JP7828795B2 - Resin composition for semiconductor encapsulation and semiconductor device - Google Patents

Description

This disclosure relates to a resin composition for semiconductor encapsulation and a semiconductor device.

Conventionally, thermosetting resin compositions have been commonly used as encapsulants for semiconductor chips such as ICs and LSIs. Among these, epoxy resin compositions are excellent encapsulants in terms of the balance between economy and performance. Epoxy resin compositions are increasingly being used, for example, in surface-mount single-sided encapsulated BGA (Ball Grid Array) and LGA (Land Grid Array) packages, which have become mainstream due to the miniaturization and thinning of electronic devices in recent years, as well as in various sensor encapsulation applications and LED reflectors.
However, single-sided encapsulated packages and sensors have a problem in recent years: the thinning of wires makes them more susceptible to wire deformation due to the flow of the encapsulating resin during molding. To reduce this wire deformation, it is essential to increase the fluidity of the encapsulating resin. Generally, to increase the fluidity of the encapsulating resin, the amount of inorganic filler added is reduced. However, reducing the amount of inorganic filler added to increase the fluidity of the encapsulating resin increases the resin shrinkage rate after molding, causing warping in single-sided encapsulated packages, which prevents them from being mounted on a substrate during surface mounting.
To solve this problem, it is known to add epoxy-modified silicone resin or liquid epoxidized polybutadiene to the epoxy resin composition (see Patent Documents 1 and 2).

Japanese Patent Publication No. 2006-152185 Japanese Patent Publication No. 2012-7091

However, adding epoxy-modified silicone resin or liquid epoxidized polybutadiene to reduce molding shrinkage, while increasing the amount, could lead to a decrease in the appearance, strength, and flame retardancy of the molded product. Furthermore, achieving both a reduction in wire deformation and a reduction in package warpage was not sufficient.

This disclosure is made in view of the above circumstances and aims to provide a semiconductor encapsulation resin composition that exhibits excellent resin fluidity and can reduce wire deformation and package warping while maintaining the appearance, strength, and flame retardancy of the molded product, as well as a semiconductor device using said semiconductor encapsulation resin composition.

As a result of diligent research to solve the above problems, the inventors of this invention have found that a semiconductor encapsulation resin composition containing a predetermined amount of a shrinkage rate modifier having a specific structure with a maximum particle size of 105 μm or less exhibits excellent resin fluidity and can reduce wire deformation and package warping while maintaining the appearance, strength, and flame retardancy of the molded product.

In other words, this disclosure relates to the following:
[1] A semiconductor encapsulation resin composition comprising (A) epoxy resin, (B) phenolic resin, (C) curing accelerator, (D) inorganic filler, and (E) shrinkage rate modifier, wherein (E) shrinkage rate modifier is a compound represented by the following general formula (1) having a maximum particle size of 105 μm or less, and the content of (D) inorganic filler is 60 to 95% by mass and the content of (E) shrinkage rate modifier is 0.3 to 3.5% by mass with respect to the total amount of the resin composition.

(In formula (1), ^R1 and ^R2 are each independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.)
[2] A semiconductor device comprising a substrate, a semiconductor element mounted on the substrate, and a cured product of the semiconductor encapsulation resin composition described in [1] above, which encapsulates the semiconductor element.

This disclosure provides a semiconductor encapsulation resin composition that exhibits excellent resin fluidity and can reduce wire deformation and package warping while maintaining the appearance, strength, and flame retardancy of the molded product, as well as a semiconductor device using the semiconductor encapsulation resin composition.

The present disclosure will be described in detail below with reference to one embodiment.

[Resin composition for semiconductor encapsulation]
The semiconductor encapsulation resin composition of this disclosure (hereinafter also simply referred to as the resin composition) contains (A) an epoxy resin, (B) a phenolic resin, (C) a curing accelerator, (D) an inorganic filler, and (E) a shrinkage rate modifier, wherein the (E) shrinkage rate modifier is a compound represented by the following general formula (1) with a maximum particle size of 105 μm or less, and the content of the (D) inorganic filler is 60 to 95% by mass and the content of the (E) shrinkage rate modifier is 0.3 to 3.5% by mass of the total amount of the resin composition.

In formula (1), ^R1 and ^R2 are each independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

[(A) Epoxy resin]
The epoxy resin (A) used in this disclosure is not particularly limited as long as it is a compound having two or more epoxy groups in one molecule, and monomers, oligomers, and polymers can all be used. (A) The epoxy resin is not particularly limited in terms of its molecular weight or molecular structure, but examples include crystalline epoxy resins such as biphenyl-type epoxy resin, bisphenol F-type epoxy resin, and stilbene-type epoxy resin; novolac-type epoxy resins such as phenol novolac-type epoxy resin and cresol novolac-type epoxy resin; polyfunctional epoxy resins such as triphenolmethane-type epoxy resin and alkyl-modified triphenolmethane-type epoxy resin; aralkyl-type epoxy resins such as phenol aralkyl-type epoxy resin having a phenylene skeleton and phenol aralkyl-type epoxy resin having a biphenylene skeleton; naphthol-type epoxy resins such as dihydroxynaphthalene-type epoxy resin and epoxy resin obtained by glycidyl etherification of a dimer of dihydroxynaphthalene; triazine nucleus-containing epoxy resins such as triglycidyl isocyanurate and monoallyl diglycidyl isocyanurate; and bridged cyclic hydrocarbon compound-modified phenol-type epoxy resins such as dicyclopentadiene-modified phenol-type epoxy resin. (A) The epoxy resin may be used alone or in combination of two or more types.
(A) The epoxy resin may be a crystalline epoxy resin such as biphenyl-type epoxy resin, bisphenol F-type epoxy resin, or stilbene-type epoxy resin, from the viewpoint of having low viscosity and (D) being able to increase the content of inorganic fillers.

(A) The epoxy resin can be handled as a solid at room temperature (23°C), and its viscosity at 150°C may be 0.005 Pa·s or higher, or 0.01 Pa·s or higher. Furthermore, the upper limit of the viscosity of (A) epoxy resin at 150°C may be 1.0 Pa·s or lower, or 0.5 Pa·s or lower. If the viscosity of (A) epoxy resin at 150°C is within the above range, manufacturing becomes easier, molded articles of the resin composition, such as tablets or crushed powder for compression molding, can be easily produced, and the fluidity during heated molding is good.
(A) The viscosity of epoxy resin at 150°C can be measured using an ICI viscometer (ASTM D4287, compliant with American Society for Testing and Materials standards).

(A) The epoxy resin content may be 2 to 20% by mass, 3 to 15% by mass, or 4 to 12% by mass, relative to the total amount of the resin composition. (A) When the epoxy resin content is 2% by mass or more, the cured product can be molded, and when it is 20% by mass or less, molding becomes easy.

[(B) Phenolic resin]
The (B) phenolic resin used in this disclosure primarily serves to enhance moldability. The (B) phenolic resin can be used without particular limitations as long as it has two or more phenolic hydroxyl groups in one molecule that can react with the epoxy groups of the epoxy resin of component (A) above.
(B) Examples of phenolic resins include novolac-type phenolic resins such as phenol novolac resin, cresol novolac resin, trisphenolmethane-type phenol novolac resin, and naphthol novolac resin; polyfunctional phenolic resins such as triphenolmethane-type phenolic resin; modified phenolic resins such as terpene-modified phenolic resin, triphenylmethane-type phenolic resin modified with formaldehyde, trihydroxyphenylmethane-type phenolic resin modified with formaldehyde, and dicyclopentadiene-modified phenolic resin; aralkyl-type phenolic resins such as phenol aralkyl resins having a phenylene skeleton and/or biphenylene skeleton, naphthol aralkyl resins having a phenylene and/or biphenylene skeleton, phenyl aralkyl-type phenolic resin, and biphenyl aralkyl-type phenolic resin; and bisphenol compounds such as bisphenol A and bisphenol F. (B) The phenolic resin may be used alone or in combination of two or more types.
(B) As the phenolic resin, at least one selected from the group consisting of novolac-type phenolic resins, polyfunctional phenolic resins, and aralkyl-type phenolic resins may be used.

(B) The phenolic resin may be a polyfunctional phenolic resin, an aralkyl phenolic resin, a triphenolmethane phenolic resin, a phenol aralkyl resin, a naphthol aralkyl resin, or a biphenyl aralkyl phenolic resin, from the viewpoint of having low viscosity and high flame retardancy.

(B) The phenolic resin can be handled as a solid at room temperature (23°C), and its viscosity at 150°C may be 0.005 Pa·s or higher, or 0.1 Pa·s or higher. Furthermore, the upper limit of the viscosity of (B) the phenolic resin at 150°C may be 2.5 Pa·s or lower, or 1.0 Pa·s or lower. If the viscosity of (B) the phenolic resin at 150°C is within the above range, manufacturing becomes easier, molded articles of the resin composition, such as tablets or crushed powder for compression molding, can be easily produced, and the fluidity during heated molding is good.
(B) The viscosity of phenolic resin at 150°C can be measured using an ICI viscometer (ASTM D4287, compliant with American Society for Testing and Materials standards).

(B) The content of phenolic resin may be 0.5 to 1.5 equivalents or 0.5 to 1.2 equivalents of hydroxyl groups in (B) phenolic resin per equivalent of epoxy groups in (A) epoxy resin. By including (B) phenolic resin in the above equivalent ratio, a molded product with balanced performance can be obtained.

[(C) Hardening accelerator]
The curing accelerator (C) used in this disclosure is not particularly limited as long as it is commonly used as a curing accelerator for epoxy resins. Examples of the curing accelerator (C) 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; quinone compounds such as 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, and phenyl-1,4-benzoquinone; and molecules obtained by adding compounds having π bonds, such as diazophenylmethane and phenolic resins. Compounds having internal polarization; tertiary amine compounds such as benzyldimethylamine, triethanolamine, dimethylaminoethanol, 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-phenyl-4-methyl-5-hydroxymethylimidazole, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'- Imidazole compounds and derivatives thereof, such as diamino-s-triazine compounds having an imidazole ring, such as ndecylimidazolyl-(1')-ethyl-s-triazine and 2,4-diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]-ethyl-s-triazine; organophosphine compounds such as tributylphosphine, methyldiphenylphosphine, triphenylphosphine, tris(4-methylphenyl)phosphine, diphenylphosphine, and phenylphosphine; and these organophosphine compounds with maleic anhydride, 1,4-benzoquinone, 2,5-tholquinone, 1,4-naphthoquinone, 2,3-dimethylbenzoquinone, and 2,6-di Examples include quinone compounds such as methylbenzoquinone, 2,3-dimethoxy-5-methyl-1,4-benzoquinone, and phenyl-1,4-benzoquinone; phosphorus compounds having intramolecular polarization obtained by adding compounds having π bonds such as diazophenylmethane and phenolic resins; tetrasubstituted phosphonium/tetrasubstituted borates such as tetraphenylphosphonium tetraphenylborate, tetraphenylphosphonium ethyltriphenylborate, and tetrabutylphosphonium tetrabutylborate; tetraphenylboron salts such as 2-ethyl-4-methylimidazole tetraphenylborate and N-methylmorpholine tetraphenylborate, and derivatives thereof. (C) The curing accelerator may be used alone or in combination of two or more types.

(C) As a curing accelerator, an imidazole compound may be used from the viewpoint of fluidity.

(C) The content of the curing accelerator may be 0.05 to 3.00% by mass, 0.10 to 2.00% by mass, or 0.15 to 1.00% by mass, based on the total amount of the resin composition. (C) A curing accelerator content of 0.05% by mass or more provides an accelerated curing effect, while a content of 3.00% by mass or less allows for good filling properties.

[(D) Inorganic filler]
The inorganic filler (D) used in this disclosure is not particularly limited as long as it is commonly used in encapsulating resin compositions. Examples of the inorganic filler (D) may be 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, fostellite, steatite, spinel, mullite, titania, etc., as well as beads formed from these, single crystal fibers, glass fibers, etc. The inorganic filler (D) may be used alone or in combination of two or more types.

(D) As the inorganic filler, fused silica may be used from the viewpoint of reducing the coefficient of thermal expansion, and alumina may be used from the viewpoint of improving thermal conductivity. In semiconductor packages, it is desirable to have high thermal conductivity in order to dissipate the heat generated from the chip to the outside. Furthermore, the shape of the (D) inorganic filler may be spherical from the viewpoint of improving fluidity during molding and reducing mold wear.

(D) The inorganic filler may have an average particle size of 1 to 50 μm or 2 to 30 μm. (D) When the average particle size of the inorganic filler is within the above range, the fluidity of the resin composition can be increased. In addition, in single-sided sealed packages, wire deformation can be reduced and the narrow-space filling ability of the resin composition can be improved.
In this disclosure, the average particle diameter refers to the particle diameter (D50) at which the cumulative total from the smaller diameter side reaches 50% in the volume-based particle size distribution obtained using a laser diffraction scattering particle size distribution analyzer. Furthermore, if multiple types of inorganic fillers are blended as component (D), the average particle diameter refers to the overall average particle diameter of the blended inorganic fillers.

(D) The content of inorganic filler is 60 to 95% by mass of the total amount of resin composition. If the content of inorganic filler is less than 60% by mass, the molding shrinkage rate of the resin composition will be large, and the resulting package may warp. If it exceeds 95% by mass, the fluidity and moldability of the resin composition may decrease. From this viewpoint, the content of inorganic filler may be 70 to 90% by mass of the total amount of the sealing resin composition.
Furthermore, if (D) the inorganic filler is silica, its content may be 76 to 85% by mass, and if it is alumina, its content may be 85 to 91% by mass.

[(E) Shrinkage rate adjusting agent]
The (E) shrinkage rate modifier used in this disclosure is a compound represented by the following general formula (1) having a maximum particle size of 105 μm or less. The semiconductor encapsulating resin composition of this disclosure, by containing the (E) shrinkage rate modifier, can reduce the molding shrinkage rate of the resin composition and reduce the warping of the resulting package. This effect is obtained because the (E) shrinkage rate modifier acts as a crystal nucleating agent and does not adversely affect the fluidity of the resin.

In general formula (1), ^R1 and ^R2 are each independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.
Examples of C1-C6 alkyl groups for ^R1 and ^R2 include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, neopentyl, and hexyl groups. ^R1 and ^R2 may also be tert-butyl and hexyl groups.

The compound represented by general formula (1) may also be tris(2,4-di-t-butylphenyl) phosphite represented by the following formula (i). (E) By using tris(2,4-di-t-butylphenyl) phosphite as a shrinkage rate modifier, in addition to the effect of reducing molding shrinkage, a flame retardant effect is also exhibited.

(E) The shrinkage rate modifier has a maximum particle size of 105 μm or less. If the maximum particle size of (E) the shrinkage rate modifier exceeds 105 μm, voids or flow marks may occur on the surface of the molded product, potentially impairing the appearance of the resulting package. From this viewpoint, the maximum particle size of (E) the shrinkage rate modifier may be 75 μm or less, or 53 μm or less.
Here, "maximum particle size" refers to the particle size measured by the dry sieving method, which is defined by the mesh size of the finest sieve through which at least 95% by mass of the sample passes.

(E) The method for adjusting the maximum particle size of the shrinkage rate adjusting agent is not particularly limited as long as it is capable of grinding to a particle size of 105 μm or less, and examples include methods using grinders such as cutting mills, ball mills, cyclone mills, hammer mills, vibration mills, cutter mills, grinder mills, and speed mills.
(E) The maximum particle size of the shrinkage rate modifier can be measured by dry sieving. Specifically, it can be measured by the method described in the examples.

(E) The content of the shrinkage rate modifier is 0.3 to 3.5% by mass of the total amount of the resin composition. If the content of (E) the shrinkage rate modifier is less than 0.3% by mass, the effect of reducing the molding shrinkage rate of the resin composition is small, and the resulting package may warp significantly. If it exceeds 3.5% by mass, the strength of the cured product may decrease. From this perspective, the content of (E) the shrinkage rate modifier may be 0.3 to 3.0% by mass or 0.5 to 2.5% by mass of the total amount of the resin composition.

[(F) Coloring agent]
The semiconductor encapsulation resin composition of this disclosure may further contain (F) a coloring agent from the viewpoint of light shielding.
(F) Examples of colorants include carbon black, titanium black, aniline blue, chrome yellow, phthalocyanine blue, and red iron oxide. (F) The colorant may also be carbon black.

If the semiconductor encapsulation resin composition of this disclosure contains (F) a colorant, the amount thereof may be 0.05 to 3.00% by mass, 0.10 to 2.00% by mass, or 0.15 to 1.00% by mass, based on the total amount of the encapsulation resin composition.

[Other ingredients]
In addition to the components described above, the semiconductor encapsulation resin composition of this disclosure may optionally contain additives such as release agents, flame retardants, coupling agents such as silane coupling agents, ion trapping agents, and waxes such as carnauba wax, which are commonly incorporated into this type of composition.
If the semiconductor encapsulation resin composition of this disclosure contains the above-mentioned additives, the amount of each additive may be 0.05 to 3.00% by mass, 0.10 to 2.00% by mass, or 0.15 to 1.00% by mass, based on the total amount of the resin composition.

In the semiconductor encapsulation resin composition of this disclosure, the total content of components (A) to (E) may be 80% by mass or more, 90% by mass or more, or 95% by mass or more.

[Physical properties of resin compositions for semiconductor encapsulation]
The semiconductor encapsulation resin composition of this disclosure may have a flow viscosity of 15 Pa·s or less, 10 Pa·s or less, or 8 Pa·s or less at 175°C.
The semiconductor encapsulation resin composition of this disclosure may have a molding shrinkage rate of 0.30% or less, 0.28% or less, or 0.25% or less.
The above flow viscosity and molding shrinkage rate can be measured by the method described in the examples.

[Preparation of resin compositions for semiconductor encapsulation]
In preparing the semiconductor encapsulation resin composition of this disclosure, (A) epoxy resin, (B) phenolic resin, (C) curing accelerator, (D) inorganic filler, (E) shrinkage rate modifier, (F) coloring agent (optionally), and various additives are thoroughly mixed (dry blended) using a mixer or the like, then melt-kneaded using a kneading device such as a hot roll or kneader, cooled, and then pulverized to an appropriate size.
The above grinding method is not particularly limited, and any general-purpose grinder can be used. Examples of grinders that can be used include cutting mills, ball mills, cyclone mills, hammer mills, vibratory mills, cutter mills, and grinder mills.

The semiconductor encapsulation resin composition disclosed herein can be used for coating, insulating, encapsulating, and other applications of various electrical components or electronic components such as semiconductor elements.

[Semiconductor equipment]
The semiconductor device of this disclosure comprises a substrate, a semiconductor element mounted on the substrate, and a cured product of the semiconductor encapsulation resin composition that encapsulates the semiconductor element.
Examples of substrates include wiring boards such as interposers, lead frames, and flexible printed circuit boards.
Examples of semiconductor devices include transistors, integrated circuits, diodes, and thyristors.

The resin composition disclosed herein can be used to encapsulate electronic components such as semiconductor elements mounted on a substrate using molding methods such as transfer molding, compression molding, and injection molding. This molding can be performed, for example, at a temperature of 120 to 200°C and a pressure of 2 to 20 MPa. By molding and encapsulating electronic components such as semiconductor elements under these conditions, resin-encapsulated electronic component devices and semiconductor devices with minimal package warping and excellent workability during mounting can be obtained. This is particularly suitable for single-sided encapsulated packages such as ball grid arrays (BGAs) and land grid arrays (LGAs) connected by bumps.

The present disclosure will now be specifically illustrated by examples, but the present disclosure is not limited in any way by these examples.

(Examples 1-3 and Comparative Examples 1-7)
The components listed in Table 1, in terms of type and quantity, were mixed in a twin-screw extruder under the conditions of a mixing temperature of 100°C and a mixing time of 5 minutes to prepare a resin composition.
The tris(2,4-di-t-butylphenyl) phosphite used in Examples 1 to 3 was ground to a maximum particle size of 53 μm by placing 100 g of tris(2,4-di-t-butylphenyl) phosphite and 500 g of 10 mm alumina balls into a 1 L ball mill and processing for 30 minutes. In Comparative Example 2, the tris(2,4-di-t-butylphenyl) phosphite used was not subjected to ball milling and had a maximum particle size of 700 μm.
The maximum particle size of the tris(2,4-di-t-butylphenyl) phosphite used in Examples 1 to 3 and in Comparative Example 2 was determined by a dry sieving method using sieves of predetermined mesh sizes, using the finest mesh size of the sieve through which at least 95% by mass of the sample could pass.

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

[(A) Epoxy resin]
• YX-4000: Biphenyl-type epoxy resin (product name, manufactured by Mitsubishi Chemical Corporation, epoxy equivalent: 185, viscosity at 150°C: 0.012 Pa·s)

[(B) Phenolic resin]
• HE910-10: Triphenolmethane-type phenolic resin (trade name, manufactured by Air Water Performance Chemical Co., Ltd., hydroxyl group equivalent: 101, viscosity at 150°C: 0.12 Pa·s)

[(C) Hardening accelerator]
• 2P4MHZ: 2-phenyl-4-methyl-5-hydroxymethylimidazole (trade name, manufactured by Shikoku Chemicals Co., Ltd.)

[(D) Inorganic filler]
AL20-75R: Spherical alumina (product name, manufactured by Nippon Steel Chemical & Material Co., Ltd., average particle size: 15 μm)

[(E) Shrinkage rate adjusting agent]
• (E-1): IRGAFOS 168 (trade name, manufactured by BASF; tris(2,4-di-t-butylphenyl) phosphite) adjusted to a maximum particle size of 53 μm.

[Other phosphite compounds]
• (e-1): ADEKA Stab 1500 (product name, manufactured by ADEKA Corporation; tetra-C12-15-alkyl(propane-2,2-diylbis(4,1-phenylene))bis(phosphite))
• (e-2): ADEKA Stab PEP-36 (product name, manufactured by ADEKA Corporation; 3,9-bis(2,6-di-tert-butyl-4-methylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane)
• (e-3): ADEKA Stab PEP-8 (trade name, manufactured by ADEKA Corporation; 3,9-bis(octadecyloxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane) • (e-4): IRGAFOS 168 (trade name, manufactured by BASF; tris(2,4-di-t-butylphenyl) phosphite), maximum particle size: 700 μm)

[Phenol compounds]
• (e-5): IRGANOX 1010 (trade name, manufactured by BASF; tetrakis[3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionic acid]pentaerythritol)

[(F) Coloring agent]
MA-600: Carbon Black (product name, manufactured by Mitsubishi Chemical Corporation)

[Other ingredients]
• Silane coupling agent: KBM-403 (product name, manufactured by Shin-Etsu Chemical Co., Ltd.)
• Release agent: Carnauba wax No. 1 (product name, manufactured by Toyo Petrolite Co., Ltd.)
• Liquid polybutadiene rubber: Ricon 657 (product name, manufactured by Tomoe Industries Co., Ltd.)

[Evaluation items]
(Evaluation of resin composition)
(1) Spiral flow Using a spiral flow measurement mold conforming to ATMM3123, the resin composition was molded under the following conditions, and the distance to the flow tip was measured.
[Molding conditions]
Mold temperature: 175℃
Injection pressure: 70 kgf/ ^cm²
Molding time: 120 seconds
[Judgment criteria]
Based on the above measurement results, the following criteria were used for evaluation.
A: 220cm or taller B: 190cm or taller but less than 220cm C: 150cm or taller but less than 190cm D: Less than 150cm

(2) Gel time The resin composition was spread in a circular shape with a diameter of 4 to 5 cm on a hot plate maintained at 175°C, kneaded at a constant speed, and the time until the resin composition thickened and eventually lost its viscosity was measured.
[Judgment criteria]
Based on the above measurement results, the following criteria were used for evaluation.
A: 45 seconds or more B: 40 seconds or more but less than 45 seconds C: 30 seconds or more but less than 40 seconds D: Less than 30 seconds

(3) Flow viscosity The resin composition was placed in an environment of 175°C and shear stress of 1.23 × ^10⁵ Pa using a flow viscosity measuring device (manufactured by Shimadzu Corporation, product name: CFT-500C), and the minimum melt viscosity (η1) was measured.
[Judgment criteria]
Based on the above measurement results, the following criteria were used for evaluation.
A: Less than 7 Pa·s B: 7 Pa·s or more, less than 15 Pa·s C: 15 Pa·s or more, less than 20 Pa·s D: 20 Pa·s or more

(4) Molding shrinkage rate A resin composition was molded using a mold with a diameter of 80 mm at room temperature (23°C) under the following conditions, and the shrinkage rate was calculated from the difference in dimensions between the molded resin composition and the diameter of the mold at room temperature.
Molding shrinkage rate = (Mold diameter at room temperature - Diameter of molded resin composition at room temperature) / Mold diameter at room temperature × 100
[Molding conditions]
Mold temperature: 175℃
Injection pressure: 70 kgf/ ^cm²
Molding time: 120 seconds Post-curing: 175℃, 8 hours

(5) Bending strength Test specimens measuring 4 mm x 10 mm x 80 mm prepared under the following conditions were measured at a temperature of 25°C in accordance with JIS K 6911:2006.
[Test specimen preparation conditions]
Mold temperature: 175℃
Injection pressure: 70 kgf/ ^cm²
Molding time: 120 seconds Post-curing: 175℃, 8 hours
[Judgment criteria]
Based on the above measurement results, the following criteria were used for evaluation.
A: 175 MPa or higher B: 130 MPa or higher and less than 175 MPa C: 100 MPa or higher and less than 130 MPa D: Less than 100 MPa

(6) Flame retardancy A flame retardancy test was conducted on a 125 mm x 13 mm x 4 mm test specimen prepared under the following conditions in accordance with the UL-94 standard.
[Test specimen preparation conditions]
Mold temperature: 175℃
Injection pressure: 70 kgf/ ^cm²
Molding time: 120 seconds Post-curing: 175℃, 8 hours

The upper end of the obtained test specimen was clamped to fix it vertically, and a predetermined blue flame with a height of 20 ± 1 mm was applied to the lower end for 10 seconds and then removed, and the burning time of the test specimen (burning time after the first flame application; t1) was measured. Immediately after extinguishing the flame, the lower end of the test specimen was applied again and then removed, and the burning time of the test specimen (burning time after the second flame application; t2) and glow time (t3) were measured. The same measurement was repeated for five test specimens, and a total of 10 data points were obtained: five data points for the first burning time and five data points for the second burning time.
[Judgment criteria]
Based on the above measurement results, the following criteria were used for evaluation.
A: The t1 for each test specimen is 10 seconds or less, t2 is 10 seconds or less, t2 + t3 is 30 seconds or less, the total t1 + t2 for all five test specimens is 50 seconds or less, and there is no combustion up to the clamp and no cotton ignition by dripping material.
B: Does not meet the criteria of A, with t1 of each test specimen being 30 seconds or less, t2 being 30 seconds or less, t2 + t3 being 60 seconds or less, the total t1 + t2 of 5 test specimens being 250 seconds or less, and no combustion up to the clamp, and no cotton ignition by dripping material.
C: Does not meet the criteria of A, with t1 of each test specimen being 30 seconds or less, t2 being 30 seconds or less, t2 + t3 being 60 seconds or less, the total t1 + t2 of 5 test specimens being 250 seconds or less, no combustion up to the clamp, and cotton ignition by dripping material.
D: The t1 for each specimen is longer than 30 seconds, or t2 is longer than 30 seconds, or t2 + t3 is longer than 60 seconds, or the total t1 + t2 for five specimens is longer than 250 seconds, or there is combustion up to the clamp.

(Evaluation after package molding)
Using the obtained resin composition, transfer molding was performed under the following conditions to produce the following evaluation package.
[Package creation conditions]
Mold temperature: 175℃
Injection pressure: 70 kgf/ ^cm²
Molding time: 120 seconds Post-curing: 175℃, 8 hours

(7) Package appearance Eight 35mm x 35mm PBGA packages (sealed size 29mm x 29mm x 1.04mm) were prepared, and the surface of the molded products was observed to check for the presence or absence of voids or flow marks. The evaluation was carried out as follows.
Voids: A stereomicroscope was used to check for the presence or absence of voids on the package surface.
Flow marks: Visually check the package surface for the presence or absence of flow marks.
[Judgment criteria]
Based on the above measurement results, the following criteria were used for evaluation.
A: No voids or flow marks on the surface. B: Voids or flow marks on the surface of 1 to 5 packages. C: Voids or flow marks on the surface of 6 to 8 packages.

(8) Package warpage A 35mm x 35mm PBGA package (encapacitation size 29mm x 29mm x 1.04mm) was fabricated using a BT substrate (thickness: 0.54mm) and solder resist PSR-4000 AUS-308. The amount of warpage of the obtained package was measured at room temperature (23°C) using a shadow moiré detector (PS200) manufactured by AKROMETRIX.
[Judgment criteria]
Based on the above measurement results, the following criteria were used for evaluation.
A: Package warp of -50 μm or more but less than 50 μm B: Package warp of -100 μm or more but less than -50 μm, or 50 μm or more but less than 100 μm C: Package warp of -150 μm or more but less than -100 μm, or 100 μm or more but less than 150 μm D: Package warp of less than -150 μm, or 150 μm or more

(9) Wire flow After forming the FBGA package (175 mm x 49 mm x 0.45 mm), the deformation of the wire (Φ20 μm, length 3 mm) was observed using an X-ray inspection device (manufactured by Pony Industries Co., Ltd.), and the wire flow rate of the most deformed part was measured.
[Judgment criteria]
Based on the above measurement results, the following criteria were used for evaluation.
A: Less than 3% B: 3% or more, less than 5% C: 5% or more, less than 10% D: 10% or more

The resin compositions of Examples 1 to 3, which contain a predetermined amount of (E) shrinkage rate modifier having a specific structure with a maximum particle size of 105 μm or less, exhibit excellent resin fluidity, high strength, and high flame retardancy. Furthermore, packages sealed with these resin compositions demonstrate superior appearance, reduced wire deformation, and reduced package warping.

Claims (8)

(A) epoxy resin, (B) phenolic resin, (C) curing accelerator, (D) inorganic filler, and (E) shrinkage rate modifier,
The (E) shrinkage rate modifier is a compound represented by the following general formula (1) with a maximum particle size of 105 μm or less,
A resin composition for semiconductor encapsulation, wherein the content of (D) inorganic filler is 60 to 95% by mass and the content of (E) shrinkage rate modifier is 0.3 to 3.5% by mass, based on the total amount of the resin composition.

(In formula (1), R1 and R2 are each independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.)
Here, the maximum particle size mentioned above refers to the particle size measured by the dry sieving method, which is defined by the mesh size of the finest sieve through which at least 95% by mass of the sample passes. The semiconductor encapsulation resin composition according to claim 1, wherein the flow viscosity at 175°C is 15 Pa·s or less and the molding shrinkage rate is 0.30% or less.
Here, the flow viscosity is defined as the minimum melt viscosity (η1) measured under an environment of shear stress of 1.23 × ^10⁵ Pa.
Furthermore, the above molding shrinkage rate was calculated by molding the resin composition under the following conditions using a mold with a diameter of 80 mm at room temperature (23°C), and then measuring the difference in diameter between the molded resin composition and the mold at room temperature.
Molding shrinkage rate = (Mold diameter at room temperature - Diameter of molded resin composition at room temperature) / Mold diameter at room temperature × 100
[Molding conditions]
Mold temperature: 175℃
Injection pressure: 70 kgf/ ^cm²
Molding time: 120 seconds
Post-curing: 175℃, 8 hours The semiconductor encapsulation resin composition according to claim 1 or 2, wherein the epoxy resin (A) has a viscosity of 0.005 Pa·s or more at 150°C. The semiconductor encapsulation resin composition according to any one of claims 1 to 3, wherein the (B) phenolic resin has a viscosity of 0.005 Pa·s or more at 150°C. The semiconductor encapsulation resin composition according to any one of claims 1 to 4, wherein the inorganic filler (D) has an average particle size of 1 to 50 μm. The semiconductor encapsulation resin composition according to any one of claims 1 to 5, wherein the inorganic filler (D) is alumina. Furthermore, the semiconductor encapsulation resin composition according to any one of claims 1 to 6, comprising (F) a coloring agent, wherein the (F) coloring agent is carbon black. A semiconductor device comprising a substrate, a semiconductor element mounted on the substrate, and a cured product of a semiconductor encapsulation resin composition according to any one of claims 1 to 7, which encapsulates the semiconductor element.