JP2001214039A - Epoxy resin composition and sealed semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an epoxy resin composition excellent in moldability and solder heat resistance with a slight influence of moisture absorption and capable of reducing the production of a leak current due to breakage of wires by corrosion of electrodes and moisture and to provide a sealed semiconductor device. SOLUTION: This epoxy resin composition consists essentially of (A) an epoxy resin, (B) a phenol resin, (C) a silane coupling agent represented by the following general formula and having epoxy groups or amino groups R1-CnH2n-Si(OR2)3, (D) an aluminum nitride powder having <=150 μm maximum grain diameter and (E) a curing accelerator using a phosphorus-based and an amine-based accelerators in combination. The aluminum nitride powder which is the component (D) is contained in an amount of 25-90 wt.% based on the whole resin composition. The sealed semiconductor device is obtained by sealing a semiconductor chip with a cured product of the composition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an epoxy resin composition excellent in moisture resistance, solder heat resistance, moldability and thermal conductivity, and a semiconductor encapsulation 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, a solder immersion method or a solder reflow method has been adopted.

[0003]

A semiconductor device sealed 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 is subjected to solder bath immersion of the entire device. There is a disadvantage that the moisture resistance is reduced. In particular, when a semiconductor device that has absorbed moisture is immersed, peeling between the sealing resin and the semiconductor chip, or between the sealing resin and the lead frame, and internal cracking of the resin occur, causing significant deterioration in moisture resistance. Leakage current occurs, and as a result, the semiconductor device has a disadvantage that long-term reliability cannot be guaranteed.

[0004] In addition, by increasing the amount of the inorganic filler, the proportion of the resin component can be reduced to reduce the moisture absorption of the resin composition.
Not only is the fluidity significantly impaired, but also the interface between the organic component such as a resin and the inorganic filler is increased, so that the internal resin cracks propagate along the interface to the external resin cracks.

[0005] Further, due to the increase in the amount of heat generated by the semiconductor element accompanying the high integration, a material having good thermal conductivity is required not only for the package structure but also for the sealing material.
Aluminum nitride powder has higher thermal conductivity than fused silica powder, so high thermal conductivity can be expected when it is used as a filler.However, when aluminum nitride powder is used as a filler, Properties and solder heat resistance could not be obtained.

The present invention has been made in order to solve the above-mentioned disadvantages, and has a small influence of moisture absorption. In particular, it has excellent moisture resistance after solder bath immersion, excellent solder heat resistance, moldability, fluidity, and a sealing resin. Epoxy that can guarantee long-term reliability without peeling of semiconductor chip or sealing resin from lead frame and internal resin cracks, no breakage of electrodes due to corrosion of electrodes, no leakage current due to moisture, and mold wear. An object is to provide a resin composition and a semiconductor sealing device.

[0007]

Means for Solving the Problems The present inventors have made intensive studies to achieve the above object, and as a result, in an epoxy resin composition, a specific silane coupling agent, aluminum nitride powder, and two types of curing accelerators. It has been found that by using an agent, a resin composition having excellent moisture resistance, solder heat resistance, moldability, fluidity, etc. can be obtained, and the present invention has been completed.

That is, the present invention provides (A) an epoxy resin,
(B) a phenolic resin, (C) a silane coupling agent having an epoxy group or an amino group represented by the following general formula,

Embedded image R ¹ —C _n H _2n —Si (OR ² ) ₃ (wherein R ¹ is an atomic group having an epoxy group or an amino group, R ² is a methyl group or an ethyl group, and n is 0) Or 1
(D) the aluminum nitride powder having a maximum particle size of 150 μm or less, (E) a phosphorus-based curing accelerator and an amine-based curing accelerator as essential components, and the above-mentioned ( An epoxy resin composition comprising the aluminum nitride powder (D) in a proportion of 25 to 90% by weight. A semiconductor sealing device is characterized in that a semiconductor chip is sealed with a cured product of the epoxy resin composition.

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 and molecular weight as long as it is a compound having at least two epoxy groups in one molecule, and is generally used as a sealing material. Can be widely encompassed. For example, an aliphatic system such as a cyclohexane derivative, a novolak type (formula 4), a biphenyl type (formula 5), a dicyclopentadiene type (formula 6), a naphthalene type (formula 7) represented by the following general formula, a polyfunctional system (Chemical Formulas 8 and 9), and aromatic epoxy resins such as bisphenol F type (formula 10) and bisphenol A type (formula 11). Among them, biphenyl type epoxy resins and dicyclopentadiene type epoxy resins are preferred.

[0011]

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

Embedded image (Wherein, R represents a hydrogen atom, a methyl group, an ethyl group, a propyl group, a butyl group or a t-butyl group)

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

Embedded image

Embedded image (Wherein, R ¹ , R ² , and R ³ represent a hydrogen atom, a methyl group, an ethyl group, a propyl group, a butyl group, and a t-butyl group, and n represents an integer of 1 or more)

Embedded image

Embedded image

Embedded image These epoxy resins can be used alone or in combination of two or more.

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 capable of reacting with the epoxy group of the epoxy resin (A). Absent. As specific compounds, for example,

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

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

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

Embedded image (However, n represents 0 or an integer of 1 or more)

Embedded image (Where n represents 0 or an integer of 1 or more). These can be used alone or in combination of two or more.

As the silane coupling agent (C) having an epoxy group or an amino group used in the present invention, those represented by the above-mentioned general formula 3 can be used. Specifically, for example,

Embedded image

Embedded image

Embedded image H ₂ N—C ₃ H ₆ Si (OCH ₃ ) _{3 and the} like can be used, and these can be used alone or in combination.

The aluminum nitride powder (D) used in the present invention has a low impurity concentration and a maximum particle size of 150 μm.
The following are preferably used: In particular, those coated on the surface with silica or phosphoric acid are preferred. Further, in order to increase the filling amount of the filler, the impurity concentration is low and the maximum particle size is 10%.
Fused silica powder, spherical alumina powder, and silicon nitride powder of 0 μm or less can be used in combination. These fillers preferably have an average particle size of 30 μm or less. More preferably, it is 10 μm or less. If the average particle size exceeds 30 μm, the moisture resistance and the moldability are poor, which is not preferable. It is preferable that the aluminum nitride powder is blended so as to contain 25 to 90% by weight based on the whole resin composition. When the proportion is less than 25% by weight, the resin composition has a high hygroscopicity and is inferior in moisture resistance after immersion in solder, and when it exceeds 90% by weight, the fluidity is extremely deteriorated and the moldability is inferior. A silane coupling agent was added to these aluminum nitride powders, and immediately a Henschel mixer,
When the treatment is performed with a super mixer or the like, the surface treatment can be uniformly performed, and the effect can be sufficiently exhibited.

As the (E) curing accelerator used in the present invention, a phosphorus-based curing accelerator and an amine-based curing accelerator are used in combination. Examples of the phosphorus-based curing accelerator include triphenylphosphine, methyldiphenylphosphine, tris (2,6-dimethoxyphenyl) phosphine, tributylphosphine, and the like. Amine-based curing accelerators include 2-methylimidazole, 2-heptadecylimidazole, 2,4-diamino-6- (2-undecylimidazolyl) -ethyl-s-triazine, 1,2-alkylenebenzimidazole, , 8-diazabicycloundecene, dimethylcyclohexylamine and the like. In particular, a combination of a phosphorus-based curing accelerator and an amine-based curing accelerator having a melting point of 100 ° C. or higher or an amine-based curing accelerator obtained by heat-kneading with a lubricant having a softening point of 100 ° C. or higher in advance is preferable.

It is desirable that the curing accelerator be incorporated in an amount of 0.01 to 5% by weight based on the whole resin composition. If the proportion is less than 0.01% by weight, the gel time of the resin composition is long, and the curing properties are significantly deteriorated. On the other hand, if it exceeds 5% by weight, the fluidity becomes extremely poor and the moldability is poor, and the electrical properties are also poor and the moisture resistance is poor.

The epoxy resin composition of the present invention comprises an epoxy resin, a phenol resin, a specific silane coupling agent,
Aluminum nitride powder and a phosphorus-based hardening accelerator and an amine-based hardening accelerator are essential components, but as far as they do not contradict the purpose of the present invention, and if necessary, for example, natural waxes, synthetic waxes, metals of fatty acids, etc. Salts, acid amides,
A release agent such as esters and paraffin, a flame retardant such as antimony trioxide, a coloring agent such as carbon black, a rubber-based or silicone-based low-stress imparting agent, 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 as follows: epoxy resin, phenol resin, the above-mentioned specific silane coupling agent, aluminum nitride powder, phosphorus-based curing accelerator and amine-based After blending the curing accelerator and other components and mixing them sufficiently uniformly with a mixer, etc., they are further melt-mixed with a hot roll or mixed with a kneader, then cooled and solidified and pulverized to an appropriate size and molded. It can be a 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. 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. After sealing with a molding material, it is heated and cured, and finally a semiconductor sealing device sealed with this cured product is obtained. Curing by heating is desirably performed by heating to 175 ° C. or higher.

[0020]

The epoxy resin composition and the semiconductor encapsulation device of the present invention use an epoxy resin, a phenol resin, a specific silane coupling agent, an aluminum nitride powder, a phosphorus-based curing accelerator and an amine-based curing accelerator.
The effect can be obtained. By using aluminum nitride powder having a maximum particle size of 150 μm or less, high filling can be achieved without impairing fluidity, interface strength between organic and inorganic components is increased, water absorption of the resin composition is reduced, moldability,
Fluidity is improved, resin cracking after solder immersion and solder reflow is eliminated, good thermal conductivity is exhibited, and deterioration of moisture resistance is reduced.

[0021]

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 77% of aluminum nitride powder (maximum particle diameter of 150 μm or less, average particle diameter of 20 μm) and 10% of fine fused spherical silica powder (average particle diameter of 0.5 μm) were put into a Henschel mixer and stirred. Meanwhile, 0.4% of the above-mentioned silane coupling agent of Chemical Formula 17 was added.

Next, 5.0% of the above-mentioned biphenyl type epoxy resin (R = CH ₃ ) of formula 5, 1.0% of tetrabromobisphenol A type epoxy resin, 1.2% of phenol novolak resin of the above formula 12, 2.5% of the above-mentioned phenol aralkyl resin of Chemical formula 13, 0.15% of tris (2,6-dimethoxyphenyl) phosphine, 0.10% of 1,2-trimethylenebenzimidazole, 0.4% of carnauba wax, carbon 0.3% of black and 2.0% of antimony trioxide are added and mixed at room temperature.
After kneading and cooling at １００100 ° C., the mixture was pulverized to produce a molding material.

Example 2 77% of aluminum nitride powder (maximum particle size of 150 μm or less, average particle size of 20 μm) and 10% of fine fused spherical silica powder (average particle size of 0.5 μm) were put into a Henschel mixer and stirred. Meanwhile, 0.4% of the above-mentioned silane coupling agent of Chemical Formula 18 was added.

Next, 5.0% of the above-mentioned biphenyl type epoxy resin (R = CH ₃ ) of formula 5, 1.0% of tetrabromobisphenol A type epoxy resin, 1.2% of phenol novolak resin of the above formula 12, 2.5% of the above-mentioned phenol aralkyl resin of Chemical Formula 13, 2.5% of the dicyclopentadiene-modified phenol resin of Chemical Formula 14, 0.1% of triphenylphosphine, 0.06% of 1,2-trimethylenebenzimidazole, Carnauba wax 0.4
%, Carbon black 0.3% and antimony trioxide 2.0% were added and mixed at room temperature, kneaded and cooled at 90 to 100 ° C., and then pulverized to produce a molding material.

Example 3 57% of aluminum nitride powder (maximum particle size of 150 μm or less, average particle size of 20 μm), 10% of fine fused spherical silica powder (average particle size of 0.5 μm), and spherical alumina powder (maximum particle size of 0.5 μm) 20.0%) was placed in a Henschel mixer, and 0.1% of the above-mentioned silane coupling agent of formula 17 and 0.3% of the silane coupling agent of formula 19 were added with stirring.

Next, 5.0% of the above-mentioned biphenyl type epoxy resin (R = CH ₃ ) of formula 5, 1.0% of tetrabromobisphenol A type epoxy resin, 1.2% of phenol novolak resin of the above formula 12, Triphenylphosphine 0.1%, 2,4-diamino-6- (2-undecylimidazolyl) -ethyl-s-triazine 0.1%, carnauba waxes 0.4%, carbon black 0.3%
And 2.0% of antimony trioxide are added and mixed at room temperature,
Further, after kneading and cooling at 90 to 100 ° C., the mixture was pulverized to produce a molding material.

Example 4 70% of aluminum nitride powder (maximum particle size of 150 μm or less, average particle size of 20 μm) and 10% of fine fused spherical silica powder (average particle size of 0.5 μm) were put into a Henschel mixer and stirred. Meanwhile, 0.4% of the above-mentioned silane coupling agent of Chemical Formula 17 was added.

Next, 7.0% of the above-mentioned dicyclopentadiene-type epoxy resin of Chemical formula 6, 1.0% of tetrabromobisphenol A-type epoxy resin, 1.7% of the above-mentioned phenol novolak resin of Chemical formula 12, and phenol of Chemical formula 13 Aralkyl resin 3.5%, triphenylphosphine 0.1%,
0.18% of 1,8-diazabicycloundecene phenol salt (softening point 120 ° C.), carnauba wax 0.4
%, Carbon black 0.3% and antimony trioxide 2.0% were added and mixed at room temperature, kneaded and cooled at 90 to 100 ° C., and then pulverized to produce a molding material.

Example 5 74% of aluminum nitride powder (maximum particle size of 150 μm or less, average particle size of 20 μm) and 10% of fine fused spherical silica powder (average particle size of 0.5 μm) were put into a Henschel mixer and stirred. Meanwhile, 0.4% of the above-mentioned silane coupling agent of Chemical Formula 17 was added.

Next, 7.0% of the above-mentioned dicyclopentadiene type epoxy resin of Chemical formula 6, 1.0% of tetrabromobisphenol A type epoxy resin, 1.2% of phenol novolak resin of Chemical formula 12, and phenol of Chemical formula 13 Aralkyl resin 3.5%, tris (2,6-dimethoxyphenyl) phosphine 0.15%, 2,4-diamino-6
0.1% of (2-undecylimidazolyl) -ethyl-s-triazine, 0.4% of carnauba wax, 0.3% of carbon black and 2.0% of antimony trioxide are added and mixed at room temperature, and further mixed at 90 to 90%. After kneading and cooling at 100 ° C., the mixture was pulverized to produce a molding material.

Example 6 74% of aluminum nitride powder (maximum particle size of 150 μm or less, average particle size of 20 μm) and 10% of fine fused spherical silica powder (average particle size of 0.5 μm) were put into a Henschel mixer and stirred. Meanwhile, 0.4% of the above-mentioned silane coupling agent of Chemical Formula 18 was added.

Next, 7.0% of the above-mentioned dicyclopentadiene type epoxy resin of the chemical formula 6, 1.0% of the tetrabromobisphenol A type epoxy resin, 1.2% of the phenol novolak resin of the above chemical formula 12, and phenol of the chemical formula 13 Aralkyl resin 3.5%, tris (2,6-dimethoxyphenyl) phosphine 0.15%, 1,8-diazabicycloundecene phenol salt (softening point 120 ° C.) 0.15%,
Carnauba wax 0.4%, carbon black 0.3
% And 2.0% of antimony trioxide were added and mixed at room temperature, kneaded and cooled at 90 to 100 ° C., and then pulverized to produce a molding material.

Comparative Example 1 77% of aluminum nitride powder (maximum particle size of 150 μm or less, average particle size of 20 μm) and 10% of fine fused spherical silica powder (average particle size of 0.5 μm) were put into a Henschel mixer and stirred. Meanwhile, 0.4% of the above-mentioned silane coupling agent of Chemical Formula 17 was added.

Next, 5.0% of the above-mentioned biphenyl type epoxy resin (R = CH ₃ ) of formula 5, 1.0% of tetrabromobisphenol A type epoxy resin, 1.2% of phenol novolak resin of the above formula 12, 2.5% of phenol aralkyl resin of formula 13, 0.2% of triphenylphosphine
%, Carnauba waxes 0.4%, carbon black 0.3% and antimony trioxide 2.0% were added and mixed at room temperature, kneaded and cooled at 90-100 ° C, and then pulverized to produce a molding material. .

Comparative Example 2 77% of aluminum nitride powder (maximum particle size of 150 μm or less, average particle size of 20 μm) and 10% of fine fused spherical silica powder (average particle size of 0.5 μm) were put into a Henschel mixer and stirred. Meanwhile, 0.4% of the above-mentioned silane coupling agent of Chemical Formula 18 was added.

Next, 5.0% of the above-mentioned biphenyl type epoxy resin (R = CH ₃ ) of formula 5, 1.0% of tetrabromobisphenol A type epoxy resin, 1.2% of phenol novolak resin of the above formula 12, 2.5% of a phenol aralkyl resin represented by Chemical Formula 13 and 2,4-diamino-6- (2-
Undecyl imidazolyl) -ethyl-s-triazine 0.2%, carnauba waxes 0.4%, carbon black 0.3% and antimony trioxide 2.0% were added and mixed at room temperature, and further mixed at 90-100 ° C. After kneading and cooling,
Pulverization produced a molding material.

Comparative Example 3 74% of aluminum nitride powder (maximum particle size of 150 μm or less, average particle size of 20 μm) and 10% of fine fused spherical silica powder (average particle size of 0.5 μm) were put into a Henschel mixer and stirred. Meanwhile, 0.4% of the above-mentioned silane coupling agent of Chemical Formula 19 was added.

Next, 7.0% of the above-mentioned dicyclopentadiene-type epoxy resin of Chemical formula 6, 1.0% of tetrabromobisphenol A-type epoxy resin, 1.2% of the above-mentioned phenol novolak resin of Chemical formula 12, and the phenol of Chemical formula 13 Aralkyl resin 3.5%, 2,4-diamino-6- (2-undecylimidazolyl) -ethyl-s-triazine 0.1
%, 1,8-diazabicycloundecene phenol salt (softening point: 120 ° C.): 0.15%, carnauba waxes: 0.4%, carbon black: 0.3% and antimony trioxide: 2.0% at room temperature Mix and add 90-10
After kneading and cooling at 0 ° C., the mixture was pulverized to produce a molding material.

Using the molding materials manufactured in Examples 1 to 6 and Comparative Examples 1 to 3, transfer was injected into a mold heated to 170 ° C., and the semiconductor chip was sealed and cured to manufacture a semiconductor sealing device. . Various tests were carried out on these semiconductor sealing devices, and the results are shown in Tables 1 and 2. The epoxy resin composition and the semiconductor sealing device of the present invention showed moisture resistance, solder heat resistance, and moldability. And excellent thermal conductivity, and a remarkable effect of the present invention could be confirmed.

[0041]

[Table 1]

[Table 2] Notes on Tables 1 and 2 * 1: Spiral flow at 175 ° C. was measured according to EMMI-I-66.

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

* 3: Transfer molded at 175 ° C., 80 kg / cm ² , 2 minutes to form a molded product (test piece), post-cured at 175 ° C. for 8 hours, and JIS-K-6
Tested according to 911.

* 4: A molded article similar to * 3 was made and 175
The sample was post-cured at 8 ° C. for 8 hours to prepare a test piece having an appropriate size, and the measurement was performed using a thermomechanical analyzer.

* 5: A molded article having a diameter of 100 mm and a thickness of 25 mm was prepared and measured using a thermal conductivity meter.

* 6: 5.3 × 5.3 mm chip is VQF
It was placed in a P80 pin (12 × 12 × 1.4 mm thick) package mold and transfer-molded at 175 ° C. for 2 minutes using a molding material, and then post-cured at 175 ° C. for 8 hours. The semiconductor encapsulation device obtained in this manner was heated at 85 ° C. and 85
%, Calculated by increased weight after 48 hours of moisture absorption.

* 7: An air reflow machine (Max2)
(40 ° C.) to examine the presence or absence of external and internal cracks.

[0048]

As is clear from the above description and Tables 1 and 2, the epoxy resin composition and the semiconductor encapsulation device of the present invention are excellent in moisture resistance, solder heat resistance, moldability and heat conductivity. It is also excellent in the filling property of a thin package and the like, is less affected by moisture absorption, has good heat dissipation, and can guarantee reliability for a long period of time.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08K 5/5455 C08K 5/5455 H01L 23/29 H01L 23/30 R 23/31 F-term (Reference) 4J002 CC04X CD01W CD02W CD04W CD05W CD06W CD07W CE00X DF017 EN029 EQ009 EU119 EU189 EW018 EX066 EX076 FD017 FD14X FD146 FD158 FD159 GJ02 GQ05 4J036 AA01 AA02 AB01 AB07 AD01 AD03 AD04 AD07 AD08 AD11 AF01 DC06 DA04 AF02 DA04 FA05 FA12 FA13 FB07 GA28 JA07 4M109 AA01 CA21 EA02 EB03 EB04 EB06 EB12 EC01 EC05 EC06

Claims (2)

[Claims] (A) an epoxy resin, (B) a phenolic resin, (C) a silane coupling agent having an epoxy group or an amino group represented by the following general formula: R ¹ -C _n H _2n —Si (OR ² ) ₃ (wherein, R ¹ is an atomic group having an epoxy group or an amino group, R ² is a methyl group or an ethyl group, n is 0 or 1)
(D) aluminum nitride powder having a maximum particle size of 150 μm or less, (E) a phosphorus-based curing accelerator and an amine-based curing accelerator as essential components. )
An epoxy resin composition comprising the aluminum nitride powder of 25 to 90% by weight. (A) an epoxy resin, (B) a phenolic resin, (C) a silane coupling agent having an epoxy group or an amino group represented by the following general formula: R ¹ -C _n H _2n —Si (OR ² ) ₃ (wherein, R ¹ is an atomic group having an epoxy group or an amino group, R ² is a methyl group or an ethyl group, n is 0 or 1)
(D) the aluminum nitride powder having a maximum particle size of 150 μm or less, (E) a phosphorus-based curing accelerator and an amine-based curing accelerator as essential components, and the above-mentioned ( A semiconductor sealing device, wherein a semiconductor chip is sealed with a cured product of an epoxy resin composition containing 25) to 90% by weight of aluminum nitride powder of D).