JP2002060466A - Epoxy resin composition and sealed semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an epoxy resin composition which is excellent in package warp, moldability, resistance to soldering heat during mounting, resin crack resistance, or the like; and to provide a one-side-sealed BGA-type semiconductor device SOLUTION: The resin composition essentially contains (A) an epoxy resin containing (a) a polyfunctional epoxy resin having a bisphenol A backbone and (b) an epoxy resin having a naphthol backbone in a weigh ratio of (a)/(b) of 0.1-2.0, (B) a phenol resin containing (c) a polyfunctional phenol resin and (d) a naphthol phenol resin in a weight ratio of (c)/(d) of 0.1-2.0, (C) an inorganic filler, and (D) a cure accelerator. The inorganic filler is contained in an amount of 25-95 wt.% of the composition. The one-side-sealed BGA-type semiconductor device is prepared by sealing with a cured item of the composition.

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 package warpage, moldability and soldering heat resistance, and a single-sided BGA (Ball Grid Array) in which a semiconductor chip is sealed with the composition. Mold sealing device.

[0002]

2. Description of the Related Art In recent years, in the field of semiconductor integrated circuits,
While the size and the number of electrodes are increasing with the increase in the degree of integration of chips, the demand for smaller and lighter package outer diameters is increasing, especially in portable information communication devices. Therefore, the QFP (Quad) in which the leads are arranged around
In Flat Package, the narrowing of the pitch due to the increase in the number of electrodes is accelerated, and the current 0.3 mm electrode pitch has reached the limit of batch reflow soldering.

[0003] Accordingly, the movement to the BGA type in which the leads are arranged in an area array on the lower surface of the package and the electrode pitch is kept at 1.5 to 1.0 mm to facilitate the soldering has been in the United States since several years ago. It has been active in the center.

However, when a BGA type package is sealed with a resin composition comprising a conventional epoxy resin such as a novolak type epoxy resin, a novolak type phenol resin, and silica powder for one-side sealing, the package warpage occurs. Had the disadvantage of being large. In addition, there is a disadvantage that the wire flows during molding due to the long loop of the bonding wire.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned drawbacks, and has a small package warpage, good flowability, excellent moldability, and
To provide an epoxy resin composition and a semiconductor encapsulation device that are excellent in solder heat resistance during mounting, have no resin cracks, have good adhesion, are excellent in moisture resistance after mounting, and can guarantee long-term reliability. Is what you do.

[0006]

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 specific epoxy resin and a specific phenol resin, the package is less warped, and A resin composition with good fluidity, excellent moldability, excellent solder heat resistance during mounting, no resin cracking, good adhesion, and excellent moisture resistance after mounting is obtained. Thus, the present invention has been completed.

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

Embedded image (Wherein, R ¹ , R ² , and R ³ represent a hydrogen atom or a carbon atom 1)
(B) an epoxy resin having a naphthol skeleton represented by the following general formula:

Embedded image (However, in the formula, R ¹ and R ² are a hydrogen atom or a C ¹ to C 1
(A) an alkyl group of 0, n represents an integer of 0 to 10) in a weight ratio of component (a) / component (b) of 0.1 to
(B) (c) a polyfunctional phenol resin represented by the following general formula:

Embedded image (Where R represents a hydrogen atom, a methyl group, an ethyl group, a propyl group, a butyl group, or a combination of two or more of a t-butyl group, and n represents an integer of 0 to 10, respectively) (D) a phenolic resin having a naphthol skeleton represented by the following general formula:

Embedded image (Wherein, R ¹ and R ² represent one or a combination of two or more of a hydrogen atom, a methyl group, an ethyl group, a propyl group, a butyl group and a t-butyl group, and n represents 0 to 10). And the weight ratio of component (c) / (d)
The phenol resin containing the component at a ratio of 0.1 to 2.0, (C) an inorganic filler and (D) a curing accelerator are essential components, and the (C) inorganic filler is added to the resin composition in an amount of 25%. An epoxy resin composition characterized in that it is contained in a proportion of up to 95% by weight. Still another aspect of the present invention is a semiconductor encapsulation apparatus characterized in that the epoxy resin composition is a cured product of a single-sided BGA type in which a semiconductor chip is encapsulated.

Hereinafter, the present invention will be described in detail.

As the polyfunctional epoxy resin (A) (a) having a bisphenol A skeleton used in the present invention, those represented by the aforementioned general formula 9 are used. As specific compounds, for example,

Embedded image

Embedded image And the like.

The epoxy resin having a naphthol skeleton (A) or (b) used in the present invention is represented by the general formula
Are used. As specific compounds,
For example,

Embedded image (Wherein, n represents an integer of 1 to 10).

By using (A) an epoxy resin in combination with (a) a polyfunctional epoxy resin having a bisphenol A skeleton and (b) an epoxy resin having a naphthol skeleton, a high glass transition temperature, high fluidity, and high adhesion can be obtained. Can be made possible.

In the present invention, (a) a polyfunctional epoxy resin having a bisphenol A skeleton and (b) an epoxy resin having a naphthol skeleton, the weight ratio of the polyfunctional epoxy resin / naphthol epoxy resin is from 0.1 to 0.1. 2.0,
Preferably, it is used in a ratio of 0.2 to 0.7. When the weight ratio is less than 0.1, an increase in water absorption, high viscosity, and a decrease in adhesive strength occur. When the weight ratio exceeds 2.0, the glass transition temperature decreases.

Further, in addition to (a) a polyfunctional epoxy resin and (b) a naphthol epoxy resin, an epibis epoxy resin, a brominated epoxy resin, a biphenyl type epoxy resin, a novolak type epoxy resin, and modified resins thereof are further added. can do. In this case, it is preferable that the total of the polyfunctional epoxy resin (a) and the naphthol epoxy resin (b) be 10% by weight or more, particularly 40 to 100% by weight of the entire epoxy resin mixture.

As the polyfunctional phenolic resin (B) (c) used in the present invention, those represented by the aforementioned general formula 11 are used. As specific compounds, for example,

Embedded image (Where n represents an integer from 0 to 10)

Embedded image (Where n represents an integer of 0 to 10).

The phenolic resin (B) (d) having a naphthol skeleton used in the present invention is represented by the general formula 1
The one indicated by 2 is used. As specific compounds, for example,

Embedded image (Where n represents an integer from 0 to 10)

Embedded image (Where n represents an integer of 0 to 10).

In the case of (B) a phenolic resin, by using (c) a polyfunctional phenolic resin and (d) a phenolic resin having a naphthol skeleton, a high glass transition temperature, a high glass transition temperature, a high fluidity, High adhesiveness can be made possible.

In the present invention, (c) a polyfunctional phenol resin having a bisphenol A skeleton and (d) a phenol resin having a naphthol skeleton have a weight ratio of polyfunctional phenol resin / naphthol phenol resin of 0.1 to 0.1.
It is used at a ratio of 2.0, preferably 0.2 to 0.7.
When the weight ratio is less than 0.1, an increase in water absorption, high viscosity, and a decrease in adhesive strength occur. When the weight ratio exceeds 2.0, the glass transition temperature decreases.

As the inorganic filler (C) used in the present invention, generally used fillers are widely used. Among them, silica powder having a low impurity concentration and an average particle diameter of 30 μm or less is preferably used. Can be. If the average particle size exceeds 30 μm, the moisture resistance and the moldability are poor, which is not preferable. 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, the resin composition has a large hygroscopicity, is inferior in moisture resistance after solder immersion, and
If it exceeds 5% by weight, the fluidity becomes extremely poor and the moldability is poor, which is not preferred.

The (D) curing accelerator used in the present invention includes a phosphorus-based curing accelerator, an imidazole-based curing accelerator,
BU-based curing accelerators and other curing accelerators are widely used. These can be used alone or in combination of two or more. The mixing ratio of the curing accelerator is 0.1 to the resin composition.
It is desirable to mix them so as to contain from 01 to 5% by weight. If the proportion is less than 0.01% by weight, the gel time of the resin composition is long, the curing properties are deteriorated, and 5% by weight.
If it exceeds, the fluidity becomes extremely poor and the moldability is inferior, and the electrical properties also deteriorate, and the moisture resistance is inferior.

The epoxy resin composition of the present invention contains the above-mentioned specific epoxy resin, the specific phenol resin, the inorganic filler and the curing accelerator as essential components. Depending on, for example, natural waxes, synthetic waxes, metal salts of linear fatty acids, acid amides, esters, release agents such as paraffins, flame retardants such as antimony trioxide, carbon black,
A coloring agent such as redwood, a silane coupling agent, a rubber-based or silicone-based low-stress imparting agent, and the like can be appropriately added and blended.

As a general method for preparing the epoxy resin composition of the present invention as a molding material, a specific epoxy resin, a specific phenol resin, an inorganic filler, a curing accelerator and other components described above are added to a predetermined component. After blending the raw material components selected in the composition ratio and mixing sufficiently uniformly with a mixer or the like, further perform a melt mixing treatment with a hot roll or a mixing treatment with a kneader or the like, then solidify by cooling, and pulverize to an appropriate size. It can be 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 encapsulating apparatus of the present invention can be easily manufactured by encapsulating a semiconductor chip using the above-mentioned 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 ℃. The substrate on which the chip is mounted can be ceramic, plastic,
Examples include, but are not limited to, polyimide films and lead frames.

[0023]

The epoxy resin composition and the semiconductor encapsulation device of the present invention use the specific epoxy resin and the specific phenol resin described above to achieve a thermal expansion while maintaining a high glass transition temperature of the resin composition. By reducing the coefficient and having high fluidity, thermomechanical properties and low stress properties are improved to suppress package warpage, good moldability, resin cracks after solder immersion and solder reflow And the deterioration of the moisture resistance is reduced.

[0024]

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, “parts” means “parts by weight”.

Example 1 4.8 parts of the epoxy resin of Chemical Formula 14 described above,
1.3 parts of an epoxy resin (n = 1) of Formula 5, 2.3 parts of a phenol resin of Formula 17 (n = 0), 1.7 parts of a phenol resin of Formula 19 (n = 0), 87 parts of fused silica powder, 0.2 parts of 2-methylimidazole as curing accelerator, 0.3 parts of carnauba wax and 0.4 of epoxysilane coupling agent
The parts were mixed at room temperature, kneaded at 90-95 ° C., and cooled and pulverized to produce a molding material (A).

Example 2 3.5 parts of the epoxy resin of Chemical Formula 14 used in Example 1 and 2.0 of the epoxy resin of Chemical Formula 15 used in Example 1 (n = 1)
Parts, phenol resin of Chemical Formula 17 (n = 0) 2.0 parts, Chemical Formula 1
2.1 parts of phenol resin (n = 0), 87 parts of fused silica powder, and 0.2 of 2-methylimidazole as a curing accelerator
Part, carnauba wax 0.3 part and epoxysilane coupling agent 0.4 part were mixed at room temperature, and 90 to 9 parts were further mixed.
The mixture was kneaded at 5 ° C. and cooled and pulverized to produce a molding material (B).

Comparative Example 1 An o-cresol novolak type epoxy resin (softening point 80
11 ° C., epoxy equivalent 200) 11 parts, novolak phenol resin (softening point 80 ° C., hydroxyl equivalent 104) 3 parts, fused silica powder 85 parts, curing accelerator 2-methylimidazole 0.3 parts, carnauba wax 0.3 Parts and 0.4 part of an epoxysilane coupling agent,
Kneaded at ~ 95 ° C, cooled and pulverized to form a molding material (C)
Was manufactured.

Comparative Example 2 11 parts of epibis epoxy resin (Epicoat 828)
3 parts of novolak type phenolic resin (softening point: 80 ° C., hydroxyl equivalent: 104), 85 parts of fused silica powder, 0.3 part of 2-methylimidazole as a curing accelerator, 0.3 part of carnauba wax, and 0.1 part of epoxysilane coupling agent. 4 parts were mixed, further kneaded at 90 to 95 ° C., and cooled and pulverized to produce a molding material (D).

The molding materials (A) to (D) thus produced
Was transferred into a mold heated to 175 ° C., cured, and the semiconductor chip was sealed to manufacture a semiconductor sealing device. Various tests were performed on these semiconductor sealing devices, and the results are shown in Table 1. The epoxy resin composition and the semiconductor sealing device of the present invention have little package warpage, fluidity, moisture resistance, The solder heat resistance was excellent, and the remarkable effect of the present invention could be confirmed.

[0030]

[Table 1] * 1: A molded article having a diameter of 50 mm and a thickness of 3 mm was prepared by transfer molding, left in a saturated steam at 127 ° C. and 2.5 atm for 24 hours, and measured by the increased weight.

* 2: A molded article was prepared in the same manner as in the case of the water absorption rate, post-cured at 175 ° C. for 8 hours, a test piece of an appropriate size was measured using a thermomechanical analyzer.

* 3: Tested according to JIS-K-6911.

* 4: Using a molding material, a silicon chip having two aluminum wirings was bonded to a normal BGA frame, transfer-molded at 175 ° C. for 2 minutes, and after 8 hours at 175 ° C. Curing was performed. The molded product thus obtained was subjected to a moisture resistance test 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: A 10 × 10 mm dummy chip is BG
A (30 × 30 × 1.2 mm) package, transfer molding was performed at 175 ° C. for 2 minutes using a molding material, and post-curing was performed at 175 ° C. for 8 hours. After the thus-manufactured semiconductor encapsulation device was subjected to a moisture absorption treatment at 30 ° C., 60% for 196 hours, IR reflow at 240 ° C. was performed for 30 seconds to evaluate the occurrence of package cracks.

* 6: 10 × 10 mm dummy chip is BG
A (30 × 30 × 1.2 mm) package, transfer molding was performed at 175 ° C. for 2 minutes using a molding material, and post-curing was performed at 175 ° C. for 8 hours. The amount of warpage of the semiconductor sealing device manufactured as described above was measured by a non-contact laser measuring device.

[0036]

As apparent from the above description and Table 1, the epoxy resin composition and the semiconductor encapsulation device of the present invention have a small package warpage, good flowability, excellent moldability, In addition, it has excellent solder heat resistance during mounting,
There is no resin crack, good adhesion, excellent moisture resistance after mounting, and long-term reliability can be guaranteed.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01L 23/31 F term (Reference) 4J002 CC03Y CC06Z CD04X CD05W DJ016 EU117 EU137 FD016 FD14Y FD14Z FD157 GJ02 4J036 AD08 AF05 DC41 DC46 FA04 FA05 FA12 FB08 JA07 4M109 AA01 BA01 BA03 BA05 CA21 EA03 EB03 EB04 EB06 EB07 EB08 EB09 EB12 EC01 EC03 EC04 EC05

Claims (2)

[Claims] (A) (a) a polyfunctional epoxy resin having a bisphenol A skeleton represented by the following general formula: (Wherein, R ¹ , R ² , and R ³ represent a hydrogen atom or a carbon atom 1)
(B) an epoxy resin having a naphthol skeleton represented by the following general formula: (However, in the formula, R ¹ and R ² are a hydrogen atom or a C ¹ to C 1
(A) an alkyl group of 0, n represents an integer of 0 to 10) in a weight ratio of component (a) / component (b) of 0.1 to
(B) (c) a polyfunctional phenol resin represented by the following general formula: (Where R represents a hydrogen atom, a methyl group, an ethyl group, a propyl group, a butyl group, or a combination of two or more of a t-butyl group, and n represents an integer of 0 to 10, respectively) (D) a phenolic resin having a naphthol skeleton represented by the following general formula: (Wherein, R ¹ and R ² represent one or a combination of two or more of a hydrogen atom, a methyl group, an ethyl group, a propyl group, a butyl group and a t-butyl group, and n represents 0 to 10). And the weight ratio of component (c) / (d)
The phenol resin containing the component at a ratio of 0.1 to 2.0, (C) an inorganic filler and (D) a curing accelerator are essential components, and the (C) inorganic filler is added to the resin composition in an amount of 25%. An epoxy resin composition characterized in that it is contained in a proportion of up to 95% by weight. (A) (a) a polyfunctional epoxy resin having a bisphenol A skeleton represented by the following general formula: (Wherein, R ¹ , R ² , and R ³ represent a hydrogen atom or a carbon atom 1)
(B) an epoxy resin having a naphthol skeleton represented by the following general formula: (However, in the formula, R ¹ and R ² are a hydrogen atom or a C ¹ to C 1
(A) an alkyl group of 0, n represents an integer of 0 to 10) in a weight ratio of component (a) / component (b) of 0.1 to
(B) (c) a polyfunctional phenol resin represented by the following general formula: (Where R represents a hydrogen atom, a methyl group, an ethyl group, a propyl group, a butyl group, or a combination of two or more of a t-butyl group, and n represents an integer of 0 to 10, respectively) (D) a phenolic resin having a naphthol skeleton represented by the following general formula: (Wherein, R ¹ and R ² represent one or a combination of two or more of a hydrogen atom, a methyl group, an ethyl group, a propyl group, a butyl group and a t-butyl group, and n represents 0 to 10). And the weight ratio of component (c) / (d)
The phenol resin containing the component in a ratio of 0.1 to 2.0, (C) an inorganic filler and (D) a curing accelerator are essential components, and the (C) inorganic filler is added to the resin composition in an amount of 25 to 25%. A single-side encapsulated B in which a semiconductor chip is encapsulated with a cured product of an epoxy resin composition contained at a ratio of about 95% by weight.
A semiconductor encapsulation device characterized by being a GA type.