Epoxy resin composition for molding

Abstract

The present invention relates to an epoxy resin composition for molding, a semiconductor device encapsulated with the same, or a vehicle part molded with the same.

Description

[Technical Field]

[0001] The present invention relates to an epoxy resin composition for molding, a semiconductor device encapsulated with the same, or a vehicle part molded with the same. [Background technology]

[0002] As the application field of semiconductors rapidly expands, centered on the automotive industry, the performance requirements for semiconductors are becoming increasingly higher, and the reliability evaluation level required to meet these requirements is also becoming higher. Such industrial demands are driving the development of semiconductor constituent materials in a variety of ways. For example, Japanese Patent Publication No. 2017-197620 relates to an epoxy resin composition for semiconductor encapsulation, which contains an epoxy resin, a phenolic resin curing agent, and a filler, and discloses a technology for improving electrical connection reliability by adjusting the filler content and the hot elastic modulus of the cured product of the epoxy resin composition.

[0003] Meanwhile, there is a trend to replace existing silicon (Si) chips with silicon carbide (SiC) chips to improve semiconductor efficiency, but silicon carbide chips have the disadvantage of being more susceptible to cracking due to external impacts (heat, load, etc.) than silicon chips due to the characteristics of the material. Also, semiconductors that require high voltage and high temperature operation, such as power semiconductors, use ceramic substrates to improve insulation and heat dissipation properties, but ceramic materials also have the disadvantage of being vulnerable to cracking due to external impacts. In particular, nitride-based ceramic materials (AlN, Si3N4) used to further improve heat dissipation properties are more susceptible to cracking than the previously used Al2O3 material.

[0004] In addition, to improve the heat dissipation characteristics of semiconductors, silver (Ag) sintering is often used to bond chips to substrates or to bond other dissimilar materials. To achieve this, a thin silver coating is often pre-formed on the part where the silver sintering material is used to enhance the bonding strength of the silver sintering material. However, because silver has weaker adhesion to the encapsulation material than conventional copper materials, it can easily peel off due to external stress. Furthermore, the various dissimilar materials used shrink and expand at different rates due to temperature changes within the semiconductor. This shrinkage and expansion creates high thermal stress within the semiconductor, and the higher the internal temperature of the semiconductor, the greater the stress. This thermal stress can cause peeling at the bond between dissimilar materials within the semiconductor or induce cracks in various materials.

[0005] Epoxy resin compositions have high mechanical strength, heat resistance, electrical insulation, adhesiveness, etc., and are excellent materials for encapsulating semiconductor elements. However, there have been problems with residual stress occurring inside the encapsulant due to differences in the linear expansion coefficient between the encapsulant and the semiconductor material or element, cure shrinkage, or high-temperature conditions such as reflow, which can cause interfacial peeling, cracks, etc. at the interface with the substrate or the encapsulated element.

[0006] Meanwhile, epoxy resin compositions can be used as molding materials for vehicle parts, specifically, to fill or fix parts. Molding materials for such vehicle parts must be stable against vibrations and heat generated during vehicle operation and, in some cases, must be able to withstand deformation or cracking due to high-speed rotation.

[0007] To address these issues, techniques have been developed to incorporate various stress relievers into epoxy resin molding compositions. While carboxylic acid anhydride-based stress relievers can provide stress-reducing properties within the composition, they are difficult to disperse within the resin composition, adversely affecting moldability. Silicone oils, another type of stress reliever, are limited in their use because increased use can cause flow marks on the surface of the molding material, adversely affecting its appearance. Silicone resins, however, are expensive and have limited stress-reducing properties. Silicone powders, while providing excellent stress-reducing properties, can reduce the strength of the resin composition, potentially leading to cracking of the molding material.

[0008] Therefore, there is a need to develop an epoxy resin composition for molding that has a better balance of heat resistance, peel resistance, thermal shock resistance, moisture resistance reliability, and internal stress relaxation. Summary of the Invention [Problem to be solved by the invention]

[0009] The present invention provides an epoxy resin composition for molding that combines high levels of heat resistance, stress reduction, and moisture resistance reliability, and has excellent handleability and reproducibility of physical properties. The present invention also provides a semiconductor device encapsulated with the epoxy resin composition or a vehicle part molded with the same. [Means for solving the problem]

[0010] The present invention provides an epoxy resin composition comprising an epoxy resin, a curing agent, a filler, and a stress relief agent, wherein the particle size of the agglomerated stress relief agent in a kneaded product produced by melt-kneading the epoxy resin composition is 1,500 nm or less. [Effects of the Invention]

[0011] After melt-kneading, the epoxy resin composition of the present invention has the effect of alleviating thermal stress in the constituent materials of the molded material or between the constituent materials, thereby preventing peeling or cracking between the constituent materials of the molded material, and suppressing cracking of the molded material or the constituent materials, by appropriately controlling the particle size of the aggregated stress relief agent in the kneaded product and stably dispersing it.

[0012] In addition, the epoxy resin composition of the present invention can improve the heat resistance, stress reduction, and moisture resistance of the semiconductor device or vehicle part to which it is applied, thereby providing high reliability. BEST MODE FOR CARRYING OUT THE INVENTION

[0013] The present invention will be described in detail below.

[0014] However, the scope of the present invention is not limited to the contents of the following description, and each component may be modified in various ways or selectively mixed as necessary. Therefore, it should be understood that the present invention includes all modifications, equivalents, and alternatives that fall within the spirit and technical scope of the present invention.

[0015] As used herein, "particle size" is measured by a conventional method known in the art, for example, laser light scattering (LLS). "Glass transition temperature" is measured by a conventional method known in the art, for example, thermomechanical analysis (TMA) or differential scanning calorimetry (DSC). "Viscosity" is measured by a conventional method known in the art, for example, using a capillary flowmeter tester (CFT) or a Brookfield viscometer.

[0016] <Epoxy resin composition> The epoxy resin composition according to the present invention includes an epoxy resin, a curing agent, a filler, and a stress relief agent. The particle size of the stress relief agent aggregated in a kneaded mixture obtained by melt-kneading the epoxy resin composition is controlled to 1,500 nm or less, thereby effectively dispersing the stress relief agent within the kneaded mixture and, ultimately, the molding material, thereby imparting low stress characteristics. Therefore, when the epoxy resin composition is used to encapsulate semiconductor devices or mold vehicle parts, a balance of heat resistance, peel resistance, thermal shock resistance, moisture resistance reliability, and internal stress relief can be ensured. The particle size of the aggregated stress relief agent can be measured using a scanning electron microscope (SEM).

[0017] The epoxy resin composition of the present invention may further contain one or more of a variety of additives commonly used in the art, such as a curing accelerator, a coupling agent, a colorant, a mold release agent, a modifier, a flame retardant, etc., to impart additional functions as needed within a range that does not impair the physical properties of the epoxy resin composition of the present invention.

[0018] Epoxy resin In the present invention, the epoxy resin is used as the main resin, and after reacting with the curing agent and curing, it forms a three-dimensional network structure, thereby imparting strong and firm adhesion to the adherend and heat resistance.

[0019] The epoxy resin may be any epoxy resin commonly used in the art, including, for example, one containing two or more epoxy groups in its molecular structure. Non-limiting examples of usable epoxy resins include bisphenol A epoxy resins, alicyclic epoxy resins, cresol novolac epoxy resins, dicyclopentadiene epoxy resins, biphenyl epoxy resins, naphthalene epoxy resins, anthracene epoxy resins, non-condensed polycyclic epoxy resins, and bisphenol fluorene-modified epoxy resins, and the epoxy resin may include one or more of these.

[0020] The softening point of the epoxy resin may be 40 to 130°C, for example, 50 to 120°C. When the softening point of the epoxy resin falls within the above range, a kneaded product with good physical properties can be obtained during the manufacturing process using a kneader, roll mill, or the like. Specifically, when the softening point of the epoxy resin exceeds the above range, the melt-kneading property during the manufacturing process is reduced, resulting in poor uniformity of the resulting epoxy resin composition. Furthermore, the high viscosity may make it difficult to ensure filling during molding of the molding material. On the other hand, when the softening point is below the above range, the resulting epoxy resin composition may suffer from caking, resulting in poor storage stability. Furthermore, the low viscosity may cause excessive leakage of the epoxy resin composition through mold gaps during use, resulting in facility contamination. Furthermore, the molding material may have poor appearance due to the formation of voids and flashes inside and outside the molding material.

[0021] The epoxy resin may have an epoxy equivalent weight (EEW) of 100 to 400 g / eq, for example, 150 to 350 g / eq, and a viscosity (based on 150°C) of 0.01 to 50 poise, for example, 0.01 to 10 poise, or another example, 0.01 to 5 poise. Epoxy resins satisfying the above physical properties have relatively low viscosity characteristics, so that even when a high content of filler is included, flowability can be ensured and kneading is easy.

[0022] The content of the epoxy resin may be 2 to 20 wt %, for example, 5 to 15 wt %, based on the total weight of the epoxy resin composition. If the content of the epoxy resin is less than the above range, adhesion, flowability, and moldability may be reduced, and if it exceeds the above range, the reliability of the molding material may be reduced due to an increase in moisture absorption, and the strength may be reduced due to a relative decrease in the filler content.

[0023] hardener The epoxy resin composition according to the present invention contains a curing agent, which reacts with the epoxy resin to promote curing of the composition.

[0024] The curing agent may be a curing agent known in the art that undergoes a curing reaction with the epoxy resin, and may be, for example, a phenolic compound having two or more phenolic hydroxyl groups in one molecule. For example, the curing agent may include one or more selected from the group consisting of phenol novolac resin, cresol novolac resin, phenol aralkyl resin, and polyfunctional phenolic compound.

[0025] The softening point of the curing agent may be 50 to 110°C, for example, 60 to 100°C. When the softening point of the curing agent falls within the above range, a melt-kneaded product with good physical properties can be obtained during the manufacturing process using a kneader, roll mill, or the like. When the softening point of the curing agent exceeds the above range, the melt-kneading property during the manufacturing process decreases, resulting in poor uniformity of the resulting epoxy resin composition. Furthermore, the high viscosity may make it difficult to ensure filling during molding of the molding material. On the other hand, when the softening point is below the above range, the resulting epoxy resin composition may suffer from caking, resulting in poor storage stability. Furthermore, the low viscosity may cause excessive leakage of the epoxy resin composition through mold gaps during use, resulting in facility contamination. Furthermore, the molding material may have poor appearance due to the formation of voids and flashes inside and outside the molding material.

[0026] The curing agent may have a hydroxyl equivalent of 80 to 300 g / eq, e.g., 100 to 230 g / eq, and a viscosity (at 150°C) of 0.01 to 10 poise, e.g., 0.01 to 8 poise. Based on the total weight of the epoxy resin composition, the content of the curing agent may be 1 to 20 wt%, e.g., 3 to 10 wt%. If the content of the curing agent is less than the above range, curability and moldability may be reduced. If the content exceeds the above range, the increased moisture absorption may result in poor reliability and reduced strength of the molding material.

[0027] The mixing ratio of the epoxy resin and the curing agent can be adjusted depending on the mechanical properties and reliability required of the molding material, for example, at an equivalent ratio of 1:0.6 to 1.3. If the equivalent ratio of the active groups of the curing agent to the epoxy groups is below the above range, the curing rate of the resin composition may be slow, and if it exceeds the above range, the strength of the cured product may be reduced. Furthermore, if the equivalent ratio is outside the above range, high-temperature thermal decomposition due to unreacted epoxy groups or the curing agent may occur.

[0028] filling material The epoxy resin composition according to the present invention includes a filler, which serves to improve the mechanical properties (e.g., strength) of the epoxy resin composition and reduce moisture absorption.

[0029] The filler may be any inorganic filler commonly used in the art, such as silica, silica nitride, alumina, aluminum nitride, boron nitride, etc., which may be used alone or in combination of two or more. The shape of the filler is not particularly limited, and both angular and spherical shapes may be used.

[0030] The particle size of the filler is not particularly limited and may be, for example, in the range of 5 to 30 μm. Furthermore, when taking into consideration the filling property in a mold, the maximum particle size of the filler may be 250 μm or less, for example, 180 μm or less.

[0031] The content of the filler may be 63 to 91 wt %, for example, 65 to 90 wt %, based on the total weight of the epoxy resin composition. If the content of the filler is less than the above range, the moisture absorption amount in the cured product of the epoxy resin composition may increase, which may reduce the reliability of the molding material. If the content of the filler is more than the above range, the fluidity may decrease, which may result in poor moldability.

[0032] Stress reliever The epoxy resin composition according to the present invention contains a stress relief agent to impart low stress properties and improve impact resistance.

[0033] The stress relief agent may have a core-shell structure. In this case, the core component is not dissolved in the epoxy resin composition, so that the stress can be reduced while suppressing a decrease in heat resistance (glass transition temperature), and the shell component has excellent compatibility and affinity with the epoxy resin composition and can be well dispersed.

[0034] The core of the stress relaxation agent may be one that has rubber elasticity but is insoluble in epoxy resins. Examples of the core include butadienes such as polybutadiene, isoprene, and chloroprene; butadiene copolymers such as butadiene-styrene; (meth)acrylates such as butyl (meth)acrylate, 2-ethylhexyl acrylate, and lauryl methacrylate; and siloxanes, and these may be used alone or in combination of two or more.

[0035] The shell of the stress relaxation agent serves to improve the affinity between the epoxy resin and the components constituting the core, and may be formed in a form graft-polymerized (bonded) to the core. To ensure stable dispersion in the epoxy resin composition, the shell may have swelling, compatibility, or affinity with the epoxy resin. For example, the shell may include (meth)acrylates such as methyl (meth)acrylate, acrylate copolymers with styrene, etc., and may contain these alone or in combination. The (co)polymer constituting the shell may be surface-treated with an organic or inorganic functional group to improve dispersibility. Non-limiting examples of the organic or inorganic functional group include organic functional groups such as hydroxyl, methyl, and ethyl groups, and inorganic functional groups such as silane groups.

[0036] The individual particle size of the stress relief agent may be 500 nm or less, for example, 20 to 500 nm, or another example, 20 to 400 nm. When the particle size is within the above range, the stress relief agent can be well dispersed in the kneaded material. When the particle size is below the above range, the viscosity of the epoxy resin composition may increase, resulting in problems such as incomplete filling of the molding material. When the particle size is above the above range, the stress-reducing properties may not be fully expressed due to agglomerated particles, and mechanical properties such as strength may be reduced.

[0037] The stress relief agent is dispersed in a kneaded mixture prepared by melt-kneading the epoxy resin composition, and may exist in a partially aggregated form. The particle size of the aggregated stress relief agent may be 1,500 nm or less, for example, 10 to 1,500 nm, or another example, 50 to 1,000 nm. If the particle size of the aggregated particles in the kneaded mixture exceeds the above-mentioned range, the stress-reducing properties may not be fully exhibited, and mechanical properties such as strength may be reduced. On the other hand, if the particle size of the aggregated particles is less than the above-mentioned range, the flowability may be poor.

[0038] Before being added to the epoxy resin composition, the stress relief agent exists as particles of tens to hundreds of microns in size, with individual particles of 500 nm or less clumping together. If the stress relief agent, which is clumped together into particles of tens to hundreds of microns in size, does not disperse and remains inside the molding material, it will not exhibit effective low-stress properties, which can lead to problems such as cracking due to external stress, reducing impact resistance.

[0039] Therefore, the present invention provides a molding material with sufficient low stress properties by appropriately dispersing a stress relaxation agent in the molding material. Specifically, by adjusting the particle size of the stress relaxation agent aggregated in the melt-kneaded mixture of the epoxy resin composition to 1,500 nm or less, it is possible to provide a molding material with excellent reliability by imparting low stress properties and impact resistance.

[0040] For example, particle size can be controlled by simultaneously adding a stress relaxation agent to an epoxy resin composition along with an epoxy resin, a curing agent, a filler, etc., and melt-kneading the mixture. However, if it is difficult to adequately control the particle size of the aggregated stress relaxation agent by melt-kneading alone, a two-step process can be used: first, a linear dispersion resin composition is formed by linearly dispersing all or a portion of the stress relaxation agent in a linear dispersion resin, and then this is added to the epoxy resin composition along with the remaining components. In this case, the linear dispersion resin can be a portion or all of one or more of the epoxy resin and the curing agent.

[0041] As one example, a portion or all of the stress relief agent may be linearly dispersed in a portion or all of the epoxy resin, and then introduced into an epoxy resin composition containing the remaining epoxy resin, the remaining stress relief agent, the curing agent, a filler, etc. As another example, a portion or all of the stress relief agent may be linearly dispersed in a portion or all of the curing agent, and then introduced into an epoxy resin composition containing the epoxy resin, the remaining stress relief agent, the remaining curing agent, a filler, etc.

[0042] For example, the resin for linear dispersion is melted at a temperature above the softening point of the resin (e.g., 150°C), and then all or part of the stress relief agent is linearly dispersed using a stirrer rotated at high speed. If necessary, the agitation temperature or speed can be increased during linear dispersion to control the agglomerated size of the stress relief agent to 1,500 nm or less. The dispersion temperature during the linear dispersion process can be controlled to 200°C or less; if the temperature exceeds 200°C, carbonization of the resin may occur.

[0043] In the linear dispersion process, the stress relaxation agent may be included in an amount of 5 to 50 wt %, for example, 10 to 30 wt %, based on the total weight of the linear dispersion resin composition. If the content of the stress relaxation agent in the linear dispersion resin composition is less than the above range, the amount of the stress relaxation agent in the epoxy resin composition may be limited. If the content exceeds the above range, the viscosity of the linear dispersion resin composition may increase, which may reduce molding and formability, and dispersibility may decrease.

[0044] The content of the stress relaxation agent may be 0.5 to 10 wt%, for example, 1 to 5 wt%, based on the total weight of the epoxy resin composition. If the content of the stress relaxation agent is less than the above range, the stress-reducing effect may not be sufficiently exhibited, and if the content exceeds the above range, mechanical properties such as strength may decrease or thermal properties such as glass transition temperature and thermal expansion coefficient may become weak.

[0045] Curing accelerator The epoxy resin composition according to the present invention may further include a curing accelerator, which serves to accelerate the curing reaction and improve high-temperature reliability and continuous workability.

[0046] The curing accelerator may be any conventional accelerator used in the art for accelerating curing reactions, without limitation. For example, imidazole compounds such as 2-methylimidazole, 2-ethyl-4-methylimidazole, and 2-phenylimidazole; amine compounds such as triethylamine, tributylamine, and benzyldimethylamine; tertiary amine compounds such as 2-(dimethylaminemethyl)phenol, 2,4,6-tris(dimethylaminomethyl)phenol, and 1,8-diazabicyclo(5,4,0)undec-7-ene; and organic phosphine compounds such as phenylphosphine, diphenylphosphine, triphenylphosphine, tributylphosphine, and tri(p-methylphenyl)phosphine. These may be used alone or in combination.

[0047] The content of the curing accelerator may be 0.05 to 1 wt %, for example, 0.05 to 0.5 wt %, based on the total weight of the epoxy resin composition. If the content of the curing accelerator is less than the above range, curing may be reduced, and if it exceeds the above range, flowability may be reduced due to over-curing.

[0048] additives The epoxy resin composition according to the present invention may further contain additives commonly used in the art to the extent that they provide a specific function or effect, do not deviate from the intended purpose, and do not impair the physical properties of the epoxy resin composition according to the present invention. Non-limiting examples of usable additives include coupling agents, colorants, mold release agents, modifiers, flame retardants, or mixtures of two or more thereof.

[0049] The epoxy resin composition of the present invention exhibits excellent flame retardancy by itself due to the high filler content, but may further contain a flame retardant to further improve the flame retardancy. The flame retardant may be, but is not limited to, metal hydroxides, phosphorus- and nitrogen-containing organic compounds (e.g., resorcinol diphosphate, phosphate, phenoxyphosphazene, melamine cyanurate, and phenol-melamine resin), which may be used alone or in combination.

[0050] The coupling agent is added to stably disperse the organic and inorganic materials, and examples of the coupling agent include epoxysilane, aminosilane, mercaptosilane, acrylsilane, and vinylsilane.

[0051] The resin composition may further contain additives such as a colorant (e.g., carbon black, red iron oxide, etc.) for imparting a hue to the resin resin composition, an ion scavenger (e.g., hydrotalcite-based), a release agent such as a long-chain fatty acid, a metal salt of a long-chain fatty acid, paraffin wax, carnauba wax, or polyethylene wax, a modifier, or a modified silicone resin.

[0052] The additives may be added within a content range known in the art, for example, 0.05 to 5 wt % each based on the total weight of the epoxy resin composition, but are not limited thereto.

[0053] The epoxy resin composition according to the present invention may be prepared by a conventional method known in the art, for example, a melt-kneading method using a Banbury mixer, a kneader, a roll, a single-screw or twin-screw extruder, a co-kneader, etc. For example, the epoxy resin composition obtained by uniformly mixing the above-described components may be melt-mixed at a temperature of 80 to 130°C using a heat kneader, cooled to room temperature, pulverized into powder, and then subjected to a sieving process to obtain a kneaded product.

[0054] The epoxy resin composition for molding according to the present invention can exhibit excellent heat resistance, peel resistance and internal stress reduction effects through good dispersion of the stress relief agent by controlling the particle size of the agglomerated stress relief agent within the kneaded material.

[0055] In particular, the epoxy resin composition for molding of the present invention has low stress properties due to the appropriately dispersed stress relaxation agent, and may have an elastic modulus (30°C) of 11 to 20 GPa. As a result, the low-stress epoxy resin composition of the present invention has the effect of suppressing the occurrence of cracks and fractures due to external stress, and can provide high reliability to semiconductor devices encapsulated using the composition and vehicle parts molded using the composition.

[0056] The epoxy resin composition of the present invention is prepared by subjecting the kneaded product to a heating and transfer molding machine (pressure 70 kg / cm) using a spiral flow mold. 2 The flowability measured after molding under conditions (temperature 175°C, curing time 120 seconds) may be 15 to 100 inches, for example 20 to 80 inches. If the spiral flow is below the above range, the flowability and fluidity may be reduced, resulting in a molded product not being molded into the desired shape or not having a smooth surface. If the spiral flow exceeds the above range, the epoxy resin composition may overflow through gaps in the mold, causing facility contamination, and may cause poor appearance due to the formation of voids and flash inside and outside the molding material.

[0057] The epoxy resin composition of the present invention can be prepared in the form of powder, granules, or sheet by processing the kneaded product in a suitable form depending on the mode of use. In particular, the epoxy resin composition of the present invention can be used for power semiconductor molding by suppressing bending or deformation of the molding target material.

[0058] In particular, the epoxy resin composition for molding of the present invention is applicable to semiconductor packaging for power modules and power semiconductor packaging, which are frequently exposed to harsh conditions (high power, high voltage), and is also applicable to highly integrated semiconductor packages and semiconductor packages made of different materials such as silicon carbide (Si-C) and nitride ceramics (AlN, Si3N4).

[0059] In addition, the epoxy resin composition for molding of the present invention can be used as a molding material for vehicle parts that require excellent vibration resistance, heat resistance, dimensional stability, and deformation resistance, and can be used to fill or fix parts.

[0060] <Semiconductor elements and vehicle parts> The present invention provides a semiconductor device encapsulated using the above-described epoxy resin composition. The semiconductor device may be a transistor, a diode, a microprocessor, a semiconductor memory, a power semiconductor, etc. The method of encapsulating a semiconductor device using the epoxy resin composition of the present invention may be performed by a molding method commonly used in the art, such as transfer molding, compression molding, or injection molding.

[0061] The present invention also provides a vehicle part molded using the above-described epoxy resin composition. For example, the above-described epoxy resin composition can be used as a molding material to fix and seal components within the vehicle part. Specifically, a permanent magnet can be inserted into an empty space formed in a rotor core, and the epoxy resin composition of the present invention can be filled between the empty space and the permanent magnet to fix the permanent magnet within the rotor core.

[0062] The present invention will be described in more detail with reference to the following examples. However, the following examples are merely intended to aid in understanding the present invention and are not intended to limit the scope of the present invention in any way.

[0063] <Mode for carrying out the invention> <Production Example 1: Production of Stress Relaxant Linearly Dispersed Resin (E-1)> After melting 75 parts by weight of orthocresol novolac epoxy resin (A-1) in a 150°C reactor, Dispermat was fixed at 700 rpm, and 25 parts by weight of stress relief agent (D-2) was slowly added in three portions over 10 minutes. The temperature was then maintained at 150°C, and the rpm was increased to 2,000 for 60 minutes of high-speed stirring. A sample of the linearly dispersed resin was taken and the degree of dispersion and particle size of the stress relief agent were measured using an electron microscope. If the particle size exceeded 500 nm, the temperature was increased to 175°C, the stirring speed was increased to 3,000 rpm, or both conditions were applied, and linear dispersion was continued while measuring the particle size every 30 minutes. When the particle size reached 500 nm or less, stirring was stopped and the mixture was immediately discharged and solidified.

[0064] <Production Example 2: Production of Stress Relaxant Linearly Dispersed Resin (E-2)> The same production method as in Production Example 1 was used, except that the stress relaxation agent (D-1) was used instead of the stress relaxation agent (D-2).

[0065] <Production Example 3: Production of stress relaxation agent linearly dispersed resin (E-3)> The same production method as in Production Example 1 was used, except that the phenol novolac type curing agent (B-1) was used instead of the epoxy resin (A-1).

[0066] <Experimental Example 1-13> The epoxy resin compositions for each experiment were prepared by blending the components according to the formulas listed in Tables 1 and 2 below. The epoxy resin compositions for each experiment were melt-mixed at temperatures between 90 and 130°C using a melt kneader and cooled to room temperature. The resulting powder was then sieved through 20 and 80 mesh sieves to obtain the kneaded products. The particle size of the stress relief agent aggregated within the epoxy resin composition kneaded products prepared in each experiment was measured using a scanning electron microscope (SEM, FEI, QUANTA 3D FEG). The magnification of the SEM was varied from 10,000 to 50,000 times depending on the particle size. The size of the aggregated stress relief agent observed in 10 randomly selected cross-sectional SEM images for each experiment was measured, and the largest size measured was recorded as the particle size of the aggregated stress relief agent, as shown in Tables 1 and 2.

[0067] [Table 1]

[0068] [Table 2]

[0069] Epoxy resin A-1: ​​Orthocresol novolac epoxy resin (softening point 62°C, epoxy equivalent 201g / eq., melt viscosity (150°C) 0.3 poise) Curing agent B-1: Phenolic resin (softening point 84°C, epoxy equivalent 107g / eq., melt viscosity (150°C) 2.0 poise) Filler C-1: Silica (average particle size 19.9 μm) Stress relaxation agent D-1: Core-shell (average particle size: 250 nm, core: Co-polymer siloxane, shell: ACRYL) Stress relaxation agent D-2: Core-shell (average particle size: 200 nm, core: butadienes, shell: acrylic) Stress relief agent D-3: Powder (average particle size: 2 μm, silicone particles) Stress relaxation agent D-4: Core-shell (average particle size: 430 nm, core: butadienes, shell: acrylic) Linear dispersion resin E-1: stress relaxation agent linear dispersion resin of Production Example 1 (softening point 66°C, epoxy equivalent 251 g / eq, melt viscosity (150°C) 6.0 poise) Linear dispersion resin E-2: Stress relaxation agent linear dispersion resin of Manufacturing Example 2 Linear dispersion resin E-3: Stress relaxation agent linear dispersion resin of Manufacturing Example 3 Curing accelerator F-1: Imidazole-based curing accelerator Additive G-1: Carbon black Additive G-2: Carnauba wax Additive G-3: Epoxysilane Additive G-4: Aluminum hydroxide <Physical property evaluation> The physical properties of the epoxy resin compositions prepared in each experimental example were measured as follows, and the results are shown in Tables 3 and 4 below.

[0070] Test specimen manufacturing The kneaded epoxy resin composition prepared in each experimental example was molded at 175°C for 120 seconds using a transfer molding method to form a test piece for evaluating physical properties, which was then cured at 175°C for 4 hours.

[0071] Spiral flow Using an evaluation mold according to EMMI-1-66, the specimen was transferred to a transfer molding press (175°C, 70 kgf / cm 2 ) was used to measure the flowability.

[0072] Elasticity / Strength Four identical test pieces measuring 125mm x 12.5mm x 6mmT were prepared, and the elastic modulus and strength were measured using a UTM (Universal test machine) 3-point bending method (distance between support spans: 100mm, crosshead speed: 2.8mm / min).

[0073] Glass transition temperature / thermal expansion coefficient Test pieces of the same size were molded and measured using a thermo-mechanical analyzer (TMA) at a heating rate of 10°C / min from room temperature to 300°C, and the glass transition temperature was determined using the onset point method. The thermal expansion coefficient was also measured in the 80~120°C range.

[0074] Ag peeling TO-247 packages were molded using MGP (Multi-gang pot) equipment with Ag-plated general-purpose lead frames. The molded packages were post-cured and passed through 260℃ IR reflow processes five times. Internal delamination was confirmed using SAT (Scanning Acoustic Tomography).

[0075] [Table 3]

[0076] [Table 4]

[0077] As can be seen from the results in Tables 3 and 4, Experimental Examples 1 to 7 according to the present invention showed excellent physical properties in all measurement items. In particular, Experimental Examples 2, 6, and 7, in which the stress relaxation agent was linearly dispersed in the epoxy resin or curing agent, showed particularly excellent strength and peel resistance.

[0078] On the other hand, Experimental Example 8, in which no stress relief agent was used, Experimental Examples 9, 10, 12, and 13, in which the particle size of the aggregated stress relief agent was outside the range of the present invention, and Experimental Examples 11 and 12, in which the content of the stress relief agent was outside the range of the present invention, showed inferior physical properties compared to Experimental Examples 1 to 7. [Industrial Applicability]

[0079] The epoxy resin composition of the present invention, after melt kneading, appropriately controls the particle size of the agglomerated stress relief agent within the kneaded product and stably disperses it, thereby alleviating thermal stress in the constituent materials of the molding object or between the constituent materials, thereby preventing delamination or cracking between the constituent materials of the molding object and suppressing cracking of the molding object or the constituent materials. Furthermore, the epoxy resin composition of the present invention can improve the heat resistance, stress reduction, and moisture resistance of the semiconductor device or vehicle part to which it is applied, thereby providing high reliability.

Claims

1. A method for producing an epoxy resin composition for molding, comprising: an epoxy resin, a curing agent, a filler, and a stress relaxation agent, providing a stress relief agent having an individual particle size of 20 to 400 nm; and adding a part or all of the stress relaxation agent to a dispersion resin in portions, and dispersing the mixture by high-speed stirring using a Dispermat while maintaining the temperature at 150°C and increasing the number of revolutions per minute from 700 rpm to 2,000 rpm to form a stress relaxation agent-dispersed resin composition, which is then added to the epoxy resin composition. the dispersing resin is at least one of a part or all of the epoxy resin; and a part or all of the curing agent; Thus, the epoxy resin composition is melt-mixed at a temperature of 90 to 130°C using a melt kneader, and then cooled to room temperature. When the kneaded product is measured using a scanning electron microscope (SEM), the particle size of the aggregated stress relief agent is less than 600 nm.

2. The stress relaxation agent has a core-shell structure, the core of the stress relaxation agent comprises one or more resins selected from the group consisting of butadienes, butadiene copolymers, (meth)acrylates, and siloxanes; 2. The method for producing an epoxy resin composition for molding according to claim 1, wherein the shell of the stress relaxation agent comprises at least one selected from the group consisting of a (meth)acrylate polymer and an acrylate copolymer.

3. one or more of the (meth)acrylate polymer and the acrylate copolymer constituting the shell are surface-treated with at least one group selected from the group consisting of a hydroxyl group, a methyl group, and an ethyl group and / or a silane group; A method for producing the epoxy resin composition for molding according to claim 2.

4. 2. The method for producing an epoxy resin composition for molding according to claim 1, wherein the stress relaxation agent is contained in an amount of 5 to 50% by weight based on the total weight of the stress relaxation agent-dispersed resin composition.

5. 2. The method for producing an epoxy resin composition for molding according to claim 1, wherein the epoxy resin composition contains 2 to 20 wt % of the epoxy resin, 1 to 20 wt % of the curing agent, 63 to 91 wt % of the filler, and 0.5 to 10 wt % of the stress relaxation agent, based on a total weight of the epoxy resin composition.

6. 2. The method for producing an epoxy resin composition for molding according to claim 1, wherein the epoxy resin composition has an elastic modulus of 11-20 GPa measured at 30° C. by a UTM (Universal Test Machine) 3-point bending method.

7. A semiconductor device encapsulated using the epoxy resin composition produced by the method for producing an epoxy resin composition for molding according to any one of claims 1 to 6.

8. A vehicle part molded using the epoxy resin composition produced by the method for producing an epoxy resin composition for molding according to any one of claims 1 to 6.

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