KR102126847B1 - Epoxy resin composition - Google Patents

Abstract

The present invention relates to an epoxy resin composition having excellent heat dissipation and dispersibility and a semiconductor device sealed using the same.

Description

Epoxy resin composition

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

The semiconductor encapsulant is a material that serves to protect the semiconductor circuit from external shocks and contaminants by sealing the semiconductor device, and has a significant influence on the productivity and reliability of the semiconductor, and occupies a large portion in the semiconductor manufacturing process.

In recent years, while miniaturization and high-functionality of electronic devices are progressing, high-functionalization is also progressing in the semiconductor package mounted therein, and the processing speed of the semiconductor elements inside the semiconductor package is becoming higher. However, as the speed of processing increases, the heat generation problem on the surface of the semiconductor device is intensified, and if efficient heat dissipation and dissipation are not achieved, there is a problem of deterioration of components, malfunction, and shortened product life. Accordingly, in recent years, demand for high heat dissipation materials has rapidly increased, mainly in power devices such as electronic devices, particularly portable devices, LEDs, and automobiles.

Epoxy resins have been used as a sealing material for circuit board materials and electronic components, as well as excellent adhesion and electrical insulation, and also excellent mechanical properties. However, since the thermal conductivity of the epoxy resin itself is only about 0.2 to 0.3 W/m·K, there is a problem in that it is used alone for encapsulating a compact and highly functional semiconductor device. In order to solve this problem, attempts to manufacture an epoxy resin composition having high heat dissipation properties by using a specific type of epoxy resin or by mixing a filler have been continuously made. For example, JP 2012-224758 discloses a high heat dissipation epoxy resin composition in which a filler is mixed with a hydroquinone type epoxy resin, however, flowability and dispersibility of the epoxy resin composition when a high content of filler is included There is a problem that this decreases.

The present invention provides an epoxy resin composition having excellent heat dissipation and dispersibility and a sealed semiconductor device using the same.

The present invention includes an epoxy resin, a curing agent, a filler, a dispersing agent and a curing accelerator, wherein the filler is 10 to 25% by weight of spherical alumina having an average particle diameter of less than 2 μm based on the total weight of the spherical alumina, and an average particle diameter of 2 μm to 20 μm Less than 10 to 40% by weight of spherical alumina, 10 to 20% by weight of spherical alumina having an average particle diameter of 20 µm or more, and 30 to 40% by weight of spherical alumina with an average particle diameter of 40 µm or more and less than 60 µm, and spherical particles having an average particle size of 60 µm or more It provides an epoxy resin composition comprising 4 to 15% by weight of alumina.

In addition, the present invention provides a semiconductor device sealed using the above-described epoxy resin composition.

The epoxy resin composition of the present invention exhibits excellent heat dissipation characteristics, and can secure high dispersibility even if it contains a high content of filler.

Hereinafter, the present invention will be described in detail. However, it is not limited only by the following contents, and each component may be variously modified or selectively mixed as necessary. Therefore, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention.

<Epoxy resin composition>

The epoxy resin composition according to the present invention includes an epoxy resin, a curing agent, a filler, a dispersing agent, and a curing accelerator, and the filler is 10 to 25% by weight of a spherical alumina having an average particle diameter of less than 2 μm based on the total weight of the spherical alumina, and an average particle diameter 10 to 40 wt% of spherical alumina having a size of 2 µm or more and less than 20 µm, 10 to 20 wt% of spherical alumina having an average particle diameter of 20 µm or more and less than 40 µm, 30 to 40 wt% of spherical alumina having an average particle diameter of 40 µm or more and less than 60 µm, and an average particle size It contains 4-15 weight% of spherical alumina 60 micrometers or more. Looking at the composition of the epoxy resin composition of the present invention as follows.

Epoxy resin

The epoxy resin composition according to the present invention includes an epoxy resin as a main resin. The epoxy resin of the present invention is cured by reacting with a curing agent by heat, and after curing, it has a three-dimensional network structure to give strong and firm adhesion to the adherend and heat resistance.

As the epoxy resin, an epoxy resin commonly used in semiconductor encapsulants can be used without limitation. Non-limiting examples of usable epoxy resins include bisphenol A type epoxy resin, cresol novolac type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, naphthalene type epoxy resin, anthracene epoxy resin, biphenyl type epoxy resin, Tetramethyl biphenyl type epoxy resin, phenol novolak type epoxy resin, bisphenol A novolak type epoxy resin, bisphenol S novolak type epoxy resin, biphenyl novolak type epoxy resin, naphthol novolak type epoxy resin, naphthol phenol coaxial furnace Bolac type epoxy resin, naphthol cresol coaxial novolac type epoxy resin, aromatic hydrocarbon formaldehyde resin modified phenol resin type epoxy resin, triphenyl methane type epoxy resin, tetraphenyl ethane type epoxy resin, dicyclopentadiene type epoxy resin, dicyclo It may include one or more of pentadiene phenol addition reaction epoxy resin, phenol aralkyl type epoxy resin, polyfunctional phenol resin, naphthol aralkyl type epoxy resin, but is not limited thereto.

The epoxy resin may have an epoxy equivalent (EEW) of 150 to 300 g/eq, a viscosity of 0.01 to 0.5 poise at 150°C, and a softening point of 60 to 180°C. Since these epoxy resins have relatively low viscosity properties, flowability can be secured even if a high content of filler is included, and kneading is easy.

If the viscosity and softening point of the epoxy resin is out of the above range, dispersibility may decrease. In addition, if the epoxy equivalent of the epoxy resin is less than 150 g/eq, the flowability may be excessively reduced, and if it exceeds 300 g/eq, the glass transition temperature (Tg) may drop and the thermal expansion coefficient may increase.

The epoxy resin may be included in 1 to 10% by weight, for example, 2 to 5% by weight based on the total amount of the epoxy resin composition. If the content of the epoxy resin is less than 1% by weight, adhesiveness, electrical insulation, flowability and formability may be deteriorated, and if the content exceeds 10% by weight, the reliability of the semiconductor becomes poor due to an increase in moisture absorption, and the relative of the filler. The heat dissipation characteristics may be reduced due to the reduction of the content.

Hardener

The epoxy resin composition according to the present invention includes a curing agent. The curing agent serves to advance the curing of the composition by reacting with the epoxy resin.

As the curing agent, a conventional curing agent known in the art for curing reaction with an epoxy resin may be used without limitation, and non-limiting examples of the curing agent that can be used include phenol novolak type resin, cresol novolak type resin, and phenol alkyl resin. , One or more selected from various novolac-type resins synthesized from phenol xylox-type resins and bisphenol A. As an example, one or more of a phenol novolac-type resin and a phenol xylotype resin may be included. The phenol novolac-type resin and the phenol xylotype resin have the advantage of excellent physical properties such as moisture resistance, heat resistance, and preservability.

The curing agent may have a viscosity of 0.5 to 1.5 poise at 150°C, a softening point of 60 to 180°C, and a hydroxy group (OH) equivalent of 90 to 150 g/eq. If the viscosity and softening point of the curing agent is out of the above range, dispersibility may decrease. In addition, if the hydroxy group equivalent of the curing agent is less than 90 g/eq, the flowability may be excessively reduced, and if it exceeds 150 g/eq, the glass transition temperature (Tg) may drop and the thermal expansion coefficient may increase.

The curing agent may be included in 1 to 10% by weight, for example, 1 to 5% by weight based on the total amount of the epoxy resin composition. When the content of the curing agent is less than 1% by weight, there may be problems in curability and moldability, and when it exceeds 10% by weight, reliability may decrease due to an increase in moisture absorption, and strength may be relatively reduced.

Filler

The epoxy resin composition according to the present invention includes a filler. The filler serves to improve the heat dissipation and strength of the encapsulant and lower the moisture absorption.

As the filler, for example, inorganic fillers such as silica, silica nitride, alumina, aluminum nitride, and boron nitride can be used alone or in combination of two or more.

The epoxy resin composition according to the present invention may include spherical alumina as a filler. For example, spherical alumina having an average spheroidization degree of 0.92 or more and an average particle diameter of 10 to 45 μm may be used.

The filler is 10 to 25% by weight of spherical alumina having an average particle diameter of less than 2 μm, 10 to 40% by weight of spherical alumina having an average particle diameter of 2 to 20 μm, and an average particle diameter of 20 to 40 μm, based on the total weight of the spherical alumina. It may include 10 to 20% by weight of spherical alumina, 30 to 40% by weight of spherical alumina having an average particle diameter of 40 μm or more and less than 60 μm, and 4 to 15% by weight of spherical alumina having an average particle diameter of 60 μm or more. For example, the filler is 20 to 25% by weight of spherical alumina having an average particle diameter of less than 2 μm, 10 to 20% by weight of spherical alumina having an average particle diameter of 2 μm or more and less than 20 μm, and an average particle size of 20 μm or more based on the total weight of the spherical alumina. It may be 10 to 15% by weight of spherical alumina less than 40 μm, 35 to 40% by weight of spherical alumina having an average particle diameter of 40 μm or more and less than 60 μm, and 10 to 15% by weight of spherical alumina having an average particle diameter of 60 μm or more. When the spherical alumina has the above-mentioned average particle size distribution, it has sufficient workability and can secure excellent heat dissipation.

The maximum particle size of the spherical alumina is not particularly limited, but may be less than 120 μm, for example, less than 100 μm. When the maximum particle diameter is 120 µm or more, workability is not sufficient, and the surface condition of the insulating layer may be poor.

The content ratio (weight ratio) between the particle size distributions of the spherical alumina is 0.2 to 1.5:1, and the average particle diameter of the spherical alumina having an average particle diameter of 60 µm or more and the spherical alumina having an average particle diameter of 20 µm or more and less than 40 µm is 0.2 to 1.5:1. The content ratio of the spherical alumina having an average particle diameter of not less than 60 μm and the spherical alumina having an average particle diameter of 40 μm or more and less than 60 μm is 0.1 to 0.5:1, and the spherical alumina having an average particle diameter of 60 μm or more and the spherical alumina having an average particle diameter of less than 2 μm. (Weight ratio) may be at least one of 0.1 to 1.5:1. When the content ratio (weight ratio) between the particle size distributions of the spherical alumina is out of the above range, the workability is insufficient, and the heat dissipation property of the epoxy resin composition may be deteriorated.

In addition, the specific surface area of the spherical alumina is 1 to 10 m 2 /g, and the impurity content may be 10 to 20 ppm. When the specific surface area and impurity content of the spherical alumina are out of the above range, dispersibility and reliability may be deteriorated.

The filler may be included in 80 to 97% by weight, for example 90 to 97% by weight based on the total amount of the epoxy resin composition. When the content of the filler is less than 80% by weight, the strength may decrease and adhesion may decrease due to an increase in moisture absorption, and when the content of the filler exceeds 97% by weight, workability may be deteriorated due to an increase in viscosity and a decrease in flowability.

Dispersant

The epoxy resin composition according to the present invention includes a dispersant. The dispersant is attached to the surface of the filler in the epoxy resin composition to prevent agglomeration by causing steric hindrance, thereby improving flowability and dispersibility.

As the dispersant, a cationic polymer, anionic polymer, or anionic oligomer may be used.

The cationic polymer may include, for example, at least one of a polymer including an alkyl ammonium salt structure and an alkylene oxide copolymer. The alkylene oxide copolymer may include, for example, at least one selected from ethylene oxide copolymer and propylene oxide copolymer.

The alkyl ammonium salt may be a compound represented by Formula 1 below.

[Formula 1]

In the above formula,

R ₁ is an alkyl group having 1 to 10 carbon atoms,

R ₂ to R ₄ are the same or different and are hydrogen or an alkyl group having 1 to 10 carbon atoms, an aryl group, an alkylaryl group, or an arylalkyl group.

The polymer containing the alkyl ammonium salt structure may also contain a hydroxy group.

The amine value of the polymer containing the alkyl ammonium salt structure may be about 30 to 50 mg KOH/g, and the acid value may be about 20 to 40 mg KOH/g. When the amine value and the acid value of the polymer containing the alkyl ammonium salt structure satisfy the above-described range, flowability and dispersibility can be secured without deteriorating the heat dissipation property of the epoxy resin composition.

As the anionic oligomer, an oligomeric polyester, for example, phosphoric acid ester may be used.

The type of the dispersant is not particularly limited, for example, commercially available DISPERBYK-140, DISPERBYK-180, DISPERBYK-181, DISPERBYK-187, BYK-151, BYK-9076, BYK-W968, BYK-W969, Hypermer KD2, Hypermer KD23, Hypermer KD4, Hypermer KD9, and the like can be used.

The dispersant may be used in an amount of about 0.01 to 5% by weight based on the total amount of the epoxy resin composition, for example, about 0.1 to 1% by weight. When the content of the dispersant exceeds 5% by weight, the heat dissipation property of the epoxy resin composition may be lowered, and when it is less than 0.01% by weight, flowability and dispersibility may be lowered.

Curing accelerator

The epoxy resin composition according to the present invention includes a curing accelerator. The curing accelerator serves to improve the cycle of high temperature reliability and continuous workability in addition to promoting the curing reaction.

The curing accelerator used in the present invention can be used without particular limitation as long as it accelerates the curing reaction of the curing agent. For example, the curing accelerator is 2-methylimidazole, 2-ethyl4methylimidazole, 2-phenyl Imidazole compounds such as midazole; Amine compounds such as triethylamine, tributylamine, and benzyldimethylamine; Tertiary amine compounds such as 2-(dimethylaminomethyl)phenol, 2,4,6-tris(dimethylaminomethyl)phenol, and 1,8-diazabicyclo(5,4,0)undec-7-ene; And phenylphosphine, diphenylphosphine, triphenylphosphine, tributylphosphine, and tri(p-methylphenyl)phosphine.

The curing accelerator may be included in an amount of 0.01 to 5% by weight, for example, 0.1 to 1% by weight based on the total amount of the epoxy resin composition. If the content of the curing accelerator is less than 0.01% by weight, curability may be lowered, and if the content exceeds 5% by weight, flowability may be reduced due to over-curing.

additive

The epoxy resin composition according to the present invention may optionally further include conventional additives known in the art, in addition to the aforementioned components, if necessary. Non-limiting examples of additives usable in the present invention may further include one or more additives selected from colorants, antifoaming agents, leveling agents, surface modifiers, adhesion improving agents, flame retardants, light absorbers, desiccants, hygroscopic agents, and waxes.

As the colorant, conventional colorants such as carbon black, bengala, organic dyes, and inorganic dyes known in the art may be used alone or in combination of two or more. As the wax, paraffin wax, natural wax, synthetic wax or a mixture thereof can be used. Natural waxes include carnauba wax, and synthetic waxes include polyethylene wax.

The content of the additive is not particularly limited, and may be 0.1 to 5% by weight based on the total amount of the epoxy resin composition.

The method for preparing the epoxy resin composition of the present invention containing the above-described components is not particularly limited, and may be prepared using a general method in the art. For example, it may be manufactured using a known melt-kneading method using a banbari mixer, a kneader, a roll, a single-screw or twin-screw extruder, a kneader, and the like. For example, after mixing the above-described components uniformly, it may be prepared by melt-mixing at a temperature of 100 to 130°C using a heat kneader, crushing to a powder state by cooling to room temperature, and blending.

<Semiconductor element>

The present invention provides a semiconductor device sealed using the epoxy resin composition as described above.

Specifically, a semiconductor device to which the composition of the present invention can be applied means an electronic circuit (integrated circuit) made by integrating and wiring transistors, diodes, resistors, and capacitors on a semiconductor chip or substrate.

The method for sealing and manufacturing a semiconductor device using the epoxy resin composition of the present invention is not particularly limited, and may be manufactured by sealing a semiconductor device by a molding method such as a transfer mold, a compression mold, or an injection mold.

Hereinafter, the present invention will be described in more detail through examples. However, the following examples are only to aid the understanding of the present invention, and the scope of the present invention is not limited to the examples in any sense.

[Example 1-9 and Comparative Example 1-6]

After mixing each component according to the composition shown in Tables 1 and 2 using a container mixer, and then tableting to a certain size through melt mixing, cooling, grinding, and blending processes, Examples 1-9 and Comparative Examples 1-6 Each of the epoxy resin composition was prepared.

Epoxy resin: 4,4-Bis(2,3-epoxypropoxy)-3,3,5,5-tetramethyl(1,1-biphenyl) (YK-4000HK, MITSUBISHI CHEMICAL, epoxy equivalent: 192 g/eq, softening point : 109℃, viscosity: 0.2 poise)

Curing agent: Phenolic novolac curing agent (KPE-F2000, KOLON, OH equivalent: 107 g/eq, softening point: 66°C, viscosity: 0.8 poise)

Filler 1: Spherical alumina (average particle diameter less than 2 μm)

Filler 2: Spherical alumina (average particle size 2 μm or more and less than 20 μm)

Filler 3: Spherical alumina (average particle size 20 µm or more but less than 40 µm)

Filler 4: Spherical alumina (average particle size 40 µm to 60 µm)

Filler 5: Spherical alumina (average particle diameter 60 µm or more)

Dispersant: Polymer containing alkyl ammonium salt structure (BYK-9076, amine value: 44 mg KOH/g, acid value: 38 mg KOH/g)

Colorant: Carbon black (MA-600, MITSUBISHI CHEMICAL, average particle size: 18 nm, pH: 7.5)

Wax: Polyethylene wax (Wax E, Clariant, Drop Point: 84℃, Acid value: 2 to 7 mg KOH/g)

Curing accelerator: 1,5-Diazabicyclo(4.3.0)non-5-ene (KPH-MN2001, KOLON, melting point 240°C, molecular weight: 152)

[Experimental Example-Property evaluation]

The physical properties of the epoxy resin compositions prepared in Examples 1-9 and Comparative Examples 1-6 were measured as follows, and the results are shown in Tables 3 and 4 below.

Spiral flow

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

Gel time

A small amount of the epoxy resin composition prepared according to each example and comparative example was spread evenly and evenly on a gel timer to measure the gelation time of the product.

Glass transition temperature (Tg)

It was evaluated by TMA (Thermomechanical Analyser).

Coefficient of linear expansion (α1, α2)

It was evaluated by TMA (Thermomechanical Analyser). The linear expansion coefficient α1 evaluated the linear expansion coefficient below Tg, and the linear expansion coefficient α2 evaluated the linear expansion coefficient above Tg.

Thermal conductivity (W/mK)

It was evaluated by LFA (Laser Flash Analysis).

From the results of Tables 3 and 4, it was confirmed that the epoxy resin composition of Examples 1-9 using the filler of the composition according to the present invention exhibits excellent effects in all measured physical properties. On the other hand, the epoxy resin composition of Comparative Example 1-6 using the filler out of the composition (particle size distribution of spherical alumina) of the present invention showed poor properties of one or more of flowability and thermal conductivity.

Claims (10)

Epoxy resin, a curing agent, a filler, a dispersing agent and a curing accelerator, wherein the filler is 10 to 25% by weight of spherical alumina having an average particle diameter of less than 2 μm based on the total weight of the spherical alumina, and spherical alumina having an average particle diameter of 2 μm or more and less than 20 μm 10 to 40 wt%, spherical alumina having an average particle diameter of 20 µm or more and less than 40 µm, 10 to 20 wt%, spheroidal alumina having an average particle diameter of 40 µm or more and less than 60 µm, and spheroidal alumina having an average particle diameter of 60 µm or more 4 to Epoxy resin composition comprising 15% by weight. The method of claim 1, wherein the filler is 20 to 25% by weight of spherical alumina having an average particle diameter of less than 2 μm based on the total weight of the spherical alumina, 10 to 20% by weight of spherical alumina having an average particle diameter of 2 μm or more and less than 20 μm, an average particle diameter Epoxy resin composition comprising 10 to 15% by weight of spherical alumina having a diameter of 20 μm or more and less than 40 μm, 35 to 40% by weight of spherical alumina having an average particle diameter of 40 μm or more and less than 60 μm, and 10 to 15% by weight of spherical alumina having an average particle diameter of 60 μm or more . According to claim 1, The content ratio (weight ratio) between the particle size distribution of the spherical alumina is a spherical alumina having an average particle diameter of 60 µm or more and a spherical alumina having an average particle diameter of 20 µm or more and less than 40 µm (weight ratio): 0.2 to 1.5: 1, the content ratio (weight ratio) of spherical alumina having an average particle diameter of 60 µm or more and spherical alumina having an average particle diameter of 40 µm or more and less than 60 µm is 0.1 to 0.5:1, and spherical alumina having an average particle diameter of 60 µm or more and 2 µm of average particle diameter The epoxy resin composition having a content ratio (weight ratio) of spherical alumina less than or equal to 0.1 to 1.5:1. The epoxy resin composition according to claim 1, wherein the spherical alumina has a specific surface area of 1 to 10 m 2 /g and an impurity content of 10 to 20 ppm. According to claim 1, Based on the total weight of the epoxy resin composition, 1 to 10% by weight of the epoxy resin, 1 to 10% by weight of the curing agent, 80 to 97% by weight of the filler, 0.01 to 5% by weight of the dispersing agent and 0.01 to cure accelerator Epoxy resin composition comprising 5% by weight. The epoxy resin composition according to claim 1, wherein the dispersant is at least one selected from the group consisting of cationic polymers, anionic polymers, and anionic oligomers. The epoxy resin composition according to claim 6, wherein the cationic polymer is a polymer containing an alkyl ammonium salt structure. The epoxy resin composition according to claim 7, wherein the amine value of the polymer containing the alkyl ammonium salt structure is 30 to 50 mg KOH/g. The epoxy resin composition according to claim 7, wherein the acid value of the polymer containing the alkyl ammonium salt structure is 20 to 40 mg KOH/g. A semiconductor device, characterized in that it is sealed using the epoxy resin composition according to any one of claims 1 to 9.