KR20200111030A - Epoxy resin composition - Google Patents

Abstract

The present invention relates to an epoxy resin composition which contains an epoxy resin, a curing agent, an adhesion improver, a coupling agent, a curing accelerator, and a filler, wherein the adhesion improver contains a triazine-based compound having an average particle size of 5 to 30 μm. When the epoxy resin composition is used as an encapsulating material for a surface-mounted discrete semiconductor for automobiles, it is possible to satisfy the high level of reliability required for automobile semiconductors such as MSL and TCT.

Description

Epoxy resin composition {EPOXY RESIN COMPOSITION}

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

As semiconductors for automobiles, a number of semiconductors such as memory/non-memory, power supply semiconductors, and micro control units (MCUs) are used. For example, a general vehicle model has an average of 40 semiconductors, and a high-end vehicle model contains more than 100 semiconductors. Such automotive semiconductors must meet more stringent quality standards (AEC-Q101) in terms of quality standards required for automotive applications, such as temperature, humidity, defect rate, and warranty life, compared to domestic and industrial semiconductors. Accordingly, the required physical properties of the epoxy resin composition, which is an encapsulating material for encapsulating automobile semiconductors, is also very high compared to encapsulants applied to other fields.

Recently, the application fields of automotive semiconductors are rapidly expanding, and the market size of automotive semiconductors is also rapidly increasing. In particular, the demand for discrete power semiconductors is continuously increasing. With the rapid growth of the automotive discrete power semiconductor market, demand is increasing from a lead-in-board package to a surface-mount package, and competition intensifies as a number of semiconductor assembly companies have entered the automotive discrete semiconductor market. have. In order to secure price competitiveness (eg, process reduction), semiconductor assembly companies are using lead frames plated with various metal materials such as copper (Cu), nickel (Ni), and silver (Ag). However, when metal materials such as copper, nickel and silver are used, MSL (Moisture Sensitivity Level) and TCT (Thermal Cycle Test), which are important reliability items required in the automotive semiconductor field due to the decrease in adhesion between the metal and the encapsulant, Peeling occurs on the back, resulting in a problem that does not satisfy reliability.

In order to secure reliability in a conventional lead frame such as Cu, Ag, Ni, etc., attempts have been made to add a silane coupling agent to the epoxy resin composition or to increase the amount thereof. In this case, the adhesion to the lead frame may be partially improved, but the adhesion enhancing effect is not relatively large, and contamination of the mold due to an increase in the amount of the coupling agent added, and the storage performance of the encapsulant composition decreased.

The present invention provides an epoxy resin composition capable of satisfying both reliability standards and continuous workability of a semiconductor, and a semiconductor device using the same.

The present invention provides an epoxy resin composition comprising an epoxy resin, a curing agent, an adhesion improver, a coupling agent, a curing accelerator and a filler, and the adhesion improver includes a triazine-based compound having an average particle size of 5 to 30 μm.

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

The epoxy resin composition according to the present invention may exhibit high adhesion and high adhesion properties with dissimilar materials such as copper, nickel, and silver used as a material of a lead frame. Accordingly, when the epoxy resin composition of the present invention is used as an encapsulation material for automotive surface-mount discrete semiconductors, it is possible to satisfy the high level of reliability required for automotive semiconductors such as MSL and TCT, and at the same time excellent continuous operation Castle can be secured.

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 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, an adhesion improving agent, a coupling agent, a curing accelerator, and a filler. If necessary, one or more additives commonly used in the art, such as a colorant, a release agent, and a flame retardant, may be further included. Hereinafter, the composition of the epoxy resin composition according to the present invention will be described in detail.

Epoxy resin

The epoxy resin composition of the present invention uses an epoxy resin as a main resin, and any general epoxy resin known in the field of semiconductor encapsulants is not particularly limited and can be used.

Examples of the epoxy resin include an epoxy compound (monomer) containing two or more epoxy groups in a molecule, an oligomer or polymer, and an oligomer or polymer generated by a ring opening reaction of the epoxy group. Examples of the epoxy resin include bisphenol type epoxy resin, glycidyl ester type epoxy resin, glycidyl amine type epoxy resin, phenol novolak type epoxy resin, cresol type epoxy resin, aliphatic epoxy resin, alicyclic epoxy resin, and Aromatic epoxy resins, epoxidized oil-based epoxy resins, and the like.

Non-limiting examples of usable epoxy resins include bisphenol A type epoxy resin, alicyclic epoxy resin, cresol novolak type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, naphthalene type epoxy resin, anthracene epoxy resin, non Phenyl type epoxy resin, tetramethyl biphenyl type epoxy resin, phenol novolak type epoxy resin, bisphenol A novolac type epoxy resin, bisphenol S novolak type epoxy resin, biphenyl novolac type epoxy resin, naphthol novolak type epoxy resin , Naphthol phenol co-condensed novolak type epoxy resin, naphthol cresol co-condensed novolak type epoxy resin, (c) aromatic hydrocarbon formaldehyde resin modified phenol resin type epoxy resin, triphenyl methane type epoxy resin, tetraphenyl ethane type epoxy resin, dicyclo There are pentadiene type epoxy resin, dicyclopentadiene phenol addition reaction type epoxy resin, phenol aralkyl type epoxy resin, polyfunctional phenol resin, naphthol aralkyl type epoxy resin, or a mixture thereof. For example, one or more selected from the group consisting of bisphenol A type epoxy resin, alicyclic epoxy resin, cresol novolak type epoxy resin, dicyclopentadiene type epoxy, and biphenyl type epoxy resin may be used.

The epoxy resin may have an epoxy equivalent (EEW) of 150 to 280 g/eq. Since such an epoxy resin has a relatively low viscosity characteristic, flowability can be secured even when a high content of inorganic filler is included, and kneading is easy.

In the present invention, the content of the epoxy resin is not particularly limited, for example, it may be 1 to 20% by weight, for example, 5 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, flowability, and moldability may be deteriorated, and if it exceeds 20% by weight, the reliability of the semiconductor becomes poor due to an increase in moisture absorption, and the content of the filler described below is relatively To decrease, the strength may decrease.

Hardener

In the epoxy resin composition of the present invention, the curing agent is a component that reacts with the epoxy resin as the main resin to advance curing of the composition. As the curing agent, a conventional curing agent known in the art that undergoes a curing reaction with an epoxy resin may be used without limitation, and a phenol resin curing agent having excellent physical properties such as moisture resistance, heat resistance, and storage property may be used as a semiconductor encapsulating curing agent.

The phenolic resin-based curing agent refers to a monomer, oligomer, or overall polymer having one or more, for example, two or more phenolic hydroxyl groups per monomer, and does not specifically limit its molecular weight and molecular structure. Non-limiting examples of the phenolic resin-based curing agent that can be used include xyloc-type phenolic resins, polyaromatic phenolic resins, polyfunctional phenolic resins, phenol novolac-type, naphthalene-type, and dicyclopentadiene-type phenolic resins. These may be used alone or in combination of two or more. For example, one or more selected from the group consisting of a phenol novolak resin, a cresol novolak resin, a phenol aralkyl resin, and a polyfunctional phenol compound may be used.

The phenol resin-based curing agent may have a hydroxyl group (OH) equivalent of 80 to 250 g/eq, for example, 100 to 210 g/eq.

The content of the curing agent may be appropriately adjusted according to the content of the main resin. For example, the content of the curing agent may be 1 to 20% by weight, other examples 3 to 7% by weight based on the total weight of the epoxy resin composition. When the content of the curing agent is less than 1% by weight, problems may occur in curability and moldability, and when it exceeds 20% by weight, reliability may decrease due to an increase in moisture absorption, and strength may be relatively lowered.

The blending ratio of the epoxy resin and the curing agent may be an equivalent ratio of 1:0.6 to 1.3 in consideration of the requirements for mechanical properties and moisture resistance reliability in automobile semiconductors. When the activator of the curing agent is less than 0.6 equivalents of the epoxy group, the curing speed of the epoxy resin composition is slowed, and when the activator of the curing agent exceeds 1.3 equivalents, the strength of the cured product tends to decrease after final curing. In addition, when the active group of the curing agent to 1 equivalent of the epoxy group is out of the range of 0.6 to 1.3 equivalents ratio, high-temperature pyrolysis may occur due to the unreacted epoxy group or the curing agent.

Adhesion enhancer

In the epoxy resin composition of the present invention, the adhesion improving agent is a component introduced to improve adhesion to the lead frame made of metal.

As the adhesion improving agent, a compound represented by the following Chemical Formula 1 may be used.

[Formula 1]

In the above formula,

R ₁ to R ₃ are the same as or different from each other, and each independently hydrogen, an alkyl group having 1 to 10 carbon atoms, or an alkylene group.

The adhesion improving agent represented by Formula 1 is a triazine-based compound having a heteroaromatic 6-membered ring structure containing 3 nitrogens, and includes 3 alkylene groups, that is, unsaturated vinylene groups in the molecule. Such a plurality of vinylene groups improve the interfacial adhesion between the encapsulant and the lead frame by forming a physical bond and/or a chemical bond with a metal material constituting the lead frame, such as copper (Cu), nickel (Ni), silver (Ag), etc. It can be continuously improved.

In Formula 1, R ₁ to R ₃ may each independently be an alkylene group having 1 to 6 carbon atoms, for example, 1 to 2 carbon atoms. For example, R ₁ to R ₃ may each independently be any one of a methylene group and an ethylene group.

As the adhesion improving agent, a triazine-based compound having an average particle size of 5 to 30 µm, another example 5 to 20 µm may be used. When the average particle size of the triazine-based compound is less than 5 µm, when mixing is performed, aggregation by mutual attraction is facilitated, thereby reducing dispersibility, and thus adhesion may be deteriorated. When the average particle size exceeds 40 µm, the gel is not melted during mixing, and thus the adhesion to the lead frame plated with copper, nickel and silver may be deteriorated.

In the present invention, the content of the adhesion improving agent is not particularly limited, and as an example may be 0.01 to 0.5% by weight based on the total weight of the epoxy resin composition. If the content of the adhesion improving agent is less than 0.01% by weight, sufficient adhesion with dissimilar materials cannot be secured, and if it exceeds 0.5% by weight, it may stick to the mold during molding due to excessive adhesion.

Coupling agent

The epoxy resin composition of the present invention may contain a coupling agent. The coupling agent serves to impart a bonding force between organic substances (eg, resin components) and inorganic substances (eg, inorganic fillers) through stable dispersibility.

As the coupling agent, conventional ones known in the art may be used without limitation. Non-limiting examples of coupling agents that can be used include silane coupling agents such as epoxy silane, amino silane, alkyl silane, alkoxy silane, ureide silane, acrylic silane, vinyl silane, mercapto silane, etc. A ring agent, an aluminum/zirconium coupling agent, and a mercapto-based coupling agent are mentioned. For example, one or more selected from the group consisting of alkoxysilane, epoxysilane, mercaptosilane, and aminosilane may be used.

In the present invention, the content of the coupling agent is not particularly limited, and for example, may be 0.01 to 2.0% by weight, and in another example, 0.05 to 1.0% by weight based on the total weight of the epoxy resin composition. If the content of the coupling agent is less than 0.01% by weight, the coupling effect between the organic material and the inorganic material may be reduced, resulting in a decrease in strength, and if it exceeds 2.0% by weight, there may be a problem of gel formation.

Hardening accelerator

The epoxy resin composition of the present invention may include a curing accelerator. The curing accelerator is a component that accelerates the curing reaction between the epoxy resin and the curing agent.

As the curing accelerator, a conventional one known in the art may be used without limitation, and for example, an amine compound, an imidazole compound, an organic phosphine compound, or a combination of two or more thereof may be used.

Non-limiting examples of amine compounds that can be used include triethylamine, tributylamine, benzyldimethylamine, triethanolamine, triethylenediamine, diethylaminoethanol, tri(dimethylaminomethyl)phenol, tri-2-ethyl Hexyl acid, 2,2-(dimethylaminomethyl)phenol, 2,4,6-tris(dimethylaminomethyl)phenol, 1,8-diazabicyclo(5,4,0)undec-7-ene, etc. .

Non-limiting examples of imidazole compounds include 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, mixtures thereof, and the like.

Non-limiting examples of organic phosphine compounds include phenylphosphine, diphenylphosphine, triphenylphosphine, tributylphosphine, tri(p-methylphenyl)phosphine, tris-4-methoxyphosphine, tetra Butylphosphonium bromide, butyltriphenylphosphonium bromide, triphenylphosphine triphenylborane, triphenylphosphine-1,4-benzoquinone, mixtures thereof, and the like. In particular, an organic phosphine compound having excellent moisture resistance and thermal hardness can be used.

In the present invention, the content of the curing accelerator may be appropriately adjusted according to the reactivity of the main resin or the curing agent. For example, the content of the curing accelerator may be 0.05 to 5% by weight, for example, 0.1 to 3% by weight, based on the total weight of the epoxy resin composition. If the content of the curing accelerator is less than 0.05% by weight, proper workability cannot be secured due to an increase in gelation time, and if it exceeds 5% by weight, moldability may decrease due to excessive shortening of the gelation time. .

Filler

The epoxy resin composition of the present invention may include a filler as a component for improving the strength of the encapsulant and lowering the moisture absorption amount.

As the filler, a filler applicable in the art may be used without limitation, and non-limiting examples that can be used include silica, silica nitride, alumina, aluminum nitride, boron nitride, and the like. The above-described components may be used alone or two or more types may be used in combination. For example, (high purity) silica fillers such as natural silica, synthetic silica, fused silica, and the like can be used.

The average particle diameter of the filler is not particularly limited, and a filler having a size of 150 μm or less may be used in consideration of filling properties in the mold. The average particle diameter of the filler may be 1 to 50 µm, for example, 1 to 30 µm, for another example. The shape of the filler is not particularly limited, and may be spherical, angular or amorphous. For example, spherical silica particles can be used.

As the filler, fused or synthetic silica having an average sphericity of 0.92 or more and an average particle diameter of 1 to 30 μm may be used. When such silica is used, mechanical strength can be improved and reliability through low moisture absorption can be improved.

In the present invention, the content of the filler is not particularly limited, and may be 70 to 91% by weight, for example, 75 to 89% by weight, based on the total weight of the epoxy resin composition. When the content of the filler is less than 70% by weight, the moisture absorption in the cured product of the epoxy resin composition increases, resulting in a decrease in reliability of the semiconductor device. On the other hand, when the content of the filler exceeds 91% by weight, it may cause loss of fluidity, resulting in poor moldability.

additive

The epoxy resin composition of the present invention may optionally further include additives commonly used in the field of encapsulants within a range that does not impair the inherent properties of the composition.

Non-limiting examples of additives that can be used include flame retardants, colorants, release agents, modifiers, low stress agents, or mixtures of two or more thereof. The content of each of these additives may be appropriately added within the content range known in the art, for example, may be 0.01 to 5% by weight, respectively, based on the total weight of the epoxy resin composition.

Although the epoxy resin composition itself may exhibit excellent flame retardancy, it may further include a conventional flame retardant in the art in order to further improve flame retardancy. Non-limiting examples of flame retardants that can be used include metal hydroxides, phosphorus and nitrogen-containing organic compounds such as resorcinol diphosphate, phosphate, phenoxyphosphazene, melamine cyanurate. ), phenolic melamine resin, or mixtures thereof. Examples of the metal hydroxide include a hydroxide of a metal selected from magnesium, calcium, strontium, barium, boron, aluminum, and gallium.

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.

A release agent is a material used to secure a release force that minimizes adhesion to the mold after molding. As the mold release agent that can be used, a long chain fatty acid, a metal salt of a long chain fatty acid, a paraffin wax, a natural wax, a synthetic wax, or a mixture thereof may be mentioned. Natural waxes include carnauba wax, and synthetic waxes include polyethylene wax.

As the low stress agent, a modified silicone resin, a modified polybutadiene, or the like may be used. The low-stressing agent may be used alone or in combination of two or more.

The method of preparing the epoxy resin composition of the present invention is not particularly limited, and may be prepared using a general method in the art. As an 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, or a conical. 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 then blending may be prepared.

The epoxy resin composition according to the present invention may be used for encapsulation of semiconductor devices containing at least one metal of copper (Cu), nickel (Ni), and silver (Ag), or having a lead frame plated with the metal. In this case, it is possible to secure excellent continuous workability while exhibiting high interfacial adhesion characteristics with the lead frame made of the aforementioned material.

<Semiconductor device>

The present invention provides a semiconductor device encapsulated by using the above-described epoxy resin composition.

A semiconductor device to which the epoxy resin composition can be applied refers to an electronic circuit (integrated circuit) manufactured by integrating and wiring a transistor, a diode, a resistor, a capacitor, etc. on a semiconductor chip or a substrate. For example, the semiconductor device may be a transistor, a diode, a microprocessor, a semiconductor memory, a semiconductor sensor, or the like. The semiconductor device may be a surface mount type semiconductor package for an automobile.

The semiconductor device includes a lead frame plated with or containing at least one metal of copper (Cu), nickel (Ni), and silver (Ag), at least one semiconductor element mounted on the lead frame, and the lead It is formed on the frame, and may be provided with a sealing portion for sealing the semiconductor device using the epoxy resin composition of the present invention.

A method of encapsulating and manufacturing a semiconductor device using the epoxy resin composition according to the present invention is not particularly limited, and may be manufactured according to a method known in the art. For example, it 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 1-4]

After finely pulverizing the epoxy resin, curing agent, filler, coupling agent, adhesion improver and additive components of the specifications shown in Table 1 below to make powder, mix each component according to the composition of Table 2 below, mix uniformly, and heat The epoxy resin composition of Example 1-4 was prepared by kneading using an extruder (Kneader), cooling, and regrinding into a powder state. In Table 2 below, the usage unit of each composition is parts by weight.

[Comparative Example 1-2]

The epoxy resin composition of Comparative Example 1-2 was prepared in the same manner as in Example 1-4, except that it was mixed according to the composition of Table 2 below.

[Experimental example. Property evaluation]

The physical properties of the epoxy resin compositions prepared in Example 1-4 and Comparative Example 1-2 were measured as follows, and the measurement results are shown in Table 3 below.

(1) Flowability (spiral flow)

The epoxy resin composition prepared in each Example and Comparative Example was heated and transferred using a spiral flow mold (EMMI-I-66 standard Spiral Flow mold) (pressure = 70 kg/㎠, temperature = 175°C, curing time = 120 seconds), and then the flowability of the product was measured.

(2) gelation time

A small amount of the epoxy resin composition prepared in each Example and Comparative Example was spread and evenly spread on a gel timer, and then the time required for gelation of the product was measured.

(3) moisture absorption

After molding a 2 mm-thick specimen, post mold cure (PMC) at 175°C for 4 hours, and then forcibly absorbed in a PCT chamber (121°C, 2 atm, RH 100%) for 24 hours to determine the moisture absorption of the specimen. Measured.

(4) adhesion

The epoxy resin composition prepared in each Example and Comparative Example was molded into a lead frame plated with Cu, Ni or Ag material, and post-cured (PMC) for 4 hours, and then the epoxy resin composition and copper were , The adhesion between the interface with the lead frame plated with nickel and silver, respectively, was measured.

(5) peeling

The epoxy resin composition prepared in each Example and Comparative Example was molded into a package and post-cured (PMC, 175°C, 4 hours), and then absorbed for 192 hours in 30°C / 60%RH through a thermohygrostat, Reflow was performed 3 times. Thereafter, the number of peelings occurring on the interface between the Cu pad and the Ni, Ag plating surface and the epoxy resin composition inside each package was counted. The analysis of the interface separation was performed using an ultrasonic microscope.

(6) gel content

After dissolving the epoxy resin composition prepared according to each Example and Comparative Example in acetone, the gel content was measured using an 80 mesh sieve.

As a result of the experiment, it can be seen that the epoxy resin composition (Example 1-4) according to the composition of the present invention has excellent adhesion to the lead frame, and a semiconductor device having high reliability when sealing semiconductor elements can be manufactured. On the other hand, in the case of the epoxy resin composition (Comparative Example 1-2) that does not contain the adhesion improving agent according to the present invention did not show sufficient adhesion to the lead frame.

Claims (5)

Including an epoxy resin, a curing agent, an adhesion improving agent, a coupling agent, a curing accelerator and a filler,
An epoxy resin composition comprising a triazine-based compound having an average particle size of 5 to 30 μm in the adhesion improving agent. The epoxy resin composition of claim 1, wherein the adhesion improving agent comprises a compound represented by the following Formula 1:
[Formula 1]

In the above formula,
R ₁ to R ₃ are the same as or different from each other, and each independently hydrogen, an alkyl group having 1 to 10 carbon atoms, or an alkylene group. The epoxy resin composition of claim 1, wherein R ₁ to R ₃ are each independently a methylene group and an ethylene group. According to claim 1, based on the total weight of the epoxy resin composition
1 to 20% by weight of an epoxy resin,
1 to 20% by weight of a curing agent,
0.01 to 0.5% by weight of an adhesion improving agent,
0.01 to 2% by weight of the coupling agent,
0.05 to 5% by weight of a curing accelerator and
70 to 91% by weight of filler
Epoxy resin composition comprising a. A semiconductor device encapsulated by using the epoxy resin composition according to any one of claims 1 to 4.