Granular semiconductor sealing resin composition, resin-sealed semiconductor device, and method for manufacturing same

Abstract

A granular semiconductor sealing resin composition according to the present disclosure comprises a thermosetting resin (A), a curing agent (B), and an inorganic filler (C), wherein the inorganic filler (C) has a 99% cumulative volume particle diameter (D99) of 7.0 µm or less, the inorganic filler (C) content is 65.0-80.0 mass% relative to the total amount of the resin composition, the minimum melt viscosity at 125°C is 1.0 to 3.5 Paꞏs before curing, and the elastic modulus at room temperature is 10 GPa or less after curing.

Description

Powdery semiconductor encapsulation resin composition, resin-encapsulated semiconductor device, and method for manufacturing the same

[0001] The present disclosure relates to a powdery semiconductor encapsulation resin composition, a resin-encapsulated semiconductor device using the same, and a method for manufacturing the same.

[0002] In recent years, with the high functionality and high speed of electronic devices, the high-density wiring and multilayer wiring of integrated circuits (IC chips) have advanced, and the amount of heat generated from semiconductor elements and semiconductor packages (hereinafter, semiconductor elements, etc.) tends to increase. Against such a background, there is an increasing demand for a resin composition (hereinafter, semiconductor encapsulation resin composition, or simply resin composition) for encapsulating semiconductor elements, etc., which has good heat dissipation properties.

[0003] In addition, in recent years, in order to meet the requirements for miniaturization, thinning, high functionality, high integration, and high speed of semiconductor packages, etc., a flip chip connection method (hereinafter, FC connection method) for connecting a semiconductor element and a wiring board through conductive protrusions called bumps has been spreading. In the FC connection method, the bump size tends to become smaller and the gap tends to become narrower. This is because, among the trends of increasing the density of elements in the package and increasing the processing capacity, in particular, the spread of through-silicon vias (hereinafter, TSV) for ensuring conduction by penetrating between chips and the spread of interposer connection, which is one of the technologies for increasing the bump density, is progressing. Especially against such a background, there is an increasing demand for a semiconductor encapsulation resin composition with good narrow part filling properties. Conventionally, in the FC connection method, a liquid curable resin (for example, Patent Document 1) has been widely used as an underfill material for filling the gap (gap) between a semiconductor element and a wiring board, but there is also a demand for a solid semiconductor encapsulation resin composition (for example, Patent Documents 2 to 4) from the viewpoints of improving manufacturing efficiency and simplicity of molding processing.

[0004] In addition, in recent years, the demand for wafer-level packages as the most advanced packages has been increasing, but in the prior art, warpage is likely to occur, and there is an increasing demand for a semiconductor encapsulation resin composition that can reduce warpage.

[0005] Japanese Patent Publication No. 2020-132723, International Publication No. 2020 / 239708, Japanese Patent Publication No. 2024-100861, Japanese Patent Publication No. 2024-25821

[0006] This disclosure relates to the following: [1] A granular semiconductor encapsulating resin composition comprising (A) a thermosetting resin, (B) a curing agent, and (C) an inorganic filler, wherein (C) the inorganic filler has a cumulative volume 99% particle size (D99) of 7.0 μm or less, and (C) the inorganic filler is present in an amount of 65.0 to 80.0% by mass of the total amount of the resin composition, wherein the minimum melt viscosity at 125°C before curing is 1.0 to 3.5 Pa·s, and the room temperature modulus after curing is 10 GPa or less. [2] The granular semiconductor encapsulating resin composition according to [1], wherein (C) the inorganic filler has a cumulative volume 90% particle size (D90) of 1.0 to 3.0 μm. [3] (C) The inorganic filler is a granular semiconductor encapsulating resin composition of [1] or [2], wherein the cumulative volume 50% particle size (D50) is 0.5 to 2.5 μm. [4] (C) The inorganic filler is a granular semiconductor encapsulating resin composition of any of [1] to [3], comprising at least one selected from silica and alumina. [5] A granular semiconductor encapsulating resin composition of any of [1] to [4], wherein at least one selected from (A) a thermosetting resin and (B) a curing agent is a resin having a softening point of 80°C or higher. [6] A granular semiconductor encapsulating resin composition according to any one of [1] to [5], wherein, by classification using a JIS standard sieve, the amount of granular semiconductor encapsulating resin composition that passes through a sieve with a nominal mesh size of 0.2 mm is 3% by mass or less of the granular semiconductor encapsulating resin composition, and the amount of granular semiconductor encapsulating resin composition that passes through a sieve with a nominal mesh size of 4.0 mm is 97% by mass or more of the granular semiconductor encapsulating resin composition.

[0007] [7] A method for manufacturing a resin-encapsulated semiconductor device, comprising the step of encapsulating a semiconductor element by compression molding using any of the powder-like semiconductor encapsulation resin compositions of [1] to [6].

[0008] [8] A resin-encapsulated semiconductor device in which a semiconductor element fixed on a substrate is encapsulated with a cured product of any of the powder-type semiconductor encapsulating resin compositions [1] to [6]. [9] The resin-encapsulated semiconductor device according to [8], wherein the semiconductor element is formed by a silicon through-electrode or flip-chip bonding.

[10] A resin-encapsulated semiconductor device in which a gap of 30 μm or less is filled with a cured product of any of the powder-type semiconductor encapsulating resin compositions [1] to [6].

[0009] In recent years, there has been a demand for solid semiconductor encapsulating resin compositions that can be used under low-temperature conditions (approximately 100 to 150°C) in transfer molding or compression molding (hereinafter referred to as molding).

[0010] Conventionally, the molding process is carried out under high-temperature conditions of approximately 170 to 180°C. However, solid semiconductor encapsulating resin compositions suitable for these high-temperature conditions have high viscosity at low temperatures (for example, around 100 to 150°C) and do not meet the requirements for narrow-space filling. Furthermore, when molding is performed under these high-temperature conditions (around 170 to 180°C), stress is likely to occur during the subsequent cooling process due to the difference in the coefficient of linear expansion between the resin and the substrate. In particular, as the size of the encapsulated molded product increases, the molded product is prone to warping after curing.

[0011] For solid semiconductor encapsulating resin compositions, it is desirable to increase the filling rate of inorganic fillers from the viewpoint of predetermined heat dissipation and handling properties such as blockage resistance. From the viewpoint of narrow-space filling, it is desirable to reduce the particle size of the inorganic fillers in the resin composition. However, if inorganic fillers with small particle sizes are used and their filling rate is increased, the fluidity of the semiconductor encapsulating resin composition during molding becomes insufficient, and the narrow-space filling performance decreases. In other words, it is difficult to satisfy the requirements for predetermined heat dissipation, handling properties before curing, and narrow-space filling performance during molding.

[0012] This disclosure is based on the discovery that a granular semiconductor encapsulating resin composition containing a predetermined inorganic filler, having a predetermined minimum melt viscosity and a predetermined room-temperature modulus, satisfies the following four characteristics: • The granular semiconductor encapsulating resin composition is less prone to "blocking" in its uncured state and has good handling properties before curing. • It exhibits appropriate fluidity during low-temperature molding, satisfying the requirement for filling narrow spaces during molding. • It exhibits appropriate fluidity during low-temperature molding, reducing "resin leakage" to the outside of the cavity during molding. • It allows for low-temperature molding and reduces warping after curing.

[0013] Here, "blocking" means that the granular semiconductor encapsulating resin composition (i.e., the uncured composition) clumps together and cannot maintain its granular state. Here, "resin leakage" means that during molding, the resin flows outside the cavity and adheres to unintended areas. Reducing "resin leakage" can result in a semiconductor device with high reliability.

[0014] The present disclosure will be described in detail below with reference to one embodiment. The definitions and meanings of terms and notations used in this disclosure are shown below. The notation "X to Y" (where X and Y are numerical values) means a numerical range with X as the lower limit and Y as the upper limit. In a numerical range (for example, a range of content, etc.), the lower and upper limits described in steps may be combined independently. The lower and upper limits of the numerical range may be replaced with the numerical values ​​described in the examples. The particle diameter at 50% cumulative volume (D50), 90% cumulative volume (D90), and 99% cumulative volume (D99) refer to the particle diameters at which the cumulative volume from the smallest particle diameter side reaches 50%, 90%, and 99%, respectively, in a volume-based particle size distribution measured by a laser diffraction scattering particle size distribution analyzer.

[0015] [Powdered Semiconductor Encapsulating Resin Composition] The powdered semiconductor encapsulating resin composition of the present disclosure (hereinafter also simply referred to as the resin composition) contains (A) a thermosetting resin, (B) a curing agent, and (C) an inorganic filler, wherein (C) the inorganic filler has a cumulative volume 99% particle size (D99) of 7.0 μm or less, and the content of (C) the inorganic filler is 65.0 to 80.0% by mass of the total amount of the resin composition, wherein the minimum melt viscosity at 125°C before curing is 1.0 to 3.5 Pa·s, and the room temperature modulus after curing is 10 GPa or less.

[0016] The powder-type semiconductor encapsulating resin composition disclosed herein contains a predetermined amount of small-particle-diameter inorganic filler, and by specifying the minimum melt viscosity and room-temperature modulus within a predetermined range, it improves handling properties before curing, enhances filling properties into narrow gaps during molding (hereinafter also referred to as narrow-part filling properties), reduces resin leakage during molding, and reduces warping after curing.

[0017] Warpage after curing is usually related to the glass transition temperature of the semiconductor encapsulating resin, the elastic modulus from the molding temperature to room temperature, and the coefficient of thermal expansion, so it is necessary to consider multiple factors. However, the inventors have found that when molding under low temperature conditions (for example, around 100-150°C), the room temperature elastic modulus is strongly correlated with warpage after curing, and the lower the room temperature elastic modulus, the smaller the warpage. This is presumed to be because, under low temperature conditions, the temperature falls below the glass transition temperature of the resin, and below a certain elastic modulus, the resin is greatly affected by gravity from the time it is unloaded after molding until it cools.

[0018] ((A) Thermosetting resin) (A) The thermosetting resin can be any thermosetting resin that can be used for semiconductor encapsulating materials, and its molecular weight, molecular structure, etc., are not particularly limited. (A) Examples of thermosetting resins include epoxy resins, imide resins, acrylic resins, etc., and from the viewpoint of shrinkage, epoxy resins may also be used.

[0019] The epoxy resin only needs to have two or more epoxy groups in one molecule, and its molecular weight and molecular structure are not particularly limited. Examples of epoxy resins include biphenyl-type epoxy resins, biphenyl novolac-type epoxy resins, cresol-type epoxy resins, cresol novolac-type epoxy resins, phenol novolac-type epoxy resins, bisphenol A-type epoxy resins, bisphenol F-type epoxy resins, bisphenol S-type epoxy resins, dicyclopentadiene-type epoxy resins, triphenylmethane-type epoxy resins, triazine skeleton-containing epoxy resins, and other heterocyclic epoxy resins, as well as stilbene-type difunctional epoxy resins, naphthalene-type epoxy resins, condensed ring aromatic hydrocarbon-modified epoxy resins, alicyclic epoxy resins, and polyfunctional epoxy resins. Among these, biphenyl-type epoxy resins, naphthalene-type epoxy resins, and polyfunctional epoxy resins may be used in particular. These epoxy resins may be used individually or in mixtures of two or more types.

[0020] The softening point of the epoxy resin may be 40 to 130°C, 50 to 110°C, or 80 to 110°C, from the viewpoint of the handling properties of the resin composition and the melt viscosity during molding. It is desirable to use at least one type with a softening point of 80°C or higher. In this specification, the softening point refers to the "ring-ball softening point" and is the value measured in accordance with ASTM D36.

[0021] Examples of commercially available epoxy resins include YX-4000 (epoxy equivalent 185, softening point 105°C), YX-4000H (epoxy equivalent 193, softening point 105°C), and YX-4000HK (epoxy equivalent 180, softening point 107°C) from Mitsubishi Chemical Corporation; NC-3000 (epoxy equivalent 273, softening point 58°C), NC-3000H (epoxy equivalent 288, softening point 91°C), and EPPN-502H (epoxy equivalent 168, softening point 67°C) from Nippon Kayaku Co., Ltd.; and N-655EXP-S (epoxy equivalent 200, softening point 55°C) from DIC Corporation (all are trade names).

[0022] (A) The content of the thermosetting resin may be 2 to 30% by mass, 6 to 26% by mass, 10 to 25% by mass, or 20 to 25% by mass, based on the total amount of the resin composition. (A) When the content of the thermosetting resin is 2% by mass or more, it becomes possible to mold the cured product, and when it is 30% by mass or less, a sufficient modulus of elasticity can be obtained. When the thermosetting resin is an epoxy resin, the content of the epoxy resin may be 2 to 30% by mass, 6 to 26% by mass, 10 to 25% by mass, or 20 to 25% by mass, based on the total amount of the resin composition.

[0023] (B) Curing agent (B) The curing agent can be used without particular limitations as long as it is capable of curing the thermosetting resin (A) and is commonly used as a sealing material for electronic components.

[0024] The curing agent may include a phenolic curing agent, from the viewpoint of balancing flame resistance, moisture resistance, electrical properties, curability, and storage stability. The phenolic curing agent has two or more phenolic hydroxyl groups per molecule and is capable of curing the resin of component (A) above.

[0025] Examples of phenolic curing agents include phenol novolac resins, cresol novolac resins, aralkyl phenolic resins, biphenyl aralkyl phenolic resins, naphthalene phenolic resins, cyclopentadiene phenolic resins, and triphenolalkane phenolic resins. Among these, biphenyl aralkyl phenolic resin may be used because it allows for appropriate adjustment of fluidity during molding and facilitates improvement of the filling properties of inorganic fillers of component (C). These may be used individually or in combination of two or more types.

[0026] The softening point of the curing agent may be 40 to 130°C, 50 to 110°C, or 80 to 110°C, from the viewpoint of the handling properties of the resin composition and the melt viscosity during molding.

[0027] (B) The curing agent and at least one selected from (A) the thermosetting resin may contain a resin having a softening point of 80°C or higher. The content of the resin having a softening point of 80°C or higher may be 5 to 40% by mass, 10 to 35% by mass, or 15 to 35% by mass, based on the total amount of the resin composition. If the content of the resin having a softening point of 80°C or higher is 5% by mass or more, blocking is less likely to occur and handling properties tend to be good. If the content of the resin having a softening point of 80°C or higher is 40% by mass or less, it becomes moderately fluid, resin leakage is easily reduced and narrow-space filling properties tend to be good.

[0028] Examples of curing agents other than phenol-based curing agents (B) include amine-based curing agents, acid anhydride-based curing agents, mercaptan-based curing agents, and catalytic curing agents.

[0029] Examples of amine-based curing agents include aliphatic polyamines and aromatic polyamines. Examples of acid anhydride-based curing agents include alicyclic acid anhydrides such as hexahydrophthalic anhydride (HHPA) and methyltetrahydrophthalic anhydride (MTHPA), and aromatic acid anhydrides such as trimellitic anhydride (TMA), pyromellitic anhydride (PMDA), and benzophenonetetracarboxylic acid (BTDA). Examples of mercaptan-based curing agents include polymercaptan compounds such as polysulfides, thioesters, and thioethers. Examples of catalytic curing agents include tertiary amine compounds such as benzyldimethylamine (BDMA) and 2,4,6-trisdimethylaminomethylphenol; imidazole compounds such as 2-methylimidazole and 2-ethyl-4-methylimidazole; BF ３ Examples include Lewis acids in complexes.

[0030] (B) The amount of curing agent may be 3 to 25% by mass, 5 to 15% by mass, or 7 to 10% by mass, based on the total amount of the resin composition, from the viewpoint of the handling properties and curing properties of the resin composition.

[0031] (C) Inorganic filler (C) There are no particular limitations on the inorganic filler, and examples include known inorganic fillers that are commonly used in semiconductor encapsulation resin compositions. Specifically, powders such as fused silica, crystalline silica, alumina, zircon, calcium silicate, calcium carbonate, potassium titanate, barium titanate, silicon carbide, silicon nitride, aluminum nitride, boron nitride, beryllia, zirconia, fossterite, steatite, spinel, mullite, titania, etc., as well as beads formed from these into spheres, single crystal fibers, glass fibers, etc. (C) The inorganic filler may be used alone or a mixture of two or more types may be used.

[0032] (C) The inorganic filler may be fused silica or crystalline silica from the viewpoint of increasing mechanical strength. (C) The inorganic filler may be alumina from the viewpoint of increasing thermal conductivity, or barium titanate from the viewpoint of increasing dielectric constant.

[0033] There are no particular restrictions on the shape of the inorganic filler, but it may be spherical from the viewpoint of improving fluidity during molding.

[0034] (C) The inorganic filler has a cumulative volume 99% particle size (D99) of 7.0 μm or less, and may be 1.0 to 7.0 μm, 1.0 to 5.0 μm, 1.0 to 4.0 μm, or 1.0 to 3.7 μm. The smaller the D99, the better the narrow-space filling performance tends to be. When D99 is 1.0 μm or more, it becomes moderately fluid, which helps reduce resin leakage and tends to result in good narrow-space filling performance. When multiple types of inorganic fillers are blended, the above refers to the particle size in the overall particle size distribution of the blended inorganic fillers.

[0035] (C) The inorganic filler may have a cumulative volume 90% particle size (D90) of 1.0 to 3.0 μm, 1.0 to 2.5 μm, or 1.0 to 2.2 μm. The smaller the D90, the better the filling properties of the resin composition can be improved. When D90 is 1.0 μm or larger, good fluidity tends to be achieved. When multiple types of inorganic fillers are blended, the D90 refers to the particle size in the overall particle size distribution of the blended inorganic fillers.

[0036] (C) The inorganic filler may have a cumulative volume 50% particle size (D50) of 0.5 to 2.5 μm, or 1.0 to 2.0 μm. The smaller the D50, the better the filling properties of the resin composition can be. When D50 is 0.5 μm or larger, good fluidity tends to be achieved. When multiple types of inorganic fillers are blended, the D50 refers to the particle size in the overall particle size distribution of the blended inorganic fillers.

[0037] (C) The inorganic filler content is 65.0 to 80.0% by mass of the total resin composition, and may be 65.0 to 75.0% by mass or 70.0 to 75.0% by mass. (C) When the inorganic filler content is 65.0% by mass or more, blocking is less likely to occur and handling properties tend to be good. Also, (C) when the inorganic filler content is 65.0% by mass or more, it is easier to adjust the minimum melt viscosity of the resin composition to 1.0 Pa·s or higher. (C) When the inorganic filler content is 80.0% by mass or less, it is easier to adjust the minimum melt viscosity of the resin composition to 3.5 Pa·s or lower and narrow-space filling properties tend to be good. Also, (C) when the inorganic filler content is 80.0% by mass or less, it is easier to adjust the room-temperature modulus of the resin composition after curing to 10 GPa or lower and warping after curing tends to be reduced.

[0038] (D) Curing accelerator (D) The curing accelerator can be used without particular limitations as long as it is one that is commonly used as a curing accelerator for (A) thermosetting resin, which is a component of the resin composition.

[0039] (D) Examples of curing accelerators include cycloamidine compounds such as 1,8-diazabicyclo[5.4.0]undecene-7, 1,5-diazabicyclo[4.3.0]nonene-5, and 5,6-dibutylamino-1,8-diazabicyclo[5.4.0]undecene-7; and these cycloamidine compounds can be combined with maleic anhydride, 1,4-benzoquinone, 2,5-thulquinone, 1,4-naphthoquinone, 2,3-dimethylbenzoquinone, 2,6-dimethylbenzoquinone, 2,3-dimethoxy-5-methyl-1,4-benzoquinone, phenyl-1,4-benzoquinone, etc. Compounds having intramolecular polarization obtained by adding compounds with π bonds such as non-compounds, diazophenylmethane, and phenolic resins; tertiary amine compounds such as benzyldimethylamine, triethanolamine, dimethylaminoethanol, and tris(dimethylaminomethyl)phenol and their derivatives; 2-methylimidazole, 2-ethylimidazole, 2-phenylimidazole, 2-ethyl-4-methylimidazole, 2-phenyl-4-methylimidazole, 2-heptadecylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2 Imidazole compounds and derivatives thereof, such as diamino-s-silicon-containing triazine compounds having an imidazole ring, including phenyl-4-methyl-5-hydroxymethylimidazole, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-undecylimidazolyl-(1')]-ethyl-s-triazine, and 2,4-diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]-ethyl-s-triazine; tributylphosphine, methyldiphenylphosphine, triphe Organic phosphine compounds such as ylphosphine, tris(4-methylphenyl)phosphine, diphenylphosphine, and phenylphosphine; phosphorus compounds having intramolecular polarization obtained by adding quinone compounds such as maleic anhydride, 1,4-benzoquinone, 2,5-tholquinone, 1,4-naphthoquinone, 2,3-dimethylbenzoquinone, 2,6-dimethylbenzoquinone, 2,3-dimethoxy-5-methyl-1,4-benzoquinone, and phenyl-1,4-benzoquinone, as well as diazophenylmethane and phenolic resins, to these organic phosphine compounds;Examples include tetra-substituted phosphonium / tetra-substituted borates such as tetraphenylphosphonium tetraphenylborate, tetraphenylphosphonium ethyltriphenylborate, and tetrabutylphosphonium tetrabutylborate; tetraphenylboron salts such as 2-ethyl-4-methylimidazole tetraphenylborate and N-methylmorpholine tetraphenylborate, and their derivatives. (D) The curing accelerator may be used alone or in a mixture of two or more types.

[0040] (D) As a curing accelerator, an imidazole-based curing accelerator may be used from the viewpoint of fluidity.

[0041] (D) The content of the curing accelerator may be 0.08 to 3.00% by mass or 0.30 to 1.00% by mass, based on the total amount of the resin composition. (D) When the content of the curing accelerator is 0.08% by mass or more, a curing acceleration effect is obtained, and when it is 3.00% by mass or less, the narrow-space filling properties tend to be good.

[0042] (Other components) In addition to the components described above, the resin composition of this embodiment may optionally contain other additives commonly used in this type of composition, such as flame retardants, carbon black, titanium black, organic dyes, colorants such as titanium dioxide and red iron oxide, mold release agents, coupling agents such as silane coupling agents, ion trapping agents, and waxes such as carnauba wax.

[0043] When the above-mentioned additive is included, the amount added should be within a range that does not impede the effects of reducing warpage, good handling, good narrow-space filling, and resin leakage. Each of these may be 0.01 to 3.00% by mass or 0.10 to 1.20% by mass, based on the total amount of the resin composition.

[0044] (Method for Producing Granular Semiconductor Encapsulation Resin Composition) The method for producing the granular semiconductor encapsulation resin composition of the present disclosure is not particularly limited. As a general method, after preliminarily mixing the components (A) to (D) and various additive components such as additives to be blended as necessary with a mixer or the like, kneading treatment is performed using a disperser, kneader, three-roll mill, or the like, and then cooling and solidifying, and it can be obtained by a method of pulverizing into an appropriate size. Further, for the obtained granular semiconductor encapsulation resin composition, the degree of dispersion, fluidity, etc. may be adjusted as appropriate. The granular semiconductor encapsulation resin composition of the present disclosure may be obtained by physical pulverization, or may be obtained by molding into a granular, spherical or flaky shape or the like.

[0045] The pulverization method is not particularly limited, and a general pulverizer can be used. For example, a cutting mill, ball mill, cyclone mill, hammer mill, vibration mill, cutter mill, grinder mill, etc. may be used, or a speed mill may be used.

[0046] Classification may be performed to adjust the pulverized product obtained by pulverization into an aggregate of particles having a predetermined particle size distribution by sieving classification, air classification, or the like. For example, when classified using a sieve of about 7 to 500 mesh, it can be suitably applied to the semiconductor device of the present disclosure.

[0047] The classification may be a classification using a JIS standard sieve (specified in JIS Z8801-1:2006). The granular semiconductor encapsulation resin composition passing through a sieve with a nominal opening of 0.2 mm is 3% by mass or less in the granular semiconductor encapsulation resin composition, and the granular semiconductor encapsulation resin composition passing through a sieve with a nominal opening of 4.0 mm is 97% by mass or more in the granular semiconductor encapsulation resin composition. The classification may be such that the granular semiconductor encapsulation resin composition passing through a sieve with a nominal opening of 0.2 mm is 3% by mass or less in the granular semiconductor encapsulation resin composition, and the granular semiconductor encapsulation resin composition passing through a sieve with a nominal opening of 1.0 mm is 97% by mass or more in the granular semiconductor encapsulation resin composition.

[0048] [Resin-Sealed Semiconductor Device] In one embodiment, a resin-sealed semiconductor device is one in which a semiconductor element fixed on a substrate is sealed with a cured product of the powder-like semiconductor encapsulating resin composition of the present disclosure, and the semiconductor element may be formed by a silicon through-electrode or a flip-chip bond.

[0049] The semiconductor elements encapsulated in a resin-encapsulated semiconductor device are not particularly limited and include, for example, integrated circuits (ICs), large-scale integrated circuits (LSIs), diodes, thyristors, transistors, etc. The substrate is not particularly limited and may be one commonly used for fixing semiconductor elements, such as a glass substrate or a package substrate. It may also be a wafer such as a silicon wafer. The material of the substrate may be, for example, glass epoxy, polyimide, polyester, or ceramic.

[0050] In other embodiments, resin-encapsulated semiconductor devices have gaps ranging from several μm to 30 μm filled with cured products of the granular semiconductor encapsulation resin composition of the Disclosure, such as flip-chip ball grid arrays (FCBGAs) and wafer-level packages (WLPs).

[0051] The resin composition of this disclosure has good handling properties before curing, good narrow-space filling properties during molding, reduced resin leakage during molding, and reduced warping after curing. Therefore, the encapsulated semiconductor element may be formed by TSV or flip-chip bonding. Furthermore, the encapsulated semiconductor package may consist of multiple semiconductor elements stacked on a large-area substrate using TSV, interposer connection, or flip-chip bonding. Even with such semiconductor elements, a highly reliable resin-encapsulated semiconductor device can be obtained by using the resin composition of this disclosure.

[0052] [Method for manufacturing a resin-encapsulated semiconductor device] In one embodiment, the method for manufacturing a resin-encapsulated semiconductor device includes a step of encapsulating a semiconductor element or the like by compression molding using the powder-granular semiconductor encapsulation resin composition of the present disclosure.

[0053] In one embodiment, compression molding includes supplying a substrate with semiconductor components mounted on it to the upper mold of a molding die, supplying the granular semiconductor encapsulating resin composition of the present disclosure into the cavity of the lower mold, clamping both the upper and lower molds with a required clamping pressure to immerse the semiconductor components in the resin composition heated and melted in the lower mold cavity, and pressing the resin composition heated and melted in the lower mold cavity with a cavity bottom member, applying a required pressure under reduced pressure, and performing compression molding. The molding conditions may be a temperature of 110 to 180°C and a pressure of 2 to 10 MPa. Post-curing may be performed after molding. Post-curing may be performed by heating at 130 to 190°C for 0.5 to 8 hours.

[0054] By undergoing a sealing process using this molding method, it is easier to achieve good filling properties and obtain a highly reliable resin-encapsulated semiconductor device.

[0055] Next, the present disclosure will be specifically described by examples. The present disclosure is not limited in any way by these examples.

[0056] (Examples 1-2 and Comparative Examples 1-4) The components of the types and amounts listed in Table 1 were kneaded in a twin-screw extruder at a kneading temperature of 100°C and a kneading time of 5 minutes to prepare a resin composition. Then, after cooling and solidifying, the mixture was pulverized to produce a powder-like semiconductor encapsulating resin composition.

[0057] The details of each component listed in Table 1 used in the preparation of the resin composition are as follows:

[0058] [(A) Thermosetting resins] ・YX-4000HK: Biphenyl-type epoxy resin (trade name, manufactured by Mitsubishi Chemical Corporation, epoxy equivalent: 180, softening point: 107°C) ・NC-3000: Biphenyl novolac epoxy resin (trade name, manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent: 273, softening point: 58°C)

[0059] [(B) Curing Agents] ・HE610C-07: Biphenyl aralkyl type phenol resin (product name, manufactured by Air Water Inc., phenol equivalent 183, softening point 73°C) ・MEHC-7800M: Zylog type phenol resin (product name, manufactured by Meiwa Chemicals Inc., phenol equivalent 170, softening point 79°C) ・MEH-7500: Triphenylmethane type phenol resin (product name, manufactured by Meiwa Chemicals Inc., hydroxyl group equivalent 97, softening point 110°C) ・SN-485: Naphthalene type phenol resin (product name, manufactured by Nippon Steel Chemicals Inc., phenol equivalent 210, softening point 85°C)

[0060] [(C) Inorganic Fillers] ・AdmaFine (registered trademark) SE-4500SQV: Fused silica (product name, manufactured by Admatex Co., Ltd., D99 = 3.7 μm, D90 = 2.2 μm, D50 = 1.0 μm) ・AdmaFine (registered trademark) SE-2500SQV: Fused silica (product name, manufactured by Admatex Co., Ltd., D99 = 1.9 μm, D90 = 1.2 μm, D50 = 0.6 μm) ・AdmaFine (registered trademark) SC-4500SQ: Fused silica (product name, manufactured by Admatex Co., Ltd., D99 = 3.7 μm, D90 = 2.2 μm, D50 = 1.0 μm) FB-310MDX: Fused silica (product name, manufactured by Denka Co., Ltd., D99 = 12.7 μm, D90 = 8.7 μm, D50 = 4.6 μm)

[0061] [(D) Curing accelerator] ・TIC-188: Inclusion-type imidazole compound (trade name, manufactured by Nippon Soda Co., Ltd.)

[0062] [(E) Coloring agent] ・MA-600: Carbon black (product name, manufactured by Mitsubishi Chemical Corporation)

[0063] [Other ingredients] • Coupling agent: Y-9669 (product name, manufactured by Momentive, 3-(N-phenyl)aminopropyltrimethoxysilane)

[0064] The shape and properties of the powdered semiconductor encapsulating resin compositions produced in Examples 1-2 and Comparative Examples 1-4 were measured and evaluated using the methods described below. The results are shown in Table 1.

[0065] [Shape: Evaluation Item] (Shape of encapsulating material) The shape of the powdered semiconductor encapsulating resin composition was confirmed visually.

[0066] [Shape: Measurement Item] (Size of granular semiconductor encapsulating resin composition) The content of granular semiconductor encapsulating resin composition passing through a sieve with a nominal mesh size of 0.2 mm and the content of granular semiconductor encapsulating resin composition passing through a sieve with a nominal mesh size of 4.0 mm were measured by classification using JIS standard sieves (as specified in JIS Z8801-1:2006).

[0067] [Characteristics: Measurement Items] (Spiral Flow) The spiral flow was measured by transfer molding the obtained resin composition at a molding temperature of 175°C and a molding pressure of 7 MPa. In Table 1, ">420" means that the upper limit of measurement (420 cm) was exceeded.

[0068] (Gel Time) The obtained resin composition was spread in a circular shape with a diameter of 3 to 5 cm on a hot plate maintained at 175°C and kneaded at a constant speed. The time it took for the resin composition to thicken and eventually lose its viscosity was measured.

[0069] (Minimum melt viscosity) The minimum melt viscosity of the obtained resin composition was measured using a HAAKE MARS rheometer under the conditions of 125°C, vibration measurement, shear stress of 500 Pa, and vibration frequency of 10 Hz. If the minimum melt viscosity is 1.0 to 3.5 Pa·s, it will have appropriate fluidity, making it easier to reduce resin leakage and improve the ability to fill narrow spaces. The viscosity may be 1.2 to 3.2 Pa·s or 1.5 to 3.0 Pa·s.

[0070] (Glass transition temperature (Tg) and thermal expansion coefficients (α1, α2) of the cured product) The obtained resin composition was molded using a transfer molding machine under the conditions of a mold temperature of 175°C, a molding pressure of 7 MPa, and a curing time of 180 seconds. Further curing was performed at 175°C for 8 hours to prepare a test specimen (3 mm × 4 mm × 17 mm). Using the obtained test specimen, the TMA curve was measured using a thermal analyzer (manufactured by Rigaku Corporation, product name: TMA / Thermo plus EVO2) under the conditions of a heating rate of 10°C / min and a load of 98 mN. The slope of the tangent line of the obtained TMA curve between 50 and 90°C was defined as the linear expansion coefficient α1, and the slope of the tangent line of the obtained TMA curve between 200 and 230°C was defined as the linear expansion coefficient α2. The temperature at the intersection of the tangent lines of the TMA curve at 90°C and 190°C was read, and this temperature was defined as the glass transition temperature (Tg).

[0071] (Molding shrinkage rate) Using the aforementioned test specimen (a specimen molded at a molding temperature of 175°C for a molding time of 180 seconds, and then subjected to a post-curing treatment at 175°C for 8 hours after molding), the molding shrinkage rate was measured in accordance with the general test method for thermosetting plastics (JIS K6911:1995 5.7 Molding shrinkage rate and heat shrinkage rate (molding material)).

[0072] (Room Temperature Modulus) The room temperature modulus of the cured product obtained by heating the resin composition at 175°C for 3 minutes was measured in accordance with JIS K6911:1995. A bending tester (Shimadzu Corporation Autograph AG-X) was used as the measuring device. If the room temperature modulus is 10 GPa or less, it is easy to obtain a suitable flexibility and a well-sealed semiconductor device. The modulus may be 3 to 10 GPa, 5 to 10 GPa, or 7 to 10 GPa.

[0073] [Characteristics: Evaluation Items]

[0074] (Blocking) Approximately 100g of the sieved resin composition was placed in moisture-proof packaging and left at 23°C for 48 hours. If no lumps were found after removal, it was marked as "○"; if lumps were found after removal, it was marked as "×".

[0075] (Filling ability) A slit with a depth of 13 μm was prepared, and the obtained resin composition was injected and cured for a sufficient amount of time at 125°C and 5 MPa. If the resin flowed 50 mm or more, it was marked as "○", and if it flowed less than 50 mm, it was marked as "×".

[0076] (Warpage) A 12-inch diameter silicon wafer (770 μm thick) was sealed with the obtained resin composition (compression molding, resin thickness 300 μm), heated at 125°C for 30 minutes to cure, and a cured test specimen was prepared. The cured test specimen was placed on a horizontal surface, and the height position of the warped outer edge on the upper surface from the horizontal surface was measured as warpage. A value of "○" was used if the warpage was less than 3.0 mm, and a value of "×" was used if it was 3.0 mm or more. If the warpage is less than 3.0 mm, it can be said that the cured test specimen has little warpage and good moldability. The warpage may be 2.5 mm or less, or 2.0 mm or less.

[0077] (Resin leakage) The mold used to prepare the cured test specimen was observed, and if there was no resin adhesion after molding, it was marked with "○", and if there was adhesion, it was marked with "×".

[0078]

[0079] The evaluation results shown in Table 1 confirm that the powder-type semiconductor encapsulating resin composition of this disclosure does not cause blocking in the uncured state, has good narrow-space filling properties during molding, is less prone to resin leakage during molding, and is less prone to warping after curing.

Claims

1. A granular semiconductor encapsulating resin composition comprising (A) a thermosetting resin, (B) a curing agent, and (C) an inorganic filler, wherein (C) the inorganic filler has a cumulative volume 99% particle size (D99) of 7.0 μm or less, and the content of (C) the inorganic filler is 65.0 to 80.0% by mass of the total amount of the resin composition, wherein the minimum melt viscosity at 125°C before curing is 1.0 to 3.5 Pa·s, and the room temperature modulus after curing is 10 GPa or less.

2. (C) The inorganic filler has a cumulative volume 90% particle size (D90) of 1.0 to 3.0 μm, the powder-like semiconductor encapsulating resin composition according to claim 1.

3. (C) The inorganic filler has a cumulative volume 50% particle size (D50) of 0.5 to 2.5 μm, the powder-like semiconductor encapsulating resin composition according to claim 1 or 2.

4. (C) The granular semiconductor encapsulating resin composition according to any one of claims 1 to 3, wherein the inorganic filler comprises at least one selected from silica and alumina.

5. The powder-type semiconductor encapsulating resin composition according to any one of claims 1 to 4, wherein at least one selected from (A) a thermosetting resin and (B) a curing agent comprises a resin having a softening point of 80°C or higher.

6. The granular semiconductor encapsulating resin composition according to any one of claims 1 to 5, wherein, by classification using a JIS standard sieve, the amount of the granular semiconductor encapsulating resin composition that passes through a sieve with a nominal mesh size of 0.2 mm is 3% by mass or less of the granular semiconductor encapsulating resin composition, and the amount of the granular semiconductor encapsulating resin composition that passes through a sieve with a nominal mesh size of 4.0 mm is 97% by mass or more of the granular semiconductor encapsulating resin composition.

7. A method for manufacturing a resin-encapsulated semiconductor device, comprising the step of encapsulating a semiconductor element by compression molding using the powder-like semiconductor encapsulation resin composition described in any one of claims 1 to 6.

8. A resin-encapsulated semiconductor device in which a semiconductor element fixed on a substrate is encapsulated with a cured product of the powder-type semiconductor encapsulation resin composition described in any one of claims 1 to 6.

9. The resin-sealed semiconductor device according to claim 8, wherein the semiconductor element is formed by a through-silicon electrode or a flip-chip junction.

10. A resin-encapsulated semiconductor device in which a gap of 30 μm or less is filled with a cured product of the powder-type semiconductor encapsulation resin composition described in any one of claims 1 to 6.

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