Epoxy resin composition, semiconductor device, and method for producing semiconductor device

Abstract

Provided are an epoxy resin composition whereby it is possible to achieve both injectability and reliability, a semiconductor device, and a method for producing the semiconductor device.　The epoxy resin composition contains a polyalkylene glycol epoxy resin, a heterocyclic compound including a nitrogen atom, and a filler. The content of the filler is 55 mass% or more and less than 77 mass% with respect to the total amount of the epoxy resin composition.

Description

Epoxy resin composition, semiconductor device, and method for manufacturing semiconductor device

[0001] One aspect of the present disclosure relates to an epoxy resin composition, a semiconductor device, and a method for manufacturing a semiconductor device.

[0002] Electronic devices incorporating semiconductor devices are required to be smaller, lighter, and have higher performance. To meet these demands, the mainstream mounting method for semiconductor devices is shifting from wire bonding to flip-chip mounting. Generally, in semiconductor devices mounted by flip-chip mounting, several to several thousand bump electrodes, each about 10 μm to 100 μm in height, are formed on a substrate. The electrodes on the substrate are connected to the semiconductor element via these bump electrodes.

[0003] In semiconductor devices mounted using flip-chip bonding, defects such as cracks can occur in the bump electrodes when subjected to thermal loads such as temperature cycles. This is due to stresses imposed on the bump electrodes due to the difference in the linear expansion coefficient between the substrate, which contains a large amount of organic material such as epoxy resin, and the semiconductor element, which contains a large amount of metal material. To prevent cracks, the following techniques are widely used: Filling the gap between the substrate and the semiconductor element with a liquid semiconductor encapsulant called underfill (also called an underfill material or encapsulant). Furthermore, forming a portion of the semiconductor encapsulant called a fillet at the corners of the chip (corner ends). This encapsulation improves thermal load resistance (thermal cycle resistance) and chip protection, protecting the chip from heat and external forces.

[0004] A sealant is generally a composition containing an epoxy resin and a filler. One example of a sealant proposed is one containing an aminophenol-type epoxy resin, an amine-based curing agent, a silica filler, and a silane coupling agent (see, for example, Patent Document 1). Another example is one containing an epoxy resin, a curing agent, a filler, and a modified polysiloxane (see, for example, Patent Document 2). Thus, various sealants have been proposed by varying the type of epoxy resin, the type of curing agent, and the like.

[0005] JP 2016-113525 A JP 2001-55488 A

[0006] In recent years, there has been a growing demand for smaller, lighter, and more powerful semiconductor devices. Accordingly, the wiring density within semiconductor devices has increased. This means that the wiring patterns on the substrates within semiconductor devices are becoming finer in pitch (i.e., the spacing between wiring patterns is becoming narrower, or what is known as narrower gaps). Therefore, there has been a demand for underfill materials that can be used even with finer pitches.

[0007] On the other hand, conventional underfill materials sometimes contain fillers to reduce the difference in linear expansion coefficient between the chip and the bump. The viscosity of an underfill material increases when it contains a large amount of filler. The viscosity of an underfill material increases significantly, especially when it contains a large amount of fine filler. Furthermore, when an underfill material contains coarse fillers, the volume of the coarse fillers can prevent the underfill material from penetrating into gaps in fine-pitched wiring patterns. Thus, conventional underfill materials can sometimes have difficulty injecting into gaps in fine-pitched wiring patterns. Therefore, improvements in the injectability of underfill materials are needed.

[0008] In response to this issue, attempts have been made to reduce the viscosity of the underfill material by reducing the filler content in the underfill material, but reducing the filler content can result in reduced reliability in terms of thermal cycle resistance, such as fillet cracking, and moisture absorption reflow.

[0009] An object of the present disclosure is to provide an epoxy resin composition, a semiconductor device, and a method for manufacturing a semiconductor device that can achieve both injectability and reliability.

[0010] The present inventors have investigated the appropriate composition of an underfill material for injection into a substrate having a fine-pitch wiring pattern. They considered that reducing the filler content of the epoxy resin composition reduces reliability in terms of thermal cycle resistance and moisture absorption reflow, while increasing the filler content increases the viscosity of the underfill material, reducing injectability and causing voids at the injection site. As a result, they discovered that an underfill material that combines injectability and reliability cannot be realized by using a polyalkylene glycol-type epoxy resin, which has flexibility as an epoxy resin, a filler, and an appropriate curing agent component.

[0011] Specifically, in order to achieve the above object, an epoxy resin composition according to one embodiment of the present disclosure contains an epoxy resin, a heterocyclic compound containing a nitrogen atom, and a filler, wherein the epoxy resin contains at least a polyalkylene glycol-type epoxy resin, and the content of the filler is 55 mass % or more and less than 77 mass % with respect to the total amount of the epoxy resin composition.

[0012] According to one embodiment of the present disclosure, it is possible to provide an epoxy resin composition that is both easy to inject and reliable, a semiconductor device, and a method for manufacturing a semiconductor device.

[0013] (Epoxy Resin Composition) The epoxy resin composition according to the embodiment contains a polyalkylene glycol-type epoxy resin, a nitrogen-containing heterocyclic compound, and a filler. The epoxy resin composition according to the embodiment preferably further contains an epoxy resin other than the polyalkylene glycol-type epoxy resin and a phenol-based curing agent, and may contain other components as necessary.

[0014] <Polyalkylene glycol-type epoxy resin> The polyalkylene glycol-type epoxy resin is contained to achieve both injectability and reliability. The polyalkylene glycol-type epoxy resin does not have a rigid ring in the molecule and is composed only of a linear structure, which is a flexible structure. Therefore, the polyalkylene glycol-type epoxy resin is a resin with a high stress relaxation effect, has flexibility, can impart flexibility to the cured product, and can reduce the elastic modulus of the cured product. Therefore, it is possible to achieve both injectability and reliability of the epoxy resin composition while maintaining a constant amount of filler.

[0015] Examples of polyalkylene glycol-type epoxy resins include polytetramethylene glycol-type epoxy resins, polyethylene glycol-type epoxy resins, and polypropylene glycol-type epoxy resins. These may be used alone or in combination of two or more. Among these, polytetramethylene glycol-type epoxy resins are preferred from the viewpoints of injectability and stress relaxation.

[0016] Regarding the molecular weight of the polyalkylene glycol-type epoxy resin, from the viewpoint of the balance between viscosity and flexibility, the weight-average molecular weight is preferably 500 to 3,000, and more preferably 1,500 to 2,500. In this specification, the weight-average molecular weight refers to a value obtained by gel permeation chromatography (GPC) using a calibration curve with standard polystyrene. If the weight-average molecular weight is less than 500, the effect of imparting flexibility is small, which may result in poor reliability. On the other hand, if the weight-average molecular weight is 3,000 or more, the epoxy resin composition will have a high viscosity, which may lead to concerns about poor injectability.

[0017] The number of epoxy groups contained in one molecule of the polyalkylene glycol epoxy resin is not particularly limited and can be appropriately selected depending on the purpose, but from the viewpoint of reliability, it is preferably 2 or more (multifunctional epoxy resin). The upper limit of the number of epoxy groups is not particularly limited and can be appropriately selected depending on the purpose, but it is preferably 5 or less.

[0018] Polyalkylene glycol-type epoxy resins may contain chlorine, a by-product produced during synthesis. Chlorine in the resin may reduce injectability and reliability. For this reason, the chlorine content of polytetramethylene glycol-type epoxy resins is preferably 1,000 ppm or less.

[0019] The polyalkylene glycol type epoxy resin is preferably used in combination with an epoxy resin other than the polyalkylene glycol type epoxy resin described below.

[0020] The content of the polyalkylene glycol-type epoxy resin is preferably 10% by mass to 30% by mass, and more preferably 15% by mass to 20% by mass, relative to the epoxy resin. If the content of the polyalkylene glycol-type epoxy resin is less than 10% by mass, the stress relaxation effect may be insufficient, resulting in reduced reliability. On the other hand, if the content of the polyalkylene glycol-type epoxy resin is more than 30% by mass, the cured product of the epoxy resin composition may become brittle, resulting in reduced reliability.

[0021] <Other Epoxy Resins> The other epoxy resins are epoxy resins other than the polyalkylene glycol-type epoxy resins described above. The other epoxy resins can be any of various epoxy resins commonly used for semiconductor encapsulation, and are not particularly limited. The number of epoxy groups contained in one molecule of the other epoxy resin is not particularly limited and can be selected appropriately depending on the purpose, but from the viewpoint of reliability, it is preferably two or more (multifunctional epoxy resin). The upper limit of the number of epoxy groups is not particularly limited and can be selected appropriately depending on the purpose, but it is preferably five or less. The epoxy equivalent of the other epoxy resin is preferably 50 g / eq. to 10,000 g / eq., more preferably 50 g / eq. to 1,000 g / eq., and even more preferably 100 g / eq. to 500 g / eq. Here, the epoxy equivalent is the mass of a resin containing one equivalent of epoxy groups, as defined in JIS K 7236:2001. It should be noted that "eq." is an abbreviation for "equivalent."

[0022] Examples of epoxy resins other than polyalkylene glycol-type epoxy resins include glycidylamine-type epoxy resins, aliphatic epoxy resins, alicyclic epoxy resins, bisphenol-type epoxy resins, novolac-type epoxy resins, fluorene-type epoxy resins, biphenyl-type epoxy resins, aminophenol-type epoxy resins, and naphthalene-type epoxy resins. Examples of glycidylamine-type epoxy resins include diglycidyl aniline, diglycidyl toluidine, and tetraglycidyl-m-xylylenediaminetetraglycidylbis(aminomethyl)cyclohexane. Examples of alicyclic epoxy resins include vinyl(3,4-cyclohexene) dioxide and 2-(3,4-epoxycyclohexyl)-5,1-spiro-(3,4-epoxycyclohexyl)-m-dioxane. Examples of bisphenol-type epoxy resins include bisphenol A-type epoxy resins and bisphenol F-type epoxy resins. Examples of bisphenol A-type epoxy resins include p-glycidyloxyphenyldimethyltrisbisphenol A diglycidyl ether. Examples of biphenyl-type epoxy resins include biphenylaralkyl epoxy resins and 3,3',5,5'-tetramethyl-4,4'-diglycidyloxybiphenyl. Examples of aminophenol-type epoxy resins include triglycidyl-p-aminophenol. Furthermore, the number of epoxy groups in the epoxy resin may be one (monofunctional) or two or more (multifunctional). Examples of monofunctional epoxy resins include p-tert-butylphenyl glycidyl ether. Examples of multifunctional epoxy resins include diepoxy resins such as 1,4-phenyldimethanol diglycidyl ether; and triepoxy resins such as trimethylolpropane triglycidyl ether and glycerin triglycidyl ether.In addition to the above, epoxy resins other than polyalkylene glycol-type epoxy resins may also include hydantoin-type epoxy resins such as 1,3-diglycidyl-5-methyl-5-ethylhydantoin; epoxy resins having a silicone skeleton such as 1,3-bis(3-glycidoxypropyl)-1,1,3,3-tetramethyldisiloxane; and epoxy resins having a plant-derived skeleton. These may be used alone or in combination of two or more. Among these, glycidylamine-type epoxy resins, bisphenol-type epoxy resins, and aliphatic epoxy resins are preferred from the standpoint of reliability. That is, it is preferable that the epoxy resin composition further contains at least one selected from glycidylamine-type epoxy resins, bisphenol-type epoxy resins, and aliphatic epoxy resins. It is more preferable to use an aliphatic epoxy resin and an aromatic epoxy resin in combination.

[0023] The content of the epoxy resin (total amount of polyalkylene glycol-type epoxy resin and other epoxy resins) is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 45% by mass to 23% by mass based on the total amount of the epoxy resin composition. When the content of the epoxy resin falls within this range, both injectability and reliability can be achieved.

[0024] <Nitrogen-Atom-Containing Heterocyclic Compound> The nitrogen-atom-containing heterocyclic compound is included to cure the epoxy resin composition. When curing the epoxy resin composition, the nitrogen-atom-containing heterocyclic compound undergoes homopolymerization with the epoxy resin or the like. In contrast, the amine-based curing agent undergoes addition polymerization with the epoxy resin or the like. Due to this difference in reaction, the nitrogen-atom-containing heterocyclic compound cures with a lower crosslink density and linear expansion coefficient than the amine-based curing agent. Therefore, by using a nitrogen-atom-containing heterocyclic compound as a curing agent, the linear expansion coefficient of the cured product of the epoxy resin composition can be reduced, particularly at temperatures above the glass transition point. This reduces the gap between the linear expansion coefficient of the cured product of the epoxy resin composition and the linear expansion coefficient of the chip at high temperatures, thereby reducing the generated stress. This improves reliability.

[0025] The nitrogen atom-containing heterocyclic compound is not particularly limited as long as it can cure the resin in the epoxy resin composition, and can be appropriately selected depending on the purpose. Examples of the heterocyclic compound include imidazole derivatives and microencapsulated nitrogen atom-containing heterocyclic compounds. Examples of imidazole derivatives include 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-ethyl-4-imidazole, 2-phenylimidazole, 1-benzyl-2-phenylimidazole, benzimidazole, 2,4-diamino-6-[2'-methylimidazolyl-(1')]ethyl-s-triazine, 2-phenyl-4,5-dihydroxymethylimidazole, and 2,3-dihydro-1H-pyrrolo[1,2-a]benzimidazole. These may be used alone or in combination of two or more. As the imidazole derivative, a commercially available product or an appropriately synthesized product may be used. Examples of commercially available products include 2P4MZ (2-phenyl-4-methylimidazole), 2MZA (2,4-diamino-6-[2'-methylimidazolyl-(1')]ethyl-s-triazine, and 2-phenyl-4-methylimidazole) (all manufactured by Shikoku Chemicals Corporation).

[0026] The nitrogen-containing heterocyclic compound may be microencapsulated. As the microencapsulated nitrogen-containing heterocyclic compound, a commercially available product may be used, or an appropriately synthesized product may be used. Examples of commercially available products include Novacure HX3941HP, Novacure HXA3042HP, Novacure HXA3922HP, Novacure HXA3792, Novacure HX3748, Novacure HX3721, Novacure HX3722, Novacure HX3088, Novacure HX3741, Novacure HX3742, Novacure HX3613 (all manufactured by Asahi Kasei Corporation), Amicure PN-23J, Amicure PN-40J (all manufactured by Ajinomoto Fine-Techno Co., Ltd.), and Fujicure FXR-1121 (manufactured by Fuji Chemical Industry Co., Ltd.). These may be used alone or in combination of two or more.

[0027] Among these, from the viewpoints of reactivity and storage stability, the nitrogen-containing heterocyclic compound is preferably 2-phenyl-4-methylimidazole or 2,4-diamino-6-[2'-methylimidazolyl-(1')]ethyl-s-triazine. That is, the nitrogen-containing heterocyclic compound is preferably at least one selected from 2-phenyl-4-methylimidazole and 2,4-diamino-6-[2'-methylimidazolyl-(1)']-ethyl-s-triazine.

[0028] The content of the nitrogen-containing heterocyclic compound is not particularly limited and can be appropriately selected depending on the purpose. The content of the nitrogen-containing heterocyclic compound is preferably 2.0% by mass to 8.0% by mass, and more preferably 2.5% by mass to 6.0% by mass, based on the epoxy resin composition excluding the filler described below. When the content of the nitrogen-containing heterocyclic compound is 2.0% by mass or more, the curing time of the epoxy resin composition can be shortened, thereby improving the productivity of electronic component devices. When the content of the nitrogen-containing heterocyclic compound is 8.0% by mass or less, the storage stability of the epoxy resin composition is improved. With regard to the content of the microencapsulated nitrogen-containing heterocyclic compound, the content of the active ingredient (nitrogen-containing heterocyclic compound) is preferably 3% by mass to 25% by mass, and more preferably 5% by mass to 20% by mass, based on the epoxy resin composition excluding the filler.

[0029] <Filler> The filler is contained in order to reduce the linear expansion coefficient of the cured product of the epoxy resin composition and to suppress volumetric shrinkage caused by the curing reaction of the epoxy resin composition.

[0030] The filler is not particularly limited as long as it is contained in a typical epoxy resin composition and can be appropriately selected depending on the purpose. Examples of fillers include inorganic particles. Examples of inorganic particles include silica and alumina. The filler may also have other functions such as coloring. Examples of such fillers include inorganic pigments such as white pigments. Examples of inorganic pigments include magnesia, titania, zirconia, boron nitride, aluminum nitride, titanium oxide, magnesium oxide, zinc oxide, aluminum oxide, diamond, potassium titanate, magnesium sulfate, sepiolite, zonolite, aluminum borate, calcium carbonate, titanium oxide, barium sulfate, zinc oxide, magnesium hydroxide, barium titanate, and zirconia oxide. These may be used alone or in combination of two or more. Among these, silica filler is preferred because it allows for a high loading.

[0031] The filler may be surface-treated with a silane coupling agent or the like. Using a surface-treated filler can suppress filler aggregation and improve dispersibility. Furthermore, improved wettability of the filler with the resin component strengthens the bond at the interface between the filler and the resin, improving the bonding between the filler and the resin component. This can suppress an increase in the viscosity of the epoxy resin composition and a decrease in the injection rate, and can improve the toughness of the cured product of the epoxy resin composition. The silane coupling agent is not particularly limited and can be selected appropriately depending on the purpose. Considering adhesion to adherends such as substrates and chips, the silane coupling agent is preferably 3-methacryloxypropyltrimethoxysilane or N-phenyl-3-aminopropyltrimethoxysilane.

[0032] The shape of the filler is not particularly limited and can be appropriately selected depending on the purpose. Examples of the shape of the filler include spherical, irregular, and flaky shapes.

[0033] From the viewpoint of injectability, the volume average particle size (hereinafter referred to as "average particle size") of the filler is preferably 0.5 μm to 2.0 μm, and more preferably 0.5 μm to 1.5 μm. The average particle size of the filler refers to the volume average particle size D50 (the particle size at 50% of the cumulative size from the small diameter side of the particle size distribution) measured using a laser diffraction particle size distribution analyzer (LS13320, manufactured by Beckman Coulter). The average particle size is measured as follows: 5 mg of filler is dispersed in 50 mg of dispersant, and the dispersion is carried out for 10 minutes using an ultrasonic disperser to prepare a measurement sample. The average particle size of this measurement sample is measured under the following conditions: a flow rate of 50 mL / sec, a measurement time of 90 seconds, a solvent of pure water, and a solvent refractive index of 1.333.

[0034] The filler content is 55% by mass or more but less than 77% by mass, preferably 60% by mass or more but less than 76% by mass, more preferably 70% by mass or more but less than 76% by mass, and even more preferably 73% by mass or more but less than 76% by mass, based on the total amount of the epoxy resin composition. When the filler content falls within this range, the viscosity of the epoxy resin composition becomes appropriate for dispensing. This improves the injectability of the underfill material during the mounting process, for example, by improving the workability of injecting the underfill material.

[0035] <Phenol-based curing agent> The phenol-based curing agent is contained in the epoxy resin composition to promote curing of the resin. There are no particular limitations on the phenol-based curing agent, and it can be appropriately selected depending on the purpose. Examples of the phenol-based curing agent include phenol, cresol, naphthol, alkylphenol, allylphenol, bisphenol, and terpene phenol. These may be used alone or in combination of two or more.

[0036] The content of the phenol-based curing agent is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 0.5% by mass to 2.0% by mass, and more preferably 0.5% by mass to 1.0% by mass.

[0037] <Other Components> The other components are not particularly limited as long as they are those commonly used in ordinary underfill materials and can be appropriately selected depending on the purpose. Examples of other components include curing agents other than heterocyclic compounds having nitrogen atoms, such as liquid acid anhydrides, liquid phenols, and aromatic amines; colorants such as dyes, pigments, and carbon black; silicone oils; surfactants; antioxidants; conventionally known flame retardants such as antimony oxides (e.g., antimony trioxide, antimony tetraoxide, and antimony pentoxide) and brominated epoxy resins; ion trapping agents; leveling agents; antifoaming agents; and reactive diluents. These may be used alone or in combination of two or more.

[0038] The content of other components is not particularly limited and can be appropriately selected depending on the purpose.

[0039] <Physical Properties of Epoxy Resin Composition> <<Viscosity>> From the viewpoint of injectability, the viscosity of the epoxy resin composition at 25°C is preferably the following value. When the epoxy resin composition immediately after preparation is rotated at 50 rpm for 1 minute using a Brookfield viscometer at 25°C, the viscosity of the epoxy resin composition is preferably 5 Pa s to 45 Pa s. When the epoxy resin composition immediately after preparation is rotated at 5 rpm for 1 minute using a Brookfield viscometer at 25°C, the viscosity of the epoxy resin composition is preferably 2 Pa s to 45 Pa s. The thixotropic index (TI value: (viscosity at 5 rpm) / (viscosity at 50 rpm)) of the epoxy resin composition is preferably 0.3 to 1.2.

[0040] <<Chlorine Amount>> The chlorine amount (total chlorine amount) in the epoxy resin composition is preferably 1,300 ppm or less, and more preferably 1,000 ppm or less. If the total chlorine amount exceeds 1,300 ppm, the injectability and reliability may deteriorate, and storage stability may also deteriorate.

[0041] <Uses of Epoxy Resin Composition> The epoxy resin composition according to the embodiment can achieve both injectability and reliability, and therefore can be suitably used as an underfill material. This epoxy resin composition can be particularly suitably used for mounting semiconductor devices having fine pitches. For example, because of its excellent injectability, the epoxy resin composition can be injected and sealed even in fine gaps where the distance between the substrate and the semiconductor element is 15 μm or less, and in fine locations where the bump pitch (the distance between the bump centers) is 150 μm or less. That is, the epoxy resin composition can be used to seal semiconductor chips with a bump pitch of 150 μm or less. Furthermore, because of its excellent reliability, cracks can be prevented from occurring between the substrate and the semiconductor element, even when sealing such fine locations.

[0042] (Method for Producing Epoxy Resin Composition) The method for producing the epoxy resin composition according to the embodiment can be appropriately selected depending on the purpose. For example, the method for producing the epoxy resin composition according to the embodiment includes mixing and stirring the above-mentioned components.

[0043] When the epoxy resin is solid, it is preferable to carry out mixing and stirring after the epoxy resin has been liquefied and fluidized by heating or the like.

[0044] The components may be mixed simultaneously, or some of the components may be mixed first and then the remaining components may be mixed in. If it is difficult to uniformly disperse the filler in the epoxy resin, the epoxy resin and filler may be mixed first and then the remaining components may be mixed in.

[0045] The device used for mixing and stirring is not particularly limited and can be appropriately selected depending on the purpose. Examples of such devices include a roll mill.

[0046] (Semiconductor Device) A semiconductor device according to an embodiment includes a support, a cured product of the epoxy resin composition described above, and a semiconductor element. Examples of the semiconductor device include a semiconductor device encapsulated with the epoxy resin composition described above, such as a semiconductor device in which a semiconductor element and a support are encapsulated with the cured product of the epoxy resin composition described above.

[0047] <Support> The support is not particularly limited as long as it can fix a semiconductor element, and can be appropriately selected depending on the purpose. Examples of the support include a substrate.

[0048] <<Substrate>> The substrate is not particularly limited and can be appropriately selected depending on the purpose. Examples of the substrate include a lead frame, a pre-wired tape carrier, a wiring board, glass, and a silicon wafer. The size, shape, and material of the substrate are not particularly limited as long as they are the size, shape, and material of commonly used substrates, and can be appropriately selected depending on the purpose.

[0049] <Semiconductor Element> The semiconductor element is not particularly limited and can be appropriately selected depending on the purpose. Examples of the semiconductor element include active elements such as semiconductor chips, transistors, diodes, and thyristors; and passive elements such as capacitors, resistors, resistor arrays, coils, and switches. The size, shape, and material of the semiconductor element are not particularly limited as long as they are the size, shape, and material of commonly used semiconductor elements, and can be appropriately selected depending on the purpose.

[0050] The cured product of the epoxy resin composition is provided between the support and the semiconductor element. The thickness of the cured product of the epoxy resin composition is not particularly limited and can be appropriately selected depending on the purpose. The thickness range is, for example, 10 μm or more and 800 μm or less. The shape of the cured product of the epoxy resin composition is not particularly limited and can be appropriately selected depending on the purpose.

[0051] (Method for Manufacturing Semiconductor Device) A method for manufacturing a semiconductor device according to an embodiment includes a step of filling an epoxy resin composition and a step of curing the epoxy resin composition, and further includes other steps as necessary.

[0052] <Step of Filling with Epoxy Resin Composition> The step of filling with the epoxy resin composition is a step of filling the gap between the support and the semiconductor element placed on the support with the epoxy resin composition. During this step, mold underfill may be performed to encapsulate the entire semiconductor element at once. The support may be any of the above. The method of filling with the epoxy resin composition is not particularly limited and can be appropriately selected depending on the purpose. Examples of this method include a dispensing method, a casting method, and a printing method. The amount of epoxy resin composition to be filled is not particularly limited and can be appropriately selected depending on the purpose. Examples of this amount include an amount that fills the entire gap between the semiconductor element and the support and covers the side surfaces of the semiconductor element with the epoxy resin composition (an amount that forms a fillet).

[0053] <Step of curing the epoxy resin composition> The step of curing the epoxy resin composition is a step of curing the epoxy resin composition between the support and the semiconductor element. The method of curing the epoxy resin composition is not particularly limited and can be selected appropriately depending on the purpose. This method includes, for example, a method of heating the epoxy resin composition. The heating temperature is not particularly limited and can be selected appropriately depending on the purpose, but from the viewpoint of reliability, it is preferably 120°C to 200°C, more preferably 130°C to 180°C, and even more preferably 140°C to 170°C. The heating time is not particularly limited and can be selected appropriately depending on the purpose, but from the viewpoint of workability, it is preferably 15 minutes to 3 hours, more preferably 30 minutes to 2 hours.

[0054] Examples 1 to 14, Comparative Examples 1 to 5 The compositions shown in Tables 1 to 4 were mixed using a triple roll mill and then homogenized to obtain epoxy resin compositions.

[0055]

[0056]

[0057]

[0058]

[0059] The polyalkylene glycol type epoxy resins used in the examples and comparative examples are as follows: Polytetramethylene glycol type epoxy resin 1 (YX-7400N, manufactured by Mitsubishi Chemical Corporation, chlorine content: 500 ppm) Polytetramethylene glycol type epoxy resin 2 (Epogose PT, manufactured by Yokkaichi Chemical Co., Ltd., chlorine content: 18,000 ppm)

[0060] The epoxy resins (epoxy resins other than polyalkylene glycol-type epoxy resins) used in the examples and comparative examples are as follows: Epoxy resin 1 (RE410S, manufactured by Nippon Kayaku Co., Ltd., bisphenol A-type epoxy resin, chlorine content: 900 ppm) Epoxy resin 2 (YDF-8170, manufactured by Nippon Steel Chemical & Material Co., Ltd., bisphenol F-type epoxy resin, chlorine content: 900 ppm) Epoxy resin 3 (jER 630, manufactured by Mitsubishi Chemical Corporation, aromatic amine-type trifunctional epoxy resin, chlorine content: 5,000 ppm) Epoxy resin 4 (EP-3980S, manufactured by ADEKA Corporation, aromatic amine-type bifunctional epoxy resin, chlorine content: 700 ppm) Epoxy resin 5 (ZX-1658GS, manufactured by Nippon Steel Chemical & Material Co., Ltd., cycloaliphatic epoxy resin, chlorine content: 600 ppm)

[0061] The heterocyclic compounds containing a nitrogen atom used in the examples and comparative examples are as follows: Imidazole derivative (Curezol 2P4MZ, manufactured by Shikoku Chemical Industry Co., Ltd., 2-phenyl-4-methyl-1H-imidazole) Triazine derivative (2MZA, manufactured by Shikoku Chemical Industry Co., Ltd., 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine)

[0062] The fillers used in the examples and comparative examples are as follows: Filler 1 (SE605H-SMG, manufactured by Admatechs Co., Ltd., silicon dioxide surface-treated with 3-methacryloxypropyltrimethoxysilane, average particle size: 2.0 μm) Filler 2 (15SM-E13, manufactured by Admatechs Co., Ltd., silicon dioxide surface-treated with 3-methacryloxypropyltrimethoxysilane, average particle size: 1.5 μm) Filler 3 (SE2200-SME, manufactured by Admatechs Co., Ltd., silicon dioxide surface-treated with 3-methacryloxypropyltrimethoxysilane, average particle size: 0.6 μm) Filler 4 (SE2200-SEE, manufactured by Admatechs Co., Ltd., silicon dioxide surface-treated with 3-glycidoxypropyltrimethoxysilane, average particle size: 0.6 μm) Filler 5 (SE1050-SMO, manufactured by Admatechs Co., Ltd., silicon dioxide surface-treated with 3-methacryloxypropyltrimethoxysilane, average particle size: 0.3 μm) Filler 6 (40SM-E2, manufactured by Admatechs Co., Ltd., silicon dioxide surface-treated with 3-methacryloxypropyltrimethoxysilane, average particle size: 4 μm)

[0063] Other components used in the examples and comparative examples are as follows: 3-glycidoxypropyltrimethoxysilane (KBM403, manufactured by Shin-Etsu Chemical Co., Ltd.) 3-isocyanatopropyltriethoxysilane (KBE9007N, manufactured by Shin-Etsu Chemical Co., Ltd.) Carbon black (Black 4, manufactured by Orion Engineered Carbons Co., Ltd.) Modified silicone (SF8421, manufactured by Dow Corning Toray Co., Ltd.) Phenol-based curing agent (MEH8000, manufactured by UBE Co., Ltd., allylphenol) Amine-based curing agent (Ethacure 100, manufactured by Albemarle Japan Co., Ltd., diethyltoluenediamine)

[0064] The viscosity of the epoxy resin compositions of the Examples and Comparative Examples was measured as follows. Furthermore, the injectability, void generation rate, reliability, and linear expansion coefficient were evaluated. The evaluation results are shown in Tables 1 to 4.

[0065] <Viscosity> The viscosity of each epoxy resin composition immediately after preparation (initial viscosity, unit: Pa s) was measured using a Brookfield viscometer when the epoxy resin composition was rotated at 50 rpm and 5 rpm at 25°C for 1 minute. The thixotropic index (TI: (viscosity at 5 rpm) / (viscosity at 50 rpm)) was calculated from the obtained viscosity values ​​at 50 rpm and 5 rpm.

[0066] <Injectability> Two pieces of gap tape (made of stainless steel (SUS), thickness: 15 μm) were placed on a glass slide, spaced 1 cm apart. Another glass slide was placed on top of them, and the two glass slides were fixed with clips. In this way, a test specimen was prepared, comprising two glass slides with a gap of 1 cm width and 15 μm height. This test specimen was placed on a hot plate set to 90°C, and each epoxy resin composition was applied to one end of the gap between the glass slides. Then, for each epoxy resin composition, the time (min) until the injection distance reached 20 mm was measured. This procedure was performed twice, and the average of the measured values ​​was used as the evaluation result of injectability.

[0067] <Void Generation Rate> A silicon chip (WALTS-TEG FC150JY (PI), manufactured by Walts) was mounted on a substrate (WALTS-KIT FC150-0103JY2x2 (SAC), manufactured by Walts). Each epoxy resin composition was applied to this substrate and heat-cured at 180°C for 60 minutes to obtain a test specimen. Five such test specimens were produced. Each epoxy resin composition was then observed using an ultrasonic flaw detector (scanning acoustic microscope, Fine SAT FS300 III), and the number of test specimens containing voids (bubbles) was counted. The void generation rate is preferably 1 / 5 or less (1 or less in each of 5 test specimens).

[0068] <Reliability> The test specimens used for the above void occurrence rate were subjected to a preconditioning test under JEDEC Level 3 conditions (30°C, 60% RH, 168 hours). Then, the test specimens were subjected to 1,000 thermal cycles (-55°C to 125°C) under Condition B. The fillet portions of each epoxy resin composition were then observed under a microscope (magnification: 10x), and the number of test specimens on which fillet cracks occurred was counted. It is preferable that the fillet crack occurrence rate be 2 / 5 (2 or less out of 5 test specimens).

[0069] <Linear Expansion Coefficient> Each epoxy resin composition was injected into a silicone rubber mold and heat-cured at 180°C for 60 minutes to obtain a test specimen (diameter 8 mm, height 20 mm). These test specimens were annealed using a TMA (thermomechanical analyzer, TMA4000SA, manufactured by BRUKER AXS) so that the temperature rose from room temperature to 220°C at a rate of 20°C per minute. Thereafter, the linear expansion coefficient was measured by a compressive load method under conditions where the temperature rose from -30°C to 230°C at a rate of 5°C per minute. The linear expansion coefficients were measured under the following measurement conditions: CTE1 was in the range of 10°C to 30°C, and CTE2 was in the range of 180°C to 200°C.

[0070] As shown in Tables 1 to 3, the epoxy resin compositions of the Examples were found to have good injectability and reliability. In contrast, the epoxy resin composition of Comparative Example 1, which contained 78% by mass of filler, had a poor injectability rating of 25 minutes. The epoxy resin composition of Comparative Example 2, which contained 50.0% by mass of filler, had a poor reliability rating of 4 / 5. Comparative Examples 3 and 4, which did not contain a polyalkylene glycol-type epoxy resin, both had poor reliability ratings of 5 / 5. Comparative Example 5, which did not contain a nitrogen-containing heterocyclic compound and used an amine-based curing agent, had a poor linear expansion coefficient rating and a poor reliability rating. From the above, it was revealed that an epoxy resin composition containing a polyalkylene glycol-type epoxy resin, a nitrogen-containing heterocyclic compound, and a filler, in which the filler content was 55% by mass or more but less than 77% by mass relative to the total amount of the epoxy resin composition, was an epoxy resin composition that achieved both good injectability and reliability.

[0071] The embodiments and examples of the present disclosure have been described. These are presented as examples and are not intended to limit the technical scope of the present disclosure. The embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made to the embodiments without departing from the spirit of the present disclosure. The embodiments and their modifications are intended to be included within the technical scope and spirit of the present disclosure, as well as within the technical ideas described in the claims and their equivalents.

Claims

1. Epoxy resin, a nitrogen-containing heterocyclic compound; and a filler, The epoxy resin contains at least a polyalkylene glycol type epoxy resin, The content of the filler is 55% by mass or more and less than 77% by mass based on the total amount of the epoxy resin composition. Epoxy resin composition.

2. The average particle size of the filler is 0.5 μm to 2.0 μm. The epoxy resin composition according to claim 1.

3. The content of the polyalkylene glycol type epoxy resin is 10% by mass to 30% by mass relative to the epoxy resin. The epoxy resin composition according to claim 1 or 2.

4. The chlorine content of the epoxy resin composition is 1,300 ppm or less. The epoxy resin composition according to claim 1 or 2.

5. The polyalkylene glycol type epoxy resin is a polytetramethylene glycol type epoxy resin. The epoxy resin composition according to claim 1 or 2.

6. Further containing at least one selected from a glycidylamine type epoxy resin, a bisphenol type epoxy resin, and an aliphatic epoxy resin. The epoxy resin composition according to claim 1 or 2.

7. The nitrogen atom-containing heterocyclic compound is at least one selected from 2-phenyl-4-methylimidazole and 2,4-diamino-6-[2'-methylimidazolyl-(1)']-ethyl-s-triazine. The epoxy resin composition according to claim 1 or 2.

8. Further containing a phenolic hardener, The epoxy resin composition according to claim 1 or 2.

9. Used for sealing semiconductor chips with bump pitch of 150 μm or less. The epoxy resin composition according to claim 1 or 2.

10. The epoxy resin composition according to claim 1 or 2 is used for sealing. Semiconductor device.

11. A step of filling a gap between a support and a semiconductor element disposed on the support with the epoxy resin composition according to claim 8; and curing the epoxy resin composition. A method for manufacturing a semiconductor device.