Epoxy resin composition for molding

Abstract

The present invention relates to: an epoxy resin composition for molding, the epoxy resin composition comprising an epoxy resin, a curing agent, a filler, a phosphazene compound, and a melamine derivative, wherein the mixing ratio of the phosphazene compound and the melamine derivative is 2 to 40:1 part by weight, and the comparative tracking index is 600 V or more; and a semiconductor device molded by using the epoxy resin composition.

Description

Epoxy resin composition for molding

[0001] The present invention relates to an epoxy resin composition for molding 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] As electronic devices become increasingly high-voltage and high-current, the semiconductors they contain are increasingly required to have improved electrical insulation capabilities under high voltage and current conditions. Furthermore, the miniaturization of electronic devices has led to a narrowing of the wiring pitch formed on substrates, placing even greater demands on the molding materials used to encapsulate semiconductor chips.

[0005] Furthermore, during prolonged use, semiconductors are prone to contamination, such as moisture and dust, between leads, resulting in tracking. To prevent this phenomenon, it is crucial to use a semiconductor sealant with a high comparative tracking index (CTI), an indicator of electrical insulation performance.

[0006] Conventionally, attempts have been made to manufacture molding compositions exhibiting a high comparative tracking index (CTI) by increasing the filler content or using resins such as dicyclopentadiene resins and flame-retardant phenolic resins. However, increasing the filler content has the problems of reduced dispersibility and poor flowability, and when phenolic resins, especially biphenyl-based phenolic resins, have many aromatic rings, so there is a problem that they are prone to forming carbonization paths and tracking may occur. On the other hand, phenolic resins having an aliphatic ring structure, such as dicyclopentadiene resins, have difficulty forming carbonization paths derived from aromatic rings, so although tracking resistance can be secured, there are problems of reduced curing and a lower glass transition temperature, such as deterioration of some physical properties. In addition, the above-described methods have limitations in that it is difficult to achieve a comparative tracking index (CTI) of 575 V or higher.

[0007] Accordingly, there is a need for the development of an epoxy resin composition for molding that has excellent tracking properties by having a high comparative tracking index (CTI) and excellent physical properties without lowering the glass transition temperature.

[0008]

[0009] The present invention provides an epoxy resin composition for molding having excellent tracking resistance due to a high comparative tracking index (CTI) and excellent physical properties without lowering the glass transition temperature, and a semiconductor device molded using the same.

[0010]

[0011] The present invention provides an epoxy resin composition for molding, which comprises an epoxy resin, a curing agent, a filler, a phosphazene compound, and a melamine derivative, wherein the mixing ratio of the phosphazene compound and the melamine derivative is 2 to 40:1 by weight, and has a comparative tracking index (CTI) of 600 V or more.

[0012]

[0013] The present invention provides an epoxy resin composition for molding having a high comparative tracking index (CTI) and excellent tracking resistance, and excellent physical properties without lowering the glass transition temperature, and a semiconductor device molded using the same. With the recent trend toward miniaturization of semiconductors, creepage distances are shortening, and semiconductors are being operated under harsher conditions in accordance with market demands, thereby increasing the possibility of tracking phenomena occurring in semiconductors. Since the epoxy resin composition for molding according to the present invention provides excellent tracking resistance of a comparative tracking index (CTI) of 600 V or more, it can provide excellent reliability to a semiconductor molded using the same. In addition, the epoxy resin composition for molding of the present invention also has excellent arc resistance related to the comparative tracking index (CTI), and can be applied to various structural materials requiring excellent arc resistance, such as a stator and a rotor core.

[0014]

[0015] 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.

[0016] The “softening point” used in this specification is measured by a conventional method known in the art, and can be measured, for example, using a dropping point meter (Dropping Point system calorimetry DP70) from Mettler Toledo. 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). “Particle size (D 50)” is measured by a conventional method known in the art, and can be measured, for example, by laser light scattering (LLS).

[0017]

[0018] <Epoxy resin composition for molding>

[0019] An epoxy resin composition for molding according to the present invention comprises an epoxy resin, a curing agent, a filler, a phosphazene compound, and a melamine derivative. The present invention provides an epoxy resin composition for molding having excellent tracking resistance, with a comparative tracking index (CTI) of 600 V or higher, by using a phosphazene compound and a melamine derivative at a specific mixing ratio.

[0020]

[0021] epoxy resin

[0022] The epoxy resin composition for molding 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 to an adherend and heat resistance, chemical resistance, and electrical insulation properties.

[0023] 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.

[0024] For example, the epoxy resin may be a polymer with formaldehyde, 1,1'-biphenyl and phenol, glycidyl ether, formaldehyde polymer with (chloromethyl)oxirane and 2-methylphenol (Cas No. 0029690-82-2), 4,4-bis(2,3-epoxypropoxy)-3,3,5,5-tetramethyl(1,1-biphenyl), 2-(chloromethyl)oxirane, 2,7-naphthalenediol polymer with ar-benzyl derivatives. 2-(chloromethyl)oxirane, ar-benzyl derivs.) or mixtures thereof.

[0025] For example, the epoxy resin may include a polymer with formaldehyde, 1,1'-biphenyl and phenol, glycidyl ether, and a polymer with (chloromethyl)oxirane and 2-methylphenol. In this case, better flame retardancy can be achieved.

[0026] The above epoxy resin may be used having an epoxy equivalent weight (EEW) of 100 to 400 g / eq, for example, 180 to 300 g / eq. If the epoxy equivalent weight is less than the above-mentioned range, the cured density may increase, resulting in poor moisture resistance reliability. If the epoxy equivalent weight exceeds the above-mentioned range, the curing property may be poor.

[0027] The above epoxy resin may be used having a softening point of 20 to 100°C, for example, 40 to 80°C. If the softening point is below the above-mentioned range, caking properties may be poor, and if it exceeds the above-mentioned range, uneven distribution may occur during manufacturing.

[0028] Based on the total weight of the epoxy resin composition for molding, the content of the epoxy resin may be 1 to 30 wt%, for example, 1 to 20 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 molding material may be deteriorated due to an increase in moisture absorption, and the strength may be reduced due to a relative decrease in the filler content.

[0029]

[0030] hardener

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

[0032] The curing agent may be any curing agent known in the art that undergoes a curing reaction with an epoxy resin. The curing agent may be a phenol-based compound having two or more phenolic hydroxyl groups in one molecule. Non-limiting examples of usable curing agents include phenol novolac resins, cresol novolac resins, phenol aralkyl resins, and multifunctional phenol compounds, and the curing agent may include one or more of these.

[0033] For example, the curing agent may include a phenol polymer with 4,4-bis(methoxymethyl)1,1-bisphenyl, a 1,3-benzenediol polymer with 4,4-bis(chloromethyl)-1,1-biphenyl and phenol, a phenol polymer with formaldehyde (Cas No. 0009003-35-4), a phenol polymer with hydroxybenzaldehyde, or a mixture thereof.

[0034] For example, the curing agent may include a phenol polymer with 4,4-bis(methoxymethyl)1,1-bisphenyl and a 1,3-benzenediol polymer with 4,4-bis(chloromethyl)-1,1-biphenyl and phenol. In this case, flame retardancy and glass transition temperature can be further improved.

[0035] The above-mentioned hardener may be used having a hydroxyl equivalent of 80 to 250 g / eq, for example, 120 to 190 g / eq. If the hydroxyl equivalent is less than the above-mentioned range, moisture resistance reliability may be poor, and if it exceeds the above-mentioned range, curing property may be poor.

[0036] The above-mentioned hardener may be one having a softening point of 20 to 140°C, for example, 50 to 110°C. If the softening point is below the above-mentioned range, caking properties may be poor, and if it exceeds the above-mentioned range, uneven distribution may occur during manufacturing.

[0037] Based on the total weight of the epoxy resin composition for molding, the content of the curing agent may be 2 to 20 wt%, for example, 2 to 10 wt%. If the content of the curing agent is less than the above-mentioned range, curability and moldability may be reduced, and if it exceeds the above-mentioned range, the reliability of the molding material may be deteriorated and the strength may be reduced due to increased moisture absorption.

[0038]

[0039] filling

[0040] The epoxy resin composition for molding of the present invention includes a filler. The filler serves to improve the mechanical properties of the epoxy resin composition for molding.

[0041] As the above-mentioned filler, any inorganic filler commonly used in the relevant technical field 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.

[0042] The shape of the above filler is not particularly limited, and both angular and spherical shapes can be used. For example, spherical silica particles, spherical alumina particles, or mixtures thereof can be used.

[0043] The above filler may include two or more types of fillers having different particle sizes. In this case, the moldability and workability of the epoxy resin composition can be further improved. For example, the filler may have an average particle size (D 50 ) is 5 to 20 um, for example 10 to 20 um, a first filler (e.g., silica) and an average particle diameter (D 50 ) may include a second filler (e.g., alumina) having a particle size of 20 to 40 um, for example, 22 to 29 um.

[0044] Based on the total weight of the epoxy resin composition for molding, the content of the filler may be 50 to 95 wt%, for example, 70 to 90 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 molding material. If the content of the filler exceeds the above-mentioned range, the fluidity may be reduced, resulting in poor moldability.

[0045]

[0046] phosphazene compounds

[0047] The epoxy resin composition for molding of the present invention comprises a phosphazene compound. The thermal decomposition of the phosphazene and the condensation reaction of the polymetaphosphoric acid generated by the thermal decomposition are endothermic reactions, which reduce heat generation due to current flow and suppress the formation of carbonized conductive paths. In addition, the protective layer generated by the thermal decomposition blocks the transfer of heat generated by current flow and prevents the access of active radicals that promote thermal decomposition, thereby suppressing the formation of carbonized conductive paths, thereby playing a role in improving the comparative tracking index (CTI) of the resin composition. The present invention provides an epoxy resin composition for molding having excellent tracking resistance, with a comparative tracking index (CTI) of 600 V or more, by using a phosphazene compound.

[0048] As the above phosphazene compound, a phosphazene compound having a hexagonal ring structure can be used. For example, the phosphazene compound can include at least one selected from the group consisting of hexaphenoxycyclotriphosphazene, hexachlorocyclotriphosphazene, octachlorocyclotetraphosphazene, decachlorocyclopentaphosphazene, ethoxypentafluorocyclotriphosphazene, diethoxytetrafluorocyclotriphosphazene, triethoxytrifluorocyclotriphosphazene, phenoxypentafluorocyclotriphosphazene, diphenoxytetrafluorocyclotriphosphazene, and triphenoxytrifluorocyclotriphosphazene.

[0049] Based on the total weight of the epoxy resin composition for molding, the content of the phosphazene compound may be 0.5 to 10 wt%, for example, 1 to 5 wt%. If the content of the phosphazene compound is less than the above-mentioned range, the effect of improving the comparative tracking index (CTI) may be insufficient, and if it exceeds the above-mentioned range, the curability and glass transition temperature may be lowered.

[0050]

[0051] melamine derivatives

[0052] The epoxy resin composition for molding of the present invention comprises a melamine derivative. The thermal decomposition of the melamine derivative is an endothermic reaction, which reduces heat generation due to current flow, and the melamine derivative sublimates at a specific temperature, thereby suppressing the formation of carbonized conductive paths, thereby improving the comparative tracking index (CTI) of the resin composition. The present invention provides an epoxy resin composition for molding having excellent tracking resistance, with a comparative tracking index (CTI) of 600 V or higher, by using a melamine derivative.

[0053] The above melamine derivative may include at least one selected from the group consisting of melamine cyanurate, melamine phosphate, melamine polyphosphate, and melamine borate.

[0054] Based on the total weight of the epoxy resin composition for molding, the content of the melamine derivative may be 0.1 to 5 wt%, for example, 0.1 to 3 wt%. If the content of the melamine derivative is less than the above-mentioned range, the effect of improving the comparative tracking index (CTI) may be insufficient, and if it exceeds the above-mentioned range, the curability and glass transition temperature may be lowered.

[0055]

[0056] The mixing ratio of the above phosphazene compound and the above melamine derivative may be a weight ratio of 2 to 40:1, for example, 2 to 20:1. If the mixing ratio of the phosphazene compound to the melamine derivative is less than the above-mentioned range, the effect of improving the comparative tracking index (CTI) may be insufficient, and if it exceeds the above-mentioned range, the curability and glass transition temperature may be lowered.

[0057]

[0058] additives

[0059] The epoxy resin composition for molding of the present invention may additionally include additives commonly used in such compositions. Non-limiting examples of usable additives include coupling agents, release agents, colorants, catalysts, flame retardants, and the like.

[0060] Coupling agents promote bonding between inorganic and organic substances and improve adhesion to metal substrates, and amino silanes, epoxy silanes, etc. can be used. Release agents are added to secure releasability between the epoxy molding compound (EMC) and the mold, and examples of the release agents include waxes such as paraffin wax, carnauba wax, polyethylene wax, and ester wax; and silicone oils such as both-terminal amine-modified silicone oils. Colorants are added to impart color to the resin composition, and examples of the colorants include carbon black, Bengala, etc. Catalysts promote curing reactions, and examples of the catalysts include imidazole compounds, naphthalene-based latent catalysts, amine compounds, organometallic compounds, organophosphorus compounds, and boron compounds. Flame retardants are added to impart flame retardancy, and examples of the flame retardant include metal hydroxides.

[0061] 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 epoxy resin composition for molding, but is not limited thereto.

[0062]

[0063] The comparative tracking index (CTI) of the epoxy resin composition for molding according to the present invention may be 600 V or higher, for example, 600 to 625 V. With the recent trend toward miniaturization of semiconductors, creepage distances are becoming shorter, and semiconductors are being operated under harsher conditions according to market demands, which increases the possibility of tracking phenomena occurring in semiconductors. Since the epoxy resin composition according to the present invention provides excellent tracking resistance of a comparative tracking index (CTI) of 600 V or higher, it can provide excellent reliability to semiconductors molded using the composition. In addition, the epoxy resin composition of the present invention also has excellent arc resistance related to the comparative tracking index (CTI), and thus can be applied to various structural materials requiring excellent arc resistance, such as stators and rotor cores.

[0064] The epoxy resin composition for molding according to the present invention can be manufactured by a conventional method known in the art, for example, a melt mixing method using a Banbury mixer, a kneader, a roll, a single-screw or twin-screw extruder, and a co-kneader. The epoxy resin composition for molding according to the present invention can be manufactured in a powder form, a granular form, etc. For example, in the case of a powder form or a granular form of an epoxy resin composition for molding, the above-described components are uniformly mixed, melt mixed at a temperature of 80 to 130°C using a heat kneader, cooled to room temperature, pulverized into a powder state, and then subjected to a sieving process, but the present invention is not limited thereto.

[0065]

[0066] Semiconductor devices

[0067] The present invention provides a semiconductor device molded using the aforementioned epoxy resin composition for molding. The semiconductor device may be a transistor, a diode, a microprocessor, a semiconductor memory, a power semiconductor, or the like.

[0068] The epoxy resin composition for molding according to the present invention can be manufactured by a conventional method in the relevant technical field, for example, a melt mixing method using a Banbury mixer, a kneader, a roll, a single-screw or twin-screw extruder, and a con-kneader.

[0069] For example, the above-described components may be uniformly mixed, melted and mixed at a temperature of 100 to 130°C using a heat kneader, cooled to room temperature, ground into a powder, and then blended, or granulated.

[0070] The epoxy resin composition for semiconductor encapsulation of the present invention can be manufactured in the form of powder, granules, etc., and the method for molding a semiconductor element using the same can be appropriately selected and performed according to a conventional method in the relevant technical field, such as transfer molding, compression molding, injection molding, etc.

[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 1-10]

[0075] After mixing each component according to the compositions described in Tables 1 and 2 below, the mixture was melt-mixed at a temperature of 100 to 130°C using a melt kneader, cooled to room temperature, pulverized into a powder state, and then subjected to a sieving process to produce a powder-type molding epoxy resin composition for each experimental example. The comparative tracking index (CTI) of each molding epoxy resin composition was measured using the following method, and is described in Tables 1 and 2 below.

[0076]

[0077] Comparative Tracking Index (CTI)

[0078] Using the epoxy resin composition for molding of each experimental example, specimens measuring 30 mm in width x 30 mm in length x 3 mm in thickness were produced by transfer molding. According to ASTM D3638, the comparative tracking index (CTI) was measured by dropping a solution (0.1 wt% NH4Cl) onto each specimen using a CTI Tester and observing whether tracking occurred.

[0079]

[0080]

[0081]

[0082]

[0083] Epoxy resin 1: Formaldehyde, polymer with 1,1'-biphenyl and phenol, glycidyl ether (EEW ​​274 g / eq, softening point 57 ℃, Mw 8,397 g / mol)

[0084] Epoxy resin 2: Formaldehyde polymer with (chloromethyl)oxirane and 2-Methylphenol (CAS NO 29690-82-2, EEW 200 g / eq, softening point 64 ℃, Mw 582.68 g / mol)

[0085] Curing agent 1: Phenol polymer with 4,4 bis(methoxymethyl)1,1-Bisphenyl (OH equivalent 175 g / eq, softening point 65 ℃, Mw 580 g / mol)

[0086] Curing agent 2: 1,3-Benzenediol polymer with 4,4-bis(chloromethyl)-1,1-biphenyl and phenol (OH equivalent weight 134 g / eq, softening point 95 ℃)

[0087] Filler: Fused silica (D50 14.4 ㎛)

[0088] Phosphazene compound: Hexa(phenoxy)cyclotriphosphazene

[0089] Melamine derivatives: melamine cyanurate

[0090] Silane: Trimethoxy[2-(7-oxabicyclo[4.1.0]hept-3-yl)ethyl]silane

[0091] Wax: Carnauba wax

[0092] Colorant: Carbon Black

[0093] Catalyst: Triphenylphosphine

[0094] Flame retardant: magnesium hydroxide

[0095] Additive: Silicon powder

[0096]

[0097] [Physical property evaluation]

[0098] The physical properties of the epoxy resin composition manufactured in each experimental example were measured as follows, and the results are shown in Tables 3 and 4 below.

[0099]

[0100] spiral flow

[0101] The epoxy resin composition manufactured according to each experimental example was molded using a spiral flow mold in a heat transfer molding machine (pressure 70 kg / cm2, temperature 175 ℃, curing time 200 seconds), and then the flowability of the product was measured.

[0102]

[0103] gelation time

[0104] A small amount of the epoxy resin composition manufactured according to each experimental example was spread widely and evenly on a gel timer, and the gelation time of the composition was measured.

[0105]

[0106] Tg

[0107] It was measured using differential scanning calorimetry (DSC).

[0108]

[0109]

[0110]

[0111]

[0112] As shown in Tables 3 and 4 above, the epoxy resin composition for molding according to the present invention exhibited excellent physical properties across all measured items. On the other hand, the molding compositions of Experimental Example 5, which did not use a melamine derivative, and Experimental Examples 6 and 7, in which the mixing ratio of the phosphazene compound and the melamine derivative was outside the range of the present invention, exhibited a low comparative tracking index (CTI). On the other hand, in the case of the molding compositions of Experimental Examples 8-10, which contained a high content of the phosphazene compound and the melamine derivative, although the mixing ratio was outside the range of the present invention, the tracking index (CTI) was high, but the spiral flow and gel time increased or decreased rapidly, and the glass transition temperature decreased rapidly.

[0113]

[0114] The present invention provides an epoxy resin composition for molding having excellent tracking resistance due to a high comparative tracking index (CTI) and excellent physical properties without lowering the glass transition temperature, and a semiconductor device molded using the same.

Claims

1. Contains epoxy resin, hardener, filler, phosphazene compound and melamine derivative, The mixing ratio of the above phosphazene compound and the above melamine derivative is 2 to 40:1 by weight, An epoxy resin composition for molding having a comparative tracking index (CTI) of 600 V or more.

2. In the first paragraph, the epoxy resin has an epoxy equivalent weight (EEW) of 100 to 400 g / eq and a softening point of 20 to 100°C, An epoxy resin composition for molding, wherein the hydroxyl equivalent of the above-mentioned hardener is 80 to 250 g / eq and the softening point is 20 to 140°C.

3. An epoxy resin composition for molding, wherein the phosphazene compound in paragraph 1 is a phosphazene compound having a hexagonal ring structure.

4. In the first paragraph, the phosphazene compound is an epoxy resin composition for molding comprising at least one selected from the group consisting of hexaphenoxycyclotriphosphazene, hexachlorocyclotriphosphazene, octachlorocyclotetraphosphazene, decachlorocyclopentaphosphazene, ethoxypentafluorocyclotriphosphazene, diethoxytetrafluorocyclotriphosphazene, triethoxytrifluorocyclotriphosphazene, phenoxypentafluorocyclotriphosphazene, diphenoxytetrafluorocyclotriphosphazene, and triphenoxytrifluorocyclotriphosphazene.

5. An epoxy resin composition for molding, wherein the melamine derivative in the first paragraph comprises at least one selected from the group consisting of melamine cyanurate, melamine phosphate, melamine polyphosphate, and melamine borate.

6. An epoxy resin composition for molding, comprising, based on the total weight of the epoxy resin composition for molding in paragraph 1, 1 to 30 wt% of the epoxy resin, 2 to 20 wt% of the curing agent, 50 to 95 wt% of the filler, 0.5 to 10 wt% of the phosphazene compound, and 0.1 to 5 wt% of the melamine derivative.

7. A semiconductor device molded using an epoxy resin composition for molding according to any one of claims 1 to 6.

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