Liquid epoxy resin composition

Abstract

The present invention relates to: a liquid epoxy resin composition and a semiconductor device molded using same, the composition comprising an epoxy resin, a curing agent, a filler and siloxane, wherein the siloxane has a symmetrical structure in which an alicyclic epoxy group is substituted at the central silicon atom.

Description

Liquid epoxy resin composition

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

[0002]

[0003] A resin composition for sealing is used as a material to seal semiconductor devices such as integrated circuits (ICs), large scale integrated circuits (LSIs), transistors, and diodes, thereby improving the characteristics and reliability of semiconductor devices. Recently, with the trend toward miniaturization, weight reduction, and higher performance of electronic devices, the integration of semiconductors has accelerated, and research is continuing in various fields to improve the performance of materials used for sealing semiconductor devices. For example, Japanese Patent Application Laid-Open No. 2017-197620 relates to an epoxy resin composition for semiconductor sealing, which includes an epoxy resin, a phenol resin curing agent, and a filler, and discloses a technology for improving electrical connection reliability by controlling the content of the filler and the thermoelastic modulus of the cured product of the epoxy resin composition.

[0004] In particular, semiconductor chips are being miniaturized to meet the demands for higher density and integration, leading to the widespread adoption of wafer-level packages, where the semiconductor chip and package are the same size. For wafer-level packages, transfer molding techniques are difficult to apply due to filling limitations, and compression molding is generally employed. In this case, solid molding compounds with poor flowability frequently lead to unfilled areas during large-area molding. Therefore, the use of liquid molding compounds is increasing.

[0005] However, in the case of molding compounds, a large amount of filler is included to improve physical properties (e.g., to suppress warpage of wafers when applied to semiconductor devices). However, in the case of liquid molding compounds, if the content of filler increases, fluidity decreases, resulting in poor ejection into the mold, and problems such as die floating, in which high shear stress is applied during molding and the wafer moves out of its original position, occur.

[0006] Accordingly, there is a need for development of a liquid epoxy resin composition for sealing material that contains a high content of filler (e.g., more than 50 wt%) and has excellent dispersibility, fluidity, dischargeability, moldability, and warpage suppression properties.

[0007]

[0008] The present invention provides a liquid epoxy resin composition having excellent dispersibility, fluidity and warpage suppression properties, and a semiconductor device molded using the same.

[0009]

[0010] 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 symmetrical siloxane in which an alicyclic epoxy group is substituted on a center silicon atom.

[0011]

[0012] The present invention provides a liquid epoxy resin composition with excellent dispersibility, fluidity, and warpage suppression properties. The liquid epoxy resin composition according to the present invention can provide excellent fluidity and warpage suppression properties even when containing a high content of filler by improving the dispersibility of the filler. Therefore, the liquid epoxy resin composition of the present invention is applicable to compression molding methods, particularly compression molding methods for manufacturing wafer-level packages.

[0013]

[0014] The present invention will be described in detail below. However, it is not limited to the following description, and each component may be modified or selectively mixed as needed. Therefore, it should be understood that all modifications, equivalents, and alternatives included within the spirit and technical scope of the present invention are included.

[0015] The “weight average molecular weight” used herein is measured by a conventional method known in the art, and can be measured, for example, by a gel permeation chromatograph (GPC) method. The “viscosity” is measured by a conventional method known in the art, and can be measured, for example, using a Brookfield viscometer at room temperature (25°C). The “glass transition temperature” is measured by a conventional method known in the art, and can be measured, for example, by a thermomechanical analysis (TMA) or differential scanning calorimetry (DSC). The “particle size (D) 50 )" is measured by a conventional method known in the art, and can be measured, for example, by a laser particle size analyzer.

[0016]

[0017] <Liquid epoxy resin composition>

[0018] A liquid epoxy resin composition according to the present invention comprises an epoxy resin, a curing agent, a filler, and a siloxane. The present invention provides a liquid epoxy resin composition having excellent mechanical properties as well as excellent dispersibility and fluidity by using a symmetrical siloxane in which an alicyclic epoxy group is substituted on a central silicon atom.

[0019]

[0020] epoxy resin

[0021] The liquid epoxy resin composition of the present invention comprises an epoxy resin. The epoxy resin is used as a main resin, and upon reaction with a curing agent and curing, forms a three-dimensional network structure, thereby imparting strong and solid adhesion properties to an adherend and heat resistance.

[0022] As the above epoxy resin, an epoxy resin commonly used in the relevant technical field can be used. Non-limiting examples of usable epoxy resins include bisphenol A type epoxy resins, alicyclic epoxy resins, cresol novolac epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, naphthalene type epoxy resins, anthracene epoxy resins, tetramethyl biphenyl type epoxy resins, phenol novolac epoxy resins, bisphenol A novolac epoxy resins, bisphenol S novolac epoxy resins, biphenyl novolac epoxy resins, naphthol novolac epoxy resins, naphthol phenol cocondensed novolac epoxy resins, naphthol cresol cocondensed novolac epoxy resins, aromatic hydrocarbon formaldehyde resin modified phenol resin epoxy resins, triphenyl methane type epoxy resins, tetraphenyl ethane type epoxy resins, dicyclopentadiene type epoxy resins, dicyclopentadiene phenol addition reaction epoxy resins, biphenyl type epoxy resins, phenol aralkyl type epoxy resins, multifunctional phenol resins, and naphthol. There are aralkyl type epoxy resins, etc., and one or more of these may be included.

[0023] For example, the epoxy resin may include a bisphenol F-type epoxy resin; an alicyclic 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.

[0024] For example, the epoxy resin may include a bisphenol F-type epoxy resin, an alicyclic epoxy resin, and an 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 dischargeability, moldability, heat resistance, and temperature cycle resistance characteristics can be secured.

[0025] The above epoxy resin may be used having an epoxy equivalent weight (EEW) of 50 to 400 g / eq, for example, 90 to 300 g / eq. If the epoxy equivalent weight is less than the above-mentioned range, the curing density may be excessively high, resulting in excessive curing shrinkage, and furthermore, brittleness may increase, causing cracks. If the epoxy equivalent weight exceeds the above-mentioned range, the curing density may be low, resulting in poor heat resistance.

[0026] The above epoxy resin may be used having a viscosity (25°C) of 100 to 2,000 Pas, for example, 200 to 1,500 Pas. If the viscosity is less than the above-mentioned range, the viscosity of the liquid epoxy resin composition may be too low, causing leakage from the mold during molding. If the viscosity is more than the above-mentioned range, the viscosity may be too high, causing fluidity to deteriorate, resulting in deteriorated ejection properties of the liquid epoxy resin composition and clogging of the ejection port. In addition, the liquid epoxy resin composition may not be sufficiently ejected into the mold, resulting in poor moldability of the product.

[0027] The above epoxy resin may be used having 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 less than the above-mentioned range, it may volatilize during molding, causing mold contamination. If it exceeds the above-mentioned range, fluidity may be reduced due to intermolecular entanglement, resulting in poor filler dispersion or reduced moldability.

[0028] Based on the total weight of the liquid epoxy resin composition, the content of the epoxy resin may be 2 to 20 wt%, for example, 5 to 10 wt%. If the content of the epoxy resin is less than the above-mentioned range, adhesion, flowability, and moldability may be reduced, and if it exceeds the above-mentioned range, the reliability of the semiconductor may be deteriorated due to an increase in moisture absorption, and the warpage phenomenon may worsen or the strength may be reduced due to an increase in the coefficient of thermal expansion caused by a relative decrease in the filler content.

[0029]

[0030] hardener

[0031] The liquid epoxy resin composition of the present invention includes a curing agent. The curing agent reacts with the epoxy resin to promote curing of the composition.

[0032] As the above curing agent, a curing agent known in the relevant technical field that undergoes a curing reaction with epoxy resin can be used, and an acid anhydride, a phenol-based compound, etc. can be used. For example, the curing agent can be an acid anhydride such as phthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, trialkyltetrahydrophthalic anhydride, or tetrahydrophthalic anhydride.

[0033] Based on the total weight of the liquid epoxy resin composition, the content of the curing agent may be 1 to 20 wt%, for example, 1 to 10 wt%. If the content of the curing agent is less than the above-mentioned range, curability and formability may be reduced, and if it exceeds the above-mentioned range, the reliability of the semiconductor may be deteriorated and the strength may be reduced due to an increase in moisture absorption.

[0034]

[0035] filling

[0036] 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 reduces moisture absorption.

[0037] As the above-mentioned filler, any inorganic filler commonly used in the field of electronic materials can be used without any particular restrictions. For example, inorganic fillers such as silica, silica nitride, alumina, aluminum nitride, and boron nitride can be used, and these can be used alone or in combination of two or more.

[0038] 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, and fused silica, and for example, spherical silica particles can be used. The filler can be used after surface treatment with epoxy silane, phenylamino silane, amino silane, etc.

[0039] The above filler may include two or more types of fillers having different particle sizes. In this case, the moldability and workability of the liquid epoxy resin composition can be further improved. For example, the filler may have an average particle size (D 50 ) of the first filler and the average particle diameter (D) of 5 to 30 um, for example 10 to 25 um 50 ) may include a second filler having a thickness of 0.1 to 3 um, for example, 0.1 to 1 um.

[0040] Based on the total weight of the liquid epoxy resin composition, the content of the filler may be 50 to 93 wt%, for example, 70 to 93 wt%. If the content of the filler is less than the above-mentioned range, the moisture absorption of the cured product may increase, which may lower the reliability of the semiconductor device, and the coefficient of thermal expansion may increase, which may cause excessive warping and stress-induced peeling, and if it exceeds the above-mentioned range, the fluidity may decrease, which may result in poor formability.

[0041]

[0042] Siloxane

[0043] The liquid epoxy resin composition of the present invention comprises siloxane. The siloxane is a symmetrical siloxane in which an alicyclic epoxy group is substituted on the central silicon atom. By using a siloxane having such a structure, a filler can be effectively dispersed, thereby providing a liquid epoxy resin composition having excellent dispersibility, fluidity, and warpage suppression properties.

[0044] The above siloxane can be represented by the following chemical formula 1.

[0045] [Chemical Formula 1]

[0046]

[0047] In the above formula,

[0048] R1 is And,

[0049] R2 is a substituted or unsubstituted hydrocarbon group having 1 to 5 carbon atoms,

[0050] R3 is a substituted or unsubstituted hydrocarbon group having 1 to 5 carbon atoms,

[0051] n is an integer from 0 to 3,

[0052] m is an integer from 2 to 8,

[0053] R4 is hydrogen or a substituted or unsubstituted hydrocarbon group having 1 to 3 carbon atoms,

[0054] R5 is hydrogen or a substituted or unsubstituted hydrocarbon group having 1 to 3 carbon atoms.

[0055] For example, in the above formula, 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.

[0056] For example, in the above formula, 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 of 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.

[0057] For example, in the above formula, R1 is , R2 is an ethyl group, n is 0, m is 4, R4 is a methyl group, and R5 is a methyl group.

[0058] For example, the siloxane may be 3-[2-(3,4-epoxycyclohexyl)ethyl]-1,1,1,3,5,5,5-heptamethyltrisiloxane.

[0059] The above siloxane may be used having a molecular weight of 200 to 800 g / mol, for example, 300 to 400 g / mol. If the molecular weight is less than the aforementioned range, sufficient steric hindrance effect may not be exerted when adsorbed on the surface of the filler, which may result in re-aggregation between adjacent fillers. If the molecular weight exceeds the aforementioned range, the molecular size may be too large compared to the specific surface area of ​​the filler, making it difficult to efficiently cover the surface of the filler.

[0060] Based on the total weight of the liquid epoxy resin composition, the content of the siloxane may be 0.1 to 2 wt%, for example, 0.2 to 0.6 wt%. If the content of the siloxane is less than the above-mentioned range, the dispersing effect may be insignificant, resulting in reduced fluidity, and if it exceeds the above-mentioned range, the glass transition temperature of the liquid epoxy resin composition may be lowered, resulting in poor heat resistance.

[0061]

[0062] additives

[0063] The liquid epoxy resin composition of the present invention may additionally include additives commonly used in such compositions. Non-limiting examples of usable additives include catalysts, colorants, and the like.

[0064] Catalysts promote the curing reaction, and may be used, for example, 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 examples of such colorants include carbon black, Bengala, etc.

[0065] 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 wt%, respectively, based on the total weight of the liquid epoxy resin composition, but is not limited thereto.

[0066]

[0067] Semiconductor devices and automotive components

[0068] The present invention provides a semiconductor device molded using the liquid epoxy resin composition described above. The semiconductor device may be a transistor, a diode, a microprocessor, a semiconductor memory, a power semiconductor, or the like.

[0069] In addition, the present invention provides a vehicle component 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 the vehicle component, and specifically, a permanent magnet can be inserted into a hollow space formed within a rotor core of a vehicle motor, and the liquid epoxy resin composition of the present invention can be filled between the hollow space and the permanent magnet to fix the permanent magnet within the rotor core.

[0070] A method for 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 a conventional method in the relevant technical field, such as transfer molding, compression molding, or injection molding.

[0071]

[0072] Hereinafter, the present invention will be described in more detail through examples. However, the following examples are intended only to aid understanding of the present invention and are not intended to limit the scope of the present invention in any way.

[0073]

[0074] [Experimental Example 1-14]

[0075] Each component was mixed and uniformly mixed according to the composition described in Table 1-3 below, and then dispersed and kneaded using a 3-roll milling machine to prepare a liquid epoxy resin composition for each experimental example.

[0076]

[0077]

[0078]

[0079]

[0080]

[0081] Epoxy resin 1: Bisphenol F epoxy resin (viscosity (25 ℃) 1,300 mPa.s, equivalent weight 159 g / eq, Mw 318 g / mol)

[0082] Epoxy resin 2: (3',4'-Epoxycyclohexane)methyl 3,4-epoxycyclohexylcarboxylate

[0083] Epoxy resin 3: p-(2,3-Epoxypropoxy)-N,N-bis(2,3-epoxypropyl)aniline

[0084] Hardener: Methylhexahydrophtalic anhydride

[0085] Filler 1: Silica(D 50 5 um, Cut size 20 um, Epoxy silane surface treatment)

[0086] Filler 2: Silica(D 500.3 um, Cut size 1.0 um, Epoxy silane surface treatment)

[0087] Siloxane 1: 3-[2-(3,4-epoxycyclohexyl)ethyl]-1,1,1,3,5,5,5-heptamethyltrisiloxane

[0088] Siloxane 2: 3-(3-glycidoxypropyl)-1,1,1,3,5,5,5-heptamethyltrisiloxane

[0089] Siloxane 3: 1,3-bis[2-(3,4-epoxycyclohexyl)ethyl]-1,1,3,3-tetramethyldisiloxane

[0090] Siloxane 4: 1,3-bis[3-glycidoxypropyl]-1,1,3,3-tetramethyldisiloxane

[0091] Catalyst: Epoxy / Amine adduct type (Cas no. 134091-76-2)

[0092] Colorant: Carbon Black

[0093]

[0094] [Physical property evaluation]

[0095] The physical properties of the liquid epoxy resin composition manufactured in each experimental example were measured as follows, and the results are shown in Table 4-6 below.

[0096]

[0097] viscosity

[0098] The viscosity of the liquid epoxy resin compositions of each experimental example was measured at 0.2 RPM and 2.0 RPM at 25°C and 120°C, respectively, using a rheometer (Anton Paar MCR302, spindle PP25, gap 0.5 mm). The thixotropic index was calculated by dividing the 2 RPM viscosity measurement value by the 0.2 RPM viscosity measurement value at each temperature.

[0099]

[0100] Coefficient of thermal expansion

[0101] The liquid epoxy resin composition of each experimental example was injected into a mold (length x width x thickness, 6 mm x 6 mm x 6 mm) and then cured at 150°C for 1 hour to prepare a specimen. The cured specimen was heated from -20°C to 300°C at a heating rate of 10°C / min using a TMA device (TA Q400, Expansion mode), and the coefficient of thermal expansion (CTE) of the recooled specimen was continuously measured. Among the results of the second measurement, the coefficient of thermal expansion at a temperature below the glass transition temperature (Tg) was expressed as CTE α1, and the coefficient of thermal expansion at a temperature exceeding Tg was expressed as CTE α2.

[0102]

[0103] Tg (glass transition temperature)

[0104] The liquid epoxy resin composition of each experimental example was injected into a mold (length x width x thickness, 60 mm x 12 mm x 3 mm) and then cured at 150°C for 1 hour to produce a specimen. Each specimen was heated from 25°C to 260°C at a heating rate of 5°C / min using DMA equipment (Perkin Elmer DMA 8000, 3 point bending mode), and the peak value of the tangent delta value was expressed as Tg.

[0105]

[0106] discharge

[0107] After the liquid epoxy resin composition of each experimental example was injected into a syringe (Nordson EFD optimum syringe barrel 10 cc), the plunger was fastened, and the dispenser (Nordson EFD Ultimus dispenser) was used to dispense at a discharge pressure of 1.0 bar for 1 minute, and the discharge performance was evaluated as follows.

[0108] [metewand]

[0109] ○: If the amount discharged is 200 g or more

[0110] X: If the amount discharged is less than 200 g

[0111]

[0112] Mold Evaluation

[0113] Manufacturing of molded products

[0114] A 12-inch wafer was used as a carrier, and a thermal foam release sheet (Nitto Revalpha tape) was adhered to the surface. Using a dicing machine (DISCO DFD6361), 500 silicon chips cut into 7.8 mm x 7.8 mm sizes were placed on the entire surface of the thermal foam release sheet at appropriate intervals. 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 tons, molding temperature 120 °C, molding time 10 minutes). 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 article having silicon chips formed thereon.

[0115]

[0116] Die floating

[0117] During molding, chips may detach from the thermal foam release sheet and become embedded in the liquid molding compound (LMC). The silicon chip surface of each molded product was observed to determine the number of chips detached from the thermal foam release sheet, and the results were evaluated as follows.

[0118] [metewand]

[0119] ○: Chip detachment occurs

[0120] X: No chip detachment

[0121]

[0122] Bending evaluation

[0123] Each molded product was placed on a flat table, and the maximum height of each end where bending occurred from the table was measured, and the average value was obtained, and the bending characteristics were evaluated as follows.

[0124] [metewand]

[0125] ○: If the average value is less than 13 mm

[0126] X: If the average value exceeds 13 mm

[0127]

[0128]

[0129]

[0130]

[0131]

[0132] As shown in Table 4-6 above, the liquid epoxy resin composition of Experimental Example 1-5 containing siloxane (siloxane 1) according to the present invention having a symmetrical structure in which an alicyclic epoxy group is substituted on the center silicon showed excellent physical properties across all measured items.

[0133] On the other hand, the liquid epoxy resin compositions of Experimental Examples 6-8 using an asymmetric siloxane (siloxane 2) not containing an alicyclic epoxy group, Experimental Examples 9-11 using a symmetric siloxane (siloxane 3) having an alicyclic epoxy group at both ends, and Experimental Examples 12-14 using a symmetric siloxane (siloxane 4) having an epoxy group at both ends exhibited inferior physical properties in all measured items compared to the liquid epoxy resin compositions of Experimental Examples 1-5. In particular, the liquid epoxy resin compositions of Experimental Examples 6-14 were found to have inferior ejection properties, die floating, and wafer warpage problems.

[0134]

[0135] The present invention provides a liquid epoxy resin composition having excellent dispersibility, fluidity and warpage suppression properties.

Claims

1. Contains epoxy resin, hardener, filler and siloxane, A liquid epoxy resin composition wherein the above siloxane is a symmetrical siloxane in which an alicyclic epoxy group is substituted on the center silicon.

2. A liquid epoxy resin composition according to claim 1, wherein the epoxy resin has an epoxy equivalent weight (EEW) of 50 to 400 g / eq, a viscosity (25°C) of 100 to 2,000 Pas, and a weight average molecular weight of 100 to 1,000 g / mol.

3. A liquid epoxy resin composition according to claim 1, wherein the curing agent is an acid anhydride.

4. In the first paragraph, the siloxane is a liquid epoxy resin composition represented by the following chemical formula 1: [Chemical Formula 1] In the above formula, R1 is And, 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, R5 is hydrogen or a substituted or unsubstituted hydrocarbon group having 1 to 3 carbon atoms.

5. A liquid epoxy resin composition in the first paragraph, wherein the siloxane has a molecular weight of 200 to 800 g / mol and a viscosity (25°C) of 0.1 to 1,000 Pas.

6. A liquid epoxy resin composition comprising, based on the total weight of the liquid epoxy resin composition, 2 to 20 wt% of the epoxy resin, 1 to 20 wt% of the hardener, 50 to 93 wt% of the filler, and 0.1 to 2 wt% of the siloxane.

7. A semiconductor device molded using a liquid epoxy resin composition according to any one of claims 1 to 6.

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