Resin composition for sealing semiconductor and semiconductor device

Abstract

A semiconductor sealing resin composition comprising (A) at least one thermosetting resin selected from the group consisting of epoxy resin and dicis-butenediamide resin, (B) a curing agent, (C) an inorganic filler, and (D) a dispersant, wherein the semiconductor sealing resin composition, under conditions of mold temperature of 175°C and injection speed of 178 mm³ / s, has a minimum melt viscosity of 1 mPa·s or more and 68000 mPa·s or less, as measured by a slit-type viscosity measuring device having a rectangular flow path with a width W of 15 mm, a thickness D of 1 mm, and a length of 175 mm, and is in granular form.

Description

Technical Field

[0001] []

[0002] The present invention relates to a resin composition for sealing semiconductors and a semiconductor device having a semiconductor element sealed by the resin composition. Prior Technology

[0003] []

[0004] In recent years, with the high-density mounting of electronic components on printed circuit boards, semiconductor devices have shifted from the previously commonly used pin-type packages to surface-mount packages as the mainstream. Surface-mount ICs and LSIs have become thin and small packages with high mounting density, and the volume occupied by the components relative to the package has also increased, while the package wall thickness has become very thin. Furthermore, the increasing multifunctionality and capacity of components has led to an increase in chip area and pin count. Consequently, the increase in the number of pads has also led to a reduction in pad pitch and pad size, i.e., narrow pad pitch.

[0005] However, it is not possible to achieve the same narrow electrode spacing as the semiconductor device itself on the substrate on which the semiconductor device is mounted. Therefore, multi-terminal configurations are achieved by extending the length of the wires extending from the semiconductor device or by twisting the wires. However, if the wires become thinner, they are easily washed away during the subsequent resin sealing step due to the resin injection pressure. This tendency is particularly pronounced in side-gate configurations.

[0006] Therefore, compression molding has gradually become the preferred method for sealing electronic components such as semiconductor wafers with resin. In compression molding, a granular resin composition is supplied in a manner that faces the object to be sealed (e.g., a substrate on which electronic components such as semiconductor wafers are disposed) held in a mold, and the object to be sealed and the granular resin composition are compressed to achieve resin sealing.

[0007] In this compression molding method, the molten granular resin flows in a direction roughly parallel to the main surface of the object being sealed, thus reducing the flow rate and minimizing deformation or damage to the sealed object caused by resin flow. It is particularly effective in reducing wire sweep, a phenomenon known as wire slippage caused by resin flow in wire bonding wiring and similar applications.

[0008] As a sealing material used in compression molding, for example, there is a resin composition as described in Patent Document 1. Patent Document 1 describes a particulate epoxy resin composition containing epoxy resin, a hardener, a hardening accelerator, an inorganic filler, a fatty acid with a melting point of 70°C or less, and a silane coupling agent with a boiling point of 200°C or more, which improves the solubility of the resin composition during sealing and improves the demolding properties after sealing. Previous technical documents Patent documents

[0009] Patent Document 1: Japanese Patent Application Publication No. 2011-153173 Summary of the Invention

[0010] [The problem that the invention aims to solve]

[0011] However, the inventors' research revealed that the resin composition described in Patent Document 1 cannot properly seal semiconductor elements, for example, the sealing material is not sufficiently filled.

[0012] The present invention was made in view of this reality, and its object is to provide a semiconductor sealing resin composition that can improve the fusibility during semiconductor sealing and can properly seal a semiconductor element mounted on a substrate by compression molding. Furthermore, the object is to provide a semiconductor device in which the semiconductor element is sealed by the aforementioned semiconductor sealing resin composition and possesses excellent reliability. [Technical means to solve the problem]

[0013] The inventors focused on the following situation: when sealing semiconductor elements by compression molding, the resin composition used as the sealing material hardly flows; furthermore, in order to sufficiently improve filling performance and prevent unfilled portions, the resin composition needs to be fully melted during sealing. The inventors discovered that by setting a specific formulation of the semiconductor sealing resin composition containing inorganic fillers, or by setting a specific formulation and setting its melt viscosity to a specific value, the inorganic fillers are highly dispersed. As a result, the solubility of the sealing resin composition is improved, which can suppress wire misalignment during sealing, thus completing the present invention.

[0014] According to the present invention, a resin composition for semiconductor sealing comprises: (A) Selected from at least one thermosetting resin from the group consisting of epoxy resin and bis(cis-butenediamide)imide resin; (B) Hardener; (C) Inorganic fillers; and (D) Dispersants, The lowest melt viscosity ηmin of the resin composition for semiconductor sealing, measured under the following <melt viscosity measurement conditions>, is 1 mPa·s or higher and 68000 mPa·s or lower. And it is granular. <Melt viscosity measurement conditions> Under conditions of mold temperature: 175℃, injection speed Q: 178 mm³ / s, a slit-type viscosity measuring device with a rectangular flow path of width W: 15 mm, thickness D: 1 mm, and length: 175 mm was used for measurement. The lowest melt viscosity 5 seconds after the start of the melt viscosity measurement was set as ηmin.

[0015] According to the present invention, a resin composition for semiconductor sealing is provided, comprising: (A) Epoxy resin; (B) Hardener; (C) Inorganic fillers; and (D) Dispersants, The aforementioned epoxy resin (A) includes, selected from, biphenyl-type epoxy resin, bisphenol-type epoxy resin, arsenic-type epoxy resin, phenolic varnish-type epoxy resin, phenolic varnish-type epoxy resin, multifunctional epoxy resin, phenolic aralkyl-type epoxy resin, naphthol-type epoxy resin, and epoxy resin containing triphenylene oxide. At least one of the following groups: nuclear epoxy resin, phenolic epoxy resin modified with bridged cyclic hydrocarbon compounds, The aforementioned dispersant (D) is a high-molecular-weight ionic dispersant with polycarboxylic acids as the main backbone. The amount of the aforementioned dispersant (D) is 0.01% by mass or more and 5.0% by mass or less relative to the total resin composition. The semiconductor sealing resin composition of this embodiment can be any shape, such as ingot, sheet, or granules.

[0016] Furthermore, according to the present invention, a semiconductor device is provided, comprising: Semiconductor devices mounted on a substrate; and Among the sealing components that seal the aforementioned semiconductor elements, The aforementioned sealing member is composed of a hardened form of the aforementioned semiconductor sealing resin composition. [Effects of the Invention]

[0017] According to the present invention, a semiconductor sealing resin composition is provided that can properly seal a semiconductor element mounted on a substrate by compression molding. [] Simple Explanation of the Diagram

[0018] []

[0019] [Figure 1] is a cross-sectional view of a semiconductor device obtained by sealing a semiconductor element mounted on a lead frame using the resin composition of this embodiment. [Figure 2] is a cross-sectional view of a semiconductor device obtained by sealing a semiconductor element mounted on a circuit board using the resin composition of this embodiment. [] Implementation

[0020] []

[0021] Hereinafter, embodiments of the present invention will be described using drawings. Furthermore, in all drawings, the same symbols are used to denote the same constituent elements, and descriptions are omitted where appropriate.

[0022] (First Implementation) The resin composition for semiconductor sealing in the first embodiment is in particulate form (hereinafter referred to as "particulate resin composition" or simply "resin composition"). The particulate resin composition of this embodiment comprises (A) at least one thermosetting resin selected from the group consisting of epoxy resin and dicis-butenediamine resin, (B) a curing agent, (C) an inorganic filler, and (D) a dispersant. Furthermore, the particulate resin composition of this embodiment has a minimum melt viscosity of 1 mPa·s or more and 68,000 mPa·s or less.

[0023] The particulate resin composition of this embodiment improves the dispersibility of inorganic fillers by including a dispersant and has low melt viscosity. As a result, when using this resin composition to seal semiconductor devices mounted on a substrate by compression molding, wire misalignment or wire deformation can be reduced. Furthermore, because this particulate resin composition has good flowability in the molten state, it does not create unfilled areas on the semiconductor device and can effectively seal the semiconductor device.

[0024] The particulate resin composition in this embodiment will be described below.

[0025] In this embodiment, the particulate resin composition preferably comprises at least 85% by mass of particles within the particle size range of 100 μm to 3 mm. If there are too many particles outside this range, the semiconductor device may not be properly sealed by compression molding. Specifically, for example, if there are too many resin components with excessively small particle sizes, these small-sized components will preferentially melt, and the resin composition used as a sealing material will not melt uniformly during compression molding, thus failing to properly seal the semiconductor device. Furthermore, if there are too many resin components with excessively large particle sizes, these small-sized components are difficult to melt, and unmelted particulate resin components remain in the molten resin composition during compression molding, thus failing to properly seal the semiconductor device. Additionally, the particle size distribution of the particulate resin composition can be measured using a general particle size analyzer. Alternatively, the particulate resin composition can be sieved using sieves of various pore sizes stacked in ascending order of pore size, and the mass of particles remaining on each sieve can be calculated.

[0026] The following examples illustrate the components used in particulate resin compositions used as sealing materials. The melt viscosity of the particulate resin composition can be set to a target value by adjusting the types or amounts of the components used.

[0027] (Thermosetting resin (A)) The thermosetting resin (A) used in the particulate resin composition of this embodiment includes at least one selected from epoxy resin and dicis-butene diimide resin.

[0028] As epoxy resins, any monomer, oligomer, or polymer having two or more epoxy groups within a single molecule can be used, and their molecular weight or molecular structure is not limited. Examples of epoxy resins include biphenyl-type epoxy resins; bisphenol-type epoxy resins such as bisphenol A-type epoxy resin, bisphenol F-type epoxy resin, and tetramethylbisphenol F-type epoxy resin; phenolic epoxy resins; phenolic varnish-type epoxy resins such as phenolic varnish-type epoxy resin and cresol phenolic varnish-type epoxy resin; multifunctional epoxy resins such as triphenol-type epoxy resins and alkyl-modified triphenol-type epoxy resins; and epoxy resins with an extended phenyl backbone. Phenolic aralkyl type epoxy resins, naphthol aralkyl type epoxy resins with an extended phenyl backbone, phenolic aralkyl type epoxy resins with a syn-extrinsic phenyl backbone, and naphthol aralkyl type epoxy resins with a syn-extrinsic phenyl backbone, etc.; dihydroxynaphthalene type epoxy resins, epoxy resins obtained by glycidylating dihydroxynaphthalene dimers, etc.; trihydroxynaphthalene type epoxy resins, etc. containing trihydroxynaphthalene. Triazine-nucleus-containing epoxy resin; dicyclopentadiene-modified phenolic epoxy resin, and other phenolic epoxy resins modified with bridged cyclic hydrocarbon compounds. These can be used alone or in combination of two or more.

[0029] From the viewpoint of suppressing warpage of molded articles obtained by curing particulate resin compositions or balancing various properties such as filling properties, heat resistance, and moisture resistance, phenolic varnish-type epoxy resins, multifunctional epoxy resins, and phenolic aralkyl-type epoxy resins are preferred. Furthermore, from the same viewpoint, the epoxy resin preferably comprises one or more of the group consisting of o-cresol phenolic varnish-type epoxy resins, phenolic aralkyl-type epoxy resins having a phenyl backbone, and triphenylmethane-type epoxy resins; more preferably, it comprises one or more of the group consisting of o-cresol phenolic varnish-type epoxy resins and phenolic aralkyl-type epoxy resins having a phenyl backbone.

[0030] The bis(cis-butene diimide) resin used as a thermosetting resin (A) is a (co)polymer of compounds having two or more cis-butene diimide groups. Compounds having two or more maleic diamide groups include, for example, at least one of the compounds represented by general formula (1) and general formula (2) below. This allows for an increase in the glass transition temperature of the cured particulate resin composition, thereby more effectively improving the heat resistance of the cured composition.

[0031]

[0032] In the above general formula (1), R1 is a divalent organic group with 1 or more carbon atoms and less than 30 carbon atoms, and may contain one or more of oxygen and nitrogen atoms. From the viewpoint of improving the heat resistance of the cured material, it is more preferable that R1 is an organic group containing an aromatic ring. In this embodiment, R1 may be exemplified, for example, by a structure such as the following general formula (1a) or (1b).

[0033]

[0034] In the above general formula (1a), R31 is a divalent organic group that may contain one or more oxygen atoms and nitrogen atoms and has 1 or more carbon atoms and less than 18 carbon atoms. Furthermore, each of the plurality of R32 is independently a hydrogen atom or a substituted or unsubstituted hydrocarbon group that has 1 or more carbon atoms and less than 4 carbon atoms.

[0035]

[0036] In the above general formula (1b), multiple Rs exist independently, where R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a phenyl group, preferably a hydrogen atom. Furthermore, m is an average value, and is a number greater than 1 and less than 5, preferably greater than 1 and less than 5, more preferably greater than 1 and less than 3, and even more preferably greater than 1 and less than 2.

[0037] As for compounds represented by the above general formula (1) that are applicable in this embodiment, for example, compounds represented by the following formulas (1-1) to (1-3) can be cited.

[0038]

[0039] In the above general formula (2), each of the multiple R2s is independently a hydrogen atom or a substituted or unsubstituted hydrocarbon group with 1 or more carbon atoms and 4 or fewer carbon atoms. n is an average value, and is a number between 0 and 10, preferably a number between 0 and 5.

[0040] Furthermore, the thermosetting resin (A) may further include thermosetting resins other than epoxy resins and dicis-butenediamide resins. Examples of such thermosetting resins include one or more selected from the group consisting of benzoxazine resins, phenolic resins, urea resins, melamine resins, unsaturated polyester resins, polyurethane resins, diallyl phthalate resins, polysiloxane resins, cyanate ester resins, polyimide resins, polyamide-imide resins, and phenylcyclobutene resins.

[0041] The content of thermosetting resin (A) relative to the total resin composition is preferably 2% by mass or more, and more preferably 4% by mass or more. If the lower limit of the blending ratio is within the above range, the reduction in fluidity during the sealing process is less likely to occur. Furthermore, the upper limit of the blending ratio relative to the total resin composition is not particularly limited, but is preferably 22% by mass or less, and more preferably 20% by mass or less. If the upper limit of the blending ratio is within the above range, the glass transition temperature of the resin composition is slightly reduced, and mutual adhesion can be appropriately suppressed. Moreover, in order to improve fluidity and fusibility, it is desirable to appropriately adjust the blending ratio according to the type of epoxy resin used.

[0042] In this embodiment, the content of any component relative to the total content of the resin composition refers to the content of the solid components in the resin composition other than the solvent, when the resin composition contains a solvent. The solid components of the resin composition refer to the non-volatile components in the resin composition, and specifically to the remainder excluding volatile components such as water and solvents.

[0043] (hardener (B)) The curing agent (B) used in the resin composition of this embodiment can be broadly classified into three categories, such as addition molding curing agents, catalyst-type curing agents, and polyaddition molding curing agents. These can be used alone or in combination of two or more.

[0044] Additive molding curing agents, in addition to aliphatic polyamines such as diethylenetriamine (DETA), triethylenetetramine (TETA), and meta-diamine (MXDA), and aromatic polyamines such as diaminodiphenylmethane (DDM), meta-phenylenediamine (MPDA), and diaminodiphenyl ether (DDS), also include one or more of the following: polyamine compounds including dicyandiamine (DICY) and organic acid diacetylhydrazine; polyamine compounds including hexahydrophthalic anhydride (HHPA) and methyltetrahydrophthalic anhydride; and polyamine compounds including dicyandiamine (DICY) and diacetylhydrazine (MXDA). Anhydrides such as alicyclic anhydrides (MTHPA), aromatic anhydrides such as 1,2,4-benzenetricarboxylic anhydride (TMA), pyrolithic anhydride (PMDA), and diphenyl ketone tetracarboxylic acid (BTDA); phenolic resin curing agents such as phenolic varnish-type phenolic resins, polyvinylphenol, and aralkyl-type phenolic resins; polysulfides, thioesters, thioethers, and other polythiolactic acid compounds; isocyanate compounds such as isocyanate prepolymers and capped isocyanates; and organic acids such as carboxylic acid-containing polyester resins.

[0045] Catalytic curing agents include, for example, one or more of the group consisting of tertiary amine compounds selected from benzyl dimethylamine (BDMA), 2,4,6-tris(dimethylaminomethylphenol) (DMP-30); imidazole compounds such as 2-methylimidazole and 2-ethyl-4-methylimidazole (EMI24); and Lewis acids such as BF3 complexes.

[0046] Polyaddition molding curing agents include, for example, one or more of the group consisting of soluble phenolic resins; urea resins such as hydroxymethyl urea resins; and melamine resins such as hydroxymethyl melamine resins.

[0047] Among these, from the viewpoint of improving the balance of flame retardancy, moisture resistance, electrical properties, curing properties, and storage stability of the obtained resin composition, phenolic resin-based curing agents are preferred. As phenolic resin-based curing agents, monomers, oligomers, and polymers having two or more phenolic hydroxyl groups within one molecule can be used, and their molecular weight and molecular structure are not limited.

[0048] Phenolic resin curing agents include, for example, phenolic varnish-type phenolic resins selected from phenol-formaldehyde resins, cresol-formaldehyde varnish resins, bisphenol-formaldehyde varnish resins, etc.; multifunctional phenolic resins such as polyvinylphenol and triphenylmethane-type phenolic resins; modified phenolic resins such as terpene-modified phenolic resins and dicyclopentadiene-modified phenolic resins; phenolic aralkyl resins having an extended phenyl backbone and / or a biphenyl backbone, naphthol aralkyl resins having an extended phenyl backbone, etc.; and one or more of the group consisting of bisphenol compounds such as bisphenol A and bisphenol F. Among these, from the viewpoint of suppressing warping of the molded article, phenolic varnish-type phenolic resins, multifunctional phenolic resins, and phenolic aralkyl-type phenolic resins are more preferably included. Furthermore, phenol-formaldehyde resins, phenolic aralkyl resins having a biphenyl backbone, and formaldehyde-modified triphenylmethane-type phenolic resins are also preferred.

[0049] The lower limit of the blending ratio of the hardener (B) relative to the total resin composition is preferably 2% by mass or more, and more preferably 3% by mass or more. Sufficient fluidity can be obtained if the lower limit of the blending ratio is within the above range. Furthermore, the upper limit of the blending ratio of the hardener relative to the total resin composition is preferably 16% by mass or less, and more preferably 15% by mass or less. Mutual adhesion can be appropriately suppressed if the upper limit of the blending ratio is within the above range. Moreover, in order to improve fluidity and meltability, it is desirable to appropriately adjust the blending ratio according to the type of hardener used.

[0050] (Inorganic packing (C)) The inorganic filler (C) used in the resin composition of this embodiment can include molten silica such as fused silica and molten spherical silica; crystalline silica and amorphous silica; silica; aluminum oxide; aluminum hydroxide; silicon nitride; and aluminum nitride. One of these can be used alone, or two or more can be used in combination. The particle shape is preferably true spherical, and by mixing particles of different sizes, the filler content can be increased. Furthermore, to improve the solubility of the resin composition, silica or aluminum oxide is preferred; as silica, molten spherical silica is preferred.

[0051] The content of inorganic filler (C) relative to the total resin composition is preferably 80.0% by mass or more and 97.0% by mass or less. If the content of inorganic filler is too low, the heat resistance of the cured resin composition tends to decrease, resulting in a decrease in the reliability of the obtained semiconductor device. Conversely, if the content of inorganic filler is high, the heat resistance of the cured resin composition is improved, resulting in a higher reliability of the obtained semiconductor device. However, as the content of inorganic filler increases, the solubility of the resin composition generally decreases, in other words, it becomes difficult to melt, and there is a tendency for wire misalignment to occur. In this embodiment, by including the dispersant described later, the heat resistance and other properties of the cured resin composition are maintained, and the solubility of the resin composition is improved, thereby suppressing the occurrence of wire misalignment.

[0052] (Dispersant (D)) The dispersant (D) used in the resin composition of this embodiment can be a high molecular weight ionic dispersant with a polycarboxylic acid backbone. Preferably, the high molecular weight ionic dispersant has a carboxyl group that functions as an adsorbent group for inorganic fillers and a site compatible with the aforementioned thermosetting resin.

[0053] Examples of such polymeric ionic dispersants include ARON A-6330 (manufactured by TOAGOSEI CO.,LTD., trade name), Hypermer KD-4, Hypermer KD8, Hypermer KD-9, and Hypermer KD-57 (manufactured by Croda Japan KK., trade name). Among these, the polymeric ionic dispersant represented by the formula (3) below is preferred. Specifically, examples include Hypermer KD-4, Hypermer KD-8, and Hypermer KD-9 (manufactured by Croda Japan KK., trade name).

[0054] (In formula (3), p and m represent the number of repeating units, p is an integer from 1 to 20, m is an integer from 1 to 5, and R3 is an alkyl group with 1 to 10 carbon atoms that can have substituents).

[0055] The polymeric ionic dispersant represented by formula (3) has carboxyl groups that adsorb onto the inorganic filler and large-volume aliphatic groups that are compatible with the aforementioned thermosetting resin. Through the adsorption of this polymeric ionic dispersant onto the inorganic filler, the inorganic filler is highly dispersed in the thermosetting resin (A). Furthermore, the steric hindrance between the large-volume aliphatic groups of the polymeric ionic dispersant inhibits the aggregation of the inorganic filler. As a result, the inorganic filler does not aggregate in the thermosetting resin (A) and remains highly dispersed.

[0056] The dispersant (D) is preferably used in an amount of 0.01% by mass or more and 5.0% by mass or less relative to the total resin composition, more preferably in an amount of 0.1% by mass or more and 2.0% by mass or less, and even more preferably in an amount of 0.2% by mass or more and 1.5% by mass or less. By incorporating the dispersant (D) in the above-mentioned amounts, the inorganic filler can be highly dispersed in the resin composition.

[0057] (Curing accelerator (E)) The resin composition of this embodiment may include a curing accelerator (E). As a curing accelerator (E), any agent capable of promoting the curing reaction between the thermosetting resin (A) and the curing agent (B) can be used without particular limitation. Examples include imidazoles such as 2-methylimidazole and 2-phenylimidazole, organophosphorus compounds such as triphenylphosphine, tributylphosphine, and trimethylphosphine, tertiary amines such as 1,8-diaza-bicyclo(5,4,0)undecene-7 (DBU), triethanolamine, and benzyldimethylamine. These agents can be used alone or in combination of two or more.

[0058] The content of the curing accelerator (E) relative to the total amount of thermosetting resin (A) and curing agent (B) is preferably 0.1% by mass or more and 2% by mass or less. If the content of the curing accelerator is less than the lower limit mentioned above, there is a tendency that the curing accelerating effect cannot be improved. Furthermore, if it is greater than the upper limit mentioned above, there is a tendency that the flowability or formability will be poor, and there is also a possibility that the manufacturing cost will increase. (Coupling agent) The resin composition of this embodiment may contain a silane coupling agent. A silane coupling agent can be used. Examples of silane coupling agents include vinyl silanes such as vinyltris(β-methoxyethoxy)silane, vinylethoxysilane, and vinyltrimethoxysilane; (meth)acrylate silanes such as γ-methacrylic acid propyltrimethoxysilane; β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane; β-(3,4-epoxycyclohexyl)methyltrimethoxysilane; β-(3,4-epoxycyclohexyl)ethyltriethoxysilane; β-(3,4-epoxycyclohexyl)methyltriethoxysilane; γ-epoxypropoxypropyltrimethoxysilane; and γ-epoxypropoxy... Epoxysilanes such as propyltriethoxysilane, N-β(aminoethyl)γ-aminopropyltrimethoxysilane, N-β(aminoethyl)γ-aminopropyltriethoxysilane, N-β(aminoethyl)γ-aminopropylmethyldiethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, N-phenyl-γ-aminopropyltriethoxysilane, and other aminosilanes, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, and other thiosilanes, etc.

[0059] The coupling agent is preferably used in an amount of 0.01% by mass or more and 1.0% by mass or less relative to the total resin composition, more preferably in an amount of 0.05% by mass or more and 0.9% by mass or less, and even more preferably in an amount of 0.08% by mass or more and 0.8% by mass or less. By incorporating the coupling agent in amounts within the above range, both the solubility and migration resistance of the obtained resin composition can be improved.

[0060] (Other additives) In addition to the components described above, conventionally known additives, such as flame retardants, colorants, polysiloxane flexible agents, and ion traps, may be used in the resin composition of this embodiment, as needed, without impairing the properties desired for the purposes of this invention.

[0061] The characteristics of the particulate resin composition in this embodiment will be described.

[0062] In this embodiment, the upper limit of the minimum melt viscosity ηmin measured by the slit-type viscosity measuring device is preferably 68,000 mPa·s or less, more preferably 60,000 mPa·s or less, further preferably 50,000 mPa·s or less, and most preferably 40,000 mPa·s or less. This improves the filling properties of the sealing material. The lower limit of the minimum melt viscosity ηmin measured by the slit-type viscosity measuring device is not particularly limited, for example, it is 1 mPa·s or more, preferably 50 mPa·s or more.

[0063] In this embodiment, the upper limit of the time t1 at which the lowest melt viscosity ηmin, as measured by the slit viscometer, is reached is preferably 15 seconds or less, more preferably 12 seconds or less, and most preferably 10 seconds or less. This improves the filling properties of the sealing material. The lower limit of the time t1 at which the lowest melt viscosity ηmin, as measured by the slit viscometer, is not particularly limited, and is, for example, 5 seconds or more. Furthermore, when t2 is defined as the moment when the melt viscosity increases to (ηmin + 1000) (mPa·s) or higher after reaching ηmin, the lower limit of t2-t1 is preferably 1 second or more. The upper limit of t2-t1 is preferably 30 seconds or less, more preferably 25 seconds or less, and most preferably 20 seconds or less. By setting t2-t1 above the above lower limit, the pot-life of the resin composition can be fully utilized, and the filling properties of the sealant can be improved. Furthermore, by setting t2-t1 below the above upper limit, uneven hardening can be suppressed, and the molding cycle can be extended, thereby preventing a decrease in manufacturing efficiency.

[0064] In this embodiment, when a resin composition is added to an aluminum cup and heated at 175°C for 3 minutes, the hardened resin composition is removed from the aluminum cup. The area of ​​the contact portion where the molten resin composition melts and diffuses on the bottom surface of the aluminum cup is defined as A1, and the area of ​​the gap portion where the molten resin composition does not contact the bottom surface of the aluminum cup is defined as A2. The fusibility (filling rate (%)) represented by ((A1 / (A1+A2))×100) is preferably 30% or more and 100% or less. This improves the filling properties of the sealing material and enables the acquisition of stable hardened properties.

[0065] (Manufacturing of particulate resin composition) As for the method for preparing the granular resin composition of this embodiment, it is not particularly limited as long as it can produce particles containing the above-mentioned components and having a particle size distribution within the range described above. Specifically, it can be manufactured, for example, in the following manner. First, the above-mentioned components and additives as needed are uniformly mixed to a predetermined content using a mixer or blender such as a tumbler mixer or a Henschel mixer. Then, the mixture is kneaded while heated using a kneader, roller, disperser, vacuum emulsifier, or planetary mixer. In addition, the temperature during kneading needs to be within a temperature range that does not produce a hardening reaction, and it also depends on the composition of the epoxy resin and the hardener, but it is preferable to perform melt kneading at around 70 to 150°C. After kneading, the mixture is cooled and cured, and the cured mixture is pulverized using a pulverizer or the like. In this way, a granular resin composition can be produced. Then, the resin composition can be sieved to make the particle size distribution within the range described above.

[0066] (use) The particulate resin composition of this embodiment is used as a sealing material for sealing semiconductor components mounted on lead frames or circuit boards using compression molding.

[0067] The semiconductor device will now be described in detail using drawings, but the present invention is not limited to the use of bonding wires. The semiconductor device includes: a lead frame or circuit board, one or more semiconductor elements stacked or mounted side by side on the lead frame or circuit board, bonding wires that electrically connect the lead frame or circuit board and the semiconductor elements, and sealing material that seals the semiconductor elements and bonding wires.

[0068] Figure 1 is a cross-sectional view showing an example of a semiconductor device obtained by sealing a semiconductor element mounted on a leadframe using a resin composition of this embodiment. A semiconductor element 401 is fixed to a die pad 403 via a die bond material hardener 402. The electrode pads of the semiconductor element 401 are connected to the leadframe 405 by wires 404. The semiconductor element 401 is sealed by a sealing material 406 made of a hardener of the resin composition of this embodiment.

[0069] Figure 2 is a cross-sectional view showing an example of a semiconductor device obtained by sealing a semiconductor element mounted on a circuit board using the resin composition of this embodiment. A semiconductor element 401 is fixed to the circuit board 408 via a die-attach material hardener 402. The electrode pads 407 of the semiconductor element 401 are connected to the electrode pads 407 on the circuit board 408 by wires 404. The surface of the circuit board 408 where the semiconductor element 401 is mounted is sealed using a sealing material 406 made of the resin composition hardener of this embodiment. The electrode pads 407 on the circuit board 408 and the solder balls 409 on the non-sealed side of the circuit board 408 are internally bonded.

[0070] Semiconductor devices using resin compositions of this embodiment as sealing materials do not experience wire misalignment or wire breakage during the sealing process, thus exhibiting excellent reliability.

[0071] (Second Implementation) The resin composition for semiconductor sealing in the second embodiment is in the form of ingots or sheets (hereinafter referred to as "ingot or sheet resin composition"). The ingot or sheet resin composition of this embodiment includes (A) epoxy resin, (B) a curing agent, (C) an inorganic filler, and (D) a dispersant. In the resin composition of this embodiment, the epoxy resin (A) includes epoxy resins selected from biphenyl-type epoxy resins, bisphenol-type epoxy resins, arsenic-type epoxy resins, phenolic varnish-type epoxy resins, phenolic varnish-type epoxy resins, multifunctional epoxy resins, phenolic aralkyl-type epoxy resins, naphthol-type epoxy resins, and those containing triphenylene oxide. It comprises at least one of the groups of nuclear epoxy resin and phenolic epoxy resin modified with bridged cyclic hydrocarbon compounds. Furthermore, in this embodiment, the dispersant (D) is a high molecular weight ionic dispersant with a polycarboxylic acid as the main backbone, and the amount of dispersant (D) relative to the total resin composition is 0.01% by mass or more and 5.0% by mass or less.

[0072] In the semiconductor sealing resin composition of the second embodiment, the aforementioned components (A) to (D) can be the same as those described in the first embodiment. Furthermore, the doping amount of these components can also be set to be the same as that in the resin composition of the first embodiment.

[0073] The semiconductor resin composition of this embodiment may further include a bis(cis-butenediamide) resin. The bis(cis-butenediamide) resin may be the same resin used in the first embodiment.

[0074] When the resin composition of this embodiment is in ingot form, it can be manufactured by the following operation: The above-mentioned components and any additives to be included as needed are uniformly mixed to a predetermined content using a mixer or blender such as a drum mixer or Hanschel mixer, and then kneaded while heated using a kneader, roller, disperser, vacuum emulsifier, or planetary mixer, and then formed into ingots. The temperature during kneading needs to be within a temperature range that does not produce a hardening reaction, and also depends on the composition of the epoxy resin and hardener, but melt kneading is preferably performed at around 70~150°C. The ingot-shaped resin composition can be used for semiconductor sealing based on known molding methods such as transfer molding, injection molding, and compression molding.

[0075] When the resin composition of this embodiment is in sheet form, it can be obtained by the following operation: the resin composition, which has been heated and mixed as described above, is heated, melted, and compressed between pressure members to form a sheet. More specifically, after forming a resin layer by supplying the resin composition to a heat-resistant release film such as a polyester film with a substantially uniform thickness, the resin layer is calendered using rollers and a hot press while being heated and softened. At this time, a heat-resistant film such as a polyester film is also placed on the resin layer. After calendering the resin layer to the desired thickness, it is cooled and cured, and the heat-resistant film is peeled off, and then cut into the desired size and shape as needed. In this way, a resin sheet for semiconductor sealing can be obtained. In addition, the heating temperature for softening the resin layer is usually around 70~150°C. The sheet resin composition can be used for semiconductor sealing based on compression molding.

[0076] The sheet-like resin composition preferably has a thickness of 0.1 mm or more and 2 mm or less. Within this range, there is no risk of breakage and it has excellent workability, making it easy to transfer into a compression molding die.

[0077] The minimum melt viscosity ηmin of the ingot or sheet resin composition of this embodiment is 1 mPa·s or more and 68,000 mPa·s or less, preferably 60,000 mPa·s or less, more preferably 50,000 mPa·s or less, and most preferably 40,000 mPa·s or less. If it exceeds the above range, there is a risk of reduced filling capacity, resulting in voids or unfilled portions. In addition, there is no particular limitation on the lower limit; for example, it is sufficient to set it to 1 mPa·s or more or 50 mPa·s or more.

[0078] The embodiments of the present invention have been described above, but these are merely examples of the present invention, and various other configurations may also be adopted. [Example]

[0079] The present invention will now be described using examples and comparative examples, but the present invention is not limited thereto.

[0080] The following shows the ingredients used in the examples and comparative examples. (Thermosetting resin) • Epoxy Resin 1: Biphenyl-type epoxy resin (manufactured by Mitsubishi Chemical Corporation, YX4000K) • Epoxy Resin 2: Biphenyl aryl type epoxy resin (manufactured by Nippon Kayaku Co., Ltd., NC3000L)

[0081] (hardener) • Hardener 1: α-Naphthol aralkyl resin (manufactured by Tohto Kasei Co., Ltd., SN-485)

[0082] (Inorganic packing) Inorganic filler 1: Alumina (Micron, AX3-10R) Inorganic filler 2: Silicon dioxide (made by TATSUMORI LTD., MUF-4)

[0083] (Dispersant) • Dispersant 1: A high molecular weight ionic dispersant with polycarboxylic acid as the main backbone (manufactured by Croda Japan KK, HYPERMER KD-9, CAS No. 58128-22-6, weight average molecular weight 760, acid value 74 mg KOH, melting point 20℃) • Dispersant 2: A high molecular weight ionic dispersant with polycarboxylic acid as the main backbone (manufactured by Croda Japan KK, HYPERMER KD-4, weight average molecular weight 1700, acid value 33 mg KOH) • Dispersant 3: A high molecular weight ionic dispersant with polycarboxylic acid as the main backbone (manufactured by Croda Japan KK, HYPERMER KD-57).

[0084] (Coupling agent) Coupling agent 1: N-phenylaminopropyltrimethoxysilane (manufactured by Dow Corning Toray Co., Ltd., CF-4083)

[0085] (hardening accelerator) • Curing accelerator 1: Tetraphenylphosphonium bis(naphthalene-2,3-dioxy)phenyl silicate (manufactured by Sumitomo Bakelite Co., Ltd.) • Hardening accelerator 2: Tetraphenylphosphonium-4,4'-sulfonyldiphenol ester (manufactured by Sumitomo Bakelite Co., Ltd.)

[0086] (Mold release agent) Release agent 1: Glycerol tri(octacoate) ester (manufactured by Clariant Japan KK, Licolub WE-4) Release agent 2: Diethanolamine di(octacoate) ester (Clariant Japan KK manufacture, Licomont NC-133)

[0087] (Coloring agent) • Colorant 1: Carbon black (manufactured by Tokai Carbon Co., Ltd., ERS-2001) (Oil) Oil 1: Carbonyl-terminated nitrile butadiene rubber (made by Chori Co., Ltd., CTBN1008SP) (Silicon dioxide) • Silicon dioxide 1: Silicon dioxide (manufactured by Admatechs Co., Ltd., SC-2500-SQ)

[0088] (Examples 1-4, Comparative Example 1) After pulverizing and mixing the raw materials of the resin composition shown in Table 1 for 5 minutes using a super mixer, the mixture was melt-blended using a co-rotating twin-screw extruder with a cylinder inner diameter of 65 mm at a screw speed of 400 rpm and a resin temperature of 100°C. Next, the melt-blended resin composition was fed from above a rotor with a diameter of 20 cm at a ratio of 2 kg / hr. Using the centrifugal force obtained by rotating the rotor at 3000 rpm, the mixture was forced through multiple small holes (1.2 mm in diameter) on the outer periphery of a cylindrical part heated to 115°C. Then, granular epoxy resin composition for sealing was obtained by cooling. The obtained granular epoxy resin composition for sealing was stirred for 3 hours at 15°C under an airflow with a relative humidity adjusted to 55% RH. The obtained epoxy resin composition for sealing was evaluated for the following items using the methods described below.

[0089] (Minimum melt viscosity (175℃)) Melt viscosity was measured using a slit-type viscosity measuring device. Specifically, using a low-pressure injection molding machine (NEC Co., Ltd. 40t manual press), the obtained sealing resin composition was injected into a rectangular flow path with a width W: 15mm, thickness D: 1mm, and length 175mm at a mold temperature of 175°C and an injection speed Q: 178mm³ / s. Pressure sensor 1, embedded 25mm upstream of the flow path of the injection molding machine, measured P1 (kgf / cm²), and pressure sensor 2, embedded 75mm upstream of the flow path, measured pressure P2 (kgf / cm²). The change in pressure loss ΔP (kgf / cm²), represented by (P1-P2), over time was determined. The distance between pressure sensor 1 and pressure sensor 2 was set to L: 50mm. Next, the pressure loss ΔP during the flow of the sealing resin composition is calculated based on the measurement results. The point where the pressure loss ΔP is the lowest is set as the minimum pressure loss ΔPmin (kgf / cm2). After the measurement begins, the pressure measurement results are unstable, so the minimum pressure loss ΔPmin (kgf / cm2) is set as the minimum pressure loss ΔP (kgf / cm2) 5 seconds after the start of the measurement. The pressure loss ΔP (kgf / cm2) mentioned above can be converted into melt viscosity η (mPa·s) using the following formula. η(mPa·s)=(ΔP / 10.1972×106 ·WD3 )×103 / 12QL The minimum melt viscosity ηmin (mPa·s) is set as the melt viscosity calculated based on the minimum pressure loss ΔPmin (kgf / cm2). Let t1 be the moment when the melt viscosity reaches ηmin (mPa·s). Let t2 be the moment when the melt viscosity increases to (ηmin +1000)(mPa·s) or higher after reaching ηmin (mPa·s). Table 1 shows ΔPmin (kgf / cm2), ηmin (mPa·s), t1, (ηmin +1000)(mPa·s) and t2.

[0090] (fusibility (filling rate)) The fusibility of the obtained resin composition was evaluated using the "filling rate" described below as an indicator. First, 7 g of the granular sealing resin composition obtained in the Examples and Comparative Examples was added to an aluminum cup (50 mm in diameter, 10 mm in outer circumference, and 70 μm in thickness), and heated in an oven set at 175 °C for 3 minutes. The hardened resin composition was removed from the aluminum cup, and the surface of the resin composition in contact with the bottom of the aluminum cup was photographed with a digital camera and imaged. The obtained image was binarized, and the area of ​​the contact portion (A1) between the molten resin composition and the bottom of the aluminum cup and the area (A2) of the void portion (A2) between the molten resin composition and the bottom of the aluminum cup in the portion where the heated resin composition melted and diffused on the bottom of the aluminum cup were measured. The filling rate (%) was calculated as shown in Equation (1). The larger the value of the filling rate (%), the better the fusibility of the resin composition. [Fill Rate (%)] Fill rate [%] = (A1 / (A1+A2)) × 100……(1) The results are shown in Table 1 below.

[0091] (Liquidity (Spiral Flow)) Using a low-pressure injection molding machine (KOHTAKI Corporation, KTS-15), resin composition was injected into a helical flow measurement mold according to EMMI-1-66, under conditions of mold temperature 175°C, injection pressure 6.9 MPa, and holding time 120 seconds, and the flow length was measured. A higher value indicates better flowability of the helical flow system. The unit is cm.

[0092] (Modulus of elasticity at room temperature (25°C)) Test specimens with a length of 80 mm or more, a height of 4 mm, and a width of 10 mm were prepared using the granular sealing resin composition obtained by the above method. After post-curing the test specimens, bending stress was slowly applied under the conditions of a crosshead speed of 2 mm / min and a distance between the support points of 64 mm. The load-strain curve was obtained, and the flexural modulus of elasticity of the test specimens was calculated. Measurements were taken at N=2, and the average value was used as the representative value.

[0093] (Modulus of elasticity at 260℃) Test specimens with a length of 80 mm or more, a height of 4 mm, and a width of 10 mm were prepared using the granular sealing resin composition obtained by the above method. After post-curing the test specimens, bending stress was slowly applied in a constant temperature bath at 260 degrees Celsius under the conditions of a crosshead speed of 2 mm / min and a distance between support points of 64 mm. The load-strain curve was obtained, and the flexural modulus of elasticity of the test specimens was calculated. Measurements were taken at N=2, and the average value was used as the representative value.

[0094] [Table 1] unit Comparative Example 1 Example 1 Example 2 Example 3 Example 4 Composition of resin components thermosetting resins Epoxy Resin 1 Quality 4.450 4.363 4.016 4.016 4.016 Epoxy Resin 2 Quality 2.115 0.485 0.446 0.446 0.446 hardener Hardener 1 Quality 3.280 3.216 3.960 2.960 2.960 Inorganic packing Inorganic packing 1 Quality 75.0 75.0 75.0 75.0 75.0 Inorganic packing 2 Quality 3.7 3.7 3.7 3.7 3.7 dispersant Dispersant 1 Quality - 0.2 1.0 - - Dispersant 2 Quality - - - 1.0 - Dispersant 3 Quality - - - - 1.0 Coupling agent Coupling agent 1 Quality 0.2 0.2 0.2 0.2 0.2 hardening accelerator Hardening accelerator 1 Quality 0.045 0.221 0.203 0.203 0.203 Hardening accelerator 2 Quality 0.360 1.765 1.624 1.624 1.624 Colorant Colorant 1 Quality 0.4 0.4 0.4 0.4 0.4 Release agent Release agent 1 Quality 0.1 0.1 0.1 0.1 0.1 Release agent 2 Quality 0.2 0.2 0.2 0.2 0.2 Oil Oil 1 Quality 0.15 0.15 0.15 0.15 0.15 Silicon dioxide Silicon dioxide 1 Quality 10 10 10 10 10 evaluate melt viscosity ΔPmin kgf / cm2 4.85 0.78 0.19 0.07 1.92 ηmin mPa·s 69000 10900 2600 900 25000 t1 s 10.8 8.4 7.2 7.2 9.0 (ηmin +1000) mPa·s 70000 12000 3600 1900 26000 t2 s 11.0 11.2 24.2 9.8 10.8 t2-t1 s 0.2 2.8 17.0 2.6 1.8 Liquidity Spiral Flow cm 61 141.0 221.0 168.0 135.0 elastic modulus Elastic modulus (room temperature) MPa 29024 26976 22191 17316 26373 Modulus of elasticity (260℃) MPa 537 337 227 216 <200 soluble Fill rate % 0.0※1 48.9 98.3 95.8 34.8

[0095] The measurement of the meltability (filling rate) of the comparative example (※1) indicates that the resin composition does not melt and remains in granular form.

[0096] The sealing resin composition of the embodiment has excellent meltability and flowability, and can be appropriately used as a sealing material for sealing semiconductor devices mounted on a substrate by compression molding.

[0097] This application claims priority based on Japanese Patent Application No. 2019-158029, filed on August 30, 2019, the entire contents of which are incorporated herein by reference.

[0098] 401: Semiconductor Components 402: Hardened body of adhesive crystal material 403: Chip Pad 404: Wire 405: Lead Frame 406: Sealing material 407: Electrode pad 408: Circuit board 409: Welding Ball

Claims

1. A resin composition for semiconductor sealing, comprising: (A) an epoxy resin; (B) a curing agent; (C) an inorganic filler; and (D) a dispersant, wherein the epoxy resin (A) comprises at least one selected from the group consisting of biphenyl-type epoxy resin, bisphenol-type epoxy resin, niobium-type epoxy resin, phenolic varnish-type epoxy resin, phenolic varnish-type epoxy resin, polyfunctional epoxy resin, phenolic aralkyl-type epoxy resin, naphthol-type epoxy resin, trinuclear epoxy resin, and phenolic epoxy resin modified with bridged cyclic hydrocarbon compounds; the inorganic filler (C) comprises alumina and silicon dioxide; the amount of the inorganic filler (C) relative to the total resin composition is 80.0% by mass or more and 97.0% by mass or less; and the dispersant (D) is a high molecular weight ionic dispersant with a polycarboxylic acid as the main backbone. The amount of the aforementioned dispersant (D) is 0.01% by mass or more and 5.0% by mass or less relative to the total resin composition. The aforementioned resin composition for semiconductor sealing is in ingot form and is used in a transfer molding method.

2. The semiconductor sealing resin composition of claim 1, further comprising a dicis-butenediamide resin.

3. For the semiconductor sealing resin composition of request item 1 or 2, the lowest melt viscosity ηmin measured under the following <melt viscosity measurement conditions> is 1 mPa·s or more and 68000 mPa·s or less. <melt viscosity measurement conditions> Under the conditions of mold temperature: 175°C and injection speed Q: 178 mm3 / s, the measurement is performed using a slit-type viscosity measuring device with a rectangular flow path having a width W: 15 mm, a thickness D: 1 mm, and a length of 175 mm. The lowest melt viscosity ηmin is set as 5 seconds after the start of the melt viscosity measurement.

4. The semiconductor sealing resin composition as claimed in claim 1 or 2, wherein, The aforementioned polymeric ionic dispersant with polycarboxylic acid as the main skeleton includes the compound represented by the following formula (3), in which p and m represent the number of repeating units, p is an integer from 1 to 20, m is an integer from 1 to 5, and R3 is an alkyl group with 1 to 10 carbon atoms that may have substituents.

5. The semiconductor sealing resin composition of claim 1 or 2 further comprises (E) a curing accelerator.

6. The semiconductor sealing resin composition as claimed in claim 1 or 2, wherein, The amount of the aforementioned dispersant (D) is 0.1% by mass or more and 2.0% by mass or less relative to the total resin composition.

7. A semiconductor device comprising: a semiconductor element mounted on a substrate; and a sealing member for sealing the semiconductor element, wherein, The aforementioned sealing member is composed of a hardened form of the semiconductor sealing resin composition of any one of claims 1 to 6.

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