JP3240861B2 - Epoxy resin composition and semiconductor device - Google Patents

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 which provides a cured product having excellent crack resistance and moisture resistance when absorbing moisture in a surface mount package, and a semiconductor encapsulated with the cured product of the composition. Related to the device.

[0002]

2. Description of the Related Art
In the semiconductor industry, resin-sealed type diodes, transistors, ICs, LSIs, and ultra-LSIs are the mainstream, and epoxy resin is generally used as the sealing resin in terms of moldability and adhesiveness compared to other thermosetting resins. Because of its excellent electrical properties, mechanical properties, moisture resistance, and the like, the above-described semiconductor device is often sealed with an epoxy resin composition.

In recent years, the degree of integration of these semiconductor devices has been increasing, and the chip size has been increasing accordingly. On the other hand, package external dimensions have been reduced in size and thickness in accordance with demands for smaller and lighter electronic devices. Further, in the method of attaching a semiconductor component to a circuit board, surface mounting of the semiconductor component has been widely performed due to a high density of components on the substrate and a reduction in thickness of the substrate.

However, when a semiconductor device is surface-mounted, it is common to immerse the entire semiconductor device in a solder bath or to pass the semiconductor device through a high-temperature zone in which the solder melts. Cracks occur in the layer, and peeling occurs at the interface between the lead frame or chip and the sealing resin. In particular, the surface of the frame is plated with silver for connecting all the lines, and peeling is likely to occur from this silver plating. Such cracks and peeling
This becomes even more noticeable if the sealing resin layer of the semiconductor device absorbs moisture before the thermal shock during surface mounting.However, in the actual working process, moisture absorption of the sealing resin layer is inevitable. In some cases, the reliability of a semiconductor device sealed with an epoxy resin later is greatly impaired.

To solve these problems, a method of adding a thermoplastic polymer to an epoxy resin composition or adding a silane coupling agent containing an amino group or a mercapto group has been proposed. Things are
Since the fluidity is reduced and the water absorption is increased, it is difficult to completely satisfy the recent demand for the encapsulation of a semiconductor device which has been increasingly sophisticated.

The present invention has been made in view of the above circumstances, and provides an epoxy resin composition which provides a cured product having excellent crack resistance and moisture resistance during moisture absorption soldering of a surface mounting package, and a cured product of the composition. It is an object of the present invention to provide a semiconductor device encapsulated with a semiconductor device.

[0007]

The present inventors have made intensive studies to achieve the above object, and as a result, have found that an epoxy resin composition containing an epoxy resin, a curing agent, and an inorganic filler as main components is further improved. By blending a silane coupling agent containing a sulfide group represented by the following formula (1) as the silane coupling agent, particularly by blending 0.01 to 5 parts by weight with respect to 100 parts by weight of the epoxy resin and the curing agent. It has been found that the adhesiveness to silver plating is remarkably improved, and that a cured product excellent in crack resistance and moisture resistance during moisture absorption soldering of a surface mounting package can be provided, and the present invention has been accomplished. Things.

Accordingly, the present invention provides an epoxy resin composition containing an epoxy resin, a curing agent and an inorganic filler as main components, and further comprising a silane coupling agent represented by the following formula (1):
An epoxy resin composition containing a sulfide group-containing silane coupling agent represented by the formula (1) in an amount of preferably 0.01 to 5 parts by weight based on 100 parts by weight of the epoxy resin and the curing agent, and the epoxy resin composition The present invention provides an epoxy resin composition sealed with a cured product of the above.

Embedded image (Wherein, R ¹ is a divalent hydrocarbon group having 1 to 5 carbon atoms, R ² is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 6 carbon atoms, R ³ is a hydrogen atom or 1 to 5 carbon atoms. Is a substituted or unsubstituted monovalent hydrocarbon group, n is 1, 2 or 3, and a is an integer of 0 to 2.)

Hereinafter, the present invention will be described in more detail. As the epoxy resin constituting the epoxy resin composition of the present invention,
It is an epoxy resin having at least two epoxy groups in one molecule, and the epoxy resin has a molecular structure, as long as it can be cured by various curing agents described below.
The molecular weight and the like are not limited, and can be appropriately selected from various conventionally known epoxy resins.

Specific examples of such epoxy resins include bisphenol A type epoxy resins, phenol novolak type epoxy resins, triphenol alkane type epoxy resins and their polymers, biphenyl type epoxy resins,
Dicyclopentadiene type epoxy resin, phenol aralkyl type epoxy resin, naphthalene ring-containing epoxy resin, glycidyl ester type epoxy resin, alicyclic epoxy resin, heterocyclic type epoxy resin, brominated epoxy resin and the like. May be used alone, or two or more may be used simultaneously. Among these, especially biphenyl type epoxy resin, phenol aralkyl type epoxy resin, naphthalene ring-containing epoxy resin,
It is preferable to use a dicyclopentadiene type epoxy resin from the viewpoint of improving crack resistance.

As the curing agent for the epoxy resin, a phenol resin is preferably used. As the phenol resin, any phenol resin containing two or more phenolic hydroxyl groups in one molecule can be used. Can be. Specifically, novolak type phenolic resin, resol type phenolic resin, phenol aralkyl resin, triphenol alkane type resin and its polymer,
Examples thereof include a naphthalene ring-containing phenol resin and a dicyclopentadiene-modified phenol resin. These curing agents may be used alone or in combination of two or more. In particular, it is preferable to mix a phenol aralkyl resin, a naphthalene ring-containing phenol resin, and a dicyclopentadiene-modified phenol resin in that the crack resistance can be improved.

The amount of the curing agent is not particularly limited, but when the above-mentioned phenol resin is used, the molar ratio of the epoxy group in the epoxy resin to the phenolic hydroxyl group in the curing agent is from 0.01 to 0.01. 5, particularly preferably in the range of 0.5 to 1.5.

Further, the composition of the present invention contains an inorganic filler. As the inorganic filler, those that are blended into a normal epoxy resin composition can be used,
This can reduce the expansion coefficient of the sealant and reduce the stress applied to the semiconductor element. Specifically, fused silica and crystalline silica having a crushed or spherical shape are mainly used, and alumina, silicon nitride, aluminum nitride and the like can also be used. The average particle size of the inorganic filler is preferably 5 to 20 microns.
Further, the filling amount of the inorganic filler is preferably 100 to 1200 parts (parts by weight, the same applies hereinafter), particularly preferably 400 to 1000 parts with respect to 100 parts of the total amount of the epoxy resin and the curing agent. If the amount is less than 100 parts, the expansion coefficient increases, the stress applied to the semiconductor element increases, and the element characteristics may deteriorate. If the amount exceeds 1200 parts, the viscosity at the time of molding increases, and the moldability may deteriorate. . In addition, in order to achieve both low expansion and moldability of the cured product,
It is preferable to use a blend of spherical and crushed products or only spherical products as the filler.

In the epoxy resin composition of the present invention, a silane coupling agent containing a sulfide group is further added to the epoxy resin composition containing the above-mentioned epoxy resin, curing agent and inorganic filler as main components.

As the silane coupling agent containing a sulfide group, an organosilicon compound represented by the following formula (1) is preferable.

[0016]

Embedded image

(Wherein, R ¹ is a divalent hydrocarbon group having 1 to 5 carbon atoms, R ² is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 6 carbon atoms, and R ³ is a hydrogen atom or carbon number. 1 to 5 substituted or unsubstituted monovalent hydrocarbon groups, n is 1, 2 or 3, and a is 0
整数 2. ) As the divalent hydrocarbon group R ¹ can be exemplified alkylene group, one of R ^2, R ³
Examples of the valent hydrocarbon group include an alkyl group, an alkenyl group, an aryl group, a cycloalkyl group and a halogen-substituted alkyl group.

Specific examples of the silane coupling agent having a sulfide group include the following compounds.

[0019]

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The amount of the silane coupling agent is 0.01 to 100 parts by weight of the epoxy resin and the curing agent.
It is preferably 5 parts by weight, more preferably 0.1 to 2 parts by weight, still more preferably 0.2 to 1 part by weight. 0.0
If the amount is less than 1 part by weight, a sufficient effect of improving the adhesiveness may not be obtained, and if it exceeds 5 parts by weight, the impact resistance of the composition may decrease.

In the composition of the present invention, in addition to the above-mentioned silane coupling agent, other silane coupling agents can be used in combination as long as the effects of the present invention are not impaired.
Specifically, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, N-β (aminoethyl) γ- Examples include aminopropylmethyldimethoxysilane, γ-aminopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, and the like.

The silane coupling agent may be mixed directly with other components, or may be obtained by surface-treating an inorganic filler with a silane coupling agent.

Further, a curing accelerator can be added to the composition of the present invention. Specific examples include imidazole or a derivative thereof, a phosphine derivative, a cycloamidine derivative, and the like. The amount of the catalyst is preferably from 0.01 to 5 parts, particularly from 0.1 to 2.5 parts, based on 100 parts of the epoxy resin, and if it is less than 0.01 part, it cannot be cured in a short time. If it exceeds 5 parts, the curing rate may be too high to obtain a good molded product.

In the composition of the present invention, if necessary,
Release agents such as carnauba wax, higher fatty acids, and synthetic waxes, and one or more other additives such as antimony oxide, phosphorus compounds, alkyl titanates, and the like can be added.

To obtain the epoxy resin composition of the present invention,
A predetermined amount of each component described above is uniformly stirred and mixed, and then the mixture is melt-kneaded by a roll, a kneader, a continuous extruder, or the like, which has been previously heated to 70 to 95 ° C., cooled, and crushed. It can be obtained in various ways.

The thus obtained epoxy resin composition of the present invention comprises DIP, QFP, PLCC, SOJ, TSO
It is effective for semiconductor packages such as P and TQFP, and in this case, it can be carried out by using a conventionally adopted molding method, for example, transfer molding, injection molding, casting method and the like. The molding temperature of the epoxy resin composition of the present invention is 150 to 180 ° C., and the post cure is 1
It is preferably performed at 50 to 185 ° C for 2 to 16 hours.

[0027]

EXAMPLES The present invention will be described below in detail with reference to examples and comparative examples, but the present invention is not limited to the following examples. In the following examples, all parts are parts by weight.

EXAMPLES AND COMPARATIVE EXAMPLES Spherical silica 300 having a specific surface area of 1.4 m ² / g and an average particle size of 15 μm was prepared by using the following epoxy resin, phenol resin and silane coupling agent in the ratio shown in Table 1. Part, specific surface area 2.5m ² /
g, 300 parts of spherical silica having an average particle size of 10 μm, specific surface area of 10 m ² / g, and spherical silica 80 having an average particle size of 1.0 μm.
Parts, antimony trioxide 8 parts, carnauba wax 1.2
Parts, 2.0 parts of carbon black, and 1 part of triphenylphosphine as a curing catalyst, and the resulting mixture was uniformly melt-kneaded with a hot two-roll to produce an epoxy resin composition. 3, Comparative Examples 1 to 3).

[0029]

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[0030]

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[0031]

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The following properties were measured for these epoxy resin compositions. The results are also shown in Table 1.

(A) Spiral flow Using a mold conforming to the EMMI standard, 175 ° C., 70 ° C.
It was measured under the condition of kg / cm ² .

(B) Mechanical strength (flexural strength, flexural modulus) 175 ° C., 70 kg / cm according to JIS-K6911
^2. A test specimen of 10 × 10 × 4 mm was molded under the condition of a molding time of 2 minutes, and a post-cured specimen at 180 ° C. for 4 hours was measured at room temperature.

(C) Glass transition temperature, expansion coefficient 175 ° C., 70 kg / cm ² , molding time 2 minutes
A test piece of × 4 × 15 mm was molded and post-cured at 180 ° C. for 4 hours.
The temperature was measured by raising the temperature.

(D) Adhesiveness (1), (2) A cylindrical product having a diameter of 15 mm and a height of 5 mm was molded on a 42 alloy plate under the conditions of 175 ° C., 70 kg / cm ² , and a molding time of 2 minutes. After 4 hours of post-curing, the adhesive strength between the molded product and the 42 alloy plate was measured with a push-pull gauge (1). Similarly, the adhesive strength to a 42-alloy plate and a silver-plated frame was measured (2).

(E) Solder crack resistance after moisture absorption A silicon chip having a size of 7 × 7 × 0.4 mm was subjected to 10 ×
It is adhered to a lead frame for QFP (42 alloy, pad silver plating) having a size of 14 × 1.4 mm, and the epoxy resin composition is molded thereon at molding conditions of 175 ° C. and 70 kg / cm.
^2. Molding was performed for 2 minutes and post-cured at 180 ° C. for 4 hours. This package was left to stand in an atmosphere of 85 ° C./85% RH for 72 hours to perform a moisture absorption process, and then passed through an infrared reflow furnace (ma × 240 ° C., 10 sec), and the number of cracks generated in the package at this time Was investigated (n = 20).

(F) Moisture resistance A 4MRAM chip was adhered to a 20-pin SOJ frame, and the epoxy resin composition was molded thereon at molding conditions of 175 ° C., 7
Molding under the condition of 0 kg / cm ² and molding time of 2 minutes, 180
Post-cured at 4 ° C. for 4 hours. This is carried out at 121 ° C./1
After leaving in an atmosphere of 00% RH for 24 hours to absorb moisture,
Immerse in a 260 ° C solder bath for 10 seconds,
The number of aluminum wiring disconnections / total number when left in a 00% RH atmosphere for 300 hours was measured.

[0039]

[Table 1]

From the results shown in Table 1, it can be seen that the epoxy resin composition containing the silane coupling agent having a specific structure according to the present invention has good flowability and curability, high adhesiveness, and especially silver. It was confirmed that a cured product having high adhesion to plating and excellent in reflow resistance was provided, and a highly reliable semiconductor device could be obtained by sealing the cured product.

[0041]

Industrial Applicability The epoxy resin composition of the present invention has good fluidity and effectiveness, as well as excellent adhesion to a substrate, a frame, etc., and is particularly effective in cracking resistance when absorbing moisture in a surface mounting package. Moisture resistance can be improved. Therefore, when a full-mold package such as an IC, an LSI, or a transistor is sealed, a highly reliable semiconductor product having excellent moldability can be manufactured with good productivity.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Yoshihiko Sakurai 1-10 Hitomi, Matsuida-machi, Usui-gun, Gunma Prefecture Inside Silicone Electronic Materials Research Laboratory Shin-Etsu Chemical Co., Ltd. (72) Toshio Shiobara Matsui, Usui-gun, Gunma Prefecture Hitomi Tamachi 1-10 Shin-Etsu Chemical Co., Ltd. Silicone Electronic Materials Technology Laboratory (56) References JP-A-4-85385 (JP, A) JP-A-59-124923 (JP, A) JP-A-4 −63860 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08L 63/00-63/10 C08K 5/548 H01L 23/29

Claims (4)

(57) [Claims] 1. An epoxy resin composition containing an epoxy resin, a curing agent and an inorganic filler as main components, and further containing a silane coupling agent having a sulfide group represented by the following formula (1) as a silane coupling agent. An epoxy resin composition characterized in that: Embedded image (Wherein, R ¹ is a divalent hydrocarbon group having 1 to 5 carbon atoms, R ² is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 6 carbon atoms, R ³ is a hydrogen atom or 1 to 5 carbon atoms. Is a substituted or unsubstituted monovalent hydrocarbon group, n is 1, 2 or 3, and a is an integer of 0 to 2.) 2. A silane coupling agent having a sulfide group represented by the above formula (1) is used in an amount of 0.01 to 5 parts by weight based on 100 parts by weight of the epoxy resin and the curing agent. The epoxy resin composition according to the above. 3. The epoxy resin composition according to claim 1, which is used for encapsulating a semiconductor. 4. A semiconductor device sealed with a cured product of the epoxy resin composition according to claim 1.