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

Abstract

For the present invention, in viscosity profiles measured under the condition having a temperature rising rate of 10°C / minute, the viscosity at temperature A°C is expressed as ρA, whereas the viscosity at temperature (A + 5)°C is expressed as ρ(A + 5). The lowest temperature AL for this liquid resin composition to have a slope B expressed as ρ(A + 5) / ρA being equal to 1.5 falls in the range of 103-140°C.

Description

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

[0001] The present disclosure relates to a liquid resin composition, an electronic component device, and a method for manufacturing the same.

[0002] In the field of element encapsulation of electronic component devices such as transistors and ICs (Integrated Circuits), resin encapsulation has become mainstream due to productivity, cost, and other factors, and various types of resin compositions have been used. Among these, epoxy resins are widely used due to their well-balanced properties, such as workability, moldability, electrical properties, moisture resistance, heat resistance, mechanical properties, and adhesion to insert parts. Liquid resin compositions are widely used as encapsulants in bare-chip mounted semiconductor devices 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 wiring substrates made of ceramic, glass / epoxy resin, glass / imide resin, polyimide film, or the like, liquid resin compositions for electronic components are used as underfill materials to fill gaps between the bump-connected semiconductor elements and the wiring substrate. These liquid resin compositions for electronic parts play an important role in protecting electronic parts from temperature, humidity, mechanical external forces, and the like.

[0003] Furthermore, with the increasing performance and power consumption of semiconductor devices, liquid encapsulants used to fill the gap between an element and a substrate are also required to have higher heat dissipation properties than before. In order to improve the heat dissipation properties of semiconductor elements encapsulated with a liquid encapsulant, it is effective to use alumina as an inorganic filler contained in the liquid encapsulant. For example, Patent Document 1 discloses a liquid encapsulant containing alumina. Furthermore, Patent Document 2 discloses a solid encapsulant containing alumina.

[0004] Patent Document 1: JP 2016-108358 A Patent Document 2: JP 2018-87299 A

[0005] The present inventors have found through their research that when a semiconductor element is encapsulated with an underfill material, the inorganic filler settles, resulting in an uneven distribution of the inorganic filler. The settling of the inorganic filler is particularly likely to occur in the gap between the semiconductor element and the wiring board. This phenomenon is particularly likely when alumina is used as the inorganic filler. If the inorganic filler becomes uneven in the gap between the semiconductor element and the wiring board, thermal stress may cause failures such as cracks in the semiconductor device. The present disclosure has been made in consideration of the above-described conventional circumstances, and one aspect of the present disclosure aims to provide a liquid resin composition that has excellent filling properties and is capable of suppressing settling of the inorganic filler in the gap. Another aspect of the present disclosure aims to provide an electronic component device using this liquid resin composition and a method for manufacturing the same.

[0006] Specific means for achieving the above object are as follows. <1> A liquid resin composition in which, in a viscosity profile measured under a heating rate of 10°C / min, where ρA is the viscosity at a temperature of A°C and ρ(A+5) is the viscosity at a temperature of (A+5)°C, the minimum temperature AL at which the slope B, expressed as ρ(A+5) / ρA, is 1.5, is in the range of 103°C to 140°C. <2> The liquid resin composition according to <1>, which is a capillary underfill material. <3> An electronic component device comprising: 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 according to <1> or <2>, disposed in a gap between the substrate and the electronic component. <4> A method for producing an electronic component device, comprising the step of sealing a gap between a substrate having a circuit layer and an electronic component disposed on the substrate and electrically connected to the circuit layer with the liquid resin composition according to <1> or <2>.

[0007] According to one aspect of the present disclosure, it is possible to provide a liquid resin composition that has excellent filling properties and is capable of suppressing sedimentation of inorganic fillers in gaps. Also, according to another aspect of the present disclosure, it is possible to provide an electronic component device using the liquid resin composition and a method for manufacturing the same.

[0008] 1 is a diagram showing viscosity profiles for Experimental Examples 1 to 6. 2 is a diagram showing viscosity profiles for Experimental Examples 7 to 11. 3 is an SEM photograph showing an example of a liquid resin composition after heat treatment in which the inorganic filler does not settle in the thickness direction. 4 is an SEM photograph showing an example of a liquid resin composition after heat treatment in which the inorganic filler settles in the thickness direction.

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

[0010] In the present disclosure, the term "process" includes not only processes that are independent of other processes, but also processes that cannot be clearly distinguished from other processes as long as the purpose of the process is achieved. In the present disclosure, numerical ranges indicated using "to" include the numerical values ​​before and after "to" as the minimum and maximum values, respectively. In numerical ranges described in stages in the present disclosure, the upper or lower limit value described in one numerical range may be replaced with the upper or lower limit value of another numerical range described in stages. Furthermore, in numerical ranges described in the present disclosure, the upper or lower limit value of that numerical range may be replaced with a value shown in the examples. In the present disclosure, each component may contain multiple corresponding substances. When multiple substances 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 substances present in the composition, unless otherwise specified. In the present disclosure, particles corresponding to each component may contain multiple types of particles. When a composition contains multiple types of particles corresponding to each component, the particle size of each component refers to the value for a mixture of the multiple types of particles present in the composition, unless otherwise specified. In the present disclosure, the terms "layer" and "film" include cases where the layer or film is formed over the entire area when the area where the layer or film is present is observed, as well as cases where the layer or film is formed over only a part of the area.

[0011] <Liquid Resin Composition> In the liquid resin composition of the present disclosure, when a viscosity profile is measured at a temperature rise rate of 10°C / min, where ρA is the viscosity at a temperature of A°C and ρ(A+5) is the viscosity at a temperature of (A+5)°C, the minimum temperature AL at which the slope B, expressed as ρ(A+5) / ρA, is 1.5, is in the range of 103°C to 140°C. The liquid resin composition of the present disclosure exhibits excellent filling properties and can suppress sedimentation of inorganic fillers in gaps. The reason for this is not clear, but is presumed to be as follows. When a liquid resin composition is used as an underfill material, the underfill material is generally adjusted to a temperature range of approximately 100°C to 110°C and filled into the gap between a semiconductor element and a wiring board. By setting the minimum temperature AL to 103°C or higher, an increase in the viscosity of the liquid resin composition is suppressed when the liquid resin composition is filled into the gap, thereby improving the filling properties of the liquid resin composition. On the other hand, by setting the minimum temperature AL to 140°C or less, the curing reaction of the liquid resin composition tends to proceed quickly after the liquid resin composition is filled into the gap. As the curing reaction progresses, the viscosity of the liquid resin composition increases, and as a result, sedimentation of the inorganic filler is suppressed. From the above, it is presumed that the liquid resin composition of the present disclosure has excellent filling properties and can suppress sedimentation of the inorganic filler in the gap.

[0012] - Viscosity Profile - The viscosity profile of the liquid resin composition referred to in this disclosure is measured at a temperature rise rate of 10°C / min using a rheometer HR-2 (manufactured by TA Instruments, aluminum cone 25 mm, temperature rise rate 10°C / min).

[0013] In the liquid resin composition of the present disclosure, the minimum temperature AL is in the range of 103°C to 140°C, preferably in the range of 104°C to 135°C, more preferably in the range of 105°C to 125°C, and even more preferably in the range of 106°C to 120°C.

[0014] The liquid resin composition of the present disclosure is not limited in its composition as long as it has a minimum temperature AL in the range of 103° C. to 140° C. The liquid resin composition of the present disclosure contains, for example, an epoxy resin, a curing agent, an inorganic filler, and a latent viscosity modifier, and may contain other components as necessary.

[0015] -Epoxy Resin- The liquid resin composition of the present disclosure may contain an epoxy resin. The epoxy resin imparts curability and adhesive properties to the liquid resin composition, and imparts heat resistance and durability to a cured product of the liquid resin composition. The epoxy resin is preferably a liquid epoxy resin. In the present disclosure, a solid epoxy resin can also be used in combination with the liquid epoxy resin. One type of epoxy resin may be used alone, or two or more types may be used in combination.

[0016] Liquid epoxy resin refers to an epoxy resin that is liquid at room temperature (25°C). Specifically, it refers to a viscosity of 1000 Pa·s or less as measured with an E-type viscometer at 25°C. The viscosity is measured using an EHD-type E-type viscometer (cone angle 3°, cone diameter 28 mm) at 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, with reference to the following: (1) When the expected viscosity is 100 Pa·s to 1000 Pa·s: rotation speed 0.5 rotations / minute; (2) When the expected viscosity is less than 100 Pa·s: rotation speed 5 rotations / minute. Solid epoxy resin refers to an epoxy resin that is solid at room temperature (25°C).

[0017] 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 obtained by epoxidizing novolac resins of phenols and aldehydes, such as orthocresol novolac-type epoxy resins; glycidyl ester-type epoxy resins obtained by reacting polybasic acids such as phthalic acid and dimer acid with epichlorohydrin; and glycidylamine-type epoxy resins obtained by reacting amine compounds such as diaminodiphenylmethane, isocyanuric acid, and aminophenol with epichlorohydrin. Examples of epoxy resins include bifunctional aliphatic epoxy compounds having two epoxy groups in the molecule, such as alkylene glycol diglycidyl ether, poly(alkylene glycol) diglycidyl ether, and alkenylene glycol diglycidyl ether.

[0018] The epoxy resin preferably contains at least one epoxy resin selected from the group consisting of naphthalene-type epoxy resins, diglycidyl ether-type epoxy resins, novolac-type epoxy resins, glycidyl ester-type epoxy resins, and glycidyl amine-type epoxy resins, and more preferably contains at least one epoxy resin selected from the group consisting of diglycidyl ether-type epoxy resins and glycidyl amine-type epoxy resins. Furthermore, from the viewpoint of reducing the viscosity of the liquid resin composition, the epoxy resin preferably contains a bifunctional aliphatic epoxy compound. The epoxy resin preferably contains at least one epoxy resin selected from the group consisting of naphthalene-type epoxy resins, diglycidyl ether-type epoxy resins, novolac-type epoxy resins, glycidyl ester-type epoxy resins, and glycidyl amine-type epoxy resins, and a bifunctional aliphatic epoxy compound. More preferably, the epoxy resin contains at least one epoxy resin selected from the group consisting of diglycidyl ether-type epoxy resins and glycidyl amine-type epoxy resins, and a bifunctional aliphatic epoxy compound.

[0019] In a first aspect of the liquid resin composition of the present disclosure, the content of the glycidylamine-type epoxy resin per 100 parts by mass of epoxy resins is less than 50 parts by mass, preferably 48 parts by mass or less, and more preferably 46 parts by mass or less. The first aspect of the liquid resin composition of the present disclosure does not need to contain a glycidylamine-type epoxy resin as the epoxy resin. When the first aspect of the liquid resin composition of the present disclosure contains a glycidylamine-type epoxy resin as the epoxy resin, the content of the glycidylamine-type epoxy resin per 100 parts by mass of epoxy resins is preferably 20 parts by mass or more, more preferably 30 parts by mass or more, and even more preferably 35 parts by mass or more. In the first aspect of the liquid resin composition of the present disclosure, the content of the glycidylamine-type epoxy resin per 100 parts by mass of epoxy resins is preferably 20 parts by mass or more but less than 50 parts by mass. In the first aspect of the liquid resin composition of the present disclosure, the content of the difunctional aliphatic epoxy compound per 100 parts by mass of the epoxy resin is preferably 20 parts by mass or less, more preferably 15 parts by mass or less, and even more preferably 12 parts by mass or less. The content of the difunctional aliphatic epoxy compound per 100 parts by mass of the epoxy resin may be 5 parts by mass or more. The content of the difunctional aliphatic epoxy compound per 100 parts by mass of the epoxy resin is preferably 5 to 20 parts by mass.

[0020] In a second aspect of the liquid resin composition of the present disclosure, the content of the glycidyl amine-type epoxy resin per 100 parts by mass of the epoxy resin is 50 parts by mass or more, preferably 60 parts by mass or more, and more preferably 70 parts by mass or more. In the second aspect of the liquid resin composition of the present disclosure, the content of the glycidyl amine-type epoxy resin per 100 parts by mass of the epoxy resin is preferably 100 parts by mass or less, more preferably 90 parts by mass or less, and even more preferably 80 parts by mass or less. The content of the glycidyl amine-type epoxy resin per 100 parts by mass of the epoxy resin is preferably 50 to 100 parts by mass. In the second aspect of the liquid resin composition of the present disclosure, the content of the bifunctional aliphatic epoxy compound per 100 parts by mass of the epoxy resin is preferably 50 parts by mass or less, more preferably 40 parts by mass or less, and even more preferably 30 parts by mass or less. The content of the bifunctional aliphatic epoxy compound per 100 parts by mass of the epoxy resin may be 15 parts by mass or more. The content of the bifunctional aliphatic epoxy compound relative to a total of 100 parts by mass of the epoxy resin is preferably 15 parts by mass to 50 parts by mass.

[0021] 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 the epoxy resin is measured by dissolving a weighed amount of epoxy resin in a solvent such as methyl ethyl ketone, adding acetic acid and a tetraethylammonium bromide acetate solution, and then potentiometric titration with a perchloric acid acetate standard solution. An indicator may be used in this titration.

[0022] Commercially available epoxy resins may be used. Specific examples of commercially available epoxy resins include an amine-type epoxy resin (product name: jER630) manufactured by Mitsubishi Chemical Corporation, a bisphenol F-type epoxy resin (product name: YDF-8170C) manufactured by Nippon Steel Chemical & Material Co., Ltd., a bisphenol A-type epoxy resin (product name: YD-128) manufactured by Nippon Steel Chemical & Material Co., Ltd., a naphthalene-type epoxy resin (product name: HP-4032D) manufactured by DIC Corporation, and the trade name "Epogose PT (general grade)" (Yokkaichi Synthetic Co., Ltd., diglycidyl ether of polytetramethylene glycol, number average molecular weight 700 to 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 content of the epoxy resin is not particularly limited, and for example, as a proportion of the solid content of the liquid resin composition, it is preferably 5% by mass to 30% by mass, more preferably 7% by mass to 28% by mass, and even more preferably 10% by mass to 25% by mass.

[0023] -Curing Agent- The liquid resin composition of the present disclosure may contain a curing agent. The curing agent may be any agent that undergoes a polymerization reaction with the epoxy resin, and either a liquid or solid curing agent may be used as long as the liquid resin composition has fluidity at room temperature (25°C). Examples of the curing agent include amine-based curing agents, phenol-based curing agents, and acid anhydride-based curing agents. Among these, amine-based curing agents are preferred as the curing agent from the viewpoint of optimizing the curing temperature of the liquid resin composition.

[0024] Examples of the amine-based curing agent include linear aliphatic amines, cyclic aliphatic amines, aliphatic aromatic amines, and aromatic amines. From the viewpoint of heat resistance and electrical properties, aromatic amines are preferred, and aromatic amines in which an amino group is directly bonded to an aromatic ring and one or two aromatic rings are contained in one molecule are more preferred. Specific examples of the amine-based curing agent include aromatic amine curing agents having one aromatic ring, such as m-phenylenediamine, 2,3-diaminotoluene, 3,4-diaminotoluene, 2,4-diaminotoluene, 3,5-diethyl-2,4-diaminotoluene, and 3,5-diethyl-2,6-diaminotoluene, and diethyltoluenediamines such as 2,4-diaminoanisole; 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfone, 4,4'-methylenebis(2-ethylaniline), 3,3'-diethyl-4,4'-diaminodiphenylmethane, 3,3', Examples of the curing agent include aromatic amine curing agents having 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 epichlorohydrin; reaction products of aromatic diamines and styrene; and polycondensates of aromatic amines and formaldehyde.

[0025] Commercially available amine curing agents may be used. Specific examples of commercially available amine curing agents include an amine curing agent manufactured by Nippon Kayaku Co., Ltd. (product name: Kayahard-AA) and an amine curing agent manufactured by Mitsubishi Chemical Corporation (product names: jER Cure (registered trademark) 113, jER Cure (registered trademark) W, etc.), but the amine curing agent is not limited to these specific examples. One type of amine curing agent may be used alone, or two or more types may be used in combination.

[0026] Examples of acid anhydride curing agents include phthalic anhydride, maleic anhydride, methyl himic anhydride, himic anhydride, succinic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, chlorendic anhydride, methyltetrahydrophthalic anhydride, 3-methylhexahydrophthalic anhydride, 4-methylhexahydrophthalic anhydride, trialkyltetrahydrophthalic anhydride maleic acid adduct, benzophenonetetracarboxylic anhydride, trimellitic anhydride, pyromellitic anhydride, hydrogenated methylnadic anhydride, trialkyltetrahydrophthalic anhydride having multiple alkyl groups obtained by Diels-Alder reaction from maleic anhydride and a diene compound, and various cyclic acid anhydrides such as dodecenyl succinic anhydride.

[0027] Examples of phenolic curing agents include novolak resins obtained by condensing or co-condensing at least one 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) in the presence of an acid catalyst; phenol-aralkyl resins; biphenyl-aralkyl resins; and naphthol-aralkyl resins. One type of curing agent may be used alone, or two or more types may be used in combination.

[0028] The ratio of the equivalent number 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, or an acid anhydride group in the case of an acid anhydride-based curing agent) to the equivalent number of the epoxy resin (equivalent number of curing agent / equivalent number of epoxy resin) is preferably set 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.

[0029] -Inorganic Filler- The liquid resin composition of the present disclosure may contain an inorganic filler. Known or commonly used inorganic fillers can be used as the inorganic filler, and are not particularly limited. Examples of 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, fosterite, steatite, spinel, mullite, and titania powders, as well as spherical beads of these fillers and glass fibers. Furthermore, examples of inorganic fillers with flame retardant properties include aluminum hydroxide, magnesium hydroxide, zinc borate, and zinc molybdate. These inorganic fillers may be used alone or in combination. Among these, fused silica is preferred from the viewpoint of reducing the linear expansion coefficient, and alumina is preferred from the viewpoint of high thermal conductivity. The shape of the inorganic filler is preferably spherical from the viewpoint of high loading of the inorganic filler and the fluidity and penetration of the liquid resin composition into fine gaps.

[0030] When alumina is contained as the inorganic filler, the content of alumina in the inorganic filler is preferably 50% by volume or more, more preferably 70% by volume or more, and even more preferably 90% by volume or more. The content of alumina in the inorganic filler may be 100% by volume.

[0031] The content of the inorganic filler is preferably 60% by mass or more, more preferably 65% ​​by mass or more, and even more preferably 70% by mass or more, based on the total mass of the liquid resin composition, from the viewpoints of moisture absorption, reduction of the linear expansion coefficient, improvement of strength, and solder heat resistance. The content of the inorganic filler may be 80% by mass or less. The content of the inorganic filler is preferably 60% by mass to 80% by mass.

[0032] The average particle size of the inorganic filler is preferably 0.5 μm to 10 μm, more preferably 1 μm to 6 μm, and even more preferably 1.5 μm to 4 μm. In the present disclosure, the average particle size of the inorganic filler refers to the average particle size of alumina when alumina is used alone as the inorganic filler, and refers to the average particle size of the inorganic filler as a whole when alumina is used in combination with other inorganic fillers.

[0033] The average particle size of an inorganic filler can be measured by the following method. The inorganic filler to be measured is added to a solvent (pure water) in a range of 0.02% to 0.08% by mass, and the mixture is vibrated in a 110W bath-type ultrasonic cleaner for 1 to 10 minutes to disperse the inorganic filler. Approximately 40 mL of the dispersion is poured into a measurement cell and measured at 25°C. A laser diffraction particle size distribution analyzer (HORIBA, Ltd., LA920 (product name)) is used as the measurement device to measure the volumetric particle size distribution. The average particle size is determined as the particle size (D50%) at which the cumulative total from the smallest diameter side in the volumetric particle size distribution reaches 50%. The refractive index used is that of alumina. When the inorganic filler is a mixture of alumina and other inorganic fillers, the refractive index used is that of alumina.

[0034] Coupling Agent—The liquid resin composition of the present disclosure may contain a coupling agent, if necessary, to strengthen the adhesion between the resin and the inorganic filler or between the resin and the constituent members of electronic components. Any known or commonly used coupling agent can be used as the coupling agent, and is not particularly limited. Examples of the coupling agent include silane compounds having at least one group selected from the group consisting of a primary amino group, a secondary amino group, and a tertiary amino group; various silane-based compounds such as epoxy silane, mercaptosilane, alkyl silane, ureidosilane, and vinyl silane; titanium-based compounds; aluminum chelates; and aluminum / zirconium-based compounds. Among these, preferred coupling agents are silane compounds having at least one group selected from the group consisting of a primary amino group, a secondary amino group, and a tertiary amino group.

[0035] -Imidazole Compound- The liquid resin composition of the present disclosure may contain an imidazole compound. The imidazole compound can function as a curing accelerator that accelerates the curing reaction between the epoxy resin and the curing agent contained in the liquid resin composition. The type of imidazole compound is not particularly limited. Examples of the imidazole compound include 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2,4-diamino-6-[2'-methylimidazolyl-(1')]ethyl-s-triazine, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, and 2,3-dihydro-1H-pyrrolo[1,2-a]benzimidazole.

[0036] The content of the imidazole compound is preferably 0.1% by mass to 8% by mass based on the total amount of the epoxy resin and the curing agent.

[0037] The liquid resin composition of the present disclosure may contain a curing accelerator other than the imidazole compound. Examples of the other curing accelerator include a cycloamidine compound, a tertiary amine compound, a derivative of a tertiary amine compound, and an organic phosphine compound. When the liquid resin composition of the present disclosure contains the other curing accelerator, the proportion of the imidazole compound in the curing accelerator is preferably 50% by mass or more, more preferably 70% by mass or more, and even more preferably 90% by mass or more.

[0038] -Latent Viscosity Modifier- The liquid resin composition of the present disclosure may contain a latent viscosity modifier. As described above, the latent viscosity modifier is not particularly limited as long as it has the property of not increasing the viscosity of the liquid resin composition in the filling temperature range of the liquid resin composition, while easily increasing the viscosity of the liquid resin composition in a temperature range higher than the filling temperature range. Examples of latent viscosity modifiers include latent curing agents for epoxy resins. The latent curing agent may be a latent curing agent in which a component capable of promoting the effects of the epoxy resin and the curing agent is microencapsulated or blocked. Specific examples of latent viscosity modifiers include Novacure (registered trademark) HX-3722, HX-3742, HX-3088, HXA9382HP, and HXA-3922HP, all of which are manufactured by Asahi Kasei Corporation. Among these, Novacure (registered trademark) HXA9382HP is preferred.

[0039] In a first aspect of the liquid resin composition of the present disclosure, the content of the latent viscosity modifier is 0.7 parts by mass to 5 parts by mass per 100 parts by mass of the total epoxy resin. When the content of the latent viscosity modifier is 0.7 parts by mass or more per 100 parts by mass of the total epoxy resin, sedimentation of the inorganic filler in the gaps tends to be easily suppressed. When the content of the latent viscosity modifier is 5 parts by mass or less per 100 parts by mass of the total epoxy resin, deterioration of the fluidity of the liquid resin composition tends to be easily suppressed. The content of the latent viscosity modifier is preferably 0.8 parts by mass to 4 parts by mass, more preferably 0.9 parts by mass to 3 parts by mass, per 100 parts by mass of the total epoxy resin. In a second aspect of the liquid resin composition of the present disclosure, the content of the latent viscosity modifier is 1.5 parts by mass or less per 100 parts by mass of the total epoxy resin. When the content of the latent viscosity modifier is 1.5 parts by mass or less per 100 parts by mass of the total epoxy resin, deterioration of the fluidity of the liquid resin composition tends to be suppressed. From the viewpoint of suppressing sedimentation of the inorganic filler in the gaps, the content of the latent viscosity modifier is preferably 0.1 parts by mass or more per 100 parts by mass of the total epoxy resin, more preferably 0.2 parts by mass or more, and even more preferably 0.3 parts by mass or more. The content of the latent viscosity modifier is preferably 0.1 to 1.5 parts by mass per 100 parts by mass of the total epoxy resin.

[0040] -Ion trapping agent- The liquid resin composition of the present disclosure may contain an ion trapping agent. The ion trapping agent that can be used in the present disclosure is not particularly limited as long as it is an ion trapping agent that is commonly used in encapsulants used in the production of semiconductor devices. Examples of ion trapping agents include compounds represented by the following general formula (VI-1) or the following general formula (VI-2).

[0041] Mg １－ａ Al ａ (OH) ２ (CO ３ ) ａ／２ ・uH ２ O (VI-1) (In the general formula (VI-1), a is 0<a≦0.5, and u is a positive number.) BiO ｂ (OH) ｃ (NO ３ ) ｄ (VI-2) (In 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.)

[0042] Ion trapping agents are commercially available. For example, "DHT-4A" (trade name, manufactured by Kyowa Chemical Industry Co., Ltd.) is a commercially available compound represented by general formula (VI-1). For example, "IXE500" (trade name, manufactured by Toagosei Co., Ltd.) is a commercially available compound represented by general formula (VI-2).

[0043] Other examples of the ion trapping agent include hydrous oxides of elements selected from magnesium, aluminum, titanium, zirconium, antimony, etc. One type of ion trapping agent may be used alone, or two or more types may be used in combination.

[0044] When the liquid resin composition contains an ion trapping agent, the content of the ion trapping agent is preferably 1 part by mass or more relative to 100 parts by mass of the epoxy resin in total, from the viewpoint of realizing sufficient moisture resistance reliability. From the viewpoint of fully exerting the effects of the other components, the content of the ion trapping agent is preferably 15 parts by mass or less relative to 100 parts by mass of the epoxy resin in total, more preferably 1 to 10 parts by mass, and even more preferably 2 to 5 parts by mass.

[0045] 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 the inorganic filler.

[0046] -Antioxidant- The liquid resin composition of the present disclosure may contain an antioxidant. Conventionally known antioxidants can be used. Examples of the antioxidant include phenolic compound-based antioxidants, organic sulfur compound-based antioxidants, amine compound-based antioxidants, and phosphorus compound-based antioxidants. One type of antioxidant may be used alone, or two or more types may be used in combination. The content of the antioxidant is preferably 0.1% by mass to 10% by mass, and more preferably 0.5% by mass to 5% by mass, based on the total epoxy resin.

[0047] Organic Solvent—An organic solvent can be blended into the liquid resin composition of the present disclosure, if necessary, to reduce viscosity. In particular, when using a solid epoxy resin and curing agent, blending an organic solvent is preferable to obtain a liquid resin composition. The organic solvent is not particularly limited, 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 sudden evaporation when curing the liquid resin composition.

[0048] The content of volatile matter, including organic solvents, etc., is not particularly limited as long as it is to an extent that bubbles are not formed when the liquid resin composition is cured, and is preferably 5% by mass or less, more preferably 1% by mass or less, and even more preferably 0.1% by mass or less, of the entire liquid resin composition. In the present disclosure, the volatile matter 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.

[0049] -Mold Release Agent- The liquid resin composition of the present disclosure may contain a mold release agent. There are no particular limitations on the type of mold release agent, and known mold release agents can be used. Specific examples include higher fatty acids, carnauba wax, and polyethylene waxes. One type of mold release agent may be used alone, or two or more types may be used in combination. When the liquid resin composition contains a mold release agent, the content of the mold release agent is preferably 10% by mass or less, based on the total amount of the epoxy resin and the curing agent, and from the viewpoint of exerting its effect, it is preferably 0.5% by mass or more.

[0050] Colorant The liquid resin composition of the present disclosure may contain a colorant (for example, carbon black). One type of colorant may be used alone, or two or more types may be used in combination.

[0051] When conductive particles such as carbon black are used as the colorant, the content of conductive particles having a particle diameter of 10 μm or more is preferably 1 mass % or less. When the liquid resin composition contains conductive particles, the content of conductive particles is preferably 3 mass % or less, and more preferably 0.01 mass % to 1 mass %, based on the total amount of the epoxy resin and the curing agent.

[0052] - Rubber Particles - The liquid resin composition of the present 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. Suitable examples of rubber particles include rubber particles such as styrene-butadiene rubber (SBR), nitrile-butadiene rubber (NBR), butadiene rubber (BR), urethane rubber (UR), and acrylic rubber (AR). Among these, from the viewpoint of heat resistance and moisture resistance, rubber particles containing acrylic rubber are preferred, and core-shell acrylic rubber particles are more preferred.

[0053] Another example of suitable rubber particles is silicone rubber particles. Examples of silicone rubber particles include silicone rubber particles crosslinked from linear polyorganosiloxanes such as polydimethylsiloxane, polymethylphenylsiloxane, and polydiphenylsiloxane; silicone rubber particles whose surfaces are coated with silicone resin; and core-shell polymer particles comprising a core of solid silicone particles obtained by emulsion polymerization or the like and a shell of an organic polymer such as an acrylic resin. The shape of these silicone rubber particles may be amorphous or spherical, and spherical silicone rubber particles are preferably used to maintain a low viscosity of the liquid resin composition. Silicone rubber particles are commercially available from Dow Corning Toray Silicone Co., Ltd., Shin-Etsu Chemical Co., Ltd., and the like.

[0054] When the liquid resin composition of the present 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 of the rubber particles in the liquid resin composition tends to be further improved. When the average particle size of the rubber particles is 10 μm or less, the stress reduction effect tends to be further improved, the permeability and fluidity of the liquid resin composition into fine gaps are improved, and voids and unfilled portions tend to be less likely to occur. The average particle size of the rubber particles is measured using the same method as for inorganic fillers. The content of the rubber particles is preferably 1 to 20 parts by mass, more preferably 2 to 15 parts by mass, and even more preferably 5 to 12 parts by mass, per 100 parts by mass of the total epoxy resin.

[0055] <Method for Producing Liquid Resin Composition> The liquid resin composition of the present disclosure can be obtained, for example, by stirring, melting, mixing, dispersing, etc., an epoxy resin, a curing agent, an inorganic filler, a latent viscosity modifier, and other components used as needed, all at once or separately, while applying heat treatment as needed. The device for mixing, stirring, dispersing, etc., these components is not particularly limited, and examples include a Raikai mill equipped with a stirrer, 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 and kneading the above components using these devices, and degassing as needed.

[0056] The viscosity of the liquid resin composition is not particularly limited. In particular, from the viewpoint of high fluidity, the viscosity 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 rpm).

[0057] Furthermore, when the liquid resin composition is used as an underfill material or the like, the viscosity at 110°C is preferably 0.5 Pa·s or less, more preferably 0.4 Pa·s or less, and even more preferably 0.3 Pa·s or less, as an indicator of the ease of filling a narrow gap of several tens to several hundreds of μm with the liquid resin composition at around 100°C to 120°C. The viscosity of the liquid resin composition at 110°C is measured using a rheometer AR2000 (manufactured by TA Instruments, aluminum cone 40 mm, shear rate 32.5 / sec).

[0058] Furthermore, the liquid resin composition preferably has a thixotropic index [(viscosity at 2.5 rpm) / (viscosity at 10 rpm)], which is the ratio of the viscosity at a rotational speed of 2.5 rpm to the viscosity at a rotational speed of 10 rpm, measured at 25°C using an E-type viscometer, of 0.3 to 1.5, more preferably 0.5 to 1.2. When the thixotropic index is within the above range, the filling ability tends to be further improved. The viscosity and thixotropic index of the liquid resin composition can be adjusted to the desired range by appropriately selecting the composition of the epoxy resin, the content of the inorganic filler, etc.

[0059] The conditions for curing the liquid resin composition are not particularly limited, but it is preferable to heat the composition at 80° C. to 165° C. for 1 minute to 150 minutes.

[0060] <Electronic Component Device> The electronic component device of the present disclosure includes 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 the present disclosure disposed in the gap between the substrate and the electronic component. The electronic component device of the present disclosure can be obtained by sealing the electronic component with the liquid resin composition of the present disclosure. By sealing the electronic component with the liquid resin composition, the electronic component device of the present disclosure has excellent reliability.

[0061] Examples of electronic component devices include electronic component devices obtained by mounting electronic components such as active elements (e.g., semiconductor chips, transistors, diodes, and thyristors) and passive elements (e.g., capacitors, resistors, resistor arrays, coils, and switches) on a substrate having a circuit layer, such as a lead frame, a wired tape carrier, a rigid wiring board, a flexible wiring board, glass, or a silicon wafer, and then encapsulating the necessary parts with the liquid resin composition of the present disclosure. In particular, semiconductor devices in which semiconductor elements are flip-chip bonded by bump connection to wiring formed on a rigid wiring board, a flexible wiring board, or glass are examples of devices to which the liquid resin composition of the present 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).

[0062] The liquid resin composition of the present disclosure is suitable as an underfill material for flip chips (e.g., capillary underfill material) with excellent reliability. The liquid resin composition of the present disclosure is particularly suitable for use in flip chip applications, not only when the bump material connecting a wiring substrate and a semiconductor element is a conventional lead-containing solder, but also when flip chip semiconductor components are made using lead-free solder, such as Sn-Ag-Cu solder. The liquid resin composition of the present disclosure tends to maintain good reliability even for flip chips bump-connected using lead-free solder, which is physically more brittle than conventional lead solder. Furthermore, the use of the liquid resin composition of the present disclosure tends to improve reliability when mounting chip-scale packages, such as wafer-level CSPs (chip size packages), on substrates. Furthermore, with the recent increase in speed of semiconductor elements, low-dielectric interlayer insulating films are often formed on semiconductor elements. The liquid resin composition of the present disclosure can also be applied to electronic component devices using a flip-chip connection method that mounts semiconductor elements having such interlayer insulating films. Furthermore, the composition exhibits good fluidity and filling properties even for flip-chip connections in which the distance between the bump connection surfaces of the wiring substrate and semiconductor element that constitute the electronic component is, for example, 200 μm or less, and tends to provide an electronic component device with excellent reliability.

[0063] <Method for Manufacturing Electronic Component Device> The 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. The step of sealing the gap between the substrate having a circuit layer and the electronic component using the liquid resin composition according to the present disclosure is not particularly limited. Examples include a post-insertion method in which, after connecting the electronic component to 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 a curing reaction of the liquid resin composition is carried out. Also included is a pre-application method in which the liquid resin composition according to the present disclosure is first applied to the surface of at least one of the substrate having a circuit layer and the electronic component, and then thermocompression-bonded to connect the electronic component to the substrate, and then the connection of the electronic component to the substrate and the curing reaction of the liquid resin composition are carried out simultaneously. Examples of methods for applying the liquid resin composition include a casting method, a dispensing method, and a printing method.

[0064] 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 % represent parts by mass and % by mass unless otherwise specified.

[0065] (Experimental Examples 1 to 12) The components were blended to obtain the compositions shown in Table 1, and the components were kneaded and dispersed using a triple roll mill and a vacuum mortar and pestle to prepare liquid resin compositions for Experimental Examples 1 to 12. Note that the blending unit for the curing agent in Table 1 is the equivalent ratio to the entire epoxy resin, and the blending unit for the inorganic filler is the mass ratio (mass %) of the inorganic filler to the entire liquid resin composition. The blending ratios for other components are on a mass basis. Experimental Examples 3, 4, 6, 8, and 9 correspond to working examples.

[0066] The materials used in preparing the liquid resin compositions and their abbreviations are listed below. (Epoxy Resins) Epoxy resin 1: Bisphenol F type epoxy resin (diglycidyl ether type epoxy resin, epoxy equivalent: 160 g / eq) Epoxy resin 2: Aminophenol type epoxy resin (glycidyl amine type epoxy resin, epoxy equivalent: 96 g / eq) Epoxy resin 3: Difunctional aliphatic epoxy compound (epoxy equivalent: 138 g / eq)

[0067] (Hardening agents) Hardener 1: Diethyltoluenediamine Hardener 2: Polycondensation product of formaldehyde and 2-ethylaniline, such as 3,3'-diethyl-4,4'-diaminodiphenylmethane

[0068] Rubber particles: silicone rubber particles; Latent viscosity modifier: Novacure HXA9382HP (Asahi Kasei Corporation); Curing accelerator: imidazole compound (2-phenyl-4-methyl-5-hydroxymethylimidazole); Colorant: carbon black; Inorganic filler: alumina (average particle size: 2.5 μm to 3.0 μm, specific gravity: 3.5 to 4.0)

[0069]

[0070] - Measurement of viscosity profile - The viscosity profile of each liquid resin composition was measured using a rheometer HR-2 (manufactured by TA Instruments, aluminum cone 25 mm, temperature rise rate 10°C / min). The viscosity profile of each liquid resin composition is shown in Figures 1 and 2. In addition, the minimum temperature AL for each liquid resin composition was determined from the viscosity profile. The results obtained are shown in Table 1.

[0071] -Filling property evaluation- A test piece was prepared by fixing a glass plate (20 mm x 20 mm x 1 mm thick) instead of a semiconductor element on a glass slide with a gap of 25 μm. This test piece was placed on a hot plate heated to 100°C, and the liquid resin composition was applied to the side (one side) of the glass plate, filling the space between the glass slide and the glass plate. It was visually confirmed whether the liquid resin composition had reached the side (one side) of the glass plate opposite the side (one side). The results are shown in Table 1. If the liquid resin composition reached the opposite side, it was recorded as "flowing" in Table 1. If the liquid resin composition did not reach the opposite side, it was recorded as "stopped" in Table 1.

[0072] —Evaluation of Sedimentation Suppression— The same test specimens as those used in the filling property evaluation were used. Each liquid resin composition was filled into the above-mentioned test specimen in the same manner as in the “Filling Property Evaluation” except for the filling temperature. The filling temperature for each Example and Comparative Example was the same as that described in Table 1. Each liquid resin composition was subjected to a heat treatment at 165°C for 2 hours. SEM images were taken of the center of each test specimen after the heat treatment (the midpoint in the direction of filling progress and the midpoint in the filling width). The image was taken at a magnification of 4000x. Based on the obtained SEM images, the presence or absence of sedimentation of the inorganic filler was determined as follows. The center of each test specimen in the SEM image was observed to determine whether there was a gradient in the dispersion of the inorganic filler in the thickness direction of the liquid resin composition after the 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 “absent.” 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 are shown in Table 1. FIG. 3 shows an SEM photograph illustrating an example in which the inorganic filler has not settled, and FIG. 4 shows an SEM photograph illustrating an example in which the inorganic filler has settled.

[0073] As is clear from the results shown in Table 1, the liquid resin compositions of the Examples had excellent filling properties and were able to suppress the settling of the inorganic filler in the gaps. On the other hand, the liquid resin compositions of the Comparative Examples had poor filling properties or the inorganic filler settling occurred.

[0074] The disclosure of Japanese Patent Application No. 2024-150129, filed on August 30, 2024, is incorporated herein by reference in its entirety. All documents, patent applications, and technical standards mentioned herein are incorporated by reference into this specification to the same extent as if each individual document, patent application, and technical standard was specifically and individually indicated to be incorporated by reference.

Claims

1. A liquid resin composition in which, in a viscosity profile measured at a temperature rise rate of 10°C / min, when the viscosity at a temperature of A°C is ρA and the viscosity at a temperature of (A+5)°C is ρ(A+5), the minimum temperature AL at which the slope B expressed as ρ(A+5) / ρA becomes 1.5 is in the range of 103°C to 140°C.

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

3. An electronic component device comprising: 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 according to claim 1 or 2 disposed in a gap between the substrate and the electronic component.

4. A method for manufacturing an electronic component device, comprising a step of sealing a 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 claim 1 or 2.

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