JP7268241B2 - epoxy resin composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to an epoxy resin composition and a semiconductor device sealed using the same.

The inverter power module package consists of an IC (Integrated Circuit), a MOSFET (Metal Oxide Semiconductor Field Effect Transistor), an IGBT (Insulated Gate Bipolar Transistor) and a diode ( Diode) It is systemized in one package form to improve the current loss efficiency. Efforts to improve efficiency, increase power consumption, and secure price competitiveness through the integration of power module packages are continuously being made. There is a demand for improved tracking resistance of the epoxy resin composition used in the sealing composition.

As an example, Japanese Patent Publication No. 2008-143950A discloses an epoxy resin composition for semiconductor encapsulation containing a metal hydroxide to improve tracking resistance. However, the current situation is that the epoxy resin compositions disclosed in the above prior art documents do not meet the latest tracking resistance standards required for semiconductor devices.

In addition, attempts have been made to increase the content of fillers and to use expensive epoxy resins to improve tracking resistance, but in these cases, it is difficult to ensure price competitiveness and molding workability. there were. Accordingly, there is a demand for development of an epoxy resin composition capable of improving tracking resistance in inverter power module packages and ensuring price competitiveness.

The present invention provides an epoxy resin composition having excellent tracking resistance and a semiconductor device encapsulated using the composition.

The present invention provides an epoxy resin composition comprising an epoxy resin, a curing agent, a filler, a curing accelerator and an additive, said additive comprising cerium oxide and a non-polar polyethylene wax.

The epoxy resin composition of the present invention exhibits excellent tracking resistance. A semiconductor device encapsulated by applying the epoxy resin composition according to the present invention can ensure high reliability, and in particular, can improve tracking resistance when applied to an inverter power module package.

The present invention will be described in detail below. However, it is not limited only by the following contents, and each component may be variously modified or selectively mixed as needed. Therefore, it should be understood to include all modifications, equivalents or alternatives falling within the spirit and scope of the invention.

<Epoxy resin composition>
The epoxy resin composition according to the present invention comprises epoxy resin, curing agent, filler, curing accelerator and additives, said additives comprising cerium oxide and non-polar polyethylene wax. The composition of the epoxy resin composition of the present invention is described below.

Epoxy resin Epoxy resin is used as the main resin in the present invention, and after curing by reacting with a curing agent, it has a three-dimensional network structure, thereby imparting properties of strong and firm adhesion to adherends and heat resistance. do.

As the epoxy resin, epoxy resins commonly used in semiconductor encapsulants can be used without limitation. Non-limiting examples of epoxy resins that can be used include bisphenol A type epoxy resins, cycloaliphatic 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, naphthol phenol cocondensation novolac type epoxy resins , naphthol cresol cocondensed novolac 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 reaction type epoxy resins, biphenyl type epoxy resins, phenol aralkyl type epoxy resins, polyfunctional phenol resins, naphthol aralkyl type epoxy resins, etc., and one or more of these may be included.

As an example, the epoxy resin may contain two or more epoxy groups in its molecular structure, such as bisphenol A type epoxy resin, alicyclic epoxy resin, cresol novolac type epoxy resin, dicyclopentadiene type epoxy resin, It may contain one or more selected from the group consisting of resins and biphenyl-type epoxy resins. When the number of epoxy groups in the molecular structure of the epoxy resin satisfies the above range, curability between the epoxy resin and the curing agent can be improved, and heat resistance can be improved.

The epoxy resin may have an epoxy equivalent weight (EEW) of 150 to 300 g/eq, a viscosity (based on 150°C) of 0.01 to 5 poise, and a softening point of 50 to 130°C. . Since such an epoxy resin has relatively low viscosity characteristics, it can ensure flowability and is easy to knead even when a high content of filler is contained.

The content of the epoxy resin is not particularly limited, but may be 2-20% by weight, for example 6-10% by weight, based on the total weight of the epoxy resin composition. If the content of the epoxy resin is less than 2% by weight, adhesion, flowability and moldability may be deteriorated. , the strength may decrease due to the relative reduction in filler content.

Curing Agent The epoxy resin composition according to the present invention contains a curing agent. The curing agent reacts with the epoxy resin to cure the composition.

As the curing agent, any conventional curing agent known in the art that undergoes a curing reaction with an epoxy resin can be used without limitation. It may be a phenolic compound having As an example, the curing agent may contain one or more selected from the group consisting of phenol novolac resins, cresol novolac resins, phenol aralkyl resins and polyfunctional phenol compounds.

The content of the curing agent is not particularly limited, but may be 1 to 20% by weight, for example 2 to 7% by weight, based on the total weight of the epoxy resin composition. If the content of the curing agent is less than 1% by weight, curability and moldability may be deteriorated. may decrease.

The compounding ratio of the epoxy resin and the curing agent is not particularly limited, but the equivalent ratio of the epoxy group of the epoxy resin and the phenolic hydroxyl group of the curing agent is 1:0.3 to 2, for example 1:0.6 to 1.3. It may be blended with. When the equivalent ratio of the phenolic hydroxyl group to one equivalent of the epoxy group is less than 0.3, the curing speed of the epoxy resin composition may decrease, and when it exceeds 2, the strength of the cured product after final curing decreases. I have something to do. Further, when the content is out of the above range, thermal decomposition of the epoxy resin composition may occur at high temperature due to unreacted epoxy groups or phenolic hydroxyl groups.

Fillers The epoxy resin composition according to the present invention contains fillers. The filler serves to improve mechanical properties (eg, strength) of the epoxy resin composition and reduce moisture absorption.

As the filler, inorganic fillers such as silica, silica nitride, alumina, aluminum nitride, and boron nitride can be used alone or in combination of two or more.

The shape 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 may be 250 μm or less, and when the particle size of the filler satisfies the above range, the filling property in the mold can be improved.

The content of the filler is not particularly limited, but may be 70-91% by weight, for example 75-89% by weight, based on the total weight of the epoxy resin composition. If the content of the filler is less than 70% by weight, the amount of moisture absorption of the cured product may increase and the reliability of the semiconductor device may be reduced. Moldability may be poor.

Curing Accelerator The epoxy resin composition according to the present invention contains a curing accelerator. The curing accelerator plays a role of accelerating the curing reaction and improving high-temperature reliability and continuous workability cycle.

The curing accelerator used in the present invention can be used without any particular limitation as long as it accelerates the curing reaction of the curing agent, and examples thereof include amine-based compounds and phosphorus-based compounds. Amine compounds include benzyldimethylamine, triethanolamine, triethylenediamine, diethylaminoethanol, tri(dimethylaminomethyl)phenol, 2-2-(dimethylaminomethyl)phenol, 2,4,6-tris(diaminomethyl) One or more selected from the group consisting of phenol and tri-2-ethylhexyl acid can be used. One or more selected from the group consisting of phosphine, triphenylphosphine, triphenylphosphine-triphenylborane, and triphenylphosphine-1,4-benzoquinone can be used.

The content of the curing accelerator is not particularly limited, but may be 0.05 to 5 wt%, for example 0.1 to 3 wt%, 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 is increased, resulting in deterioration of workability. , the moldability may deteriorate.

Additives The epoxy resin composition according to the present invention contains cerium oxide (CeO ₂ ) and non-polar polyethylene wax as additives.

Cerium oxide is a substance with high heat stability, and can increase the volume resistance of the epoxy resin to improve tracking resistance. Therefore, when using the epoxy resin composition to which this is applied, the electrical reliability of the semiconductor device is improved. The average particle size of the cerium oxide is not particularly limited, but may be 2.0 μm or less, for example, 0.1 to 2.0 μm. If the average particle size of the cerium oxide is out of the range described above, the dispersibility may be reduced and the tracking resistance may be deteriorated.

The content of the cerium oxide is not particularly limited, but may be 0.1-5% by weight based on the total weight of the epoxy resin composition. If the cerium oxide content is less than 0.1% by weight, the effect of improving the tracking resistance is weak, and if it exceeds 5% by weight, the moisture absorption rate increases and the reliability of the semiconductor device may deteriorate. .

Non-polar polyethylene wax exhibits excellent tracking resistance because it is not polar and has high surface insulating properties.

The content of the non-polar polyethylene wax is not particularly limited, but may be 0.01-0.5% by weight based on the total weight of the epoxy resin composition. If the content of the non-polar polyethylene wax is less than 0.01% by weight, the effect of improving the tracking resistance is weak, and if it exceeds 0.5% by weight, unevenness occurs during molding, resulting in poor workability. can be.

The epoxy resin composition according to the present invention may optionally further contain conventional additives known in the art, in addition to the components described above. Non-limiting examples of additives that can be used in the present invention include one selected from among coupling agents, flame retardants, colorants, release agents, modifiers, adhesion improvers and stress reducers. It may further comprise one or more additives.

The coupling agent is not particularly limited as long as it is used in an epoxy resin composition for semiconductor encapsulation. For example, one of epoxysilane, mercaptosilane, methylsilane and aminosilane or a mixture thereof Available.

Usual flame retardants such as metal hydroxides, phosphorus- and nitrogen-containing organic compounds can be used as the flame retardant. As the metal hydroxide, a metal hydroxide selected from magnesium, calcium, strontium, barium, boron, aluminum and gallium or a mixture thereof can be used. As the phosphorus- and nitrogen-containing organic compound, resorcinol One selected from among diphosphates (Resorcinol diphosphate), Phosphate, Phenoxy phosphazene and Melamine cyanurate or mixtures thereof can be used.

As the coloring agent, ordinary coloring agents such as carbon black, organic dyes and inorganic dyes can be used singly or in combination of two or more.

As the mold release agent, usual mold release agents such as long-chain fatty acids, metal salts of long-chain fatty acids, paraffin wax, and carnauba wax can be used singly or in combination of two or more.

As the stress-lowering agent, ordinary stress-lowering agents such as modified silicone resins and modified polybutadiene can be used alone, or two or more of them can be used in combination.

The content of the additive is not particularly limited, and may be 0.01 to 5% by weight based on the total weight of the epoxy resin composition.

The method for producing the epoxy resin composition of the present invention containing the components described above is not particularly limited, and can be produced using a general method in the art. As an example, it can be manufactured using a known melt-kneading method using a Banbury mixer, kneader, rolls, single-screw or twin-screw extruder and kneader. For example, each component is uniformly mixed, melt-kneaded at a temperature of 100° C. to 130° C. using a heat kneader, cooled to room temperature, pulverized into powder, and blended. can be manufactured.

<Semiconductor element>
The present invention provides a semiconductor device encapsulated using the epoxy resin composition as described above.

A semiconductor device to which the epoxy resin composition of the present invention can be applied means an electronic circuit (integrated circuit) manufactured by integrating and wiring transistors, diodes, resistors, capacitors, etc. on a semiconductor chip or substrate. The method for encapsulating and manufacturing a semiconductor device using the epoxy resin composition is not particularly limited, and can be manufactured by encapsulating a semiconductor element by a molding method such as transfer molding, compression molding, or injection molding.

EXAMPLES The present invention will now be described more specifically based on examples. However, the following examples are merely for helping understanding of the present invention, and the scope of the present invention is not limited to the examples in any way.

[Examples 1 to 7]
Each component was finely pulverized according to the composition shown in Table 1 below to prepare a powder, which was then kneaded using a heated extruder, cooled, and then pulverized again to obtain the powder of Examples 1 to 7. were produced respectively. The content of each component shown in Table 1 below means % by weight based on the total weight of the epoxy resin composition.

[Comparative Examples 1 to 8]
Epoxy resin compositions of Comparative Examples 1 to 8 were produced in the same manner as in Examples, except for the compositions shown in Table 2 below. The content of each component shown in Table 2 below means weight % based on the total weight of the epoxy resin composition.

エポキシ樹脂１：ビフェニル型エポキシ樹脂（ＹＸ－４０００Ｋ、日本エポキシ社）
エポキシ樹脂２：ジシクロペンタジエン型エポキシ樹脂（ＨＰ－７２００、ＤＩＣ社）
硬化剤１：フェノールアラルキル樹脂（ＭＥＨ－７８００ＳＳ、メイワ社）
硬化剤２：フェノールノボラック樹脂（ＫＰＨ－Ｆ２００１、コーロン社）
充填剤：非定型シリカ（ＤＱ－１１５０、Ｎｏｖｏｒａｙ社）
硬化促進剤：アミン系触媒（ＫＰＨ－ＭＮ２００１、コーロン社）
添加剤（耐クラッキング剤）１－１：セリウムオキシド（Ｒｈｏｄｉａ社、平均粒径０．２μｍ）
添加剤（耐クラッキング剤）１－２：セリウムオキシド（Ｒｈｏｄｉａ社、平均粒径２．２μｍ）
添加剤（耐クラッキング剤）１－３：セリウムオキシド（Ｒｈｏｄｉａ社、平均粒径０．０５μｍ）
添加剤（耐クラッキング剤）１－４：セリウムオキシド（Ｒｈｏｄｉａ社、平均粒径１．３μｍ）
添加剤（離型剤）２－１：非極性ポリエチレンワックス（ＳＡＮＷＡＸ １６１－Ｐ、ＳＡＮＹＯ ＣＨＥＭＩＣＡＬ社）
添加剤（離型剤）２－２：カルナウバワックス（Ｃ－Ｗａｘ、ＫＡＨＬ社）
添加剤（離型剤）２－３：極性ポリエチレンワックス（Ｗａｘ ２０２０、Ｂａｋｅｒ Ｐｅｔｒｏｌｉｔｅ社）
添加剤（カップリング剤）３－１：３－（Ｎ－フェニルアミノ）プロピルトリメトキシシラン（Ｙ－９６６９、モメンティブ社）
添加剤（カップリング剤）３－２：３－（２－アミノエチル）－３－アミノプロピル－ジメトキシシラン（ＫＢＭ－６０２、信越社）
添加剤（カップリング剤）３－３：３－メルカプトプロピルトリメトキシシラン（ＫＢＭ－８０３、信越社）
添加剤（難燃剤）４：水酸化アルミニウム（ＡｌＯ（ＯＨ）、ナバルテック社）
添加剤（着色剤）５：カーボンブラック（ＭＡ－６００、三菱化学社）

Epoxy resin 1: Biphenyl type epoxy resin (YX-4000K, Nippon Epoxy Co., Ltd.)
Epoxy resin 2: dicyclopentadiene type epoxy resin (HP-7200, DIC Corporation)
Curing agent 1: phenol aralkyl resin (MEH-7800SS, Meiwa Co., Ltd.)
Curing agent 2: phenol novolac resin (KPH-F2001, Kolon Co., Ltd.)
Filler: Amorphous silica (DQ-1150, Novoray)
Curing accelerator: amine catalyst (KPH-MN2001, Kolon Co., Ltd.)
Additive (anti-cracking agent) 1-1: Cerium oxide (Rhodia, average particle size 0.2 μm)
Additive (anti-cracking agent) 1-2: Cerium oxide (Rhodia, average particle size 2.2 μm)
Additive (anti-cracking agent) 1-3: Cerium oxide (Rhodia, average particle size 0.05 μm)
Additive (anti-cracking agent) 1-4: Cerium oxide (Rhodia, average particle size 1.3 μm)
Additive (release agent) 2-1: non-polar polyethylene wax (SANWAX 161-P, SANYO CHEMICAL)
Additive (release agent) 2-2: Carnauba wax (C-Wax, KAHL)
Additive (release agent) 2-3: Polar polyethylene wax (Wax 2020, Baker Petrolite)
Additive (coupling agent) 3-1: 3-(N-phenylamino)propyltrimethoxysilane (Y-9669, Momentive)
Additive (coupling agent) 3-2: 3-(2-aminoethyl)-3-aminopropyl-dimethoxysilane (KBM-602, Shin-Etsu Co., Ltd.)
Additive (coupling agent) 3-3: 3-mercaptopropyltrimethoxysilane (KBM-803, Shin-Etsu Co., Ltd.)
Additive (flame retardant) 4: aluminum hydroxide (AlO (OH), Navartec)
Additive (colorant) 5: carbon black (MA-600, Mitsubishi Chemical Corporation)

[Evaluation of the physical properties]
The physical properties of the coating compositions prepared according to each example and comparative example were measured as follows, and the results are shown in Tables 3 and 4 below.

spiral flow
The epoxy resin composition prepared according to each example and comparative example was molded using a spiral flow mold with a heat transfer molding machine (pressure 70 kg/cm ² , temperature 175° C., curing time 120 seconds). sex was measured.

gelation time
A small amount of the epoxy resin composition prepared according to each example and comparative example was widely and uniformly applied to a gel timer to measure the gelling time of the composition.

Tracking resistance (CTI)
A test piece with a thickness of 3 mm was molded using the epoxy resin composition prepared according to each example and comparative example, and after PMC (175° C., 4 hours), tracking resistance was measured using a CTI tester. bottom.

Dielectric constant (Dk)
Circular test pieces with a thickness of 2 mm were molded using the epoxy resin compositions prepared according to each example and comparative example, and after PMC (175° C., 4 hours), the dielectric constant was measured using a dielectric constant measuring apparatus.

Peeling The epoxy resin composition prepared according to each example and comparative example was molded into a package, and after PMC (175°C, 4 hours), the temperature and humidity were kept under the conditions of 30°C/60% RH for 192 hours. Moisturized. Thereafter, reflow was performed three times at 260° C., and the number of packages in which peeling occurred at the interface between the copper, nickel and silver surfaces (plating) inside the package and the epoxy resin composition was measured. An ultrasonic microscope was used for the analysis of interfacial delamination.

From the results in Tables 3 and 4, it can be confirmed that the epoxy resin compositions of Examples 1 to 7 according to the present invention are generally superior in physical properties to the epoxy resin compositions of Comparative Examples 1 to 8. rice field. In particular, the epoxy resin compositions of Examples 1 to 7 were excellent in tracking resistance, and it was found that a semiconductor device sealed using this could ensure high reliability.

The epoxy resin composition of the present invention exhibits excellent tracking resistance. A semiconductor device encapsulated by applying the epoxy resin composition according to the present invention can ensure high reliability, and in particular, can improve tracking resistance when applied to an inverter power module package.

Claims (3)

As an epoxy resin composition containing an epoxy resin, a curing agent, a filler, a curing accelerator and additives,
the additive comprises cerium oxide and a non-polar polyethylene wax;
The cerium oxide has an average particle size of 0.1 to 2.0 μm,
Based on the total weight of the epoxy resin composition, containing 0.01 to 0.5% by weight of the non-polar polyethylene wax,
The epoxy resin composition , wherein the filler does not contain cerium oxide . The epoxy resin composition according to claim 1, comprising 0.1 to 5% by weight of the cerium oxide based on the total weight of the epoxy resin composition. Based on the total weight of the epoxy resin composition, comprising 2-20% by weight of epoxy resin, 1-20% by weight of curing agent, 70-91% by weight of filler and 0.05-5% by weight of curing accelerator. 2. The epoxy resin composition according to 1.