Semiconductor-sealing resin composition and semiconductor device

Abstract

A semiconductor sealing resin composition comprises (A) at least one thermosetting resin selected from epoxy resin and bismaleimide resin, (B) a curing agent, (C) an inorganic filler, and (D) a dispersant. The semiconductor sealing resin composition is used at a mold temperature of 175°C and an injection speed Q of 178 mm. 3 Under the condition of / second, the lowest melt viscosity measured by a slit viscometer with a rectangular flow path having a width W: 15 mm, a thickness D: 1 mm, and a length of 175 mm is 1 mPa·s or more and 68000 mPa·s or less. The resin composition for semiconductor sealing is in particulate form.

Description

[0001] This application is a divisional application of the same patent application, filed on August 25, 2022, with application number 202080060595.3. Technical Field

[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. Background Technology

[0003] In recent years, with the high-density mounting of electronic components on printed circuit boards, the mainstream of semiconductor devices has shifted from the previously commonly used pin-type packages to surface-mount packages. Surface-mount ICs, LSIs, and other components have become thin and small packages for high-density mounting, increasing the volume occupied by the components relative to the package, and making the package walls very thin. Furthermore, the increasing multifunctionality and capacity of components has led to larger chip areas and more pins. Consequently, the increased number of pads has also driven the reduction in pad spacing and pad size, the so-called narrow pad spacing.

[0004] However, it is not possible to achieve the same narrow electrode spacing as semiconductor elements on a substrate carrying semiconductor elements. Therefore, multi-terminal requirements are addressed by extending the length of the metal wires extending from the semiconductor elements or by softening the metal wires. However, if the metal wires become thinner, they are prone to shifting due to the resin injection pressure during the subsequent resin sealing step. This tendency is particularly pronounced in side-gate systems.

[0005] Therefore, compression molding has gradually become a method for resin sealing electronic components such as semiconductor chips. In this compression molding method, a granular resin composition is supplied in a manner that is opposite to the object to be sealed (such as a substrate on which electronic components such as semiconductor chips are disposed) held in a mold, and the object to be sealed and the granular resin composition are compressed to achieve resin sealing.

[0006] According to 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 so-called wire sweep, which occurs when wiring in wire bonding and other applications deforms or breaks due to resin flow.

[0007] 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 curing agent, a curing 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, and having a specific particle size. This composition can improve the meltability of the resin composition during sealing and can improve the demolding properties after sealing.

[0008] Existing technical documents Patent documents Patent Document 1: Japanese Patent Application Publication No. 2011-153173 Summary of the Invention

[0009] The technical problem to be solved by the invention However, the inventors of this invention discovered during their research that the resin composition described in Patent Document 1 has issues such as insufficient filling of the sealing material, which prevents proper sealing of the semiconductor element.

[0010] The present invention was made in view of this situation, and its object is to provide a semiconductor sealing resin composition that can improve the meltability during semiconductor sealing and can properly seal a semiconductor element mounted on a substrate by compression molding. Furthermore, its object is to provide a semiconductor device with excellent reliability in which the semiconductor element is sealed by the above-described semiconductor sealing resin composition.

[0011] means for solving technical problems The inventors of this invention focused on the need for the resin composition, as a sealing material, to be almost non-flowing and to sufficiently improve filling properties to avoid unfilled portions during the sealing process in order to seal semiconductor elements by compression molding. The inventors discovered that by setting the semiconductor sealing resin composition containing inorganic fillers to a specific formulation, 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 meltability of the sealing resin composition is improved, which can suppress metal wire deviation during sealing, thus completing this invention.

[0012] According to the present invention, a resin composition for sealing semiconductors is provided, comprising: (A) At least one thermosetting resin selected from epoxy resin and bismaleimide resin; (B) Curing agent; (C) Inorganic fillers; and (D) Dispersant, The lowest melt viscosity η of the semiconductor sealing resin composition was measured under the following <melt viscosity measurement conditions>. minFor a range of 1 mPa·s or more and 68000 mPa·s or less, The resin composition for semiconductor sealing is in granular form.

[0013] <Melt Viscosity Measurement Conditions> Mold temperature: 175℃, injection speed Q: 178mm 3 Under the condition of / second, 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 after 5 seconds after the start of the melt viscosity measurement was taken as η. min .

[0014] Furthermore, according to the present invention, a semiconductor device is provided, comprising: Semiconductor components mounted on a substrate; and A sealing component that seals the aforementioned semiconductor element. The aforementioned sealing component is composed of a cured product of the aforementioned semiconductor sealing resin composition.

[0015] According to the present invention, a resin composition for sealing semiconductors is provided, comprising: (A) Epoxy resin; (B) Curing agent; (C) Inorganic fillers; and (D) Dispersant, The epoxy resin (A) mentioned above comprises at least one selected from biphenyl-type epoxy resin, bisphenol-type epoxy resin, zirconia-type epoxy resin, phenolic varnish-type epoxy resin, phenolic varnish-type epoxy resin, multifunctional epoxy resin, phenolic alkyl-type epoxy resin, naphthol-type epoxy resin, triazine-containing epoxy resin, and phenolic epoxy resin modified with bridged cyclic hydrocarbon compounds. The dispersant (D) mentioned above is a high-molecular-weight ionic dispersant with polycarboxylic acid as the main backbone. The amount of the above dispersant (D) is more than 0.01% by mass and less than 5.0% by mass relative to the total resin composition.

[0016] The semiconductor sealing resin composition of this embodiment can be any shape, such as ingot, sheet, or granules.

[0017] The effects of the invention 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. Attached Figure Description

[0018] Figure 1 This is a diagram showing the cross-sectional structure of a semiconductor device obtained by sealing a semiconductor element mounted on a lead frame using the resin composition of this embodiment.

[0019] Figure 2 This is a diagram showing the cross-sectional structure of a semiconductor device obtained by sealing a semiconductor element mounted on a circuit board using the resin composition of this embodiment. Detailed Implementation

[0020] Hereinafter, embodiments of the present invention will be described using the accompanying drawings. In all the drawings, the same reference numerals are used to denote the same constituent elements, and descriptions are omitted where appropriate.

[0021] (First Implementation) The semiconductor sealing resin composition 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 epoxy resin and bismaleimide 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.

[0022] The particulate resin composition of this embodiment exhibits improved dispersibility due to the inclusion of a dispersant and inorganic filler, and also has a low melt viscosity. As a result, when using this resin composition to seal semiconductor devices mounted on a substrate via compression molding, metal wire misalignment or deformation can be reduced. Furthermore, this particulate resin composition has good flowability in the molten state, thus preventing unfilled areas from forming on the semiconductor device and enabling effective sealing.

[0023] The particulate resin composition in this embodiment will now be described.

[0024] In this embodiment, the particulate resin composition preferably contains at least 85% by mass within a particle size range of 100 μm to 3 mm. If there are too many particles outside this range, there is a tendency to fail to properly seal the semiconductor element during compression molding. Specifically, for example, if there are too many resin compositions with excessively small particle sizes, these small-sized resin compositions melt preferentially, and the resin composition used as a sealing material will not melt uniformly during compression molding, resulting in a tendency to fail to properly seal the semiconductor element. Conversely, if there are too many resin compositions with excessively large particle sizes, these large-sized resin compositions are difficult to melt, and during compression molding, unmelted and residual particulate resin compositions remain in the molten resin composition, leading to a situation where the semiconductor element cannot be properly sealed. Furthermore, the particle size distribution of the particulate resin composition can be measured using a general particle size analyzer. Alternatively, sieves of various aperture sizes can be repeatedly sieved in ascending order of aperture size, thereby sieving the particulate resin composition and calculating the particle size distribution based on the mass of particles remaining on each sieve.

[0025] The following examples illustrate the components used in particulate resin compositions as sealing materials. The melt viscosity of the particulate resin composition can be set to a target value by adjusting the types or proportions of the components used.

[0026] (Thermosetting resin (A)) The thermosetting resin (A) used in the particulate resin composition of this embodiment comprises at least one selected from epoxy resin and bismaleimide resin.

[0027] As epoxy resins, any monomer, oligomer, or polymer having two or more epoxy groups within one molecule can be used, without limitations on molecular weight or molecular structure. 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; zirconia-type epoxy resins; phenolic varnish-type epoxy resins such as phenolic varnish-type epoxy resin and cresolic varnish-type epoxy resin; multifunctional epoxy resins such as triphenol-type epoxy resins (e.g., triphenol-methane-type epoxy resin and alkyl-modified triphenol-methane-type epoxy resin); phenolic arylalkyl-type epoxy resins with a phenylene backbone; and naphthalene-type epoxy resins with a phenylene backbone. Phenolic alkyl-type epoxy resins include phenolic alkyl-type epoxy resins, phenolic alkyl-type epoxy resins with a biphenyl-like backbone, and naphthol alkyl-type epoxy resins with a biphenyl-like backbone; naphthol-type epoxy resins include dihydroxynaphthalene-type epoxy resins and epoxy resins obtained by glycidyl etherification of dihydroxynaphthalene dimers; triazine-core-containing epoxy resins include triglycidyl trimisocyanate and monoallyl diglycidyl trimisocyanate; and phenolic epoxy resins modified with bridged cyclic hydrocarbon compounds, such as dicyclopentadiene-modified phenolic epoxy resins. These can be used alone or in combination of two or more.

[0028] 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 alkyl-type epoxy resins are preferred. Furthermore, from the same viewpoint, the epoxy resin preferably comprises one or more selected from o-cresol phenolic varnish-type epoxy resins, phenolic alkyl-type epoxy resins having a biphenyl-like backbone, and triphenylmethane-type epoxy resins; more preferably, it comprises one or more selected from o-cresol phenolic varnish-type epoxy resins and phenolic alkyl-type epoxy resins having a biphenyl-like backbone.

[0029] The bismaleimide resin used as a thermosetting resin (A) is a (co)polymer of a compound having two or more maleimide groups.

[0030] Compounds having two or more maleimide groups include, for example, at least one of the compounds shown in general formula (1) and general formula (2). This increases the glass transition temperature of the cured particulate resin composition and more effectively improves the heat resistance of the cured product. In the above general formula (1), R 1 It is a divalent organic group with 1 to 30 carbon atoms, and may contain one or more oxygen and nitrogen atoms. From the viewpoint of improving the heat resistance of the cured product, R is more preferred. 1 It is an organic group containing an aromatic ring. In this embodiment, R is used as... 1 For example, the structure of the following general formula (1a) or (1b) can be exemplified. In the above general formula (1a), R 31 It can be an organic group containing one or more carbon atoms of the type selected from oxygen and nitrogen atoms, and having a divalent oxidation state of 1 to 18. Furthermore, multiple R... 32 Each is a substituted or unsubstituted hydrocarbon group, consisting of 1 to 4 hydrogen atoms or carbon atoms. In the above general formula (1b), multiple Rs exist independently, where R represents hydrogen atoms, alkyl groups having 1 to 5 carbon atoms, or phenyl groups, preferably hydrogen atoms. Furthermore, m is an average value, which is a number between 1 and 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.

[0031] As for the compounds represented by the above general formula (1) applicable in this embodiment, for example, the compounds represented by the following formulas (1-1) to (1-3) can be cited. In the above general formula (2), multiple R 2 Each is an independently substituted or unsubstituted hydrocarbon group with 1 to 4 hydrogen or carbon atoms. n is an average value, which is 0 to 10, preferably 0 to 5.

[0032] Furthermore, the thermosetting resin (A) may also include thermosetting resins other than epoxy resins and bismaleimide resins. Examples of such thermosetting resins include one or more selected from benzoxazine resins, phenolic resins, urea resins, melamine resins, unsaturated polyester resins, polyurethane resins, diallyl phthalate resins, silicone resins, cyanate ester resins, polyimide resins, polyamide-imide resins, and benzocyclobutene resins.

[0033] The content of thermosetting resin (A) relative to the total resin composition is preferably 2% by mass or more, more preferably 4% by mass or more. If the lower limit of the mixing ratio is within the above range, the decrease in fluidity is less likely to occur during the sealing step. Furthermore, there is no particular limitation on the upper limit of the mixing ratio of the total resin composition, but it is preferably 22% by mass or less, more preferably 20% by mass or less relative to the total amount of the resin composition. If the upper limit of the mixing ratio is within the above range, the decrease in the glass transition temperature of the resin composition is less, and mutual adhesion can be appropriately suppressed. In addition, in order to improve fluidity and meltability, it is desirable to appropriately adjust the mixing ratio according to the type of epoxy resin used.

[0034] In this embodiment, the content of any component relative to the total resin composition refers to the content of all 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, which are the remainder after removing volatile components such as water or solvents.

[0035] (Curing agent (B)) The curing agent (B) used in the resin composition of this embodiment can be broadly classified into three categories, such as addition polymerization type curing agents, catalyst type curing agents, and condensation type curing agents. They can be used alone or in combination of two or more.

[0036] Addition polymerization curing agents may contain one or more of the following substances: polyamine compounds, including aliphatic polyamines such as diethylenetriamine (DETA), triethylenetetramine (TETA), and m-phenylenediamine (MXDA); aromatic polyamines such as diaminodiphenylmethane (DDM), m-phenylenediamine (MPDA), and diaminodiphenyl sulfone (DDS); and dicyandiamide (DICY), organic acid dihydrazides, etc.; acid anhydrides, including hexahydrophthalic anhydride (HH... Alicyclic anhydrides such as PA, methyltetrahydrophthalic anhydride (MTHPA), aromatic anhydrides such as trimellitic anhydride (TMA), pyromellitic dianhydride (PMDA), and benzophenone tetracarboxylic dianhydride (BTDA); phenolic resin curing agents such as phenolic varnish-type phenolic resin, polyvinylphenol, and aralkyl-type phenolic resin; polysulfides, thioesters, thioethers, and other polythiol compounds; isocyanate prepolymers, end-capped isocyanates, and other isocyanate compounds; and organic acids such as carboxylic acid-containing polyester resins.

[0037] Catalyst-type curing agents may contain one or more of the following substances: tertiary amine compounds such as benzyl dimethylamine (BDMA) and 2,4,6-tris-dimethylaminomethylphenol (DMP-30); imidazole compounds such as 2-methylimidazole and 2-ethyl-4-methylimidazole (EMI24); Lewis acids such as BF3 complexes.

[0038] Condensation-type curing agents include, for example, one or more selected from methyl phenolic resins, urea resins such as hydroxymethyl urea resins, and melamine resins such as hydroxymethyl melamine resins.

[0039] 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, it is more preferable to include a phenolic resin-based curing agent. As a phenolic resin-based curing agent, monomers, oligomers, and polymers having two or more phenolic hydroxyl groups per molecule can all be used, and their molecular weight and molecular structure are not limited.

[0040] Phenolic resin curing agents may include one or more of the following substances: phenolic varnish-type phenolic resins such as phenolic varnish resin, cresol phenolic varnish resin, and bisphenol phenolic varnish resin; multifunctional phenolic resins such as polyvinylphenol and triphenylmethane-type phenolic resin; modified phenolic resins such as terpene-modified phenolic resin and dicyclopentadiene-modified phenolic resin; phenolic aralkyl-type phenolic resins such as phenolic aralkyl resins having a phenylene backbone and / or a biphenylene backbone, and naphthol aralkyl resins having a phenylene backbone; and bisphenol compounds such as bisphenol A and bisphenol F. Among these, from the viewpoint of suppressing warping of the molded body, phenolic varnish-type phenolic resins, multifunctional phenolic resins, and phenolic aralkyl-type phenolic resins are more preferred. Furthermore, phenolic varnish resins, phenolic aralkyl resins having a biphenylene backbone, and formaldehyde-modified triphenylmethane-type phenolic resins are also preferred.

[0041] The lower limit of the proportion of curing agent (B) relative to the total resin composition is preferably 2% by mass or more, more preferably 3% by mass or more. Sufficient fluidity can be obtained if the lower limit of the proportion is within the above range. Furthermore, the upper limit of the proportion of curing agent relative to the total resin composition is preferably 16% by mass or less, more preferably 15% by mass or less. Mutual adhesion can be appropriately suppressed if the upper limit of the proportion is within the above range. Moreover, in order to improve fluidity and meltability, it is desirable to appropriately adjust the proportion according to the type of curing agent used.

[0042] (Inorganic packing (C)) Examples of inorganic fillers (C) used in the resin composition of this embodiment include: molten silica such as fused silica and molten spherical silica; crystalline silica and amorphous silica; silica; alumina; aluminum hydroxide; silicon nitride; and aluminum nitride. One or more of these fillers may be used alone or in combination. The particle shape is preferably as spherical as possible, and the filler content can be increased by mixing particles of different sizes. Furthermore, to improve the meltability of the resin composition, silica or alumina is preferred; molten spherical silica is preferred as the silica used.

[0043] The content of inorganic filler (C) is preferably 80.0% by mass or more and 97.0% by mass or less relative to the total resin composition. If the content of inorganic filler is too low, the heat resistance of the cured resin composition tends to decrease, and the reliability of the obtained semiconductor device tends to decrease. On the other hand, if the content of inorganic filler is high, the heat resistance of the cured resin composition can be improved, and the reliability of the obtained semiconductor device can be improved. However, as the content of inorganic filler increases, the meltability of the resin composition generally decreases, in other words, it becomes difficult to melt, and there is a tendency for metal wire deviation to occur. In this embodiment, by including the dispersant described later, the heat resistance and other properties of the cured resin composition can be maintained, and the meltability of the resin composition can be improved, and the occurrence of metal wire deviation can be suppressed.

[0044] (Dispersant (D)) As the dispersant (D) used in the resin composition of this embodiment, a high molecular weight ionic dispersant with polycarboxylic acid as the main backbone can be used. The high molecular weight ionic dispersant preferably has a carboxyl group that functions as an adsorbent group for adsorption onto inorganic fillers and a site that is compatible with the above-mentioned thermosetting resin.

[0045] Examples of such polymeric ionic dispersants include ARON A-6330 (manufactured by Toa Synthetic 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, polymeric ionic dispersants represented by the formula (3) below are preferred. Specifically, examples include Hypermer KD-4, Hypermer KD-8, and Hypermer KD-9 (manufactured by Croda Japan KK., trade name). (In equation (3), p and m represent the number of repeating units, where p is an integer from 1 to 20, m is an integer from 1 to 5, and R 3 (It can be an alkyl group with 1 to 10 carbon atoms that may have substituents).

[0046] The polymeric ionic dispersant shown in formula (3) has carboxyl groups that adsorb onto the inorganic filler and large 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 aliphatic groups of the polymeric ionic dispersant inhibits the aggregation of the inorganic filler. As a result, the inorganic filler is highly dispersed in the thermosetting resin (A) without agglomeration.

[0047] The amount of dispersant (D) relative to the total resin composition is preferably 0.01% by mass to 5.0% by mass, more preferably 0.1% by mass to 2.0% by mass, and even more preferably 0.2% by mass to 1.5% by mass. By using dispersant (D) in amounts within the above range, the inorganic filler can be highly dispersed in the resin composition.

[0048] (Cure accelerator (E)) The resin composition of this embodiment may include a curing accelerator (E). As the 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 or 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 can be used alone or in combination of two or more.

[0049] 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 accelerator effect cannot be improved. In addition, if it is greater than the upper limit mentioned above, there is a tendency that the flowability or moldability will be poor, and sometimes it will lead to an increase in manufacturing costs.

[0050] (Coupled agent) The resin composition of this embodiment may contain a silane coupling agent. Examples of silane coupling agents include vinyl silanes such as vinyltris(β-methoxyethoxy)silane, vinylethoxysilane, and vinyltrimethoxysilane; (meth)acrylate silanes such as γ-methacryloyloxypropyltrimethoxysilane; 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, aminosilanes such as 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 thiosilanes such as γ-mercaptopropyltrimethoxysilane and γ-mercaptopropyltriethoxysilane.

[0051] The amount of coupling agent relative to the total resin composition is preferably 0.01% by mass to 1.0% by mass, more preferably 0.05% by mass to 0.9% by mass, and even more preferably 0.08% by mass to 0.8% by mass. By using coupling agent in amounts within the above range, both improved meltability and migration resistance of the obtained resin composition can be achieved.

[0052] (Other additives) In addition to the components described above, conventionally known additives, such as flame retardants, colorants, silicone flexible agents, and ion traps, may be used in the resin composition of this embodiment as needed, without impairing the desired properties for the purposes of this invention.

[0053] The characteristics of the particulate resin composition in this embodiment will be described.

[0054] In this embodiment, the lowest melt viscosity η is measured using a slit-type viscosity measuring device. min The upper limit is 68000 mPa·s or less, preferably 60000 mPa·s or less, more preferably 50000 mPa·s or less, and even more preferably 40000 mPa·s or less. Therefore, the sealing material has good filling properties. The lowest melt viscosity η measured using a slit-type viscosity measuring device... min There is no particular limitation on the lower limit, for example, it is 1 mPa·s or more, preferably 50 mPa·s or more.

[0055] In this embodiment, the lowest melt viscosity η measured using a slit-type viscosity measuring device is achieved. min The upper limit of time t1 is 15 seconds or less, preferably 12 seconds or less, and more preferably 10 seconds or less. Therefore, the sealing material has good filling properties. The lowest melt viscosity η measured using a slit-type viscosity measuring device is achieved. min There is no particular restriction on the lower limit of time t1, for example, it can be more than 5 seconds.

[0056] And, it will reach η min The melt viscosity then increases to reach (η) min When t2 is defined as the time of +1000 (mPa·s) or higher, the lower limit of t2-t1 is 1 second or more. The upper limit of t2-t1 is 30 seconds or less, preferably 25 seconds or less, and more preferably 20 seconds or less. By setting t2-t1 to the lower limit or above, the pot life of the resin composition can be sufficiently obtained, and the filling properties of the sealant can be good. Furthermore, by setting t2-t1 to the upper limit or below, uneven curing can be suppressed, and the molding cycle can be extended, thereby preventing a decrease in manufacturing efficiency.

[0057] In this embodiment, a resin composition is added to an aluminum cup and heated at 175°C for 3 minutes. The cured resin composition is then removed from the aluminum cup. In the portion of the heated resin composition that has melted and expanded on the bottom surface of the aluminum cup, the area of ​​the contact portion where the molten resin composition contacts the bottom surface of the aluminum cup is designated 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 designated as A2. The meltability (filling rate (%)) expressed as (A1 / (A1+A2))×100 is preferably 30% to 100%. Therefore, the sealing material has good filling properties and stable cured properties can be obtained.

[0058] (Preparation of particulate resin composition) As for the method for preparing the granular resin composition of this embodiment, there are no particular limitations as long as it is possible to produce a granular resin composition containing the above-mentioned components and having a particle size distribution within the above-mentioned range. Specifically, it can be produced, for example, in the following manner. First, the above-mentioned components and additives as needed are uniformly mixed in a specified amount using a mixer or blender such as a drum mixer or Henschel mixer. Then, the mixture is kneaded while heated using a kneader, roller, disperser, vacuum emulsifier, or planetary mixer. The temperature during kneading needs to be within a temperature range where a curing reaction will not occur. Although it also depends on the composition of the epoxy resin and the curing agent, it is preferable to perform melt kneading at around 70 to 150°C. After kneading, the mixture is cooled and cured, and then pulverized using a pulverizer or the like. This allows the production of a granular resin composition. Then, the resin composition can be sieved to achieve a particle size distribution within the above-mentioned range.

[0059] (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.

[0060] Hereinafter, a semiconductor device will be described in detail with reference to the accompanying drawings. 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 electrically connecting the lead frame or circuit board to the semiconductor elements, and sealing material sealing the semiconductor elements and bonding wires. However, the present invention is not limited to the use of bonding wires.

[0061] Figure 1This diagram shows a cross-sectional structure of a semiconductor device obtained by sealing a semiconductor element mounted on a lead frame using the resin composition of this embodiment. The semiconductor element 401 is fixed to the chip pad 403 via a cured chip bonding material 402. The electrode pads of the semiconductor element 401 are connected to the lead frame 405 by metal wires 404. The semiconductor element 401 is sealed by a sealing material 406 made of a cured resin composition of this embodiment.

[0062] Figure 2 This diagram shows a cross-sectional structure of a semiconductor device obtained by sealing a semiconductor element mounted on a circuit board using the resin composition of this embodiment. The semiconductor element 401 is fixed to the circuit board 408 via a cured chip bonding material 402. The electrode pads 407 of the semiconductor element 401 are connected to the electrode pads 407 on the circuit board 408 by metal wires 404. The surface of the circuit board 408 on which the semiconductor element 401 is mounted is sealed using a sealing material 406 made of the cured resin composition of this embodiment. The electrode pads 407 on the circuit board 408 are internally bonded to the solder holes 409 on the non-sealed side of the circuit board 408.

[0063] Semiconductor devices using the resin composition of this embodiment as a sealing material do not experience metal wire misalignment or metal wire breakage during the sealing process, thus exhibiting excellent reliability.

[0064] (Second Implementation) The semiconductor sealing resin composition in the second embodiment is in tablet or sheet form (hereinafter referred to as "tablet or sheet resin composition"). The tablet or sheet resin composition of this embodiment comprises (A) an 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) comprises at least one selected from biphenyl-type epoxy resin, bisphenol-type epoxy resin, uranium-type epoxy resin, phenolic varnish-type epoxy resin, phenolic varnish-type epoxy resin, multifunctional epoxy resin, phenolic alkyl-type epoxy resin, naphthol-type epoxy resin, triazine-containing 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 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.

[0065] In the semiconductor sealing resin composition of the second embodiment, the same components (A) to (D) as those described in the first embodiment can be used. Furthermore, the amounts of these components can also be the same as those in the resin composition of the first embodiment.

[0066] The semiconductor resin composition of this embodiment may further comprise a bismaleimide resin. The bismaleimide resin may be the same resin used in the first embodiment.

[0067] 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 necessary additives are uniformly mixed in a specified amount using a mixer or blender such as a drum mixer or Henschel mixer. Then, the mixture is kneaded while heated using a kneader, roller, disperser, vacuum emulsifier, or planetary mixer, and then formed into ingots. The mixing temperature needs to be within a range where a curing reaction will not occur. Although this also depends on the composition of the epoxy resin and the curing agent, melt mixing at around 70 to 150°C is preferred. The ingot-shaped resin composition can be used for semiconductor seals based on known molding methods such as transfer molding, injection molding, and compression molding.

[0068] 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 components 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 in this way, it is cooled and cured, the heat-resistant film is peeled off, and it is further cut into the desired size and shape as needed. Therefore, a resin sheet for semiconductor sealing can be obtained. The heating temperature for softening the resin layer is typically around 70 to 150°C. The sheet resin composition can be used for semiconductor sealing based on compression molding.

[0069] The sheet resin composition preferably has a thickness of 0.1 mm to 2 mm. Within this range, it exhibits excellent workability and is free from breakage, making it easy to transport to a compression molding die.

[0070] The lowest melt viscosity η of the ingot or sheet resin composition of this embodiment min The pressure is between 1 mPa·s and 68,000 mPa·s, preferably between 60,000 mPa·s, more preferably between 50,000 mPa·s, and most preferably between 40,000 mPa·s. If the pressure exceeds these ranges, the filling performance decreases, potentially resulting in voids or unfilled areas. Furthermore, there are no particular restrictions on the lower limit; for example, it can be set to 1 mPa·s or 50 mPa·s or more.

[0071] The embodiments of the present invention have been described above, but these are merely examples of the present invention, and various configurations other than those described above may also be used.

[0072] [Example] The present invention will now be described using examples and comparative examples, but the present invention is not limited thereto.

[0073] The following shows the ingredients used in the examples and comparative examples.

[0074] (Thermosetting resin) • Epoxy Resin 1: Biphenyl type epoxy resin (manufactured by Mitsubishi Chemical Corporation, YX4000K) • Epoxy Resin 2: Biphenyl aralkyl type epoxy resin (manufactured by Nippon Kayaku Co., Ltd., NC3000L) (Curing agent) • Curing agent 1: α-Naphthol aralkyl resin (manufactured by Toto Chemical Co., Ltd., SN-485) (Inorganic packing) Inorganic filler 1: Alumina (manufactured by Micron, AX3-10R) • Inorganic filler 2: Silica (manufactured by Ryusei Corporation, MUF-4) (Dispersant) • Dispersant 1: Polycarboxylic acid-based ionic dispersant (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: Polycarboxylic acid-based ionic dispersant (manufactured by Croda Japan KK., HYPERMER KD-4, weight average molecular weight 1700, acid value 33mgKOH) • Dispersant 3: Polycarboxylic acid-based ionic dispersant (manufactured by Croda Japan KK., HYPERMER KD-57) (Coupled agent) • Coupling agent 1: N-phenylaminopropyltrimethoxysilane (manufactured by Toray Dow Corning, CF-4083) (Curing accelerator) • Curing Accelerator 1: Tetraphenylphosphonium bis(naphthalene-2,3-dioxo)phenylsilicate (manufactured by Sumitomo Bakelite Co., Ltd.) • Curing Accelerator 2: Tetraphenylphosphonium-4,4'-sulfonyl diphenol salt (manufactured by Sumitomo Bakelite Co., Ltd.) (Mold release agent) Release agent 1: Glycerol tribrown ester (manufactured by Clariant Japan KK, Licolub WE-4) Release agent 2: Diethanolamine di-phosphoric acid ester (manufactured by Clariant Japan KK, Licomont NC-133) (Coloring agent) • Colorant 1: Carbon black (manufactured by Tokai Carbon Co., Ltd., ERS-2001) (Oil) Oil 1: Carbonyl-terminated nitrile rubber (manufactured by Chori GLEX Co., Ltd., CTBN 1008SP) (Silicon dioxide) • Silica 1: Silica (manufactured by Admatechs Co., Ltd., SC-2500-SQ) (Examples 1-4, Comparative Example 1) The raw materials for the resin compositions shown in Table 1 were pulverized and mixed for 5 minutes using a super mixer. The mixture was then melt-blended using a co-rotating twin-screw extruder with a barrel 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 20 cm diameter rotor at a ratio of 2 kg / hr. Using 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 section heated to 115°C. After cooling, a granular epoxy resin composition for sealing was obtained. The obtained granular sealing resin composition was stirred for 3 hours at 15°C under an airflow with a relative humidity adjusted to 55% RH. The obtained sealing resin composition was evaluated for the following items according to the methods shown below.

[0075] (Lowest melt viscosity (175℃)) Melt viscosity was measured using a slit-type viscometer. Specifically, a low-pressure transfer molding machine (NECCo., Ltd. 40t manual press) was used with a mold temperature of 175°C and an injection speed Q of 178mm. 3 The obtained sealing resin composition is injected into a rectangular flow path with a width W: 15 mm, a thickness D: 1 mm, and a length of 175 mm at a speed of / second. Pressure sensor 1, embedded 25 mm upstream of the flow path in the transfer molding machine, measures P1 (kgf / cm²). 2 The pressure P2 (kgf / cm) is measured using a pressure sensor 2 embedded 75mm upstream of the flow path. 2And measure the pressure loss ΔP (kgf / cm²) represented by (P1-P2). 2 The pressure change over time is measured. The distance L between pressure sensor 1 and pressure sensor 2 is 50 mm. Next, the pressure loss ΔP during the flow of the sealing resin composition is calculated based on the measurement results, and the point where the pressure loss ΔP is the lowest is set as the minimum pressure loss ΔP. min (kgf / cm) 2 Because the pressure measurement results are unstable immediately after the measurement begins, the minimum pressure loss ΔP min (kgf / cm) 2 Set the minimum pressure loss ΔP 5 seconds after the start of the measurement. min (kgf / cm) 2 ).

[0076] The pressure loss ΔP (kgf / cm) mentioned above 2 The following formula can be used to convert the melt viscosity η (mPa·s).

[0077] η (mPa·s) = (ΔP / 10.1972×10 6 WD 3 )×10 3 / 12QL The minimum pressure loss ΔP min (kgf / cm) 2 The converted melt viscosity is used as the minimum melt viscosity η. min (mPa·s).

[0078] To achieve a melt viscosity of η min Let the time (mPa·s) be t1. And, η is reached... min After (mPa·s), the melt viscosity increases and will reach (η). min The time of points with a strength of +1000 (mPa·s) or higher is set as t2.

[0079] ΔP is represented in Table 1. min (kgf / cm) 2 ), η min (mPa·s), t1, (η) min +1000 (mPa·s) and t2.

[0080] (Melability (filling rate)) The meltability 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 cured 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 (A1) of the contact portion where the molten resin composition contacts the bottom of the aluminum cup in the portion where the heated resin composition melts and expands on the bottom of the aluminum cup, and the area (A2) of the void portion where the molten resin composition does not contact 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 meltability of the resin composition.

[0081] [Fill Rate (%)] Fill rate [%] = (A1 / (A1+A2)) × 100……(1) The results are shown in Table 1 below.

[0082] (Flowability (Swirl Length)) Using a low-pressure transfer molding machine (KOHTAKI Corporation, KTS-15), the resin composition was injected into a mold for measuring swirl length 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. Swirl length is an indicator of flowability; a higher value indicates better flowability. The unit is cm.

[0083] (Elastic modulus at room temperature (25°C)) The granular sealing resin composition obtained according to the above method was used to prepare test pieces with a length of 80 mm or more, a height of 4 mm, and a width of 10 mm. After post-curing the test pieces, 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 pieces was calculated. Measurements were taken with N=2, and the average value was used as the representative value.

[0084] (Elastic modulus at 260℃) The granular sealing resin composition obtained according to the above method was used to prepare test pieces with a length of 80 mm or more, a height of 4 mm, and a width of 10 mm. After post-curing the test pieces, 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 pieces was calculated. Measurements were taken with N=2, and the average value was used as the representative value.

[0085] [Table 1] The measurement of meltability (filling rate) of the comparative example (※1) indicates that the resin composition does not melt and remains in granular form.

[0086] The sealing resin composition of the embodiments has excellent melt and flow properties, making it suitable as a sealing material for sealing semiconductor components mounted on a substrate by compression molding.

[0087] 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.

Claims

1. A resin composition for semiconductor sealing, characterized in that, Include: (A) Epoxy resin; (B) Curing agent; (C) Inorganic fillers; and (D) Dispersant, The epoxy resin (A) comprises at least one selected from biphenyl-type epoxy resin, bisphenol-type epoxy resin, zirconia-type epoxy resin, phenolic varnish-type epoxy resin, phenolic varnish-type epoxy resin, multifunctional epoxy resin, phenolic alkyl-type epoxy resin, naphthol-type epoxy resin, triazine-containing epoxy resin, and phenolic epoxy resin modified with bridged cyclic hydrocarbon compounds. The inorganic filler (C) comprises alumina and silicon dioxide. The dispersant (D) is a high-molecular-weight ionic dispersant with polycarboxylic acid as the main backbone. The amount of the dispersant (D) is more than 0.01% by mass and less than 5.0% by mass relative to the total resin composition.

2. The semiconductor sealing resin composition according to claim 1, characterized in that, The semiconductor sealing resin composition is in the form of ingots or sheets.

3. The semiconductor sealing resin composition according to claim 1, characterized in that, The semiconductor sealing resin composition is in granular form.

4. The resin composition for semiconductor sealing according to any one of claims 1 to 3, characterized in that, It also contains bismaleimide resin.

5. The resin composition for semiconductor sealing according to any one of claims 1 to 4, characterized in that, The lowest melt viscosity η measured under the following <melt viscosity measurement conditions> min For a range of 1 mPa·s or more and 68000 mPa·s or less, <Melt Viscosity Measurement Conditions> Mold temperature: 175℃, injection speed Q: 178mm 3 Under the condition of / second, 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 after 5 seconds after the start of the melt viscosity measurement was taken as η. min .

6. The semiconductor sealing resin composition according to any one of claims 1 to 5, characterized in that, The polycarboxylic acid-based ionic dispersant comprises the compound shown in formula (3). In equation (3), p and m represent the number of repeating units, where p is an integer from 1 to 20, m is an integer from 1 to 5, and R 3 It can be an alkyl group with 1 to 10 carbon atoms that may have substituents.

7. The semiconductor sealing resin composition according to any one of claims 1 to 6, characterized in that, It also contains (E) curing accelerator.

8. The resin composition for semiconductor sealing according to any one of claims 1 to 7, characterized in that, The amount of the dispersant (D) is more than 0.1% by mass and less than 2.0% by mass relative to the total resin composition.

9. The resin composition for semiconductor sealing according to any one of claims 1 to 8, characterized in that, The amount of the inorganic filler (C) is more than 80.0% by mass and less than 97.0% by mass relative to the total resin composition.

10. A semiconductor device, characterized in that, include: Semiconductor components mounted on a substrate; and A sealing component that seals the semiconductor element. The sealing component is composed of a cured product of the semiconductor sealing resin composition according to any one of claims 1 to 9.

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