WO2020179988A1 - Epoxy resin composition - Google Patents

Abstract

The present invention relates to an epoxy resin composition for sealing semiconductor devices, the epoxy resin composition having low dielectric properties.

Description

Epoxy resin composition

The present invention relates to an epoxy resin composition for sealing semiconductor devices having low dielectric properties.

Along with the growth of the mobile device and Internet of Things (IoT) fields, mobile communication technology standards based on this have also rapidly developed. With the recent entering of the 5G communication era, research and development on various technologies required to quickly and accurately deliver high-capacity information are continuously being conducted. In the existing LTE or 4G communication era, the improvement of materials constituting the semiconductor package circuit board (PCB) has been centered, but as the 5G communication era enters, not only the package circuit board but also the improvement of the semiconductor encapsulation composition is required.

The semiconductor encapsulant is a material that protects the internal circuit of the semiconductor from external impacts and contaminants, and semiconductor encapsulants used in mobile devices in recent years not only provide basic properties such as heat dissipation and flow, but also reduce transmission loss when transmitting high-frequency signals. It is required to show a low dielectric constant (Dk) and a dielectric loss tangent (Df) in order to reduce, and related studies are being actively conducted.

For example, Korean Patent Application Laid-Open No. 10-2014-0127957 discloses a low-dielectric epoxy resin composition formed by reacting a phenol resin and epihalohydrin under a base catalyst. However, the epoxy resin composition does not satisfy the low dielectric constant (Dk) and dielectric loss tangent (Df) characteristics required by the recent mobile communication technology, and thus the demand for a composition for encapsulating semiconductor devices having low dielectric properties continues. There is a situation.

The present invention provides an epoxy resin composition having low dielectric properties and a semiconductor device encapsulated using the same.

The present invention provides an epoxy resin composition comprising an epoxy resin, a curing agent and a filler, and the curing agent includes an ester-based resin.

The epoxy resin composition according to the present invention secures a low dielectric constant and a dielectric loss tangent, so that when applied to a semiconductor device, it minimizes transmission loss during high-frequency signal transmission and enables fast information transmission. In addition, the epoxy resin composition according to the present invention can effectively protect the semiconductor internal circuit by having a low moisture absorption rate.

Hereinafter, the present invention will be described. However, it is not limited only by the following contents, and each component may be variously modified or selectively used as necessary. Therefore, it is to be understood as including all changes, 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 and a filler, and the curing agent includes an ester-based resin. In addition, the epoxy resin composition according to the present invention may further include a curing accelerator and additives commonly used in the art, if necessary. Hereinafter, the composition of the epoxy resin composition of the present invention will be described.

Epoxy resin

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

As the epoxy resin, an epoxy resin commonly used in a semiconductor device encapsulant may be used without limitation. Non-limiting examples of usable epoxy resins include bisphenol A type epoxy resin, cresol novolak 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 novolac type epoxy resin, bisphenol A novolac type epoxy resin, bisphenol S novolac type epoxy resin, biphenyl novolac type epoxy resin, naphthol novolac type epoxy resin, naphthol phenol co-condensation furnace Rock type epoxy resin, naphthol cresol co-condensed novolak 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 At least one of a pentadiene phenol addition reaction type epoxy resin, a phenol aralkyl type epoxy resin, a polyfunctional phenol resin, and a naphthol aralkyl type epoxy resin may be mentioned, but is not limited thereto.

The epoxy equivalent (EEW) of the epoxy resin is 100 to 400 g/eq, for example 150 to 300 g/eq, a softening point of 30 to 150°C, for example 40 to 130°C, and a viscosity (based on 150°C) of 0.01 To 30 poise, for example 0.02 to 20 poise. Since such an epoxy resin has a relatively low viscosity characteristic, flowability can be secured even if a high content of a filler is included, and kneading is easy.

If the epoxy equivalent of the epoxy resin is less than 100 g/eq, flowability may be excessively decreased, and if it exceeds 400 g/eq, the glass transition temperature (Tg) may decrease and the coefficient of thermal expansion may increase. In addition, when the softening point and viscosity of the epoxy resin are out of the above range, dispersibility may be reduced.

The epoxy resin may be included in 1 to 20% by weight, for example, 1 to 10% by weight based on the total weight of the epoxy resin composition. If the content of the epoxy resin is less than 1% by weight, adhesiveness, electrical insulation, flowability, and moldability may be deteriorated, and if the content exceeds 20% by weight, the reliability of the semiconductor becomes poor due to the increase in moisture absorption, and Heat dissipation characteristics may be deteriorated due to a decrease in content.

Hardener

The epoxy resin composition according to the present invention includes a curing agent. The curing agent reacts with the epoxy resin to promote curing of the composition.

The epoxy resin composition according to the present invention includes an ester-based resin as a curing agent. The ester-based resin can be used without particular limitation as long as the main chain of the constituent molecule is a resin containing an ester bond. For example, the ester-based resin may be prepared by polymerizing a carboxylic acid compound and a glycol compound or a phenol compound under a catalyst and a solvent.

The kind of the carboxylic acid compound is not particularly limited, for example, terephthalic acid, isophthalic acid, 1,4-cyclohexane dicarboxylic acid, or 1 selected from the group consisting of dipic acid, sebacic acid, phthalic anhydride, trimellitic anhydride, benzoic acid, tetrahydrophthalic anhydride Species or mixtures thereof may be used.

The type of the glycol compound is not particularly limited, for example, ethylene glycol, propylene glycol, 1,2-butylene glycol, and neopentyl glycol. ), 1,6-nucleic acid diol (1,6-Haxanediol), glycerol (Glycerol) one selected from the group consisting of, or a mixture thereof may be used.

The kind of the phenolic compound is not particularly limited, and for example, phenol, cresol, pt-butylphenol, 1-Naphthol, 2-Naphthol, cate Cole (Catechol), resorcinol (Resorcinol), hydroquinone (Hydroquinone) one selected from the group consisting of or a mixture thereof may be used.

The hydroxy group (OH) equivalent of the ester-based resin may be 50 to 400 g/eq, for example 100 to 300 g/eq, and the softening point may be 25 to 130°C, for example 50 to 100°C, and viscosity (Based on 150° C.) may be 0.1 to 3 poise, for example, 0.3 to 1.5 poise. When the hydroxy group (OH) equivalent of the ester-based resin exceeds 400 g/eq, the curing density decreases after the curing reaction and reliability may decrease, and when it is less than 50 g/eq, the curing reaction rate increases and the gel The incidence rate is high and the stability may be reduced. When the softening point exceeds 130° C., the viscosity increases and flowability decreases, resulting in poor moldability, and when the softening point is less than 25° C., dispersibility may decrease and the yield may decrease due to aggregation. If the viscosity exceeds 3 poise, flowability may decrease, resulting in poor moldability, and if the viscosity is less than 0.1 poise, dispersibility may decrease and yield may decrease due to aggregation.

The epoxy resin composition according to the present invention may further include a phenolic resin as a curing agent. Non-limiting examples of phenolic resins that can be used include one or more selected from phenol novolak-type resins, cresol novolac-type resins, phenol alkyl resins, phenol xylok-type resins, and various novolak-type resins synthesized from bisphenol A. have.

The hydroxy group (OH) equivalent of the phenolic resin is 50 to 200 g/eq, for example 80 to 150 g/eq, the softening point is 50 to 150°C, for example 60 to 100°C, and the viscosity (based on 150°C) is 0.5 to 2.5 poise, for example 1.0 to 2.0 poise. When the hydroxy group (OH) equivalent, softening point and viscosity of the phenolic resin are out of the above-described ranges, dispersibility and flowability of the epoxy resin composition may be deteriorated.

For example, the blending ratio of the ester-based resin and the phenol-based resin may be a weight ratio of 1: 0.1 to 5, for example, 1: 0.1 to 3. When the blending ratio of the ester-based resin and the phenol-based resin satisfies the above-described range, corrosion resistance and adhesion can be improved, and a low dielectric constant and dielectric loss tangent can be secured.

The curing agent may be included in 1 to 20% by weight, for example, 1 to 10% by weight based on the total weight of the epoxy resin composition. If the content of the curing agent is less than 1% by weight, problems may occur in curability and moldability, and if it exceeds 20% by weight, reliability may decrease due to an increase in moisture absorption, and strength may be relatively lowered.

Filler

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

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

For example, the epoxy resin composition according to the present invention may include spherical silica as a filler, and for example, spherical silica having an average particle diameter of 5 to 30 μm may be used. When the spherical silica has the above-described average particle size distribution, it has sufficient workability and excellent heat dissipation properties can be secured.

The filler may be included in an amount of 70 to 95% by weight, for example, 80 to 95% by weight, based on the total weight of the epoxy resin composition. If the content of the filler is less than 70% by weight, strength may decrease due to an increase in moisture absorption and adhesion may decrease, and if the content of the filler exceeds 95% by weight, processability may be poor due to increased viscosity and lower flowability.

Hardening accelerator

The epoxy resin composition according to the present invention may include a curing accelerator. The curing accelerator plays a role in accelerating the curing reaction and improving the cycle of high temperature reliability and continuous workability.

The curing accelerator used in the present invention may 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-ethyl-4-methylimidazole, 2- Imidazole compounds such as phenylimidazole and (4-methyl-2-phenyl-1H-imidazol-5-yl)methanol; 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, 0.01 to 2% by weight, based on the total weight of the epoxy resin composition. If the content of the curing accelerator is less than 0.01% by weight, curability may decrease, and if the content exceeds 5% by weight, flowability may decrease due to overcuring.

additive

The epoxy resin composition according to the present invention may optionally further include conventional additives known in the art in addition to the above-described components as necessary. Non-limiting examples of the additives that can be used in the present invention include at least one selected from a coupling agent, a colorant, an antifoaming agent, a leveling agent, an adhesion improving agent, a flame retardant, a light absorbing agent, a drying agent, a desiccant, and a wax.

As a material for enhancing the adhesion of the coating film, the coupling agent may be a silane-based compound such as mercaptoalkylakoxysilane or gammaglydoxypropyltrimethoxysilane. As the colorant, conventional colorants such as carbon black, bengala, organic dyes, inorganic dyes, etc. 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 may be used. Carnauba wax or the like may be used as the natural wax, and polyethylene wax may be used as the synthetic wax.

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

The method for preparing the epoxy resin composition of the present invention is not particularly limited, and may be prepared using a method known in the art. As an example, a melt-kneading method using a half-bari mixer, a kneader, a roll, a single-screw or twin-screw extruder, a conicaler, etc. may be used. For example, after uniformly mixing the above-described components, melt-mixing at a temperature of 100 to 130°C using a heat kneader, cooling to room temperature, pulverizing into a powder state, and blending can be prepared.

<Semiconductor element>

The present invention provides a semiconductor device sealed by using the epoxy resin composition as described above. Specifically, the semiconductor device to which the composition of the present invention can be applied refers to an electronic circuit (integrated circuit) made by integrating and wiring a transistor, a diode, a resistor, a capacitor, etc. on a semiconductor chip or a substrate.

The method of encapsulating and manufacturing a semiconductor device using the epoxy resin composition of the present invention is not particularly limited, and may be manufactured by encapsulating 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 intended to aid understanding of the present invention, and the scope of the present invention is not limited to the examples in any sense.

[Example 1-6]

According to the composition shown in Table 1 below, each component was blended using a container mixer, followed by melt mixing, cooling, pulverization, and blending processes, and then tableted to a predetermined size to prepare the epoxy resin compositions of Examples 1-6. The unit used in Table 1 below is weight percent.

[Comparative Example 1-4]

Except for those according to the composition shown in Table 2 below, the epoxy resin composition of Comparative Example 1-4 was prepared in the same manner as in Example 1-6, respectively. The unit used in Table 2 is weight percent.

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 (at 150 ℃): 0.2 poise)

Curing agent 1-1: ester resin (OH equivalent: 209 g/eq, softening point: 78 °C, viscosity (150 °C): 0.6 poise)

Curing agent 1-2: ester resin (OH equivalent: 185 g/eq, softening point: 135 °C, viscosity (150 °C): 1.8 poise)

Curing agent 1-3: ester resin (OH equivalent: 169 g/eq, softening point: 152 °C, viscosity (150 °C): 1.6 poise)

Curing agent 2: phenolic resin (Phenol polymer with hydroxybenzaldehyde, MEH-7500-3S, Meiwa Kasei, OH equivalent: 103 g/eq, softening point: 83 ℃, viscosity (150 ℃): 1.4 poise)

Filler: spherical silica (average particle diameter 15 µm)

Coupling agent: 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane (KBM-403, ShinEtsu Corporation, specific gravity (25 ℃): 1.070, flash point: 135 ℃, refractive index (25 ℃): 1.429, boiling point ( ℃/mmHg): 120/2)

Colorant: carbon black (MA-600, MITSUBISHI CHEMICAL, maximum cut size: 20 nm)

Wax: polyethylene wax (Wax E, Clariant, Drop Point: 84 ℃, acid value: 2 to 7 mgKOH/g)

Curing accelerator: (4-methyl-2-phenyl-1H-imidazol-5-yl) methanol (2P4MHZ-PW, Shikoku company, melting point: 240 ℃, molecular weight: 152 g/mol)

[Experimental Example-Evaluation of Physical Properties]

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

Specimen preparation

The epoxy resin composition prepared according to Example 1-6 and Comparative Example 1-4 was molded by transfer molding at 175°C for 70 seconds using a heat transfer molding machine to produce a 33 mm in diameter and 2.5 mm high package, which was then 175°C. After 4 hours post-cure (PMC: post mold cure) was cooled to room temperature.

Dielectric constant (Dk) and dielectric loss tangent (Df)

It was evaluated at 30℃ under the conditions of 1Hz and 1.5V with a dielectric property analyzer (Impedance Analyzer, Novocontrol).

Moisture absorption

The moisture absorption was evaluated by comparing the weight of the specimen before and after leaving it for 24 hours in PCT conditions (121°C, 2 atm, 100%RH).

Spiral flow

Measurements were made with a heat transfer molding machine (pressure = 70kg/cm2, temperature = 175°C, curing time = 120 seconds) using a Spiral Flow mold of EMMI-I-66 standard.

Gel time

A small amount of the epoxy resin composition prepared according to Example 1-6 and Comparative Example 1-4 was spread widely and evenly on a gel timer, and the time required for gelation of the product was measured.

Coefficient of thermal expansion (α1, α2)

After molding in a heat transfer molding machine (pressure=70kg/㎠, temperature=175℃, curing time=120 seconds) using a specimen making mold (width=60mm, length=10mm, thickness=3mm), in an oven at 175℃ After post-curing for 4 hours, the specimen was cut (width = 10 mm, length = 10 mm, thickness = 3 mm) and measured by TMA (Thermo Mechanical Analyser).

Glass transition temperature

After molding in a heat transfer molding machine (pressure=70kg/㎠, temperature=175℃, curing time=120 seconds) using a specimen making mold (width=60mm, length=10mm, thickness=3mm), in an oven at 175℃ After post-curing for 4 hours, the specimen was cut (width = 10 mm, length = 10 mm, thickness = 3 mm) and measured by TMA (Thermo Mechanical Analyser).

Flexural Modulus

After molding in a heat transfer molding machine (pressure=70kg/㎠, temperature=175℃, curing time=120 seconds) using a specimen making mold (width = 125mm, length = 12.5mm, thickness = 6mm), an oven at 175℃ After curing for 4 hours at, it was measured by UTM (Universal Testing Machine).

Mold Shrinkage

After molding in a heat transfer molding machine (pressure=70kg/㎠, temperature=175℃, curing time=120 seconds) using a specimen making mold (width = 125mm, length = 12.5mm, thickness = 6mm), an oven at 175℃ After curing for 4 hours at, the length of the contracted specimen was measured using a Vernier Calipers.

Hot Hardness

Immediately after the spiral flow mold, it was measured using a Shore-D type hardness tester on the surface of the hardened product above the mold.

As shown in Tables 3 and 4, it was confirmed that the epoxy resin composition of Example 1-6 according to the present invention exhibited excellent effects in all measured physical properties. In particular, the epoxy resin composition of Example 1-6 has a lower dielectric constant and dielectric loss tangent than the epoxy resin composition of Comparative Example 1-4 without using the ester-based resin according to the present invention, and can minimize the moisture absorption rate. It could be confirmed that there is.

The epoxy resin composition according to the present invention secures a low dielectric constant and a dielectric loss tangent, so that when applied to a semiconductor device, it minimizes transmission loss during high-frequency signal transmission and enables fast information transmission. In addition, the epoxy resin composition according to the present invention can effectively protect the semiconductor internal circuit by having a low moisture absorption rate.

Claims (5)

1. Including an epoxy resin, a curing agent and a filler,

   The curing agent includes an ester-based resin,

   The hydroxy group (OH) equivalent of the ester-based resin is 50 to 400 g/eq, and the softening point is 25 to 130°C.
2. The epoxy resin composition of claim 1, wherein the curing agent further comprises a phenolic resin.
3. The epoxy resin composition according to claim 2, wherein the blending ratio of the ester-based resin and the phenol-based resin is 1:0.1 to 5 weight ratio.
4. The epoxy resin composition according to claim 1, comprising 1 to 20% by weight of an epoxy resin, 1 to 20% by weight of a curing agent, and 70 to 95% by weight of a filler based on the total weight of the epoxy resin composition.
5. A semiconductor device, characterized in that it is sealed using the epoxy resin composition according to any one of claims 1 to 4.