KR101947282B1 - Epoxy resin composition - Google Patents

Abstract

The present invention relates to an epoxy resin composition and a semiconductor device sealed using the same. The epoxy resin composition includes: two kinds of epoxy resins having a predetermined structure; a hardening agent; a hardening accelerator; and filler. According to the present invention, the epoxy resin composition has excellent bending properties, crack resistance, heat resistance, and flowability.

Description

EPOXY RESIN COMPOSITION [0002]

The present invention relates to an epoxy resin composition and a semiconductor device sealed with the epoxy resin composition.

2. Description of the Related Art Recently, the use of ultra-small package parts has been increasing due to the weight reduction, miniaturization and thinning of electronic devices. When a chip manufactured by a semiconductor process such as an IC (Integrated Circuit) is mounted on a printed circuit board, a semiconductor sealing material is used to protect the semiconductor device from external physical and chemical impacts. Such semiconductor encapsulating materials are required to have excellent heat resistance, flowability, moldability, and reliability.

BOC (Board on Chip) type stacked packages are repeatedly exposed at low and high temperature conditions during manufacture. At this time, if the difference in the degree of thermal expansion between the substrate and the chip-sealing material is large, warpage or cracks are generated in the package, and pores are formed or incomplete molding occurs during sealing of the package, .

Therefore, there is a demand for the development of a new encapsulant having excellent glass transition temperature and thermal expansion coefficient, low flexural modulus, and excellent flowability as well as excellent flexural characteristics and crack resistance.

The present invention provides an epoxy resin composition excellent in flexural characteristics, crack resistance, formability, heat resistance, flowability, and the like and a semiconductor device sealed using the composition.

The epoxy resin composition of the present invention comprises an epoxy resin containing a first epoxy resin represented by the following formula (1) and a second epoxy resin represented by the following formula (2), a curing agent, a curing accelerator and a filler, The mixing ratio of the second epoxy resin is 1: 1-2 weight ratio, and the content of the filler is 80-85 weight% based on the total weight of the epoxy resin composition.

(In the above formulas (1) and (2)

R ₁ to R ₉ are the same or different and are each independently selected from the group consisting of hydrogen or a C ₁ -C ₁₂ alkyl group,

a, b, c, d, e and f are each an integer of 1 to 4,

x is 0 or 1,

n is an integer of 1 to 7).

The epoxy resin composition of the present invention has a high glass transition temperature (Tg) and a high thermal expansion coefficient (CTE) and a low flexural modulus, and is excellent in crack resistance, flexural characteristics, heat resistance, moldability, flowability, moldability and reliability An excellent cured product can be formed.

Hereinafter, the present invention will be described in detail. However, it should be understood that the present invention is not limited to the following embodiments, and various elements may be modified or selectively mixed according to need. Accordingly, it is to be understood that the invention includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

≪ Epoxy resin composition &

The epoxy resin composition of the present invention comprises an epoxy resin containing a first epoxy resin represented by the following formula (1) and a second epoxy resin represented by the following formula (2), a curing agent, a curing accelerator and a filler, The mixing ratio of the second epoxy resin is 1: 1-2 weight ratio, and the content of the filler is 80-85 weight% based on the total weight of the epoxy resin composition.

Hereinafter, each constitution of the epoxy resin composition for sealing semiconductor devices of the present invention will be described.

Epoxy resin

In the epoxy resin composition according to the present invention, the epoxy resin reacts with the curing agent by heat to cure, and forms a three-dimensional network structure after curing, so that the epoxy resin can be firmly and strongly adhered to the semiconductor element.

In the present invention, in order to lower the flexural modulus while improving the glass transition temperature (Tg) of the cured product and to improve the flowability, a first epoxy resin represented by the following formula (1) and a second epoxy resin represented by the following formula Epoxy resin is mixed. For example, the first epoxy resin and the second epoxy resin are mixed in a ratio of 1: 1 to 2: 1. When any one of the first epoxy resin and the second epoxy resin is used alone or when the mixing ratio of the first epoxy resin and the second epoxy resin is out of the above range, heat resistance, flexural characteristics, flowability, crack resistance And the like may be deteriorated.

[Chemical Formula 1]

(2)

(In the above formulas (1) and (2)

R ₁ to R ₉ are the same or different and are each independently selected from the group consisting of hydrogen or a C ₁ -C ₁₂ alkyl group,

a, b, c, d, e and f are each an integer of 1 to 4,

x is 0 or 1,

n is an integer of 1 to 7).

The epoxy resin represented by the above formula (1) is one kind of a multifunctional epoxy resin having three epoxy groups in the molecule. Since the cross-linking density and the glass transition temperature of the cured product are high and the curing shrinkage is small, the adhesive property, reliability, heat resistance, , Crack resistance and the like can be improved.

Examples of the epoxy resin represented by the formula (1) include a multifunctional epoxy resin represented by the following formula (1a) and a multifunctional epoxy resin represented by the following formula (1b).

[Formula 1a]

[Chemical Formula 1b]

The epoxy equivalent of the epoxy resin represented by Formula 1 is not particularly limited. For example, when the epoxy equivalent is about 200-250 g / eq, the crack resistance of the cured product can be further improved. The softening point of the epoxy resin represented by the above formula (1) is not particularly limited. However, when the temperature is about 50-70 ° C, crack resistance and heat resistance of the cured product can be improved.

The epoxy resin represented by Formula 2 is a kind of phenol aralkyl type epoxy resin and can improve the fluidity of the resin composition, the flame retardancy of the package, and the molding characteristics. Particularly, since the phenol aralkyl type epoxy resin has a biphenyl structure in the main chain based on the phenol skeleton, hygroscopicity, toughness, oxidation resistance and crack resistance can be secured.

Examples of the epoxy resin represented by Formula 2 include phenol aralkyl type epoxy resins represented by Formula 2a, but are not limited thereto.

(2a)

(In the formula (2a), the average value of n is an integer of 1 to 7.)

The epoxy equivalent of the epoxy resin represented by the general formula (2) is not particularly limited, but the flowability, heat resistance, flexural characteristics and the like of the cured product can be further improved when it is about 250-300 g / eq. The softening point of the epoxy resin represented by the formula (2) is not particularly limited, but the heat resistance of the cured product can be further improved, for example, at about 50-70 ° C. The viscosity of the epoxy resin represented by the formula (2) is not particularly limited, but may be, for example, about 0.5-1.0 poise.

The epoxy resin composition of the present invention may further comprise an epoxy resin commonly known in the art other than the epoxy resin of Formula 1 and the epoxy resin of Formula 2, if necessary. Examples thereof include bisphenol type epoxy resins such as bisphenol A, bisphenol E, bisphenol F, bisphenol M, bisphenol S and bisphenol H, glycidyl ether type epoxy resins, glycidylamine type epoxy resins, phenol novolak type epoxy resins , Cresol novolak type epoxy resin, dimeric acid-modified epoxy resin, etc. These may be used alone or in combination of two or more kinds. The content of such an epoxy resin is not particularly limited, and may be, for example, 0.1-5 wt% based on the total weight of the epoxy resin composition, and in another example, about 0.2-4 wt%.

In the resin composition of the present invention, the content of the epoxy resin is not particularly limited and may be, for example, about 5-15% by weight based on the total weight of the epoxy resin composition, and in another example about 7-12% by weight. When the epoxy resin has the above-mentioned range, adhesiveness, heat resistance, flowability, moldability and the like can be further improved.

Hardener

In the epoxy resin composition according to the present invention, the curing agent is a component that reacts with the epoxy resin to advance the curing of the composition.

The curing agent usable in the present invention is not particularly limited as long as it is commonly known in the art. Examples thereof include phenol aralkyl type phenol resins, phenol novolac type phenol resins, xylock type phenol resins, cresol novolak type phenol resins, naphthol type phenol resins, terpene type phenol resins, multifunctional type phenol resins, dicyclopentadiene type phenol Resin, naphthalene type phenol resin, novolak type phenol resin synthesized from bisphenol A and resole, polyhydric phenol compound including tris (hydroxyphenyl) methane, dihydroxybiphenyl, acid anhydride including maleic anhydride and phthalic anhydride , Aromatic amines such as metaphenylenediamine, diaminodiphenylmethane, and diaminodiphenylsulfone, but are not limited thereto. These may be used alone or in combination of two or more.

In particular, in the case of a multifunctional phenol resin-based curing agent, the glass transition temperature can be further improved to increase the warpage reduction effect of the package. Non-limiting examples of such a multifunctional phenol resin-based curing agent include a phenol resin represented by the following formula (3).

(3)

(In the formula 3, the average value of n is 1 to 7).

The OH equivalent of the multifunctional phenol resin-based curing agent is not particularly limited, but when the OH equivalent is about 90-115 g / eq, the adhesion of the cured product can be further improved. The polyfunctional phenol resin-based curing agent can improve the flowability when the softening point is about 70-95 ° C.

Such a curing agent can control the mixing ratio with the epoxy resin in accordance with the requirements of mechanical properties and moisture resistance reliability. For example, the mixing ratio of the curing agent to the epoxy resin may be 1: 1 to 2: 1 by weight, and may be 1: 1.4 to 1.7: 1 by weight.

In the resin composition of the present invention, the content of the curing agent is not particularly limited and may be, for example, about 1-10% by weight, and in another example about 3-8% by weight based on the total weight of the epoxy resin composition.

Hardening accelerator

In the epoxy resin composition of the present invention, the curing accelerator is a component that accelerates the curing reaction between the epoxy resin and the curing agent.

The curing accelerator usable in the present invention is not particularly limited as long as it is commonly used in the art. Examples thereof include tertiary amines, organometallic compounds, organic phosphorus compounds, imidazoles, and boron compounds.

Nonlimiting examples of the tertiary amine include benzyldimethylamine, triethanolamine, triethylenediamine, diethylaminoethanol, tri (dimethylaminomethyl) phenol, 2-2- (dimethylaminomethyl) 6-tris (diaminomethyl) phenol, etc. These may be used alone or in combination of two or more.

Non-limiting examples of the organometallic compound include chromium acetylacetonate, zinc cetylacetonate, nickel acetylacetonate, etc. These may be used alone or in combination of two or more.

Non-limiting examples of the organic phosphorus compound include tris-4-methoxyphosphine, tetrabutylphosphonium bromide, butyltriphenylphosphonium bromide, phenylphosphine, diphenylphosphine, triphenylphosphine, triphenylphosphine Triphenylphosphine borane, triphenylphosphine-1,4-benzoquinone adduct, etc. These may be used alone or in combination of two or more.

Non-limiting examples of the imidazoles include 2-methylimidazole, 2-phenylimidazole, 2-aminoimidazole, 2-methyl-1-vinylimidazole, Sol, 2-heptadecyl imidazole, etc. These may be used alone or in combination of two or more.

Non-limiting examples of the boron compound include tetraphenylphosphonium-tetraphenylborate, triphenylphosphine tetraphenylborate, tetraphenylboron salt, trifluoroborane-n-hexylamine, trifluoroborane monoethylamine, Tetrafluoroborane triethylamine, tetrafluoroborane amine, etc. These may be used alone or in combination of two or more.

In the resin composition of the present invention, the content of the curing accelerator is not particularly limited, and may be, for example, about 0.05-5% by weight based on the total weight of the epoxy resin composition, and alternatively 0.1-2% by weight. When the content of the curing accelerator is in the range described above, the flowability can be improved without lowering the curability and reducing the hardening.

Filler

In the epoxy resin composition according to the present invention, the filler serves to improve the mechanical properties (e.g., strength, etc.) of the cured product.

The fillers usable in the present invention are not particularly limited as long as they are fillers conventionally used in the art. Examples include, but are not limited to, silica, calcium carbonate, magnesium carbonate, alumina, magnesia, clay, talc, calcium silicate, titanium oxide, antimony oxide, aluminum nitride, silicon nitride, boron nitride and glass fiber.

The form of the filler is not particularly limited, and fillers of various shapes and spheres may be used. The average particle diameter of such a filler is not particularly limited, and may be, for example, about 5-20 mu m, and in another example about 8-17 mu m. When the average particle diameter of the filler is in the above-mentioned range, the mechanical properties of the cured product can be further improved.

In the epoxy resin composition of the present invention, the content of the filler is preferably about 80-85 wt% based on the total weight of the epoxy resin composition. This is because a cured product having a high thermal expansion coefficient (CTE) is formed when the content of the filler is in the above-described range with a content smaller than that of the filler used in the conventional epoxy resin composition, The warpage characteristics and crack resistance can be improved.

additive

The epoxy resin composition according to the present invention may further include additives commonly used in the art in addition to the above-described components, depending on the purpose of use of the composition and the use environment thereof.

Examples of the additive include releasing agents such as higher fatty acids, higher fatty acid metal salts, natural fatty acids, paraffin wax, ethylene wax, and ester wax; Coloring agents such as carbon black, organic dyes and inorganic dyes; Coupling agents such as epoxy silane, aminosilane, alkylsilane, mercaptosilane, and alkoxysilane; Modified silicone oils, silicone powders, silicone resins, organopolysiloxanes; Flame retardants such as phosphazene, zinc borate, aluminum hydroxide, and magnesium hydroxide; Defoamer; Pigments; Dyes, etc. These may be used alone or in combination of two or more.

The content of the additive is not particularly limited, and may be, for example, about 0.05-10% by weight, and in another example about 0.1-5% by weight. For example, when a coupling agent, a stress relieving agent, a releasing agent and a coloring agent are mixed with the additive, 0.1 to 1 wt% of a coupling agent, 0.1 to 1 wt% of a stress relaxation agent, 0.05 to 1 wt%, based on the total weight of the epoxy resin composition, By weight of release agent and 0.1 to 1% by weight of colorant.

The above-mentioned epoxy resin composition can be produced by a method commonly known in the art, for example, a known melt-kneading method using a Banbury mixer, a kneader, a roll, a single or twin extruder, and a cone. For example, the above-mentioned respective components are uniformly mixed, melt-mixed at a temperature of about 100-130 using a heat kneader, cooled to room temperature, pulverized into a powder state, The composition of the present invention can be obtained.

The epoxy resin composition of the present invention is superior to conventional epoxy resin compositions in heat resistance, moldability, flowability, reliability, warpage characteristics and crack resistance. Therefore, when the semiconductor element is sealed with the epoxy resin composition of the present invention, the defective formation rate of the semiconductor element can be lowered.

<Semiconductor device>

The present invention provides a semiconductor device sealed with the above-described epoxy resin composition. Such a semiconductor device is sealed with an epoxy resin composition excellent in heat resistance, moldability, flowability, reliability, bending property and crack resistance, so that the defective molding rate can be reduced during sealing, and durability and life can be improved .

The semiconductor device may be sealed by a method commonly known in the art. A molding method such as a transfer mold, a compression mold, and an injection mold, but the present invention is not limited thereto.

Examples of such sealed semiconductor devices include transistors, diodes, microprocessors, semiconductor memories, and the like. They may have a variety of package structures, for example, a BOC (Board on Chip) package structure.

Hereinafter, the present invention will be described more specifically by way of examples. However, the following examples are provided to aid understanding of the present invention and are not intended to limit the scope of the present invention in any sense.

[ Example  1-4] and [ Comparative Example  1-6] -Preparation of Epoxy Resin Composition

Epoxy resin compositions of Examples 1-4 and Comparative Examples 1-6 were prepared using epoxy resin, curing agent, filler, releasing agent, curing accelerator, stress relieving agent, coupling agent and colorant according to the composition shown in Table 1 below. Here, the content unit of each component is% by weight based on the total weight of the resin composition. The specifications of the raw materials constituting each composition are shown in Table 2 below.

[ Experimental Example  1] - Property Evaluation of Epoxy Resin Composition

The epoxy resin compositions prepared in Examples 1-4 and Comparative Examples 1-6 and the BOC type laminated packages sealed with the above compositions were evaluated for physical properties according to the following evaluation methods, Respectively.

One) Spiral Flow (spiral flow)

The epoxy resin composition was molded using a spiral flow mold in a heat transfer molding machine (pressure: 70 kg / cm 2, temperature: 175 ° C, curing time: 120 seconds), and then the flowability of the product was measured.

2) Glass transition temperature ( Tg )

TMA (Thermomechanical Analyzer).

3) Coefficient of linear expansion

TMA (Thermomechanical Analyzer). a1 represents a coefficient of linear expansion at a temperature lower than Tg, and a2 represents a coefficient of linear expansion at a temperature higher than Tg.

4) Flexural strength, Flexural modulus (Flexural modulus)

A standard specimen (125 mm x 12.6 mm x 6.4 mm) was prepared in accordance with ASTM D-790, cured at 175 DEG C for 4 hours, and then measured at room temperature using a UTM (Universal Testing Machine).

5) Warpage

(62 mm x 240 mm x 1.1 mm) package by molding with transfer molding at 175 DEG C for 70 seconds using a heat transfer molding machine and then post-cured (PMC) at 175 DEG C for 4 hours And then cooled to room temperature. The fabricated packages were measured for height differences from the ground at the center and ends of the upper diagonal direction using a non-contact laser measuring machine.

6) T / C cycle

After the package having been subjected to the evaluation of the warpage characteristics was dried at 125 ° C for 24 hours, 3,000 cycles (one cycle means that the package was left at -65 ° C for 10 minutes, at 25 ° C for 5 minutes, and at 150 ° C for 10 minutes) , And the presence or absence of cracks in the package was visually evaluated. If a crack occurred at this stage, the evaluation was not carried out.

As shown in Table 3, the epoxy resin composition of Example 1-4 according to the present invention had excellent flow properties, high glass transition temperature and thermal expansion coefficient, low flexural modulus, Can be confirmed. On the other hand, when the epoxy resin according to the present invention is not used (Comparative Examples 1 and 3-6) and the epoxy resin mixing ratio is out of the range (Comparative Example 2), the flowability, the bending property and / Or the glass transition temperature and the thermal expansion coefficient are low and / or the flexural modulus is high.

Claims (6)

An epoxy resin composition comprising a first epoxy resin represented by the following formula (1) and a second epoxy resin represented by the following formula (2), a curing agent, a curing accelerator and a filler,
Wherein the mixing ratio of the first epoxy resin and the second epoxy resin is 1: 1-2 weight ratio,
Wherein the content of the filler is 80-85% by weight based on the total weight of the epoxy resin composition:
[Chemical Formula 1]

(2)

(In the above formulas (1) and (2)
R ₁ to R ₉ are the same or different and are each independently selected from the group consisting of hydrogen or a C ₁ -C ₁₂ alkyl group,
a, b, c, d, e and f are each an integer of 1 to 4,
x is 0 or 1,
the average value of n is an integer of 1 to 7.) delete The epoxy resin composition according to claim 1, wherein the first epoxy resin has an epoxy equivalent of 200-250 g / eq and a softening point of 50-70 ° C. The epoxy resin composition according to claim 1, wherein the second epoxy resin has an epoxy equivalent of 250-300 g / eq, a softening point of 50-70 ° C, and a viscosity of 0.5-1.0 poise. The epoxy resin composition according to claim 1, wherein the curing agent is a multifunctional phenol resin-based curing agent having an OH equivalent of 90-115 g / eq and a softening point of 70-95 ° C. A semiconductor device sealed with the epoxy resin composition according to any one of claims 1 to 5.