Liquid epoxy resin composition

Abstract

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

Description

Technology Field

[0001] The present invention relates to a liquid epoxy resin composition and a semiconductor device molded using the same. Background Technology

[0002] Encapsulating resin compositions are used as materials to improve the characteristics and reliability of semiconductor devices by sealing semiconductor devices such as integrated circuits (ICs), large-capacity integrated circuits (LSIs), transistors, and diodes. Recently, as the high integration of semiconductors accelerates in accordance with the trends of miniaturization, lightweighting, and high performance of electronic devices, research to improve the performance of materials used for sealing semiconductor devices is being conducted in various ways. For example, Japanese Patent Publication No. 2017-197620 relates to an epoxy resin composition for semiconductor sealing comprising an epoxy resin, a phenolic resin curing agent, and a filler, and discloses a technology that improves electrical connection reliability by controlling the content of the filler and the thermal modulus of the cured product of the epoxy resin composition.

[0003] In particular, as semiconductor chips are becoming smaller in response to the demand for high density and integration, wafer-level packaging, where the size of the chip and the package are the same, is being widely applied. Due to filling limitations, it is difficult to apply the transfer molding method to wafer-level packaging, so the compression molding method is generally used. In this case, the use of solid molding compounds with poor flowability frequently results in unfilled areas during large-area molding, leading to an increasing trend of using liquid molding compounds.

[0004] However, in the case of molding compounds, a large amount of filler is included to improve physical properties (e.g., to suppress wafer warping when applied to semiconductor devices). In the case of liquid molding compounds, if the filler content increases, fluidity decreases, resulting in poor ejection into the mold and high shear stress being applied during molding, which causes problems such as die floating where the wafer deviates from its original position.

[0005] Accordingly, there is a need to develop a liquid epoxy resin composition for sealants that contains a high content of filler (e.g., more than 50 wt%) and has excellent dispersibility, fluidity, extrusion, moldability, and warping inhibition properties. The problem to be solved

[0006] The present invention provides a liquid epoxy resin composition with excellent dispersibility, fluidity, and bending inhibition properties, and a semiconductor device molded using the same. means of solving the problem

[0007] The present invention provides a liquid epoxy resin composition comprising an epoxy resin, a curing agent, a filler, and a siloxane, wherein the siloxane is a siloxane with a symmetric structure in which an alicyclic epoxy group is substituted on a center silicon. Effects of the invention

[0008] The present invention provides a liquid epoxy resin composition having excellent dispersibility, fluidity, and warping inhibition properties. The liquid epoxy resin composition according to the present invention can provide excellent fluidity and warping inhibition properties even when containing a high content of filler by improving the dispersibility of the filler. Accordingly, the liquid epoxy resin composition of the present invention is applicable to compression molding methods, particularly compression molding methods for manufacturing wafer-level packages. Specific details for implementing the invention

[0009] The present invention will be described in detail below. However, it is not limited to the following description, and each component may be modified in various ways or selectively combined as needed. Accordingly, it should be understood that the invention includes all modifications, equivalents, and substitutions that fall within the spirit and scope of the invention.

[0010] As used herein, “weight-average molecular weight” is measured by conventional methods known in the art, for example, by the gel permeation chromatograph (GPC) method. “Viscosity” is measured by conventional methods known in the art, for example, by using a Brookfield viscometer at room temperature (25 °C). “Glass transition temperature” is measured by conventional methods known in the art, for example, by thermomechanical analysis (TMA) or differential scanning calorimetry (DSC). “Particle size (D 50 )" is measured by conventional methods known in the relevant technical field, and can be measured, for example, by a laser particle size analyzer.

[0012] Liquid Epoxy Resin Composition

[0013] The liquid epoxy resin composition according to the present invention comprises an epoxy resin, a curing agent, a filler, and a siloxane. By using a siloxane with a symmetric structure in which an alicyclic epoxy group is substituted on a center silicon, the present invention provides a liquid epoxy resin composition having excellent mechanical properties and excellent dispersibility and fluidity.

[0015] Epoxy resin

[0016] The liquid epoxy resin composition of the present invention comprises an epoxy resin. The epoxy resin is used as the main resin and, by reacting with a curing agent and curing to form a three-dimensional network structure, can impart properties of strong and rigid adhesion to a substrate and heat resistance.

[0017] As the above epoxy resin, an epoxy resin commonly used in the relevant technical field may be used. Non-limiting examples of available 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, tetramethylbiphenyl 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 novolak type epoxy resin, naphthol cresol coaxial novolak type epoxy resin, aromatic hydrocarbon formaldehyde resin modified phenol resin type epoxy resin, triphenylmethane type epoxy resin, tetraphenylethane type epoxy resin, dicyclopentadiene type epoxy resin, dicyclopentadiene phenol addition type epoxy resin, biphenyl type epoxy resin, phenol aralkyl type epoxy resin, polyfunctional phenol resin, and naphthol. There are aracle-type epoxy resins, etc., and one or more of these may be included.

[0018] For example, the above epoxy resin may include a bisphenol F type epoxy resin; a cycloaliphatic epoxy resin such as (3',4'-epoxycyclohexane)methyl 3,4-epoxycyclohexyl carboxylate; an aminophenol type epoxy resin such as p-(2,3-epoxypropoxy)-N,N-bis(2,3-epoxypropyl)aniline; or a mixture thereof.

[0019] For example, the above epoxy resin may include bisphenol F-type epoxy resin, alicyclic epoxy resin, and aminophenol-type epoxy resin. In this case, the viscosity, modulus, glass transition temperature, etc. of the liquid epoxy resin composition can be effectively controlled, and excellent extrusion, moldability, heat resistance, and temperature cycle resistance characteristics can be secured.

[0020] The above epoxy resin may be used with an epoxy equivalent (EEW) of 50 to 400 g / eq, for example, 90 to 300 g / eq. If the epoxy equivalent is below the aforementioned range, the curing density may be excessively high, leading to excessive curing shrinkage and increased brittleness, which may cause cracking; if it exceeds the aforementioned range, the curing density may be low, resulting in poor heat resistance.

[0021] The above epoxy resin may have a viscosity (25°C) of 100 to 2,000 Pas, for example, 200 to 1,500 Pas. If the viscosity is below the aforementioned range, the viscosity of the liquid epoxy resin composition is too low, so leakage from the mold may occur during molding. If the viscosity exceeds the aforementioned range, the viscosity is too high, so fluidity is reduced, the dischargeability of the liquid epoxy resin composition is reduced, and clogging of the discharge port may occur. Additionally, the liquid epoxy resin composition may not be sufficiently discharged into the mold, resulting in poor moldability of the product.

[0022] The above epoxy resin may have a weight-average molecular weight of 100 to 1,000 g / mol, for example, 200 to 350 g / mol. If the weight-average molecular weight is below the aforementioned range, it may volatilize during molding and cause mold contamination, and if it exceeds the aforementioned range, fluidity may decrease due to intermolecular entanglement, resulting in poor dispersion of fillers or reduced moldability.

[0023] Based on the total weight of the liquid epoxy resin composition, the content of the epoxy resin may be 2 to 20 weight%, for example, 5 to 10 weight%. If the content of the epoxy resin is less than the aforementioned range, adhesion, flowability, and moldability may be reduced, and if it exceeds the aforementioned range, the reliability of the semiconductor may be poor due to increased moisture absorption, and the warping phenomenon may worsen or strength may be reduced due to an increase in the coefficient of thermal expansion caused by a relative decrease in the filler content.

[0025] hardener

[0026] The liquid epoxy resin composition of the present invention includes a curing agent. The curing agent reacts with the epoxy resin to facilitate the curing of the composition.

[0027] As the above curing agent, a curing agent known in the relevant technical field for curing with an epoxy resin may be used, and acid anhydrides, phenolic compounds, etc. may be used. For example, the above curing agent may be an acid anhydride such as phthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, trialkyltetrahydrophthalic anhydride, tetrahydrophthalic anhydride.

[0028] Based on the total weight of the liquid epoxy resin composition, the content of the curing agent may be 1 to 20 weight%, for example, 1 to 10 weight%. If the content of the curing agent is less than the aforementioned range, curability and moldability may be reduced, and if it exceeds the aforementioned range, the reliability of the semiconductor may be poor and strength may be reduced due to increased moisture absorption.

[0030] filling

[0031] The liquid epoxy resin composition of the present invention includes a filler. The filler improves the mechanical properties (e.g., strength, heat resistance, etc.) of the liquid epoxy resin composition, controls the viscosity of the liquid epoxy resin composition to provide appropriate flowability, and serves to reduce moisture absorption.

[0032] As the above filler, inorganic fillers commonly used in the field of electronic materials can be used without special restrictions. For example, inorganic fillers such as silica, silica nitride, alumina, aluminum nitride, and boron nitride can be used, and these can be used individually or in combination of two or more types.

[0033] The shape of the above filler is not particularly limited, and both angular and spherical shapes can be used. Non-limiting examples of fillers that can be used in the present invention include natural silica, synthetic silica, fused silica, etc., and, for example, spherical silica particles can be used. The above filler can be used after surface treatment with epoxy silane, phenylamino silane, amino silane, etc.

[0034] The above filler may include two or more types of fillers with different particle sizes. In this case, the moldability and workability of the liquid epoxy resin composition can be further improved. For example, the above filler has an average particle size (D 50 A first filler having a diameter of 5 to 30 μm, for example, 10 to 25 μm, and an average particle size (D 50 It may include a second filler having a thickness of 0.1 to 3 μm, for example, 0.1 to 1 μm.

[0035] Based on the total weight of the liquid epoxy resin composition, the content of the filler may be 50 to 93 weight%, for example, 70 to 93 weight%. If the content of the filler is less than the aforementioned range, the moisture absorption of the cured product increases, which may reduce the reliability of the semiconductor device, and the coefficient of thermal expansion increases, leading to excessive warping and causing delamination due to stress; if it exceeds the aforementioned range, fluidity decreases, which may result in poor moldability.

[0037] Silroksan

[0038] The liquid epoxy resin composition of the present invention comprises a siloxane. The siloxane is a siloxane with a symmetric structure in which an alicyclic epoxy group is substituted on a center silicon atom. By using a siloxane with such a structure, the filler can be effectively dispersed, thereby providing a liquid epoxy resin composition with excellent dispersibility, fluidity, and bending inhibition properties.

[0039] The above siloxane can be represented by the following chemical formula 1.

[0040] [Chemical Formula 1]

[0041]

[0042] In the above formula,

[0043] R1 is And,

[0044] R2 is a substituted or unsubstituted hydrocarbon group having 1 to 5 carbon atoms, and

[0045] R3 is a substituted or unsubstituted hydrocarbon group having 1 to 5 carbon atoms, and

[0046] n is an integer from 0 to 3, and

[0047] m is an integer from 2 to 8, and

[0048] R4 is hydrogen, or a substituted or unsubstituted hydrocarbon group having 1 to 3 carbon atoms, and

[0049] R5 is hydrogen, or a substituted or unsubstituted hydrocarbon group having 1 to 3 carbon atoms.

[0050] For example, in the above equation, R1 is R2 is a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms, R3 is a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms, n is an integer from 0 to 3, m is an integer from 2 to 8, R4 is hydrogen, or a substituted or unsubstituted alkyl group having 1 to 3 carbon atoms, and R5 is hydrogen, or a substituted or unsubstituted alkyl group having 1 to 3 carbon atoms.

[0051] For example, in the above equation, R1 is R2 is a substituted or unsubstituted alkyl group having 1 to 3 carbon atoms, R3 is a substituted or unsubstituted alkyl group having 1 to 3 carbon atoms, n is 0 or 1, m is an integer from 2 to 4, R4 is a substituted or unsubstituted alkyl group having 1 to 3 carbon atoms, and R5 is a substituted or unsubstituted alkyl group having 1 to 3 carbon atoms.

[0052] For example, in the above equation, R1 is R2 is an ethyl group, n is 0, m is 4, R4 is a methyl group, and R5 is a methyl group.

[0053] For example, the above siloxane may be 3-[2-(3,4-epoxycyclohexyl)ethyl]-1,1,1,3,5,5,5-heptamethyltrisiloxane.

[0054] As the above siloxane, a molecular weight of 200 to 800 g / mol, for example 300 to 400 g / mol, may be used. If the molecular weight is below the aforementioned range, it is difficult to exert a sufficient steric hindrance effect when adsorbed onto the surface of the filler, so re-aggregation between adjacent fillers may occur; if it exceeds the aforementioned range, the molecular size is too large relative to the specific surface area of ​​the filler, so it may not be able to efficiently cover the surface of the filler.

[0055] Based on the total weight of the liquid epoxy resin composition, the content of the siloxane may be 0.1 to 2 weight%, for example, 0.2 to 0.6 weight%. If the content of the siloxane is below the aforementioned range, the dispersion effect may be negligible and fluidity may be reduced, and if it exceeds the aforementioned range, the glass transition temperature of the liquid epoxy resin composition may be lowered and heat resistance may be poor.

[0057] additives

[0058] The liquid epoxy resin composition of the present invention may additionally include additives commonly used in said composition. Non-limiting examples of usable additives include catalysts and colorants.

[0059] The catalyst promotes the curing reaction and may include epoxy / amine adducts, imidazole compounds, naphthalene-based latent catalysts, amine compounds, organometallic compounds, organophosphorus compounds, boron compounds, etc. Colorants are added to impart color to the resin composition, and carbon black, Bengala, etc. may be used as colorants.

[0060] The above additives may be added within a content range known in the relevant technical field, and for example, may be included in an amount of 0.01 to 5 weight% each with respect to the total weight of the liquid epoxy resin composition, but are not limited thereto.

[0062] Semiconductor Devices and Automotive Parts

[0063] The present invention provides a semiconductor device molded using the aforementioned liquid epoxy resin composition. The semiconductor device may be a transistor, a diode, a microprocessor, a semiconductor memory, a power semiconductor, etc.

[0064] In addition, the present invention provides a vehicle part molded using the aforementioned liquid epoxy resin composition. For example, the aforementioned liquid epoxy resin composition can be used as a molding material to fix and seal a component within a vehicle part. Specifically, a permanent magnet can be inserted into a void space formed within the rotor core of a vehicle motor, and the liquid epoxy resin composition of the present invention can be filled between the void space and the permanent magnet to fix the permanent magnet within the rotor core.

[0065] The method of molding a semiconductor device or a vehicle part using the liquid epoxy resin composition of the present invention can be appropriately selected and performed according to conventional methods in the relevant technical field, such as transfer molding, compression molding, injection molding, etc.

[0067] The present invention will be explained in more detail below through examples. However, the following examples are intended only to aid in understanding the present invention and do not imply that the scope of the present invention is limited to these examples in any way.

[0069] [Experimental Example 1-14]

[0070] Each component was formulated and uniformly mixed according to the compositions listed in Table 1-3 below, and then dispersed and kneaded using a 3-roll milling machine to prepare the liquid epoxy resin composition of each experimental example.

[0072]

[0073]

[0074]

[0075] Epoxy resin 1: Bisphenol F epoxy resin (viscosity (25 ℃) 1,300 mPa.s, equivalent weight 159 g / eq, Mw 318 g / mol)

[0076] Epoxy Resin 2: (3',4'-Epoxycyclohexane)methyl 3,4-epoxycyclohexylcarboxylate

[0077] Epoxy resin 3: p-(2,3-Epoxypropoxy)-N,N-bis(2,3-epoxypropyl)aniline

[0078] Hardener: Methylhexahydrophtalic anhydride

[0079] Filler 1: Silica(D 50 5 µm, Cut size 20 µm, Epoxy silane surface treatment)

[0080] Filler 2: Silica(D 50 0.3 µm, Cut size 1.0 µm, Epoxy silane surface treatment)

[0081] Siloxane 1: 3-[2-(3,4-epoxycyclohexyl)ethyl]-1,1,1,3,5,5,5-heptamethyltrisiloxane

[0082] Siloxane 2: 3-(3-glycidoxypropyl)-1,1,1,3,5,5,5-heptamethyltrisiloxane

[0083] Siloxane 3: 1,3-bis[2-(3,4-epoxycyclohexyl)ethyl]-1,1,3,3-tetramethyldisiloxane

[0084] Siloxane 4: 1,3-bis[3-glycidoxypropyl]-1,1,3,3-tetramethyldisiloxane

[0085] Catalyst: Epoxy / Amine adduct type (Cas no. 134091-76-2)

[0086] Colorant: Carbon Black

[0088] [Physical Property Evaluation]

[0089] The physical properties of the liquid epoxy resin compositions prepared in each experimental example were measured as follows, and the results are shown in Table 4-6 below.

[0091] viscosity

[0092] The viscosity of the liquid epoxy resin composition of each experimental example was measured at 25°C and 120°C at 0.2 RPM and 2.0 RPM, respectively, using a rheometer (Anton Paar MCR302, spindle PP25, gap 0.5 mm). At each temperature, the thixotropic index was calculated by dividing the viscosity measurement at 0.2 RPM by the viscosity measurement at 2 RPM.

[0094] coefficient of thermal expansion

[0095] After injecting the liquid epoxy resin composition of each experimental example into a mold (length x width x thickness, 6 mm x 6 mm x 6 mm), specimens were prepared by curing at 150 ℃ for 1 hour. The cured specimens were heated from -20 ℃ to 300 ℃ at a heating rate of 10 ℃ / min using a TMA device (TA Q400, Expansion mode), and the coefficient of thermal expansion (CTE) of the re-cooled specimens was measured continuously. Among the second measurement results, the coefficient of thermal expansion at a temperature below the glass transition temperature (Tg) was denoted as CTE α1, and the coefficient of thermal expansion at a temperature above Tg was denoted as CTE α2.

[0097] Tg (glass transition temperature)

[0098] After injecting the liquid epoxy resin composition of each experimental example into a mold (length x width x thickness, 60 mm x 12 mm x 3 mm), specimens were prepared by curing at 150 ℃ for 1 hour. Each specimen was heated from 25 ℃ to 260 ℃ at a heating rate of 5 ℃ / min using a DMA device (Perkin Elmer DMA 8000, 3 point bending mode), and the peak value of the tangent delta value was expressed as Tg.

[0100] Dischargeability

[0101] After injecting the liquid epoxy resin composition of each experimental example into a syringe (Nordson EFD optimum syringe barrel 10 cc), the plunger was attached and the mixture was dispensed for 1 minute at a discharge pressure of 1.0 bar using a dispenser (Nordson EFD Ultimus dispenser), and the dispensing performance was evaluated as follows.

[0102] [metewand]

[0103] ○: When the dispensed amount is 200 g or more

[0104] X: If the dispensed amount is less than 200 g

[0106] Mold evaluation

[0107] Manufacturing of molded products

[0108] Using a 12-inch wafer as a carrier, 500 silicon chips, cut to a size of 7.8 mm x 7.8 mm using a dicing machine (DISCO DFD6361), were mounted on the front surface of the thermal foam release sheet (Nitto Revalpha tape) at appropriate intervals, on a surface adhered to the thermal foam release sheet. The silicon chips formed on the carrier wafer were molded using a compression mold (ASM Compression molding machine) with the liquid epoxy resin composition of each experimental example to a diameter of 297 mm and a thickness of 100 μm (pressure 30 ton, molding temperature 120 °C, molding time 10 min). After curing each molded specimen at 150 °C for 1 hour, the thermal foam release sheet was foamed and removed on a 200 °C hot plate to obtain a molded product with silicon chips formed thereon.

[0110] Die floating

[0111] During molding, chips may detach from the thermal foam release sheet and become embedded in the liquid molding compound (LMC). The number of chips detached from the thermal foam release sheet was verified by observing the silicone chip surface of each molded product, and evaluated as follows.

[0112] [metewand]

[0113] ○: Chip detachment occurred

[0114] X: No chip detachment occurred

[0116] Bending evaluation

[0117] Each molded product was placed on a flat table, and the maximum height of both ends where bending occurred from the table was measured and the average value was calculated, and the bending characteristics were evaluated as follows.

[0118] [metewand]

[0119] ○: When the average value is 13 mm or less

[0120] X: When the average value exceeds 13 mm

[0122]

[0123]

[0124]

[0125] As shown in Table 4-6 above, the liquid epoxy resin composition of Experimental Example 1-5, which includes a siloxane (siloxane 1) according to the present invention having a symmetric structure in which an alicyclic epoxy group is substituted on a center silicon, exhibited excellent physical properties across all measured items.

[0126] On the other hand, the liquid epoxy resin compositions of Experimental Examples 6-8, which used an asymmetric siloxane (siloxane 2) that does not contain alicyclic epoxy groups; Experimental Examples 9-11, which used a symmetric siloxane (siloxane 3) that has alicyclic epoxy groups at both ends; and Experimental Examples 12-14, which used a symmetric siloxane (siloxane 4) that has epoxy groups at both ends, exhibited inferior physical properties compared to the liquid epoxy resin composition of Experimental Examples 1-5 across all measured items. In particular, it was confirmed that the liquid epoxy resin composition of Experimental Examples 6-14 exhibited inferior extrusion properties, die floating, or wafer warping problems.

Claims

Claim 1 A liquid epoxy resin composition comprising an epoxy resin, a curing agent, a filler, and a siloxane, wherein the epoxy resin comprises a bisphenol F-type epoxy resin, an alicyclic epoxy resin, and an aminophenol-type epoxy resin, and the siloxane is a siloxane having a symmetric structure in which an alicyclic epoxy group is substituted at a center silicon. Claim 2 A liquid epoxy resin composition according to claim 1, wherein the epoxy equivalent (EEW) of the epoxy resin is 50 to 400 g / eq, the viscosity (25 ℃) is 100 to 2,000 Pas, and the weight-average molecular weight is 100 to 1,000 g / mol. Claim 3 A liquid epoxy resin composition according to claim 1, wherein the curing agent is an acid anhydride. Claim 4 In claim 1, the liquid epoxy resin composition wherein the siloxane is represented by the following chemical formula 1: [Chemical Formula 1] In the above equation, R1 is R2 is a substituted or unsubstituted hydrocarbon group having 1 to 5 carbon atoms, R3 is a substituted or unsubstituted hydrocarbon group having 1 to 5 carbon atoms, n is an integer from 0 to 3, m is an integer from 2 to 8, R4 is hydrogen, or a substituted or unsubstituted hydrocarbon group having 1 to 3 carbon atoms, and R5 is hydrogen, or a substituted or unsubstituted hydrocarbon group having 1 to 3 carbon atoms. Claim 5 A liquid epoxy resin composition according to claim 1, wherein the molecular weight of the siloxane is 200 to 800 g / mol and the viscosity (25 ℃) is 0.1 to 1,000 Pas. Claim 6 A liquid epoxy resin composition according to claim 1, comprising, based on the total weight of the liquid epoxy resin composition, 2 to 20 weight% of the epoxy resin, 1 to 20 weight% of the curing agent, 50 to 93 weight% of the filler, and 0.1 to 2 weight% of the siloxane. Claim 7 A semiconductor device molded using a liquid epoxy resin composition according to any one of claims 1 to 6.

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