Underfill material, semiconductor package and method for manufacturing semiconductor package

Abstract

An underfill material, comprising a curable resin component and inorganic particles, wherein a number-base percentage of particles having a particles size of

Description

[Technical Field]

[0001] This invention relates to an underfill material, a semiconductor package, and a method for manufacturing a semiconductor package. [Previous Technology]

[0002] With the miniaturization and thinning of electronic components and devices incorporating semiconductor wafers and other elements, bare-chip mounting, a mounting technology for electronic components and devices that mounts unpackaged semiconductor wafers (bare wafers) onto a substrate, has become mainstream. In flip-chip mounting, where the active side of a semiconductor wafer is connected to the substrate side as a type of bare-chip mounting, a liquid, curable resin composition called an underfill material is used to fill the space between the semiconductor wafer and the substrate, which are connected via bumps. For example, Patent Document 1 describes an underfill material comprising a multifunctional epoxy resin and a curing agent containing phenolic compounds and acid anhydrides. The underfill material plays an important role in protecting the semiconductor wafer from external forces such as temperature, humidity, and mechanical stress. [Prior Art Documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2004-256646 [Summary of the Invention]

[0004] [Problem to be Solved by the Invention] In flip-chip semiconductor devices, solder balls were previously mainly used as bumps to connect semiconductor elements to the substrate. On the other hand, with the miniaturization and high integration of semiconductor devices leading to an increase in the number of terminals, the use of copper pillars with solder-covered front ends to replace the previous solder balls is increasing. Furthermore, from the viewpoint of improving the integration of semiconductor devices, technologies for three-dimensional mounting of components, such as 2.XD (2.X-dimensional) mounting and 3D (3D) mounting, are being developed. In these mounting technologies, an intermediate substrate with through electrodes, called an interposer, is disposed on the substrate, and components are mounted on it.

[0005] As the integralness of semiconductor devices increases, the gaps filled by the underfill material tend to narrow. Therefore, existing underfill materials may not be sufficient to adequately seal the gaps in highly integrated semiconductor devices. This disclosure is made in view of the above situation, and its objective is to provide an underfill material with excellent filling properties, a semiconductor package obtained using said underfill material, and a method for manufacturing the same. [Means for Solving the Problem]

[0006] The means for solving the aforementioned problem include the following embodiments. <1> An underfill material comprising a curable resin component and inorganic particles, wherein the inorganic particles comprise at least 10% of the total number of particles with a particle size of 0.5 μm or less, and at least 5% of the total number of inorganic particles with a particle size of 3 μm or more. <2> The underfill material as described in <1>, wherein the curable resin component comprises an epoxy resin. <3> The underfill material as described in <2>, wherein the epoxy resin comprises at least one selected from the group consisting of bisphenol type epoxy resin, naphthalene type epoxy resin, and trifunctional or higher glycidylamine type epoxy resin. <4> The underfill material as described in any one of <1> to <3> comprises a surface treatment agent, wherein the surface treatment agent has a coverage rate of 50% or more on the inorganic particles. <5> A semiconductor package comprising a substrate, a semiconductor element, and a cured form of the underfill material as described in any one of <1> to <4>. <6> A semiconductor package as described in <5>, wherein the hardener is disposed in the gap between the substrate and the semiconductor element. <7> A semiconductor package as described in <5> further includes an interposer disposed between the substrate and the semiconductor element. <8> A semiconductor package as described in <7>, wherein the hardener is disposed in at least one selected from the group consisting of the gap between the substrate and the interposer, and the gap between the interposer and the semiconductor element. <9> A method of manufacturing a semiconductor package, comprising filling at least one selected from the group consisting of the gap between the substrate and the semiconductor element, the gap between the substrate and the interposer, and the gap between the interposer and the semiconductor element using an underfill material as described in any one of <1> to <4>; and hardening the underfill material. [Effects of the Invention]

[0007] According to the present invention, an underfill material with excellent filling properties is provided, as well as a semiconductor package obtained using the underfill material and a method for manufacturing the same.

Implementation Method

[0009] Hereinafter, the embodiments for carrying out the present invention will be described in detail. However, the present invention is not limited to the following embodiments. In the following embodiments, the constituent elements (including element steps, etc.) are not essential unless specifically stated otherwise. The same applies to numerical values ​​and their ranges, which do not limit the present invention.

[0010] In this disclosure, the term "step" includes not only steps independent of other steps, but also steps that are not clearly distinguishable from other steps, as long as the purpose of the step is achieved. In this disclosure, the numerical range represented by "~" includes the minimum and maximum values ​​recorded before and after "~", respectively. In the numerical ranges recorded in stages in this disclosure, the upper or lower limit value recorded in one numerical range can also be replaced by the upper or lower limit value of other numerical ranges recorded in stages. In addition, the upper or lower limit value of the numerical range recorded in this disclosure can also be replaced by the value shown in the embodiment. In this disclosure, each component may also contain multiple equivalent substances. When multiple substances equivalent to each component are present in the composition, unless otherwise specified, the content or percentage of each component refers to the total content or percentage of the multiple substances present in the composition. In this disclosure, each component may also contain multiple equivalent particles. In the case where there are multiple particles in the composition that correspond to each component, unless otherwise specified, the particle size of each component refers to the value of the mixture of the multiple particles present in the composition.

[0011] <Bottom Filler Material> The bottom filler material disclosed herein comprises a curable resin component and inorganic particles. The inorganic particles contain particles with a particle size of 0.5 μm or less, accounting for less than 10% of the total number of inorganic particles, and particles with a particle size of 3 μm or more, accounting for less than 5% of the total number of inorganic particles.

[0012] Compared to previous bottom-filling materials, the bottom-filling material disclosed herein exhibits superior filling performance in narrow voids. This is because the particle size distribution of the inorganic particles contained in the bottom-filling material possesses characteristics not found in the particle size distribution of inorganic particles contained in previous bottom-filling materials. Specifically, the proportion of inorganic particles with a diameter of 0.5 μm or less and particles with a diameter of 3 μm or greater in the total inorganic particles contained in the bottom-filling material disclosed herein is smaller than that in the inorganic particles contained in previous bottom-filling materials. This is believed to be related to the improved filling performance of the bottom-filling material.

[0013] (Inorganic Particles) In this disclosure, the proportion of inorganic particles with a diameter of 0.5 μm or less and the proportion of inorganic particles with a diameter of 3 μm or more are determined by image analysis. There are no particular limitations on the image analysis method. Examples include observing the inorganic particles themselves, the ash content of the bottom packing material (the residue after removing organic components from the bottom packing material) using an optical microscope or an electron microscope, and dispersions containing inorganic particles. The counting of inorganic particles can be performed visually or using an image analysis system. From the viewpoint of measurement accuracy, image analysis is performed when the total number of inorganic particles being measured is 100 or more, and the magnification is 1000x or more. In this disclosure, the particle size of the inorganic particles is set as the equivalent circle diameter of the observed particles.

[0014] From the viewpoint of the filling properties of the bottom filling material, the proportion of the number of particles with a particle size of 0.5 μm or less contained in the inorganic particles is at least 10% of the total number of inorganic particles, preferably at least 5%, more preferably at least 1%, and even more preferably at least 0.1%. The proportion of the number of particles with a particle size of 0.5 μm or less contained in the inorganic particles can be 0% of the total number of inorganic particles.

[0015] From the viewpoint of the filling properties of the bottom filling material, the proportion of the number of particles with a particle size of 3 μm or more contained in the inorganic particles is 5% or less of the total number of inorganic particles, preferably 3% or less, more preferably 1% or less, and even more preferably 0.1% or less. The proportion of the number of particles with a particle size of 3 μm or more contained in the inorganic particles can be 0% of the total number of inorganic particles.

[0016] From the viewpoint of the filling properties of the bottom filling material, the volume average particle size of the inorganic particles is preferably 0.6 μm to 2.5 μm, more preferably 0.7 μm to 2.3 μm, and even more preferably 0.8 μm to 2 μm. The volume average particle size of the inorganic particles is determined by laser diffraction-scattering method. Specifically, the volume average particle size of the inorganic particles is determined as the particle size (D50) when the cumulative volume from the small diameter side in the particle size distribution based on the volume obtained by laser diffraction-scattering method is 50%.

[0017] There are no particular restrictions on the material of the inorganic particles contained in the bottom filler. Specifically, examples include silicon dioxide, aluminum oxide, calcium carbonate, zirconium silicate, calcium silicate, silicon nitride, aluminum nitride, boron nitride, beryllium oxide, zircon, forsterite, block talc, spinel, mullite, titanium dioxide, talc, clay, mica, etc. In addition, inorganic particles with flame-retardant properties can also be used. Examples of inorganic particles with flame-retardant properties include aluminum hydroxide, magnesium hydroxide, composite metal hydroxides such as magnesium and zinc hydroxides, zinc borate, etc.

[0018] From the viewpoint of reducing the thermal expansion coefficient of the hardened bottom filler material, silicon dioxide is preferred as the inorganic particle, and from the viewpoint of improving thermal conductivity, alumina is preferred. The bottom filler material may contain only one type of inorganic particle or two or more types. When the bottom filler material contains two or more types of inorganic particles, the ratio of the number of particles with a particle size of 0.5 μm or less and the ratio of the number of particles with a particle size of 3 μm or more are the total value relative to the two or more types of inorganic particles.

[0019] There is no particular limitation on the amount of inorganic particles contained in the underfill material. From the viewpoint of reducing the coefficient of thermal expansion of the hardened underfill material, a higher amount of inorganic particles is preferable. For example, the content of inorganic particles is preferably 50% by mass or more of the total underfill material, and more preferably 55% by mass or more. From the viewpoint of suppressing the increase in viscosity of the underfill material, a lower amount of inorganic particles is preferable. For example, the content of inorganic particles is preferably 80% by mass or less of the total underfill material, and more preferably 75% by mass or less.

[0020] There are no particular restrictions on the shape of the inorganic particles contained in the bottom filler material. From the viewpoint of the fillability of the bottom filler material, the inorganic particles are preferably spherical.

[0021] (Curing Resin Component) There are no particular limitations on the types of curing resin components included in the underfill material. From the viewpoint of balancing the properties of the underfill material, it is preferable that the underfill material contains epoxy resin and a hardener as the curing resin component.

[0022] There are no particular restrictions on the type of epoxy resin contained in the underfill material. Examples include bisphenol type epoxy resin, naphthalene type epoxy resin, glycidylamine type epoxy resin, hydrogenated bisphenol type epoxy resin, alicyclic epoxy resin, alcohol ether type epoxy resin, cyclic aliphatic epoxy resin, fluorene type epoxy resin, and siloxane type epoxy resin. The underfill material may contain only one type of epoxy resin or two or more types.

[0023] Preferably, the epoxy resin comprises at least one selected from the group consisting of bisphenol type epoxy resin, naphthalene type epoxy resin and glycidylamine type epoxy resin with trifunctionality or higher.

[0024] There are no particular limitations on the types of bisphenol type epoxy resins, such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, and bisphenol AD ​​type epoxy resin. For use as a bottom filler material, the bisphenol type epoxy resin is preferably liquid at room temperature (25°C, and so on), and more preferably bisphenol F type epoxy resin which is liquid at room temperature.

[0025] There are no particular limitations on the type of naphthalene-type epoxy resin. Preferably, the naphthalene-type epoxy resin used in the underfill material is liquid at room temperature. Examples of naphthalene-type epoxy resins that are liquid at room temperature include 1,6-bis(glycidoxy)naphthalene.

[0026] There are no particular restrictions on the types of trifunctional or higher glycidylamine type epoxy resins. Preferably, trifunctional or higher glycidylamine type epoxy resins used as underfill materials are liquid at room temperature.

[0027] As a trifunctional or higher glycidylamine type epoxy resin that is liquid at room temperature, triglycidyl-p-aminophenol can be cited as an example.

[0028] The bottom filler material may include epoxy resin that is liquid at room temperature and epoxy resin that is solid at room temperature. In this case, from the viewpoint of maintaining sufficiently low viscosity, the proportion of epoxy resin that is solid at room temperature is preferably less than 20% by mass of the total epoxy resin.

[0029] There are no particular restrictions on the type of hardener contained in the bottom filler material, and it can be selected according to the desired properties of the bottom filler material. Examples include amine hardeners, phenol hardeners, acid anhydride hardeners, polythiol hardeners, polyamide hardeners, isocyanate hardeners, block isocyanate hardeners, etc. One type of hardener can be used alone, or two or more can be used in combination.

[0030] The hardener used in the bottom filler material is preferably liquid at room temperature, and from the viewpoint of adhesion to the adhered material, an amine hardener is preferred. Examples of amine hardeners include aliphatic amine compounds such as diethylenetriamine, triethylenetetramine, n-propylamine, 2-hydroxyethylaminopropylamine, cyclohexylamine, and 4,4'-diamino-dicyclohexylmethane; aromatic amine compounds such as formaldehyde and 2-ethylaniline condensates such as diethyltoluenediamine, 2-methylaniline, and 3,3'-diethyl-4,4'-diaminodiphenylmethane; imidazole compounds such as imidazole, 2-methylimidazole, 2-ethylimidazole, and 2-isopropylimidazole; and imidazoleline compounds such as imidazoline, 2-methylimidazoline, and 2-ethylimidazoline. Among these, aromatic amine compounds are preferred.

[0031] From the viewpoint of minimizing unreacted components, the formulation ratio of epoxy resin and hardener is preferably set such that the ratio of the number of functional groups of the hardener (active hydrogen in the case of amine hardener) to the number of epoxy groups of the epoxy resin (number of functional groups of hardener / number of epoxy groups of epoxy resin) is in the range of 0.5 to 2.0, more preferably in the range of 0.6 to 1.3. From the viewpoint of formability and reflow resistance, it is further preferably set in the range of 0.8 to 1.2.

[0032] (Curing accelerator) The underfill material may also contain a curing accelerator. There are no particular restrictions on the type of curing accelerator, and it can be selected according to the type of curing resin component contained in the underfill material, the desired characteristics of the underfill material, etc.

[0033] When the bottom filler material contains a curing accelerator, the amount of the curing accelerator is preferably 0.1 to 30 parts by weight relative to 100 parts by weight of the curing resin component, and more preferably 1 to 15 parts by weight.

[0034] (Surface Treatment Agent) The bottom filler material may also contain a surface treatment agent. Examples of surface treatment agents include silane compounds such as epoxy silanes, phenyl silanes, mercapto silanes, amino silanes, phenylamino silanes, alkyl silanes, ureosilanes, and vinyl silanes, as well as titanium compounds, aluminum chelate compounds, and aluminum / zirconium compounds. Among these, silane compounds are preferred. A single surface treatment agent may be used, or two or more may be used in combination.

[0035] As a surface treatment agent, specifically examples include: phenyltrimethoxysilane, dimethoxydiphenylsilane, phenyltriethoxysilane, and other silane compounds containing phenyl groups; vinyltrimethoxysilane, vinyltriethoxysilane, and other silane compounds containing vinyl groups; 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, and other silane compounds containing epoxy groups; and styryltrimethoxysilane and other styryltrimethoxysilane compounds containing styrene groups. Silane compounds containing the methacryl group, such as 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, and 3-methacryloxypropyltriethoxysilane; silane compounds containing the acryloxyl group, such as 3-propenyloxypropyltrimethoxysilane. Hydrochlorides of N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N-(1,3-dimethyl-butylene)propylamine, N-phenyl-3-aminopropyltrimethoxysilane, and N-(vinylbenzyl)-2-aminoethyl-3-aminopropyltrimethoxysilane, and other silane compounds containing amino groups; 3-ureidopropyltrialkoxysilane and other silane compounds containing urea groups; 3-isocyanate-propyltriethoxysilane and other silane compounds containing isocyanate groups; Silane compounds having a mercapto group, such as 3-mercaptopropylmethyldimethoxysilane and 3-mercaptopropyltrimethoxysilane; etc. Among said silane compounds, from the viewpoint of improving the filling performance of the bottom filler material, it is preferable to include at least one selected from the group consisting of silane compounds having a phenyl group, silane compounds having an epoxy group, silane compounds having an amino group, and silane compounds having a methacrylic group.

[0036] When the bottom filler material contains a surface treatment agent, the coverage rate of the surface treatment agent on the inorganic particles, as determined by the following formula (1), is preferably 50% or more. That is, the amount of surface treatment agent contained in the bottom filler material is preferably such that the coverage rate of the surface treatment agent on the inorganic particles is 50% or more, as determined by the following formula (1). Formula (1): Coverage rate of surface treatment agent on inorganic particles (%) = (B / A) × 100

[0037] In the formula, A represents the surface area of ​​the inorganic particles contained in the bottom filling material, which is calculated using the following formula (2). When the bottom filling material contains two or more types of inorganic particles, the surface area A of the inorganic particles is the sum of the surface areas of the two or more types of inorganic particles. Formula (2): Surface area A (m 2) of inorganic particles = amount of inorganic particles (g) × specific surface area of ​​inorganic particles (m 2 / g)

[0038] In the formula, B is the coverage area of ​​the surface treatment agent on the inorganic particles, which is calculated using the following formula (3). When the bottom filling material contains two or more surface treatment agents, the coverage area B of the surface treatment agent on the inorganic particles is the sum of the coverage areas of the two or more surface treatment agents on the inorganic particles. Formula (3): Coverage area B (m 2) of surface treatment agent on inorganic particles = amount of surface treatment agent (g) × minimum coverage area of ​​surface treatment agent (m 2 / g)

[0039] In the above formula, the minimum coating area of ​​the surface treatment agent is calculated using the following formula: Minimum coating area (m² / g) = (6.02 × 10²³ × 13 × 10⁻²⁰) / molecular weight of the surface treatment agent

[0040] In the above formula, the specific surface area of ​​the inorganic particles is determined by the Brunauer-Emmett-Teller (BET) method or the image analysis method. The specific surface area of ​​the inorganic particles obtained by the BET method can be determined according to Japanese Industrial Standards (JIS) Z 8830:2013 and based on the nitrogen adsorption capacity of the inorganic particles. The specific surface area of ​​the inorganic particles obtained by the image analysis method can be calculated by assuming, in the same manner as the particle size determination, that the particles in the acquired image are spherical.

[0041] When the surface treatment agent covers 50% or more of the inorganic particles, the underfill material exhibits excellent shelf life (viscosity increase during storage is suppressed). This is believed to be because, by sufficiently coating the surface of the inorganic particles contained in the underfill material with the surface treatment agent, the reaction of the functional groups (silyl groups, etc.) on the surface of the inorganic particles is reduced, or the adhesion between the inorganic particles and the surrounding curing resin components is improved, thereby suppressing the sedimentation of the inorganic particles. The surface treatment agent coverage of the inorganic particles is preferably 60% or more, more preferably 70% or more, and even more preferably 80% or more. The surface treatment agent coverage of the inorganic particles can be 200% or less.

[0042] (Coloring agent) The bottom filler material may also contain a coloring agent. Examples of coloring agents include carbon black, organic dyes, organic pigments, red lead, iron oxide (Bengala), etc. A single coloring agent may be used, or two or more may be used in combination.

[0043] When the bottom filler material contains a colorant, the amount of colorant is preferably 0.01 to 10 parts by weight relative to 100 parts by weight of the curing resin component, and more preferably 0.1 to 5 parts by weight.

[0044] In addition to the aforementioned components, the bottom filling material may also contain various additives known in the art.

[0045] (Application of underfill material) Underfill material can be used in various mounting techniques. For example, underfill material is preferably used for sealing gaps between a substrate and an interposer disposed on the substrate, gaps between an interposer and a semiconductor element disposed on the interposer, and gaps between a substrate and a semiconductor element disposed on the substrate.

[0046] There are no particular limitations on the method of filling the gaps with bottom filler material. For example, a dispenser or similar well-known method can be used.

[0047] From the viewpoint of filling properties, the bottom filler material preferably has sufficiently low viscosity at the time of filling. Specifically, the viscosity at 110°C is preferably 0.5 Pa·s or less, more preferably 0.30 Pa·s or less, and even more preferably 0.20 Pa·s or less. The viscosity of the bottom filler material at 110°C may be 0.05 Pa·s or more.

[0048] In this disclosure, the viscosity of the bottom filler material at 110°C is a value measured by a rheometer (e.g., TA Instruments' "AR2000") on a 40 mm parallel plate under a shear rate of 32.5 / (1 / s).

[0049] From an operational point of view, the underfill material preferably has sufficiently low viscosity at room temperature. Specifically, the viscosity at 25°C is preferably below 100 Pa·s, more preferably below 80 Pa·s, and even more preferably below 70 Pa·s. The viscosity of the underfill material at 25°C may be above 5 Pa·s.

[0050] In this disclosure, the viscosity of the bottom filler material at 25°C is a value measured using the method described in the examples.

[0051] The bottom filler material disclosed herein is also preferably used for filling relatively narrow gaps. For example, it is also preferably used for filling gaps (dimensions in the thickness direction of the package) of 30 μm or less, gaps (dimensions in the direction perpendicular to the thickness direction of the package) of 40 μm or less, etc.

[0052] <Semiconductor Packaging> The semiconductor package disclosed herein includes a substrate, a semiconductor element, and a hardened form of the underfill material.

[0053] The semiconductor package may also include an interposer disposed between the substrate and the semiconductor element. In this case, the hardened underfill material is disposed, for example, at least one of the group consisting of the gap between the substrate and the interposer, and the gap between the interposer and the semiconductor element.

[0054] Specific structures for semiconductor packaging can be listed below (1) to (4). (1) A structure comprising a substrate, a semiconductor element disposed on the substrate, and a hardened form of underfill material disposed in the gap between the substrate and the semiconductor element. (2) A structure comprising a substrate, an interposer disposed on the substrate, a semiconductor element disposed on the interposer, and a hardened form of underfill material disposed in the gap between the interposer and the semiconductor element. (3) A structure comprising a substrate, an interposer disposed on the substrate, a semiconductor element disposed on the interposer, and a hardened form of underfill material disposed in the gap between the substrate and the interposer. (4) A structure comprising a substrate, an interposer disposed on the substrate, a semiconductor element disposed on the interposer, a hardened form of underfill material disposed in the gap between the interposer and the semiconductor element, and a hardened form of underfill material disposed in the gap between the substrate and the interposer.

[0055] There are no particular restrictions on the types of substrate, interposer, and semiconductor elements included in a semiconductor package; they can be selected from those commonly used in the field of semiconductor packaging. Examples of interposers include silicon interposers, glass interposers, and organic interposers. Semiconductor packages can also be in a state where semiconductor elements are arranged three-dimensionally, referred to as 2.XD (2.X-dimensional) mounting, 3D (3D) mounting, etc. Examples of 2.XD mounting include 2.1D mounting, 2.3D mounting, and 2.5D mounting.

[0056] A semiconductor package may have only the hardened form of the underfill material as the hardened form of the underfill material, or it may have the hardened form of the underfill material and the hardened form of another underfill material as the hardened form of the underfill material.

[0057] <Method for Manufacturing Semiconductor Package> The method for manufacturing a semiconductor package disclosed herein includes filling at least one of the group consisting of a gap between a substrate and a semiconductor element, a gap between a substrate and an interposer, and a gap between an interposer and a semiconductor element using the underfill material; and hardening the underfill material.

[0058] There are no particular limitations on the types of substrate, interposer, and semiconductor device used in the method, and they can be selected from those commonly used in the field of semiconductor packaging. There are no particular limitations on the method of filling the gap between the substrate or interposer and the semiconductor device with an underfill material, and on the method of hardening the underfill material after filling; known methods can be used. [Example]

[0059] Hereinafter, the bottom filling material disclosed herein will be specifically described by means of embodiments, but the scope of the disclosure is not limited to these embodiments.

[0060] (Preparation of bottom filler material) The bottom filler material is prepared by mixing the components shown in Table 1 in the amounts (parts by mass) shown in Table 1. Details of each component are as follows.

[0061] Epoxy Resin 1…Liquid bisphenol F type epoxy resin, epoxy equivalent: 160 g / eq; Epoxy Resin 2…Triglycidyl-p-aminophenol, epoxy equivalent: 95 g / eq; Curing Agent 1…Curing agent containing diethyltoluenediamine, liquid at room temperature, active hydrogen equivalent: 45 g / eq; Curing Agent 2…Curing agent containing 3,3'-diethyl-4,4'-diaminodiphenylmethane, liquid at room temperature, active hydrogen equivalent: 63 g / eq; Colorant…Carbon black, average particle size: 24 nm; Surface Treatment Agent 1…3-glycidyloxypropyltrimethoxysilane, minimum coating area: 330 m² / g; Surface Treatment Agent 2…Phenylacetyltrimethoxysilane, minimum coating area: 393 m² / g

[0062] Inorganic particles 1…Spherical silica inorganic particles with a volume average particle size of 1.0 μm and a specific surface area of ​​3 m² / g 2…Spherical silica inorganic particles with a volume average particle size of 1.0 μm and a specific surface area of ​​3 m² / g 3…Spherical silica inorganic particles with a volume average particle size of 0.5 μm and a specific surface area of ​​5 m² / g 4…Spherical silica inorganic particles with a volume average particle size of 1.4 μm and a specific surface area of ​​4 m² / g 5…Spherical silica inorganic particles with a volume average particle size of 0.5 μm and a specific surface area of ​​5 m² / g 6…Spherical silica with a volume average particle size of 0.4 μm and a specific surface area of ​​7 m² / g

[0063] [Table 1] unit Example Comparative example 1 2 3 4 5 6 7 8 9 10 11 1 2 3 4 Epoxy Resin 1 Quality 50 50 50 50 50 50 50 50 50 50 50 50 50 50 50 Epoxy Resin 2 Quality 50 50 50 50 50 50 50 50 50 50 50 50 50 50 50 Hardener 1 Quality 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 Hardener 2 Quality 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 Colorant Quality 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 Surface treatment agent 1 Quality 0.3 0.7 1.3 1.7 2.2 3.2 2.2 1.00 1.00 1.00 Surface treatment agent 2 Quality 0.3 1.3 3.2 2.2 Inorganic particles 1 Quality 219 219 221 221 219 221 219 221 221 Inorganic particles 2 Quality 219 219 Inorganic particles 3 Quality 219 Inorganic Particles 4 Quality 219 Inorganic particles 5 Quality 219 Inorganic Particles 6 Quality 219 The proportion of inorganic particles with a diameter of less than 0.5 μm % 0 0 0 0 0 0 0 0 0 2 2 30 5 28 95 The proportion of inorganic particles with a diameter of 3 μm or larger % 0 0 0 0 0 0 0 0 0 0 0 0 11 0 0 Surface area A of inorganic particles m 2 657 657 663 663 657 663 657 663 663 657 657 1095 876 1095 1533 Coverage area B m 2 103 232 434 564 723 1059 123 517 1262 723 861 330 330 330 - coverage rate % 16 35 65 85 110 160 19 78 190 110 131 30 38 30 - Viscosity (25℃, 0h) Pa·s 44 35 32 31 35 33 38 27 19 twenty four 34 15 8 13 11 Applicable period % 641 163 32 35 54 32 778 44 62 26 75 33 28 36 300 Fill time sec 109 107 85 120 100 106 97 83 92 94 69 124 95 134 stop Narrow-pitch fill - OK OK OK OK OK OK OK OK OK OK OK NG NG OK OK

[0064] (Observation using a scanning electron microscope) The prepared bottom filler material was heated at 800°C for 4 hours, and the ash content was observed using a scanning electron microscope (magnification: 5,000x). Based on the obtained images, the ratio of the number of inorganic particles with a particle size of 0.5 μm or less to the ratio of the number of inorganic particles with a particle size of 3 μm or more were determined. The results are shown in Table 1. The ash content of the bottom filler material obtained in Example 1 is shown in Figure 1, the ash content of the bottom filler material obtained in Example 10 is shown in Figure 2, the ash content of the bottom filler material obtained in Comparative Example 1 is shown in Figure 3, the ash content of the bottom filler material obtained in Comparative Example 2 is shown in Figure 4, the ash content of the bottom filler material obtained in Comparative Example 3 is shown in Figure 5, and the ash content of the bottom filler material obtained in Comparative Example 4 is shown in Figure 6.

[0065] (Viscosity Measurement) The viscosity (Pa·s) at 25°C was measured immediately after the preparation of the bottom filler material and after the bottom filler material was placed at 25°C for 24 hours. The measurement was performed using an E-type viscometer (manufactured by Tokyo Keiki Co., Ltd., VISCONIC EHD type (trade name)), with the cone angle set to 3° and the rotation speed set to 10 revolutions per minute (rpm).

[0066] (Evaluation of Pot Life) Based on the viscosity A measured immediately after the bottom filler material is prepared, and the viscosity B after being left at 25°C for 24 hours, the pot life (the rate of viscosity increase after 24 hours) is calculated using the following formula: Pot Life (%) = {(BA) / A} × 100

[0067] (Filling Time) A glass plate (20 mm × 30 mm × 1 mm thick) was fixed to a glass slide using spacers to prepare a test piece with a gap of 25 μm. Underfill material was applied to one side (one of the 20 mm edges) of the glass plate on a heated plate at 110°C. The time (in seconds) it took for the underfill material to penetrate between the glass slide and the glass plate and reach the opposite side of the glass plate was measured. The shorter the time until it reaches the opposite side, the better the filling performance. "Stop" in Table 1 means that the underfill material has not reached the opposite side of the glass plate.

[0068] (Narrow Pitch Filling Performance) A test element group (TEG, size: 20 mm × 20 mm, bump diameter: 23 μm) with copper pillar bumps was fixed onto a glass slide to prepare a test piece with a gap of 17 μm and a pitch of 30 μm. Underfill material was applied to one side (one of the 20 mm edges) of the TEG on a heated plate at 110°C. The narrow pitch filling performance of the underfill material was evaluated according to the following criteria: OK: The underfill material reached the opposite side of the TEG. NG: The underfill material did not reach the opposite side of the TEG.

[0069] As shown in Table 1, the underfill materials of the embodiments in which the proportion of particles with a diameter of 0.5 μm or less was less than 10% of the total number of inorganic particles, and the proportion of particles with a diameter of 3 μm or more was less than 5% of the total number of inorganic particles, showed good results in both filling time and narrow-pitch filling performance. In the embodiments, Examples 3 to 6 and Examples 8 to 11, where the surface treatment agent coverage of inorganic particles was 50% or more, showed excellent pot life compared to Examples 1, 2, and 7, where the surface treatment agent coverage of inorganic particles was less than 50%. The underfill materials of the comparative examples in which the proportion of particles with a diameter of 0.5 μm or less exceeded 10% of the total number of inorganic particles, or the proportion of particles with a diameter of 3 μm or more exceeded 5% of the total number of inorganic particles, had lower evaluations in either or both of filling time and narrow-pitch filling performance than the embodiments. [Simplified Explanation of the Diagram]

[0008] Figure 1 is a scanning electron microscope (SEM) image of the ash content of the bottom filling material obtained in Example 1. Figure 2 is a SEM image of the ash content of the bottom filling material obtained in Example 10. Figure 3 is a SEM image of the ash content of the bottom filling material obtained in Comparative Example 1. Figure 4 is a SEM image of the ash content of the bottom filling material obtained in Comparative Example 2. Figure 5 is a SEM image of the ash content of the bottom filling material obtained in Comparative Example 3. Figure 6 is a SEM image of the ash content of the bottom filling material obtained in Comparative Example 4.

Claims

1. A bottom filler material comprising a curable resin component and inorganic particles, wherein the inorganic particles contain particles with a particle size of 0.5 μm or less in a proportion of less than 10% of the total number of inorganic particles, and particles with a particle size of 3 μm or more in a proportion of less than 5% of the total number of inorganic particles.

2. The bottom filler material as described in claim 1, wherein, The curable resin component includes epoxy resin.

3. The bottom filler material as described in claim 2, wherein, The epoxy resin comprises at least one selected from the group consisting of bisphenol type epoxy resins, naphthalene type epoxy resins, and glycidylamine type epoxy resins with trifunctionality or higher.

4. The bottom filler material as claimed in any one of claims 1 to 3, comprising a surface treatment agent, wherein the surface treatment agent has a coverage rate of more than 50% for the inorganic particles.

5. A semiconductor package comprising a substrate, a semiconductor element, and a hardened form of an underfill material as claimed in any one of claims 1 to 4.

6. The semiconductor package as described in claim 5, wherein, The hardened material is disposed in the gap between the substrate and the semiconductor element.

7. The semiconductor package as claimed in claim 5 further includes an interposer disposed between the substrate and the semiconductor element.

8. The semiconductor package as described in claim 7, wherein, The hardener is disposed in at least one of the group consisting of the gap between the substrate and the interposer, and the gap between the interposer and the semiconductor element.

9. A method of manufacturing a semiconductor package, comprising filling at least one selected from the group consisting of a gap between a substrate and a semiconductor element, a gap between a substrate and an interposer, and a gap between an interposer and a semiconductor element, using an underfill material as described in any one of claims 1 to 4; and hardening the underfill material.

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