Liquid resin composition, electronic component device, and method for manufacturing the same

Abstract

To provide a liquid resin composition that exhibits excellent filling properties, can suppress the sedimentation of inorganic fillers within gaps, and has excellent thermal conductivity. [Solution] The liquid resin composition contains an epoxy resin, a curing agent, and an inorganic filler containing magnesite.

Description

[Technical Field]

[0001] This disclosure relates to liquid resin compositions, electronic component devices, and methods for manufacturing the same. [Background technology]

[0002] Traditionally, in the field of element encapsulation for electronic components such as transistors and ICs (Integrated Circuits), resin encapsulation has been the mainstream method due to its productivity and cost-effectiveness, and various types of resin compositions have been applied. Among these, epoxy resins are widely used because they offer a good balance of various properties such as workability, moldability, electrical properties, moisture resistance, heat resistance, mechanical properties, and adhesion to inserts. Liquid resin compositions are widely used as encapsulants in semiconductor devices with bare chip mounting, such as COB (Chip on Board), COG (Chip on Glass), and TCP (Tape Carrier Package). Furthermore, in semiconductor devices (flip chips) in which semiconductor elements are directly bump-connected to a wiring board made of ceramic, glass / epoxy resin, glass / imide resin, polyimide film, etc., liquid resin compositions for electronic components are used as underfill materials to fill the gaps between the bump-connected semiconductor elements and the wiring board. These liquid resin compositions for electronic components play an important role in protecting electronic components from temperature, humidity, and mechanical external forces.

[0003] Furthermore, with the increasing performance and power consumption of semiconductor devices, liquid encapsulants used to fill the gaps between elements and substrates are required to have higher heat dissipation properties than before. To improve the heat dissipation of semiconductor elements encapsulated with liquid encapsulants, it is effective to use alumina as the inorganic filler contained in the liquid encapsulant. For example, Patent Document 1 discloses a liquid sealing material containing alumina. Furthermore, Patent Document 2 discloses a solid sealing material containing alumina. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2016-108358 [Patent Document 2] Japanese Patent Publication No. 2018-87299 [Overview of the project] [Problems that the invention aims to solve]

[0005] Through the inventors' research, it was found that when semiconductor elements are sealed with underfill material, the inorganic filler settles, resulting in a non-uniform distribution of the inorganic filler. In particular, this settling phenomenon of the inorganic filler is likely to occur within the gap between the semiconductor element and the wiring substrate. This phenomenon is especially likely to occur when alumina is used as the inorganic filler. When the inorganic filler becomes non-uniform within the gap between the semiconductor element and the wiring substrate, it can cause failures such as cracks when thermal stress is generated in the semiconductor device. Therefore, there is a need to investigate other inorganic fillers that can suppress the sedimentation of inorganic fillers within the gap while maintaining the excellent thermal conductivity exhibited by alumina. This disclosure has been made in view of the above-mentioned prior circumstances, and one embodiment of this disclosure aims to provide a liquid resin composition that has excellent filling properties, can suppress the settling of inorganic fillers in gaps, and has excellent thermal conductivity. Another embodiment of this disclosure aims to provide an electronic component device using this liquid resin composition and a method for manufacturing the same. [Means for solving the problem]

[0006] The specific means for achieving the aforementioned objectives are as follows: <1> A liquid resin composition containing an epoxy resin, a curing agent, and an inorganic filler containing magnesite. <2> The inorganic filler content is 60% to 85% by mass. <1> The liquid resin composition described above. <3> The proportion of the magnesite in the inorganic filler is 50% by mass or more. <1> or <2> The liquid resin composition described above. <4> The specific surface area of ​​the inorganic filler is 5.0 m². 2 / g~10.0m 2 / g <1> ~ <3> A liquid resin composition according to any one of the following items. <5> The average particle size of the inorganic filler is 0.2 μm to 1.5 μm. <1> ~ <4> A liquid resin composition according to any one of the following items. <6> The curing agent includes an amine-based curing agent. <1> ~ <5> A liquid resin composition according to any one of the following items. <7> The epoxy resin includes a glycidylamine-type epoxy resin. <1> ~ <6> A liquid resin composition according to any one of the following items. <8> The epoxy resin comprises a difunctional aliphatic epoxy compound. <1> ~ <7> A liquid resin composition according to any one of the following items. <9> The epoxy resin comprises a glycidylamine-type epoxy resin and a difunctional aliphatic epoxy compound. <1> ~ <6> A liquid resin composition according to any one of the following items. <10> The volatile content is 5% by mass or less. <1> ~ <9> A liquid resin composition according to any one of the following items. <11> It is a capillary underfill material. <1> ~ <10> A liquid resin composition according to any one of the following items. <12> A substrate having a circuit layer, An electronic component arranged on the substrate and electrically connected to the circuit layer, Displaced in the gap between the substrate and the electronic component <1> ~ <11> A cured product of a liquid resin composition according to any one of the following items, An electronic component device equipped with the following features. <13> The gap between a substrate having a circuit layer and an electronic component disposed on the substrate and electrically connected to the circuit layer is <1> ~ <11> A method for manufacturing an electronic component device, comprising the step of sealing it using a liquid resin composition described in any one of the items. [Effects of the Invention]

[0007] According to one aspect of the present disclosure, it is possible to provide a liquid resin composition that is excellent in filling properties, can suppress sedimentation of an inorganic filler in a gap, and is excellent in thermal conductivity. Further, according to another aspect of the present disclosure, it is possible to provide an electronic component device using this liquid resin composition and a method for manufacturing the same.

Brief Description of the Drawings

[0008] [Figure 1] It is a figure which shows the viscosity profile of the liquid resin composition of Example 1, Comparative Example 1, and Comparative Example 2. [Figure 2] It is a cross-sectional photograph of the test piece about Example 1. [Figure 3] It is a cross-sectional photograph of the test piece about Comparative Example 1. [Figure 4] It is a cross-sectional photograph of the test piece about Comparative Example 2.

Modes for Carrying Out the Invention

[0009] Hereinafter, the present disclosure will be described in detail. However, the present disclosure is not limited to the following embodiments. In the following embodiments, the components thereof (including element steps and the like) are not essential unless otherwise specified. The same applies to numerical values and ranges thereof, which do not limit the present disclosure.

[0010] In the present disclosure, the term "step" includes not only a step independent of other steps but also a step that cannot be clearly distinguished from other steps as long as the purpose of the step is achieved. In the numerical range indicated by "~" in the present disclosure, the numerical values described before and after "~" are included as the minimum value and the maximum value, respectively. In the numerical ranges described step by step in the present disclosure, the upper limit value or the lower limit value described in one numerical range may be replaced with the upper limit value or the lower limit value of the numerical range described in other step-by-step descriptions. Further, in the numerical ranges described in the present disclosure, the upper limit value or the lower limit value of the numerical range may be replaced with the value shown in the examples. In this disclosure, each component may contain multiple types of the corresponding substance. If multiple types of the substance corresponding to each component are present in the composition, the content or amount of each component means the total content or amount of the multiple types of substances present in the composition, unless otherwise specified. In this disclosure, each component may include multiple types of particles. If multiple types of particles corresponding to each component are present in the composition, the particle size of each component refers to the value for a mixture of such multiple types of particles present in the composition, unless otherwise specified. In this disclosure, the terms “layer” or “film” include cases where, when the region in which the layer or film exists is observed, it is formed not only over the entire region but also over only a portion of the region.

[0011] <Liquid resin composition> The liquid resin composition of this disclosure contains an epoxy resin, a curing agent, and an inorganic filler containing magnesite. As a result of diligent research, the inventors discovered that by using magnesite as an inorganic filler, they could obtain a liquid resin composition that exhibits excellent filling properties, suppresses the settling of the inorganic filler within the gaps, and has excellent thermal conductivity, thus completing the present invention.

[0012] The components constituting the liquid resin composition of this disclosure will be described below. The liquid resin composition of this disclosure contains an epoxy resin, a curing agent, and an inorganic filler containing magnesite, and may contain other components as needed.

[0013] -Epoxy resin- The liquid resin composition of this disclosure contains an epoxy resin. The epoxy resin imparts curability and adhesiveness to the liquid resin composition, and imparts heat resistance and durability to the cured product of the liquid resin composition. The epoxy resin is preferably a liquid epoxy resin. In this disclosure, a solid epoxy resin may also be used in combination with the liquid epoxy resin. Epoxy resins may be used individually or in combination of two or more types.

[0014] Note that liquid epoxy resin refers to epoxy resin that is liquid at room temperature (25°C). Specifically, it means that the viscosity measured with an E-type viscometer at 25°C is 1000 Pa·s or less. Specifically, the above viscosity is measured using an E-type viscometer EHD type (cone angle 3°, cone diameter 28 mm), with a measurement temperature of 25°C, a sample volume of 0.7 ml, and the rotation speed set according to the expected viscosity of the sample, as shown below, and the measurement taken 1 minute after the start of measurement. (1) When the expected viscosity is 100 Pa·s to 1000 Pa·s: Rotation speed 0.5 revolutions / minute (2) If the expected viscosity is less than 100 Pa·s: Rotation speed 5 revolutions / minute Furthermore, a solid epoxy resin is defined as an epoxy resin that is solid at room temperature (25°C).

[0015] The type of epoxy resin is not particularly limited. Examples of epoxy resins include naphthalene-type epoxy resins; diglycidyl ether-type epoxy resins such as bisphenol A, bisphenol F, bisphenol AD, bisphenol S, and hydrogenated bisphenol A; novolac-type epoxy resins, such as orthocresol novolac-type epoxy resins, which are epoxidized novolac resins of phenols and aldehydes; glycidyl ester-type epoxy resins obtained by the reaction of polybasic acids such as phthalic acid and dimer acid with epichlorohydrin; and glycidylamine-type epoxy resins obtained by the reaction of amine compounds such as diaminodiphenylmethane, isocyanuric acid, and aminophenol with epichlorohydrin. Examples of epoxy resins include difunctional aliphatic epoxy compounds having two epoxy groups in their molecule, such as alkylene glycol diglycidyl ether, poly(alkylene glycol) diglycidyl ether, and alkenylene glycol diglycidyl ether.

[0016] The epoxy resin preferably includes at least one epoxy resin selected from the group consisting of naphthalene-type epoxy resin, diglycidyl ether-type epoxy resin, novolac-type epoxy resin, glycidyl ester-type epoxy resin, and glycidylamine-type epoxy resin, and more preferably includes a glycidylamine-type epoxy resin. Furthermore, from the viewpoint of reducing the viscosity of the liquid resin composition, it is preferable that the epoxy resin contains a bifunctional aliphatic epoxy compound. The epoxy resin preferably comprises at least one epoxy resin selected from the group consisting of naphthalene-type epoxy resin, diglycidyl ether-type epoxy resin, novolac-type epoxy resin, glycidyl ester-type epoxy resin, and glycidylamine-type epoxy resin, and a difunctional aliphatic epoxy compound, and more preferably comprises a glycidylamine-type epoxy resin and a difunctional aliphatic epoxy compound. When the epoxy resin includes a glycidylamine-type epoxy resin, the proportion of the glycidylamine-type epoxy resin in the total epoxy resin is preferably 50% by mass or more, more preferably 60% by mass or more, and even more preferably 70% by mass or more. In this case, the proportion of the glycidylamine-type epoxy resin in the total epoxy resin may be 80% by mass or less. Furthermore, the proportion of the difunctional aliphatic epoxy compound in the total epoxy resin is preferably 50% by mass or less, more preferably 40% by mass or less, and even more preferably 30% by mass or less. The proportion of the difunctional aliphatic epoxy compound in the total epoxy resin may be 15% by mass or more.

[0017] From the viewpoint of viscosity adjustment, the epoxy equivalent of the epoxy resin is preferably 80 g / eq to 400 g / eq, more preferably 85 g / eq to 350 g / eq, and even more preferably 90 g / eq to 320 g / eq. The epoxy equivalent of epoxy resin is measured by dissolving the weighed epoxy resin in a solvent such as methyl ethyl ketone, adding acetic acid and tetraethylammonium bromide acetic acid solution, and then performing potentiometric titration with perchloric acid acetic acid standard solution. An indicator may also be used in this titration.

[0018] Commercially available epoxy resins may be used. Specific examples of commercially available epoxy resins include amine-type epoxy resin (product name: jER630) manufactured by Mitsubishi Chemical Corporation, bisphenol F-type epoxy resin (product name: YDF-8170C) manufactured by Nippon Steel Chemical & Material Co., Ltd., bisphenol A-type epoxy resin (product name: YD-128) manufactured by Nippon Steel Chemical & Material Co., Ltd., naphthalene-type epoxy resin (product name: HP-4032D) manufactured by DIC Corporation, and the product name "Epogose PT (general grade)" (Yokkaichi Gosei Co., Ltd., diglycidyl ether of polytetramethylene glycol, number average molecular weight 700-800). The epoxy resin is not limited to these specific examples. One type of epoxy resin may be used alone, or two or more types may be used in combination. The epoxy resin content is not particularly limited; for example, it is preferably 5% to 30% by mass, more preferably 7% to 28% by mass, and even more preferably 10% to 25% by mass, as a percentage of the solid content of the liquid resin composition.

[0019] -Hardening agent- The liquid resin composition of this disclosure contains a curing agent. The curing agent can be any agent that polymerizes with the epoxy resin, and can be in liquid or solid form as long as the liquid resin composition is fluid at room temperature (25°C). Examples of curing agents include amine-based curing agents, phenol-based curing agents, and acid anhydride-based curing agents. Among these, amine-based curing agents are preferred from the viewpoint of optimizing the curing temperature of the liquid resin composition.

[0020] Examples of amine-based curing agents include linear aliphatic amines, cyclic aliphatic amines, fatty aromatic amines, and aromatic amines. From the viewpoint of heat resistance and electrical properties, aromatic amines are preferred, and it is more preferable that the amino group is directly bonded to the aromatic ring, and that the aromatic amine contains one or two such aromatic rings per molecule. Specifically, amine-based curing agents include diethyltoluenediamine such as m-phenylenediamine, 2,3-diaminotoluene, 3,4-diaminotoluene, 2,4-diaminotoluene, 3,5-diethyl-2,4-diaminotoluene, 3,5-diethyl-2,6-diaminotoluene, and 2,4-diaminoanisole, which are aromatic amine curing agents with one aromatic ring; 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfone, 4,4'-methylenebis(2-ethylaniline), 3,3'-diethyl-4,4'-diaminodiphenylmethane, 3,3', Examples include aromatic amine curing agents with two aromatic rings, such as 5,5'-tetramethyl-4,4'-diaminodiphenylmethane and 3,3',5,5'-tetraethyl-4,4'-diaminodiphenylmethane; hydrolysis condensates of aromatic amine curing agents; aromatic amine curing agents having a polyether structure, such as polytetramethylene oxide di-p-aminobenzoate and polytetramethylene oxide di-para-aminobenzoate; condensates of aromatic diamines and epichlorohydrins; reaction products of aromatic diamines and styrene; and polycondensates of aromatic amines and formaldehyde.

[0021] Commercially available amine-based curing agents may be used. Specific examples of commercially available amine-based curing agents include those manufactured by Nippon Kayaku Co., Ltd. (product name: Kayahard-AA) and Mitsubishi Chemical Corporation (product names: jER Cure® 113, jER Cure® W, etc.), but amine-based curing agents are not limited to these specific examples. Amine-based curing agents may be used individually or in combination of two or more types.

[0022] Examples of acid anhydride-based curing agents include phthalic anhydride, maleic anhydride, methylhymic anhydride, hymic anhydride, succinic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, chloride anhydride, methyltetrahydrophthalic anhydride, 3-methylhexahydrophthalic anhydride, 4-methylhexahydrophthalic anhydride, trialkyltetrahydrophthalic anhydride maleic acid adduct, benzophenonetetracarboxylic anhydride, trimellitic anhydride, pyromellitic anhydride, hydrogenated methylnadic anhydride, and various cyclic acid anhydrides such as trialkyltetrahydrophthalic anhydride and dodecenyl succinic anhydride, which are obtained by the Diels-Alder reaction from maleic anhydride and a diene compound and have multiple alkyl groups.

[0023] Examples of phenolic curing agents include novolac resins, phenolic aralkyl resins, biphenyl aralkyl resins, and naphthol aralkyl resins, obtained by condensing or co-condensing at least one compound selected from the group consisting of phenolic compounds (e.g., phenol, cresol, xylenol, resorcinol, catechol, bisphenol A, and bisphenol F) and naphthol compounds (e.g., α-naphthol, β-naphthol, and dihydroxynaphthalene) with an aldehyde compound (e.g., formaldehyde, acetaldehyde, propionaldehyde, benzaldehyde, and salicylaldehyde) under an acidic catalyst. The hardening agent may be used alone or in combination of two or more types.

[0024] It is preferable to set the ratio of the number of equivalent units of the functional group of the curing agent (for example, an amino group in the case of an amine-based curing agent, a phenolic hydroxyl group in the case of a phenol-based curing agent, and an acid anhydride group in the case of an acid anhydride-based curing agent) to the number of equivalent units of the epoxy resin (number of equivalent units of curing agent / number of equivalent units of epoxy resin) in the range of 0.6 to 1.4, more preferably in the range of 0.7 to 1.3, and even more preferably in the range of 0.8 to 1.2.

[0025] -Inorganic filler- The liquid resin composition of this disclosure contains an inorganic filler containing magnesite. Other known or conventional inorganic fillers other than magnesite may be used in combination. Other inorganic fillers include silica such as fused silica and crystalline silica, calcium carbonate, clay, alumina, silicon nitride, silicon carbide, boron nitride, calcium silicate, potassium titanate, aluminum nitride, beryllia, zirconia, zircon, fossilite, steatite, spinel, mullite, titania, and other powders, as well as beads formed from these materials and glass fibers. Furthermore, inorganic fillers with flame-retardant properties include aluminum hydroxide, magnesium hydroxide, zinc borate, and zinc molybdate. These inorganic fillers may be used individually or in combination of two or more types. From the viewpoint of achieving high density of the inorganic filler and ensuring fluidity and penetration of the liquid resin composition into fine gaps, a spherical shape is preferred for the inorganic filler.

[0026] The proportion of magnesite in the inorganic filler is preferably 50% by mass or more, more preferably 70% by mass or more, even more preferably 90% by mass or more, and particularly preferably 99% by mass or more. The proportion of magnesite in the inorganic filler may be 100% by mass or less. The proportion of magnesite in the inorganic filler is preferably 50% by mass to 100% by mass. Magnesite may be synthetic magnesite.

[0027] From the viewpoint of hygroscopicity, reduction of linear expansion coefficient, improvement of strength, and solder heat resistance, the inorganic filler content is preferably 60% by mass or more, more preferably 65% ​​by mass or more, and even more preferably 70% by mass or more, relative to the total liquid resin composition. From the viewpoint of keeping the viscosity of the liquid resin composition within a fillable range, the inorganic filler content is preferably 85% by mass or less, more preferably 80% by mass or less, and even more preferably 75% by mass or less. The inorganic filler content is preferably 60% by mass to 85% by mass.

[0028] The average particle diameter of the inorganic filler is preferably 0.2 μm to 1.5 μm, more preferably 0.5 μm to 1.4 μm, and even more preferably 0.8 μm to 1.3 μm. In the present disclosure, the average particle diameter of the inorganic filler refers to the average particle diameter of magnesite when magnesite is used alone as the inorganic filler, and the average particle diameter of the entire inorganic filler when magnesite and other inorganic fillers are used in combination as the inorganic filler.

[0029] The average particle diameter of the inorganic filler can be measured by the following method. The inorganic filler to be measured is added to a solvent (pure water) within the range of 0.02 mass% to 0.08 mass%, and vibrated for 1 minute to 10 minutes with a bath-type ultrasonic cleaner of 110 W to disperse the inorganic filler. About 40 mL of the dispersion liquid is injected into a measurement cell and measured at 25°C. The measuring device uses a laser diffraction particle size distribution meter (manufactured by Horiba, Ltd., LA920 (trade name)) to measure the volume-based particle size distribution. The average particle diameter is determined as the particle diameter (D50%) when the cumulative from the small-diameter side in the volume-based particle size distribution reaches 50%. The refractive index uses the refractive index of alumina. In the case where the inorganic filler is a mixture of magnesite and other inorganic fillers, the refractive index shall use the refractive index of alumina.

[0030] From the viewpoint of further suppressing sedimentation, the specific surface area of the inorganic filler is preferably 5.0 m 2 / g or more, more preferably 5.1 m 2 / g or more, and even more preferably 5.3 m 2 / g or more. From the viewpoint of viscosity control, the specific surface area of the inorganic filler is preferably 10.0 m 2 / g or less, more preferably 9.0 m 2 / g or less, and even more preferably 8.0 m 2 / g or less. The specific surface area of the inorganic filler is preferably 5.0 m 2 / g to 10.0 m 2 / g. The specific surface area (BET specific surface area) of inorganic fillers can be measured from the nitrogen adsorption capacity in accordance with JIS Z 8830:2013. The QUANTACHROME AUTOSORB-1 (product name) can be used as the evaluation device. When measuring the BET specific surface area, it is preferable to first perform a pretreatment by removing moisture by heating, as moisture adsorbed on the sample surface and within the structure is thought to affect the gas adsorption capacity. In the pretreatment, a measurement cell containing 0.05 g of the sample is subjected to a vacuum pump to reduce the pressure to 10 Pa or less, then heated to 110°C and maintained at that temperature for 3 hours or more. After this, the cell is allowed to cool naturally to room temperature (25°C) while maintaining the reduced pressure. After this pretreatment, the evaluation temperature is set to 77 K, and the evaluation pressure range is set to less than 1 in relative pressure (equilibrium pressure relative to saturated vapor pressure) for measurement.

[0031] -Curing accelerator- The liquid resin composition of this disclosure may contain a curing accelerator. The type of curing accelerator is not particularly limited, and known curing accelerators can be used. Specifically, cycloamidine compounds such as 1,8-diaza-bicyclo[5.4.0]undecene-7, 1,5-diaza-bicyclo[4.3.0]nonene, and 5,6-dibutylamino-1,8-diaza-bicyclo[5.4.0]undecene-7; cycloamidine compounds with maleic anhydride, 1,4-benzoquinone, 2,5-tholquinone, 1,4-naphthoquinone, 2,3-dimethylbenzoquinone, 2,6-dimethylbenzoquinone, 2,3-dimethoxy-5-methyl-1,4-benzoquinone, and 2,3-di Compounds having intramolecular polarization obtained by adding quinone compounds such as methoxy-1,4-benzoquinone and phenyl-1,4-benzoquinone, diazophenylmethane, and phenolic resins that have π bonds; tertiary amine compounds such as benzyldimethylamine, triethanolamine, dimethylaminoethanol, and tris(dimethylaminomethyl)phenol; derivatives of tertiary amine compounds; 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl Examples include imidazole compounds such as -4-methyl-5-hydroxymethylimidazole; derivatives of imidazole compounds; organic phosphine compounds such as tributylphosphine, methyldiphenylphosphine, triphenylphosphine, tris(4-methylphenyl)phosphine, diphenylphosphine, and phenylphosphine; phosphorus compounds having intramolecular polarization obtained by adding compounds having π bonds such as maleic anhydride, the above quinone compounds, diazophenylmethane, and phenolic resins to organic phosphine compounds; tetraphenylboron salts such as tetraphenylphosphonium tetraphenylborate, triphenylphosphine tetraphenylborate, 2-ethyl-4-methylimidazole tetraphenylborate, and N-methylmorpholine tetraphenylborate; derivatives of tetraphenylboron salts; and adducts of phosphine compounds such as triphenylphosphonium-triphenylborane and N-methylmorpholine tetraphenylphosphonium-tetraphenylborate with tetraphenylboron salts. The curing accelerator may be used alone or in combination of two or more types.

[0032] The content rate of the curing accelerator is preferably 0.1 mass% to 8 mass% with respect to the total amount of the epoxy resin and the curing agent.

[0033] - Ion trap agent - The liquid resin composition of the present disclosure may contain an ion trap agent. The ion trap agent that can be used in the present disclosure is not particularly limited as long as it is an ion trap agent generally used in a sealing material used for manufacturing semiconductor devices. Examples of the ion trap agent include compounds represented by the following general formula (VI-1) or the following general formula (VI-2).

[0034] Mg 1-a Al a (OH)2(CO3) a / 2 ·uH2O (VI-1) (In the general formula (VI-1), a is 0 < a ≤ 0.5, and u is a positive number.) BiO b (OH) c (NO3) d (VI-2) (In the general formula (VI-2), b is 0.9 ≤ b ≤ 1.1, c is 0.6 ≤ c ≤ 0.8, and d is 0.2 ≤ d ≤ 0.4.)

[0035] The ion trap agent is commercially available. Examples of the compound represented by the general formula (VI-1) include "DHT-4A" (trade name, Kyowa Chemical Industry Co., Ltd.) which is commercially available. Also, examples of the compound represented by the general formula (VI-2) include "IXE500" (trade name, Toagosei Co., Ltd.) which is commercially available.

[0036] In addition, examples of ion trap agents other than those described above include hydrous oxides of elements selected from magnesium, aluminum, titanium, zirconium, antimony, etc. The ion trap agent may be used alone or in combination of two or more.

[0037] When a liquid resin composition contains an ion trapping agent, the content of the ion trapping agent is preferably 1 part by mass or more per 100 parts by mass of the total epoxy resin, from the viewpoint of achieving sufficient moisture resistance reliability. From the viewpoint of fully exhibiting the effects of other components, the content of the ion trapping agent is preferably 15 parts by mass or less per 100 parts by mass of the total epoxy resin, more preferably 1 to 10 parts by mass, and even more preferably 2 to 5 parts by mass.

[0038] Furthermore, the average particle size of the ion trapping agent is preferably 0.1 μm to 3.0 μm, and the maximum particle size is preferably 10 μm or less. The average particle size of the ion trapping agent can be measured in the same manner as in the case of inorganic fillers.

[0039] -Antioxidant- The liquid resin composition of this disclosure may contain an antioxidant. Conventionally known antioxidants can be used. Examples of antioxidants include phenolic compound-based antioxidants, organosulfur compound-based antioxidants, amine compound-based antioxidants, and phosphorus compound-based antioxidants. Antioxidants may be used individually or in combination of two or more types. The antioxidant content is preferably 0.1% to 10% by mass, and more preferably 0.5% to 5% by mass, relative to the total epoxy resin.

[0040] -Organic Solvents- The liquid resin composition of this disclosure may contain organic solvents as needed to reduce viscosity. In particular, when using a solid epoxy resin and a curing agent, it is preferable to incorporate organic solvents to obtain a liquid resin composition. There are no particular restrictions on the organic solvents, and examples include alcohol-based solvents such as methyl alcohol, ethyl alcohol, propyl alcohol, and butyl alcohol; ketone-based solvents such as acetone and methyl ethyl ketone; glycol ether-based solvents such as ethylene glycol ethyl ether, ethylene glycol methyl ether, ethylene glycol butyl ether, propylene glycol methyl ether, dipropylene glycol methyl ether, propylene glycol ethyl ether, and propylene glycol methyl ether acetate; lactone-based solvents such as γ-butyrolactone, δ-valerolactone, and ε-caprolactone; amide-based solvents such as dimethylacetamide and dimethylformamide; and aromatic solvents such as toluene and xylene. One type may be used alone, or two or more types may be used in combination. Among these, organic solvents with a boiling point of 170°C or higher are preferred from the viewpoint of avoiding bubble formation due to rapid volatilization when curing the liquid resin composition.

[0041] The content of volatile components, including organic solvents, is not particularly limited as long as it does not form bubbles when the liquid resin composition is cured. It is preferably 5% by mass or less, more preferably 1% by mass or less, and even more preferably 0.1% by mass or less, relative to the total liquid resin composition. In this disclosure, the volatile content of the liquid resin composition is calculated based on the weight difference before and after heating the liquid resin composition at 180°C for 30 minutes.

[0042] -Release agent- The liquid resin composition of this disclosure may contain a release agent. The type of release agent is not particularly limited, and known release agents can be used. Specifically, examples include higher fatty acids, carnauba wax, and polyethylene wax. One type of release agent may be used alone, or two or more types may be used in combination. When a liquid resin composition contains a release agent, the release agent content is preferably 10% by mass or less relative to the total amount of epoxy resin and curing agent, and from the viewpoint of exhibiting its effect, it is preferably 0.5% by mass or more.

[0043] -Colorants- The liquid resin composition of this disclosure may contain a coloring agent (e.g., carbon black). The coloring agent may be used alone or in combination of two or more types.

[0044] When using conductive particles such as carbon black as a coloring agent, it is preferable that the content of conductive particles with a particle size of 10 μm or larger is 1% by mass or less. When the liquid resin composition contains conductive particles, the content of conductive particles is preferably 3% by mass or less, and more preferably 0.01% to 1% by mass, relative to the total amount of epoxy resin and curing agent.

[0045] -Rubber particles- The liquid resin composition of this disclosure may contain rubber particles from the viewpoint of reducing the thermal expansion of the cured product. One type of rubber particle may be used alone, or two or more types may be used in combination. Examples of suitable rubber particles include styrene-butadiene rubber (SBR), nitrile-butadiene rubber (NBR), butadiene rubber (BR), urethane rubber (UR), and acrylic rubber (AR). Among these, rubber particles containing acrylic rubber are preferred from the viewpoint of heat resistance and moisture resistance, and core-shell type acrylic rubber particles are more preferred.

[0046] Another example of suitable rubber particles is silicone rubber particles. Examples of silicone rubber particles include silicone rubber particles obtained by crosslinking linear polyorganosiloxanes such as polydimethylsiloxane, polymethylphenylsiloxane, and polydiphenylsiloxane; silicone rubber particles whose surface is coated with silicone resin; and core-shell polymer particles containing a core of solid silicone particles obtained by emulsion polymerization or the like and a shell of an organic polymer such as acrylic resin. The shape of these silicone rubber particles may be amorphous or spherical, but it is preferable to use spherical silicone rubber particles in order to keep the viscosity of the liquid resin composition low. Silicone rubber particles are commercially available from companies such as Toray Dow Corning Silicone Co., Ltd. and Shin-Etsu Chemical Co., Ltd.

[0047] When the liquid resin composition of this disclosure contains rubber particles, the average particle size of the rubber particles is preferably fine in order to uniformly modify the liquid resin composition. The average particle size of the rubber particles is preferably in the range of 0.05 μm to 10 μm, and more preferably in the range of 0.1 μm to 5 μm. When the average particle size of the rubber particles is 0.05 μm or more, the dispersibility in the liquid resin composition tends to improve further. When the average particle size of the rubber particles is 10 μm or less, the stress reduction improvement effect tends to improve further, the penetration into fine gaps and fluidity of the liquid resin composition improve, and the likelihood of voids and unfilled areas tends to decrease. The average particle size of rubber particles is measured using the same method as for inorganic fillers. The rubber particle content is preferably 1 to 20 parts by mass, more preferably 2 to 15 parts by mass, and even more preferably 3 to 10 parts by mass, per 100 parts by mass of the total epoxy resin.

[0048] <Method for preparing liquid resin composition> The liquid resin composition of this disclosure can be obtained, for example, by stirring, melting, mixing, dispersing, etc., an epoxy resin, a curing agent, an inorganic filler, and other components used as needed, either together or separately, while applying heat treatment as necessary. The apparatus for mixing, stirring, and dispersing these components is not particularly limited and includes a mixing machine equipped with a stirring device, a heating device, etc., a three-roll mill, a ball mill, a planetary mixer, a bead mill, etc. The liquid resin composition can be obtained by mixing, kneading, and degassing the above components as needed using these apparatus.

[0049] The viscosity of the liquid resin composition is not particularly limited. However, from the viewpoint of high fluidity, it is preferably 0.1 Pa·s to 50.0 Pa·s at 25°C, more preferably 1.0 Pa·s to 50.0 Pa·s, and even more preferably 10.0 Pa·s to 50.0 Pa·s. The viscosity of the liquid resin composition is measured at 25°C using an E-type viscometer (cone angle 3°, rotation speed 10 revolutions / min).

[0050] Furthermore, when using the liquid resin composition as an underfill material or for other applications, as an indicator of ease of filling when filling narrow gaps of several tens to several hundreds of micrometers in size at around 100°C to 120°C, the viscosity at 110°C is preferably 0.5 Pa·sPa·s or less, more preferably 0.4 Pa·sPa·s or less, and even more preferably 0.3 Pa·s or less. The viscosity of the liquid resin composition at 110°C is measured using a rheometer HR-2 (manufactured by TA Instruments, with a 40 mm aluminum cone and a shear rate of 32.5 / sec).

[0051] Furthermore, the liquid resin composition preferably has a oscillating index [(viscosity at 2.5 revolutions / min) / (viscosity at 10 revolutions / min)], which is the ratio of the viscosity at a rotation speed of 2.5 revolutions / min to the viscosity at a rotation speed of 10 revolutions / min, measured using an E-type viscometer at 25°C, between 0.3 and 1.5, and more preferably between 0.5 and 1.2. When the oscillating index is within the above range, the filling properties tend to improve further. Note that the viscosity and oscillating index of the liquid resin composition can be set to a desired range by appropriately selecting the composition of the epoxy resin, the content of the inorganic filler, etc.

[0052] The curing conditions for the liquid resin composition are not particularly limited, but heating at 80°C to 165°C for 1 minute to 150 minutes is preferred.

[0053] <Electronic Components and Devices> The electronic component apparatus of this disclosure comprises a substrate having a circuit layer, an electronic component disposed on the substrate and electrically connected to the circuit layer, and a cured product of the liquid resin composition of this disclosure disposed in the gap between the substrate and the electronic component. The electronic component apparatus of this disclosure can be obtained by encapsulating the electronic component with the liquid resin composition of this disclosure. Because the electronic component is encapsulated with the liquid resin composition, the electronic component apparatus of this disclosure is highly reliable.

[0054] Examples of electronic component devices include those obtained by mounting electronic components such as semiconductor chips, active elements such as transistors, diodes, and thyristors, and passive elements such as capacitors, resistors, resistor arrays, coils, and switches on a substrate having a circuit layer such as a lead frame, a pre-wired tape carrier, a rigid wiring board, a flexible wiring board, glass, or a silicon wafer, and then sealing the necessary parts with the liquid resin composition of this disclosure. In particular, semiconductor devices to which semiconductor elements are flip-chip bonded by bump connection to wiring formed on rigid wiring boards, flexible wiring boards, or glass are examples of devices to which the liquid resin composition of this disclosure can be applied. Specific examples include electronic component devices such as flip-chip BGA (Ball Grid Array), LGA (Land Grid Array), and COF (Chip On Film).

[0055] The liquid resin composition of this disclosure is suitable as a highly reliable underfill material for flip chips (e.g., capillary underfill material). The liquid resin composition of this disclosure is particularly suitable for use in flip chip applications where the bump material connecting the wiring substrate and semiconductor element is not only conventional lead-containing solder, but also lead-free solder such as Sn-Ag-Cu-based solder is used. Even for flip chips with bump connections using lead-free solder, which is physically more brittle than conventional lead solder, the liquid resin composition of this disclosure tends to maintain good reliability. Furthermore, applying the liquid resin composition of this disclosure when mounting chip-scale packages such as wafer-level CSPs (Chip Size Packages) onto a substrate tends to improve reliability. Furthermore, in recent years, with the increasing speed of semiconductor devices, low dielectric constant interlayer insulating films are sometimes formed on semiconductor devices. The liquid resin composition of this disclosure can also be applied to flip-chip connected electronic component devices that incorporate semiconductor devices having such interlayer insulating films. Furthermore, even for flip-chip connections where the distance between the bump connection surface of the wiring board constituting the electronic component and the semiconductor element is, for example, 200 μm or less, it exhibits good fluidity and filling properties, and tends to provide electronic component devices with excellent reliability.

[0056] <Manufacturing method for electronic component devices> A method for manufacturing an electronic component device according to the present disclosure includes a step of sealing the gap between a substrate having a circuit layer and an electronic component disposed on the substrate and electrically connected to the circuit layer using the liquid resin composition according to the present disclosure. There are no particular limitations on the process of sealing the gap between a substrate having a circuit layer and an electronic component using the liquid resin composition of this disclosure. For example, there is a post-application method in which, after connecting the electronic component and the substrate having a circuit layer, the liquid resin composition is applied to the gap between the electronic component and the substrate using capillary action, and then the curing reaction of the liquid resin composition is carried out. There is also a pre-application method in which the liquid resin composition of this disclosure is applied to at least one surface of the substrate having a circuit layer and the electronic component, and when the electronic component is connected to the substrate by heat-pressing, the connection of the electronic component and the substrate and the curing reaction of the liquid resin composition are carried out in a single process. Methods for applying the liquid resin composition include casting, dispensing, and printing. [Examples]

[0057] The present disclosure will be described below based on examples, but the present disclosure is not limited to the following examples. In the following examples, parts and % refer to parts by mass and mass %, respectively, unless otherwise specified.

[0058] (Example 1, Comparative Example 1, and Comparative Example 2) Each component was blended to achieve the composition shown in Table 1, and the mixture was kneaded and dispersed using a three-roll and vacuum mixing machine to prepare the liquid resin compositions of Example 1, Comparative Example 1, and Comparative Example 2. In Table 1, the blending units for the curing agent are in terms of equivalent weight relative to the total epoxy resin, and the blending units for the inorganic filler are in terms of the mass-based proportion (mass%) of the inorganic filler to the total liquid resin composition. The blending ratios for other components are based on mass.

[0059] The materials used in the preparation of the liquid resin composition and their abbreviations are shown below. (Epoxy resin) • Epoxy resin 1: Aminophenol-type epoxy resin (glycidylamine-type epoxy resin, epoxy equivalent: 96 g / eq) • Epoxy resin 2: Bifunctional aliphatic epoxy compound (epoxy equivalent: 138 g / eq)

[0060] (Hardening agent) • Hardener 1: Diethyltoluenediamine • Hardener 2: Polycondensate of formaldehyde such as 3,3'-diethyl-4,4'-diaminodiphenylmethane and 2-ethylaniline

[0061] • Rubber particles: Silicone rubber particles • Curing accelerator: Imidazole compound (2-phenyl-4-methyl-5-hydroxymethylimidazole) • Coloring agent: Carbon black Inorganic filler 1: Magnesite (average particle size: 1.2 μm, specific gravity: 3.0, specific surface area: 5.5 m²) 2 / g) • Inorganic filler 2: Silica (average particle size: 1.4 μm, specific gravity: 2.2) • Inorganic filler 3: Alumina (average particle size: 2.5 μm ~ 3.0 μm, specific gravity: 3.5 ~ 4.0)

[0062] [Table 1]

[0063] -Measurement of viscosity profile- The viscosity profile of each liquid resin composition was measured using a rheometer HR-2 (manufactured by TA Instruments, with a 40 mm aluminum cone and a shear rate of 32.5 / sec). The viscosity profiles of each liquid resin composition are shown in Figure 1.

[0064] -Filling performance evaluation- A test specimen was prepared by creating a 25 μm gap on a glass slide and fixing a glass plate (20 mm × 20 mm × 1 mm thick) in place of a semiconductor element. The test specimen was placed on a hot plate heated to 110°C, and the liquid resin composition was applied to one side of the glass plate, filling the space between the glass slide and the glass plate. Visual inspection was performed to determine whether the liquid resin composition reached the side of the glass plate opposite to the side it was applied to. The results are shown in Table 1. If it reached the opposite side, it was indicated as "flowing" in Table 1. If it did not reach the opposite side, it was indicated as "stopping" in Table 1.

[0065] -Evaluation of subsidence suppression- The same test specimens used for the filling performance evaluation were employed. The liquid resin compositions of Example 1, Comparative Example 1, and Comparative Example 2 were filled in the same manner as the "Filling Performance Evaluation" method. Each liquid resin composition was subjected to a heat treatment at 165°C for 2 hours. SEM imaging was performed on the center of each test specimen after heat treatment (the midpoint in the filling direction and the midpoint in the filling width). The imaging conditions were set to x4000 magnification. Based on the obtained SEM images, the presence or absence of sedimentation of the inorganic filler was determined as follows. At the center of each specimen in the SEM image, we observed whether there was a gradient in the dispersion of the inorganic filler in the thickness direction of the liquid resin composition after heat treatment. If there was no gradient in the dispersion of the inorganic filler in the thickness direction (i.e., the inorganic filler had not settled), it was evaluated as "none," and if there was a gradient in the dispersion of the inorganic filler in the thickness direction (i.e., the inorganic filler had settled), it was evaluated as "present." The results obtained are shown in Table 1. Furthermore, SEM images of Example 1, Comparative Example 1, and Comparative Example 2 are shown in Figure 2-4.

[0066] - Thermal conductivity evaluation - Using the liquid resin composition obtained above, a cured product was prepared under the conditions of heating temperature 165°C and curing time 2 hours. Then, a test specimen measuring 10 mm × 10 mm × 1 mm was prepared for evaluation of thermal conductivity. Next, the thermal diffusivity in the thickness direction of the prepared test specimen was measured. The thermal diffusivity was measured using the laser flash method (device: LFA467 nanoflash, NETZSCH). Pulsed light irradiation was performed under the conditions of pulse width 0.31 (ms) and applied voltage 247 V. The measurement was performed at an ambient temperature of 25°C ± 1°C. The density of the above test specimen was measured using an electronic hydrometer (AUX220, Shimadzu Corporation). The specific heat was calculated using the theoretical specific heat of the liquid resin composition, calculated from the literature values ​​of the specific heat of each material and the blending ratio. Next, the value of the thermal conductivity was obtained by multiplying the specific heat and density by the thermal diffusivity using equation (1). λ=α×Cp×ρ...Equation (1) (In equation (1), λ is the thermal conductivity (W / (m·K)) and α is the thermal diffusivity (m 2 ρ is density (kg / m³), Cp is specific heat (J / (kg·K)), and ρ is density (kg / m³). 3 ) will be shown respectively. The results are shown in Table 1.

[0067] As is clear from the results shown in Table 1, the liquid resin composition of the example exhibited excellent filling properties, suppressed the sedimentation of inorganic fillers within gaps, and had excellent thermal conductivity. On the other hand, the liquid resin composition of the comparative example had poor thermal conductivity or the inorganic filler sedimented.

Claims

1. A liquid resin composition containing an epoxy resin, a curing agent, and an inorganic filler containing magnesite.

2. The liquid resin composition according to claim 1, wherein the content of the inorganic filler is 60% by mass to 85% by mass.

3. The liquid resin composition according to claim 1, wherein the proportion of the magnesite in the inorganic filler is 50% by mass or more.

4. The specific surface area of ​​the inorganic filler is 5.0 m². ２ / g to 10.0m ２ The liquid resin composition according to claim 1, wherein the amount is / g.

5. The liquid resin composition according to claim 1, wherein the average particle size of the inorganic filler is 0.2 μm to 1.5 μm.

6. The liquid resin composition according to claim 1, wherein the curing agent comprises an amine-based curing agent.

7. The liquid resin composition according to claim 1, wherein the epoxy resin comprises a glycidylamine-type epoxy resin.

8. The liquid resin composition according to claim 1, wherein the epoxy resin comprises a bifunctional aliphatic epoxy compound.

9. The liquid resin composition according to claim 1, wherein the epoxy resin comprises a glycidylamine-type epoxy resin and a difunctional aliphatic epoxy compound.

10. The liquid resin composition according to claim 1, wherein the volatile content is 5% by mass or less.

11. The liquid resin composition according to claim 1, which is a capillary underfill material.

12. A substrate having a circuit layer, An electronic component arranged on the substrate and electrically connected to the circuit layer, A cured product of the liquid resin composition according to any one of claims 1 to 11 is disposed in the gap between the substrate and the electronic component, An electronic component device equipped with the following features.

13. A method for manufacturing an electronic component device, comprising the step of sealing the gap between a substrate having a circuit layer and an electronic component disposed on the substrate and electrically connected to the circuit layer using the liquid resin composition described in any one of claims 1 to 11.

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