Epoxy resin composition

Abstract

The invention relates to an epoxy resin composition and a semiconductor device encapsulated by the epoxy resin composition.

Description

Technical Field

[0001] The invention relates to an epoxy resin composition and a semiconductor device encapsulated by the epoxy resin composition. Background Art

[0002] The inverter power module package refers to the systematization of devices such as IC (Integrated Circuit), MOSFET (Metal Oxide Semiconductor Field Effect Transistor), IGBT (Insulated gate bipolar transistor) and diode (Diode) which are separately installed on PCB (Printed circuit board) into a package form to reduce current loss and improve efficiency. Efforts to improve efficiency and power and ensure price competitiveness through the integration of power module packages are ongoing. At the same time, it is necessary to improve the tracking resistance of epoxy resin compositions used as semiconductor encapsulation compositions to meet insulation-related standards when designing packages.

[0003] As an example, Japanese Patent Publication No. 2008-143950A discloses an epoxy resin composition for semiconductor sealing containing a metal hydroxide to improve tracking resistance. However, the actual situation is that the epoxy resin composition disclosed in the above prior art does not meet the latest tracking resistance standards required for semiconductor devices.

[0004] In addition, attempts have been made to increase the content of fillers or apply expensive epoxy resins to improve the tracking resistance, but in such cases, it is difficult to ensure price competitiveness and molding workability. Therefore, the actual situation is that it is necessary to develop an epoxy resin composition that can improve the tracking resistance characteristics in the inverter power module package and ensure price competitiveness. Summary of the invention

[0005] (Problems to be solved by the invention)

[0006] The present invention provides an epoxy resin composition with excellent tracking resistance and a semiconductor device encapsulated by the epoxy resin composition.

[0007] (Measures taken to solve the problem)

[0008] The invention provides an epoxy resin composition, which comprises an epoxy resin, a curing agent, a filler, a curing accelerator and an additive. The additive comprises cerium oxide and non-polar polyethylene wax.

[0009] (Effects of the Invention)

[0010] The epoxy resin composition of the present invention shows excellent tracking resistance. A semiconductor device encapsulated by using the epoxy resin composition of the present invention can ensure high reliability, and can also improve tracking resistance when used in an inverter power module package. DETAILED DESCRIPTION

[0011] Hereinafter, the present invention will be described in detail. However, the present invention is not limited to the following contents, and each component can be variously deformed or selectively mixed as required. Therefore, it should be understood that all changes, equivalents or substitutes included in the thought and technical scope of the present invention are included.

[0012] <Epoxy resin composition>

[0013] The epoxy resin composition according to the present invention comprises epoxy resin, curing agent, filler, curing accelerator and additives, wherein the additives comprise cerium oxide and non-polar polyethylene wax. The composition of the epoxy resin composition of the present invention is observed as follows.

[0014] Epoxy resin

[0015] In the present invention, the epoxy resin is used as a main resin, and after being cured by reacting with a curing agent, the epoxy resin has a three-dimensional network structure, thereby imparting a property of strong and firm adhesion to an adherend and heat resistance.

[0016] As the epoxy resin, epoxy resins commonly used in semiconductor packaging materials can be used without limitation. Non-limiting examples of epoxy resins that can be used include bisphenol A type epoxy resins, alicyclic epoxy resins, cresol novolac type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, naphthalene type epoxy resins, anthracene epoxy resins, tetramethylbiphenyl type epoxy resins, phenol novolac type epoxy resins, bisphenol A novolac type epoxy resins, bisphenol S novolac type epoxy resins, biphenyl novolac type epoxy resins, naphthol novolac type epoxy resins. Resin-type epoxy resin, naphthol phenol co-condensation linear phenolic resin type epoxy resin, naphthol cresol co-condensation linear phenolic resin type epoxy resin, aromatic hydrocarbon formaldehyde resin modified phenolic resin type epoxy resin, triphenylmethane type epoxy resin, tetraphenylethane type epoxy resin, dicyclopentadiene type epoxy resin, dicyclopentadiene phenol addition reaction type epoxy resin, biphenyl type epoxy resin, phenol aralkyl type epoxy resin, multifunctional phenolic resin, naphthol aralkyl type epoxy resin, etc., may contain more than one of them.

[0017] As an example, the epoxy resin may be an epoxy resin including two or more epoxy groups in the molecular structure, and may include one or more selected from the group consisting of bisphenol A epoxy resin, alicyclic epoxy resin, cresol novolac epoxy resin, dicyclopentadiene epoxy resin and biphenyl epoxy resin. When the number of epoxy groups in the molecular structure of the epoxy resin meets the above-mentioned range, the curability between the epoxy resin and the curing agent can be improved, and the heat resistance can be improved.

[0018] The epoxy resin may have an epoxy equivalent weight (EEW) of 150 to 300 g / eq, a viscosity (150° C. basis) of 0.01 to 5 poise, and a softening point of 50 to 130° C. Such an epoxy resin has a relatively low viscosity characteristic, and therefore, fluidity can be ensured even when a high content of filler is included, and kneading is easy.

[0019] The content of the epoxy resin is not particularly limited, but can be 2 to 20% by weight, for example, 6 to 10% by weight, based on the total weight of the epoxy resin composition. When the content of the epoxy resin is less than 2% by weight, the adhesion, fluidity and moldability are reduced, and when it exceeds 20% by weight, the moisture absorption increases, resulting in poor reliability of the semiconductor, and the strength is reduced due to the relatively reduced filler content.

[0020] Curing agent

[0021] The epoxy resin composition according to the present invention contains a curing agent, which reacts with the epoxy resin to cure the composition.

[0022] As the curing agent, any common curing agent known in the art that undergoes a curing reaction with the epoxy resin can be used without limitation. As an example, the curing agent may be a phenolic compound having two or more phenolic hydroxyl groups in the molecular structure. As an example, the curing agent may include one or more selected from the group consisting of phenol novolac type resins, cresol novolac type resins, phenol aralkyl resins, and polyfunctional phenol compounds.

[0023] The content of the curing agent is not particularly limited, but can be 1 to 20% by weight, for example, 2 to 7% by weight, based on the total weight of the epoxy resin composition. When the content of the curing agent is less than 1% by weight, curability and moldability are reduced, and when the content exceeds 20% by weight, the moisture absorption increases, resulting in poor reliability and reduced strength of the semiconductor.

[0024] The mixing ratio of the above-mentioned epoxy resin and curing agent is not particularly limited, but the equivalent ratio of the epoxy group of the epoxy resin to the phenolic hydroxyl group of the curing agent can be 1:0.3 to 2, for example, it can be mixed in a ratio of 1:0.6 to 1.3. When the equivalent ratio of the phenolic hydroxyl group to 1 equivalent of the epoxy group is less than 0.3, the curing speed of the epoxy resin composition will decrease, and when it exceeds 2, the strength of the cured product after the final curing will decrease. In addition, when it deviates from the above range, the epoxy resin composition will undergo thermal decomposition at high temperatures due to unreacted epoxy groups or phenolic hydroxyl groups.

[0025] Fillers

[0026] The epoxy resin composition according to the present invention contains a filler. The filler plays a role in improving the mechanical properties (for example, strength) of the epoxy resin composition and reducing the moisture absorption.

[0027] As the filler, for example, inorganic fillers such as silicon dioxide, silicon nitride, aluminum oxide, aluminum nitride, and boron nitride can be used alone or in combination of two or more.

[0028] The form of the filler is not particularly limited, and both angular and spherical fillers can be used. Non-limiting examples of fillers that can be used in the present invention include natural silica, synthetic silica, fused silica, etc. For example, spherical silica particles can be used. The particle size of the filler can be 250 μm or less. When the particle size of the filler meets the range described above, the filling property in the metal mold can be improved.

[0029] The content of the filler is not particularly limited, but can be 70 to 91% by weight, for example, 75 to 89% by weight, based on the total weight of the epoxy resin composition. When the content of the filler is less than 70% by weight, the moisture absorption of the cured product increases, thereby reducing the reliability of the semiconductor device. When the content of the filler exceeds 91% by weight, the fluidity decreases, thereby deteriorating the moldability.

[0030] Curing accelerator

[0031] The epoxy resin composition according to the present invention contains a curing accelerator, which accelerates the curing reaction, improves high-temperature reliability, and prolongs the period of continuous workability.

[0032] The curing accelerator used in the present invention can be used without particular restriction as long as it promotes the curing reaction of the above-mentioned curing agent. As an example, amine compounds and phosphorus compounds can be used. As amine compounds, one or more selected from the group consisting of benzyldimethylamine, triethanolamine, triethylenediamine, diethylaminoethanol, tris(dimethylaminomethyl)phenol, 2-2-(dimethylaminomethyl)phenol, 2,4,6-tris(diaminomethyl)phenol, and tri-2-ethylhexanoic acid can be used, and as phosphorus compounds, one or more selected from the group consisting of tri-4-methoxyphosphine, tetrabutylphosphine bromide, butyltriphenylphosphine bromide, phenylphosphine, diphenylphosphine, triphenylphosphine, triphenylphosphine triphenylborane, and triphenylphosphine-1,4-benzoquinone can be used.

[0033] The content of the curing accelerator is not particularly limited, but can be 0.05 to 5% by weight, for example, 0.1 to 3% by weight, based on the total weight of the epoxy resin composition. When the content of the curing accelerator is less than 0.05% by weight, the gelation time increases, resulting in reduced workability. When the content exceeds 5% by weight, the gelation time is excessively shortened, thereby reducing moldability.

[0034] additive

[0035] The epoxy resin composition according to the present invention contains cerium oxide (CeO2) and non-polar polyethylene wax as additives.

[0036] Cerium oxide is a substance with high heat resistance stability, which increases the volume resistance value of epoxy resin and can improve the tracking resistance. Therefore, when an epoxy resin composition using cerium oxide is used, the electrical reliability of the semiconductor device is improved. The average particle size of the above-mentioned cerium oxide is not particularly limited, but can be less than 2.0 μm, for example, it can be 0.1 to 2.0 μm. When the average particle size of cerium oxide deviates from the range described above, the dispersibility is reduced, and the tracking resistance is reduced.

[0037] The content of the cerium oxide is not particularly limited, but can be 0.1 to 5% by weight based on the total weight of the epoxy resin composition. When the content of the cerium oxide is less than 0.1% by weight, the effect of improving the anti-tracking property is low, and when the content exceeds 5% by weight, the moisture absorption rate increases, thereby reducing the reliability of the semiconductor device.

[0038] Non-polar polyethylene wax has no polarity and thus has high surface insulation, thus showing excellent anti-tracking performance.

[0039] The content of the non-polar polyethylene wax is not particularly limited, but can be 0.01 to 0.5% by weight based on the total weight of the epoxy resin composition. When the content of the non-polar polyethylene wax is less than 0.01% by weight, the effect of improving the anti-tracking property is low, and when it exceeds 0.5% by weight, spots are generated during molding, thereby deteriorating the workability.

[0040] The epoxy resin composition according to the present invention can further selectively contain common additives known in the art in addition to the above-mentioned ingredients. As non-limiting examples of additives that can be used in the present invention, it can further contain one or more additives selected from coupling agents, flame retardants, colorants, release agents, modifiers, adhesion enhancers and stress reducing agents.

[0041] The coupling agent is not particularly limited as long as it is a coupling agent used in the epoxy resin composition for semiconductor sealing, and for example, one of epoxysilane, mercaptosilane, methylsilane and aminosilane or a mixture thereof can be used.

[0042] As the flame retardant, a common flame retardant such as a metal hydroxide, a phosphorus- and nitrogen-containing organic compound can be used. As the metal hydroxide, a metal hydroxide selected from magnesium, calcium, strontium, barium, boron, aluminum and gallium or a mixture thereof can be used, and as the phosphorus- and nitrogen-containing organic compound, one selected from resorcinol diphosphate, phosphate, phenoxy phosphazene and melamine cyanurate or a mixture thereof can be used.

[0043] As the colorant, common colorants such as carbon black, organic dyes, and inorganic dyes can be used alone or in combination of two or more.

[0044] As the release agent, common release agents such as long-chain fatty acids, metal salts of long-chain fatty acids, paraffin wax, and carnauba wax can be used alone or in combination of two or more.

[0045] As the stress reducing agent, common stress reducing agents such as modified silicone resin and modified polybutadiene can be used alone or in combination of two or more.

[0046] The content of the above additives is not particularly limited, and may be 0.01 to 5 weight % based on the total weight of the epoxy resin composition.

[0047] The method for preparing the epoxy resin composition of the present invention comprising the aforementioned components is not particularly limited, and can be prepared using a general method in the art. As an example, it can be prepared using a known melt-kneading method utilizing a Banbury mixer, a kneader, a roller, a single-screw or twin-screw extruder, and a kneader. For example, after each component is mixed evenly, melt-mixing can be performed using a heat kneader at a temperature of 100° C. to 130° C., and after cooling to room temperature, the mixture is crushed into a powder state, and then mixed and prepared.

[0048] <Semiconductor devices>

[0049] The present invention provides a semiconductor device encapsulated by the epoxy resin composition as described above.

[0050] The semiconductor device to which the epoxy resin composition of the present invention can be applied refers to an electronic circuit (integrated circuit) made by integrating transistors, diodes, resistors, capacitors, etc. on a semiconductor chip or substrate and wiring them. The method of encapsulating and manufacturing the semiconductor device using the above-mentioned epoxy resin composition is not particularly limited, and the semiconductor device can be encapsulated and manufactured by molding methods such as transfer molds, compression molds, and injection molds.

[0051] Modes for carrying out the invention

[0052] Hereinafter, the present invention will be further specifically described by way of examples. However, the following examples are only provided to help understand the present invention, and the scope of the present invention is not limited to the examples in any sense.

[0053] [Examples 1-7]

[0054] Each component was crushed into fine powder and mixed according to the composition ratio described in Table 1 below, and then kneaded and cooled using a heated extruder, and then crushed again to prepare epoxy resin compositions of Examples 1 to 7. The content of each component described in Table 1 below refers to weight % based on the total weight of the epoxy resin composition.

[0055] [Table 1]

[0056] Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Epoxy resin 1 2.06 2.11 2.11 1.97 1.90 2.06 2.06 Epoxy Resin 2 5.81 5.81 5.81 5.76 5.76 5.81 5.76 Curing agent 1 0.45 0.50 0.50 0.41 0.31 0.45 0.50 Curing agent 2 2.50 2.50 2.50 2.50 2.50 2.50 2.50 Fillers 86.50 86.20 86.00 86.00 86.00 86.50 83.00 Curing accelerator 0.11 0.11 0.11 0.11 0.11 0.11 0.11 Additive 1-1 0.50 0.80 1.00 1.00 1.00 4.00 Additives 1-2 Additives 1-3 Additives 1-4 0.50 Additive 2-1 0.10 0.10 0.10 0.28 0.45 0.10 0.10 Additive 2-2 0.25 0.15 0.15 0.25 0.25 0.25 0.25 Additives 2-3 Additive 3-1 0.30 0.30 0.30 0.30 0.30 0.30 0.30 Additive 3-2 0.10 0.10 0.10 0.10 0.10 0.10 0.10 Additive 3-3 0.10 0.10 0.10 0.10 0.10 0.10 0.10 Additive 4 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Additive 5 0.22 0.22 0.22 0.22 0.22 0.22 0.22 total 100.00 100.00 100.00 100.00 100.00 100.00 100.00

[0057] [Comparative Examples 1-8]

[0058] The epoxy resin compositions of Comparative Examples 1 to 8 were prepared in the same manner as in Example 1 except for the composition ratios described in Table 2. The content of each component described in Table 2 is % by weight based on the total weight of the epoxy resin composition.

[0059] [Table 2]

[0060] Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Comparative Example 7 Comparative Example 8 Epoxy resin 1 2.11 2.11 2.11 2.06 2.06 2.06 1.80 2.06 Epoxy Resin 2 5.81 5.81 5.81 5.76 5.81 5.76 5.76 5.76 Curing agent 1 0.50 0.50 0.50 0.50 0.45 0.50 0.26 0.50 Curing agent 2 2.50 2.50 2.50 2.50 2.50 2.50 2.50 2.50 Fillers 86.20 86.20 86.20 86.00 86.00 86.00 86.00 81.00 Curing accelerator 0.11 0.11 0.11 0.11 0.11 0.11 0.11 0.11 Additive 1-1 0.80 1.00 1.00 6.00 Additives 1-2 0.80 0.80 1.00 Additives 1-3 1.00 Additives 1-4 Additive 2-1 0.10 0.10 0.10 0.60 Additive 2-2 0.25 0.25 0.15 0.25 0.25 0.25 0.25 0.25 Additives 2-3 0.10 0.10 Additive 3-1 0.30 0.30 0.30 0.30 0.30 0.30 0.30 0.30 Additive 3-2 0.10 0.10 0.10 0.10 0.10 0.10 0.10 0.10 Additive 3-3 0.10 0.10 0.10 0.10 0.10 0.10 0.10 0.10 Additive 4 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Additive 5 0.22 0.22 0.22 0.22 0.22 0.22 0.22 0.22 total 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00

[0061] Epoxy resin 1: Biphenyl type epoxy resin (YX-4000K, Japan Epoxy Resin Co., Ltd.)

[0062] Epoxy resin 2: dicyclopentadiene type epoxy resin (HP-7200, DIC Corporation)

[0063] Curing agent 1: phenol aralkyl resin (MEH-7800SS, Meiwa)

[0064] Curing agent 2: phenol novolac type resin (KPH-F2001, Kolon Corporation)

[0065] Filler: Amorphous silica (DQ-1150, Novoray)

[0066] Curing accelerator: amine catalyst (KPH-MN2001, Kolon)

[0067] Additive (anti-tracking agent) 1-1: cerium oxide (Rhodia, average particle size 0.2 μm)

[0068] Additive (anti-tracking agent) 1-2: cerium oxide (Rhodia, average particle size 2.2 μm)

[0069] Additive (anti-tracking agent) 1-3: cerium oxide (Rhodia, average particle size 0.05 μm)

[0070] Additive (anti-tracking agent) 1-4: cerium oxide (Rhodia, average particle size 1.3 μm)

[0071] Additive (release agent) 2-1: non-polar polyethylene wax (SANWAX 161-P, Sanyo Chemical)

[0072] Additive (release agent) 2-2: Carnauba wax (C-Wax, KAHL)

[0073] Additive (release agent) 2-3: Polar polyethylene wax (Wax 2020, Baker Petrolite)

[0074] Additive (coupling agent) 3-1: 3-(N-phenylamino)propyltrimethoxysilane (Y-9669, Momentive)

[0075] Additive (coupling agent) 3-2: 3-(2-aminoethyl)-3-aminopropyl-dimethoxysilane (KBM-602, Shin-Etsu Co., Ltd.)

[0076] Additive (coupling agent) 3-3: 3-mercaptopropyltrimethoxysilane (KBM-803, Shin-Etsu Co., Ltd.)

[0077] Additive (flame retardant) 4: aluminum hydroxide (AlO(OH), Nabaltec)

[0078] Additive (colorant) 5: Carbon black (MA-600, Mitsubishi Chemical Corporation)

[0079] [Physical property evaluation]

[0080] After the physical properties of the coating compositions prepared according to the respective Examples and Comparative Examples were measured as follows, the results are shown in Tables 3 and 4 below.

[0081] Spiral flow

[0082] The epoxy resin compositions prepared according to the embodiments and comparative examples were placed in a heated conveying molding machine (pressure 70 kg / cm 2 The fluidity of the product was measured after molding in a vacuum oven (temperature of 175°C and curing time of 120 seconds).

[0083] Gelation time

[0084] A small amount of the epoxy resin composition prepared according to each example and comparative example was placed in a gel timer and spread evenly, and the time required for the composition to gel was measured.

[0085] Tracking Resistance (CTI)

[0086] The epoxy resin composition prepared according to each of the Examples and Comparative Examples was used to mold a 3 mm thick test piece and subjected to PMC (175° C., 4 hours), and then the tracking resistance was measured using a CTI tester.

[0087] Dielectric constant (Dk)

[0088] The epoxy resin compositions prepared according to the examples and comparative examples were used to mold a 2 mm thick circular test piece and subjected to PMC (175° C., 4 hours) and then measured using a dielectric constant meter.

[0089] Stripping

[0090] The epoxy resin compositions prepared according to the examples and comparative examples were molded into packages and subjected to PMC (175°C, 4 hours) and then subjected to moisture absorption for 192 hours at 30°C / 60%RH in a thermo-hygrostat. Thereafter, reflow was performed three times at 260°C to measure the number of packages in which peeling occurred at the interface between the copper, nickel, and silver surfaces (plating) and the epoxy resin composition inside the package. The boundary peeling was analyzed using an ultrasonic microscope.

[0091] [Table 3]

[0092]

[0093] [Table 4]

[0094]

[0095] From the results of Table 3 and Table 4 above, it can be confirmed that the epoxy resin composition according to Example 1-7 of the present invention has excellent overall physical properties compared to the epoxy resin composition of Comparative Examples 1-8. In particular, it can be seen that the epoxy resin composition of Example 1-7 has excellent tracking resistance, and the semiconductor device sealed using the epoxy resin composition can ensure high reliability.

[0096] (Industrial Applicability)

[0097] The epoxy resin composition of the present invention shows excellent tracking resistance. A semiconductor device encapsulated by using the epoxy resin composition of the present invention can ensure high reliability, and can also improve tracking resistance when used in an inverter power module package.

Claims

1. An epoxy resin composition, characterized in that Including epoxy resin, curing agent, filler, curing accelerator and additives, The epoxy resin is an epoxy resin used in semiconductor packaging materials. The above additives include cerium oxide and non-polar polyethylene wax, The epoxy resin composition comprises 0.01 to 0.5 weight percent of the non-polar polyethylene wax based on the total weight of the epoxy resin composition. The average particle size of the cerium oxide is 0.1 to 2.0 μm. The epoxy resin composition comprises 0.1 to 5 weight % of the cerium oxide, based on the total weight of the epoxy resin composition. The epoxy resin composition comprises 2 to 20 weight % of epoxy resin, 1 to 20 weight % of curing agent, 70 to 91 weight % of filler and 0.05 to 5 weight % of curing accelerator based on the total weight of the epoxy resin composition.

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