity measuring device.

* 5: 80 transistor semiconductor devices
Transfer molding was performed using the molding material, and the number of semiconductor devices having cavities on the surface thereof was counted.

[0028]

As is apparent from the above description and Table 1 and FIG. 1, the epoxy resin composition and the semiconductor device of the present invention maintain the curability at the molding temperature and the melt viscosity at the molding temperature or lower. Therefore, it is possible to obtain a semiconductor molding material which improves moldability while maintaining heat dissipation, and a semiconductor device using the same.

[Brief description of the drawings]

FIG. 1 is a graph showing a comparison of a low-viscosity molten state maintaining time at 165 ° C. between Example 1 of the present invention and Comparative Example 1.

Continuation of the front page (51) Int.Cl. ⁷ identification code FI H01L 23/29 H01L 23/30 R 23/31 (58) Investigated field (Int.Cl. ⁷ , DB name) C08G 59/32 C08G 59 / 62 C08G 59/40 C08L 63/04 C08K 3/36 H01L 23/29

Claims (2)

(57) [Claims] (A) a polyfunctional epoxy resin represented by the following general formula: (Wherein, R1 to R4 represent a hydrogen atom or an alkyl group, and n represents an integer of 1 or more) (B) a phenolic resin, (C) a urea-based curing accelerator represented by the following structural formula, and 2] (D) A crystalline silica powder or a fused silica powder having a maximum particle size of 100 μm or less is an essential component, and the silica powder of (D) is contained in a proportion of 30 to 90% by weight based on the whole resin composition. Epoxy resin composition. (A) a polyfunctional epoxy resin represented by the following general formula: (Wherein, R1 to R4 are a hydrogen atom or an alkyl group, and n is an integer of 1 or more) (B) a phenolic resin, (C) a urea-based curing accelerator represented by the following structural formula: (D) an epoxy resin composition containing a crystalline silica powder or a fused silica powder having a maximum particle size of 100 μm or less as an essential component, and containing the silica powder of (D) in a proportion of 30 to 90% by weight based on the entire resin composition. A semiconductor sealing device, wherein a semiconductor element is sealed with a cured product.