JP6351927B2 - Resin composition for sealing and method for manufacturing semiconductor device - Google Patents

Description

  The present invention relates to a resin composition used as a sealing material for electronic components such as semiconductor elements, and a semiconductor device using the same.

  As a sealing material in semiconductor devices such as transistors, ICs, LSIs, etc., there is a resin composition based on an epoxy resin, in which a curing agent, a curing accelerator, an inorganic filler such as silica powder, and a colorant are blended. Widely used.

  Conventionally, transfer molding is generally used as a sealing process using such a sealing material. However, recently, compression molding has been attracting attention as a useful method when the sealing thickness on the semiconductor element is thin or the bonding wire is thin and long.

  In other words, with the recent trend toward high-density mounting of electronic components on printed wiring boards, the mainstream of semiconductor devices has shifted from pin insertion type packages to surface mounting type packages, and surface mounting type packages have also become thinner. Downsizing and downsizing. In the surface-mounted package that is reduced in thickness and size, the occupied volume of the semiconductor element with respect to the package is increased, and the thickness of the coating covering the semiconductor element is reduced. In addition, with the increase in the functionality and capacity of semiconductor elements, the chip area and the number of pins have increased, and further, the increase in the number of electrode pads has led to a reduction in pad pitch and pad size, so-called narrow pad pitch. Progressing.

  On the other hand, since the substrate on which the semiconductor element is mounted cannot be made as narrow as the electrode pads as the semiconductor element, the number of terminals can be increased by increasing the wire length of the bonding wire drawn from the semiconductor device or by making the wire thinner. It corresponds. However, if the wire becomes thin, the wire is likely to be flowed by the injection pressure of the resin in the subsequent resin sealing step. This tendency is particularly remarkable in the side gate type transfer molding.

  Therefore, a compression molding method has been used as a sealing process instead of transfer molding (see, for example, Patent Document 1). In this method, an object to be sealed (for example, a substrate on which a semiconductor element is mounted) is adsorbed to the upper mold, while powder resin (sealing material) is supplied to the lower mold so as to oppose it. While raising the mold, the object to be sealed and the sealing material are pressurized and sealed. According to the compression molding method, since the molten granular resin flows in a direction substantially parallel to the main surface of the object to be sealed, the amount of flow can be reduced, and the object to be sealed by the flow of the resin (for example, It can be expected to reduce deformation and breakage of wires, wirings, etc. on a substrate on which a semiconductor element is mounted.

However, even if the sealing material used for the conventional transfer molding is applied to the compression molding method, the desired effect as described above cannot be obtained sufficiently due to its low filling property. Examples of the sealing material suitable for the compression molding method include an epoxy resin, a curing agent, a curing accelerator, an inorganic filler, and the like, and have a particle size distribution in which particles having a particle size of 100 μm to 3 mm are 85% by mass or more. By setting the powdery resin composition (for example, see Patent Document 2) and the degree of compression within a range of 6 to 11%, adhesion to a hopper or the like and a cross-linking phenomenon are prevented, and fluidity is stabilized. By improving the measurement accuracy (see, for example, Patent Document 3), the bulk density is 0.8 g / cm ³ or more and 1.1 g / cm ³ to improve the transportability and weighing accuracy. (For example, refer to Patent Document 4) and the like have been proposed.

  However, in any case, the sealing thickness is thin, and the materials for sealing semiconductor elements connected by thin and long bonding wires are particularly reduced in wire deformation / breakage (wire flow) and formability. It was not enough in terms of improvement.

JP 2008-279599 A JP 2011-153173 A JP 2000-232188 A JP 2008-303366 A

  The present invention has been made to solve the above-described problems of the prior art, and is suitable for a compression molding method, which can sufficiently reduce wire flow during molding and sufficiently improve moldability. An object of the present invention is to provide a highly reliable semiconductor device encapsulated with the resin composition for encapsulating, and such an encapsulating resin composition.

  As a result of intensive studies to achieve the above object, the present inventors have found that the degree of compression of the powdery sealing resin composition, as described later, reduces wire flow and moldability in the compression molding method. As a result, the present invention has been completed.

That is, the sealing resin composition according to one embodiment of the present invention includes (A) a biphenyl type epoxy resin, (B) a phenol resin curing agent, (C) a curing accelerator, and (D) spherical silica as essential components. to a resin composition for semiconductor encapsulation of the particulate is not more than 19% compression of 12% or more, which is defined by the following formula, in the particle size distribution obtained by the standard sieve method using Tyler sieves, 0.212 mm greater It is characterized by having one peak in each of a particle size range of 0.71 mm or less and a particle size range of more than 0.71 mm and 1.4 mm or less.
Compressibility (%) = {(tap bulk density−initial bulk density) / tap bulk density} × 100
In the above formula, the tap bulk density and the initial bulk density are values measured according to JIS R1628, respectively.

  Moreover, the semiconductor device which concerns on the other aspect of this invention is characterized by sealing a semiconductor element by compression molding using the said resin composition for sealing.

  ADVANTAGE OF THE INVENTION According to this invention, it is suitable for the compression molding method, the wire flow at the time of shaping | molding can fully be reduced, and the resin composition for sealing which can fully improve moldability, and such resin for sealing A highly reliable semiconductor device sealed with the composition can be obtained.

  Embodiments of the present invention will be described below.

First, each component used for the resin composition for sealing of this invention is demonstrated.
As long as the biphenyl type epoxy resin of component (A) used in the present invention is an epoxy resin having a biphenyl skeleton, it is generally used as a sealing material for electronic parts without being limited by molecular structure, molecular weight, etc. Can be widely used. The biphenyl skeleton in the present invention includes those obtained by hydrogenation of at least one aromatic ring of biphenyl rings.
Specific examples of the biphenyl type epoxy resin include, for example, 4,4′-bis (2,3-epoxypropoxy) biphenyl, 4,4′-bis (2,3-epoxypropoxy) -3,3 ′, 5, Epoxy obtained by reacting 5′-tetramethylbiphenyl, epichlorohydrin and a biphenol compound such as 4,4′-biphenol or 4,4 ′-(3,3 ′, 5,5′-tetramethyl) biphenol Examples thereof include resins. Among these, 4,4′-bis (2,3-epoxypropoxy) -3,3 ′, 5,5′-tetramethylbiphenyl, 4,4 ′-(3,3 ′, 5,5′-tetra Methyl) biphenyl glycidyl ether is preferred. A biphenyl type epoxy resin may be used individually by 1 type, and 2 or more types may be mixed and used for it.

  Examples of commercially available products used as biphenyl type epoxy resins include, for example, YX-4000 (epoxy equivalent 185, softening point 105 ° C.), YX-4000H (epoxy equivalent 193, softening point 105 ° C.) manufactured by Mitsubishi Chemical Corporation. ), NC-3000 (epoxy equivalent 273, softening point 58 ° C.), NC-3000H (epoxy equivalent 288, softening point 91 ° C.) (all are trade names) manufactured by Nippon Kayaku Co., Ltd. .

  By using a biphenyl type epoxy resin, the melt viscosity of the composition can be maintained in a favorable range even when spherical silica of component (D) described later is used in a high content, and for sealing with excellent heat resistance A resin composition can be obtained.

  In the sealing resin composition of the present invention, one or more epoxy resins other than the biphenyl type epoxy resin can be blended within a range that does not impair the effects of the present invention. Examples of epoxy resins other than biphenyl type epoxy resins include 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, Heterocyclic epoxy resins such as triphenolmethane type epoxy resins and triazine nucleus-containing epoxy resins, stilbene type bifunctional epoxy compounds, naphthalene type epoxy resins, condensed ring aromatic hydrocarbon modified epoxy resins, alicyclic type epoxy resins, etc. It is done.

  As the phenol resin curing agent of component (B) used in the present invention, if it has two or more phenolic hydroxyl groups in the molecule that can react with the epoxy group of the biphenyl type epoxy resin of component (A), It is used without particular limitation. Specifically, a phenol novolak resin, a cresol novolak resin, an aralkyl type phenol resin, a naphthalene type phenol resin, a cyclopentadiene type phenol resin, a triphenolalkane type phenol resin, a polyfunctional type phenol resin, or the like can be used. These may be used individually by 1 type, and may mix and use 2 or more types.

式（１）中、Ｒ^１はフェノール性水酸基を有する１価の有機基、Ｒ^２はフェノール性水酸基を有する２価の有機基、ｎは１〜５の整数である。
Ｒ^１は、下記式（１−１）〜（１−３）で示される基から選ばれることが好ましく、Ｒ^２は、下記式（１−４）〜（１−６）で示される基から選ばれることが好ましい。原料の入手のしやすさの観点からは、Ｒ^１は下記式（１−１）で示される基がより好ましく、Ｒ^２は下記式（１−４）で示される基がより好ましい。

式（１−２）、（１−３）、（１−５）、（１−６）において、Ｒ^３は、水素原子、メチル基、エチル基、プロピル基、ブチル基、イソプロピル基、イソブチル基等の炭素数１〜４のアルキル基、及びメトキシ基、エトシキ基、プロポキシ基、ブトキシ基等の炭素数１〜４のアルコキシ基から選ばれ、なかでも水素原子、メチル基、メトキシ基が好ましく、水素原子がより好ましい。式（１−３）、及び（１−６）において、複数のＲ^３はすべてが同一であっても異なっていてもよい。 (B) As a phenol resin hardening | curing agent of a component, the phenol resin represented by following General formula (1) from a fluidity | liquidity and a flame-resistant viewpoint is preferable.

In formula (1), R ¹ is a monovalent organic group having a phenolic hydroxyl group, R ² is a divalent organic group having a phenolic hydroxyl group, and n is an integer of 1 to 5.
R ¹ is preferably selected from the groups represented by the following formulas (1-1) to (1-3), and R ² is selected from the groups represented by the following formulas (1-4) to (1-6). It is preferable to be selected. From the viewpoint of easy availability of raw materials, R ¹ is more preferably a group represented by the following formula (1-1), and R ² is more preferably a group represented by the following formula (1-4).

In formulas (1-2), (1-3), (1-5), and (1-6), R ³ represents a hydrogen atom, a methyl group, an ethyl group, a propyl group, a butyl group, an isopropyl group, or an isobutyl group. Selected from an alkyl group having 1 to 4 carbon atoms such as, and an alkoxy group having 1 to 4 carbon atoms such as a methoxy group, an ethoxy group, a propoxy group, and a butoxy group, and among them, a hydrogen atom, a methyl group, and a methoxy group are preferable. A hydrogen atom is more preferable. In the formulas (1-3) and (1-6), all of the plurality of R ³ may be the same or different.

For example, when R ¹ is a group represented by the above formula (1-1) and R ² is a group represented by the above formula (1-4), the phenol resin represented by the general formula (1) is represented by the following formula: It can be synthesized by reacting imidazolidinone, phenol, and formaldehyde in the presence of an acidic catalyst.

  A commercial item can also be used as a phenol resin represented by General formula (1). As a commercial item, Showa Denko Co., Ltd. product TAM-005 (brand name) etc. are mentioned, for example.

  The blending amount of the (B) component phenolic resin curing agent is the number of phenolic hydroxyl groups (b) of the (B) component phenolic resin curing agent with respect to the epoxy group number (a) of the (A) component epoxy resin. The range in which the ratio (b) / (a) is from 0.5 to 1.6 is preferred, and the range from 0.6 to 1.4 is more preferred. When the ratio (b) / (a) is 0.5 or more, the glass transition point of the cured product is good. On the other hand, when the ratio is 1.6 or less, the reactivity is good and sufficient crosslinking density is obtained. Therefore, a cured product having excellent heat resistance and high strength can be obtained.

  Examples of the curing accelerator for the component (C) used in the present invention include imidazole, 2-heptadecylimidazole, 2-methylimidazole, 2-ethylimidazole, 2-isopropylimidazole, 2-undecylimidazole, and 1,2-dimethyl. Imidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 4-methylimidazole, 4-ethylimidazole, 2-phenyl-4-hydroxymethylimidazole, 2-ethyl-4-methylimidazole, 1-cyanoethyl-2 -Methylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2-undecylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2 − Phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2- Undecylimidazolium trimellitate, 1-cyanoethyl-2-phenyl-4,5-di (cyanoethoxy) methylimidazole, 1-dodecyl-2-methyl-3-benzylimidazolium chloride, 1-benzyl-2-phenyl Imidazole hydrochloride, 1-benzyl-2-phenylimidazolium trimellitate, 2,4-diamino-6- [2'-methylimidazolyl- (1 ')]-ethyl-s-triazine, 2,4-diamino- 6- [2'-Undecylimidazolyl- (1 ')] Ethyl-s-triazine, 2,4-diamino-6- [2'-ethyl-4'-methylimidazolyl- (1 ')]-ethyl-s-triazine, 2,4-diamino-6- [2'- Imidazoles such as methylimidazolyl- (1 ′)]-ethyl-s-triazine, 2-phenylimidazole isocyanuric acid adduct, 2-methylimidazole isocyanuric acid adduct, 2-phenylimidazoline; 1,8-diazabicyclo [5, Diazabicyclo such as 4,0] undecene-7 (DBU), 1,5-diazabicyclo [4,3,0] nonene, 5,6-dibutylamino-1,8-diazabicyclo [5,4,0] undecene-7 Compounds and salts thereof; triethylamine, triethylenediamine, benzyldimethylamine, α-methylbenzyldimethylamine, Tertiary amines such as tanolamine, dimethylaminoethanol, tris (dimethylaminomethyl) phenol; trimethylphosphine, triethylphosphine, tributylphosphine, diphenylphosphine, triphenylphosphine, tri (p-methylphenyl) phosphine, tri (nonylphenyl) ) Organic phosphine compounds such as phosphine, methyldiphenylphosphine, dibutylphenylphosphine, tricyclohexylphosphine, bis (diphenylphosphino) methane, 1,2-bis (diphenylphosphino) ethane; tetraphenylphosphonium tetraphenylborate, triphenylphosphine Examples thereof include tetra- or triphenylboron salts such as tetraphenylborate and triphenylphosphine triphenylborane. Among these, imidazoles are preferable from the viewpoint of good fluidity and moldability. These may be used individually by 1 type, and may mix and use 2 or more types.

  The blending amount of the curing accelerator of component (C) is usually 0.5 parts by mass with respect to 100 parts by mass of the total amount of biphenyl type epoxy resin of component (A) and phenolic resin curing agent of component (B). The amount is 5.0 parts by mass or less, preferably 1.5 parts by mass or more and 4.0 parts by mass or less, more preferably 2.5 parts by mass or more and 3.5 parts by mass or less. If the blending amount is less than 0.5 parts by mass, the curability is not very effective. On the other hand, if it exceeds 5.0 parts by mass, the fluidity and moldability of the composition are lowered.

  The spherical silica as the component (D) used in the present invention preferably has an average particle size of 10 μm or more and 30 μm or less as a whole, and more preferably 12 μm or more and 25 μm or less. When the average particle size is less than 10 μm, the fluidity of the resin composition is lowered and the moldability may be impaired. On the other hand, if the average particle size exceeds 30 μm, there is a risk of foaming. The average particle size of the spherical silica can be determined by, for example, a laser diffraction type particle size distribution measuring device, and the average particle size is a particle size (d50 with an integrated weight of 50% in the particle size distribution measured with the same device. ).

  Further, the spherical silica of component (D) is (D1) spherical silica having a particle size of less than 5 μm, 15% by mass to 30% by mass, more preferably 15% by mass to 25% by mass, and (D2) particle size of 5 μm or more. It is preferable that spherical silica having a particle size of less than 50 μm is contained in an amount of 50% by mass to 80% by mass and (D3) spherical silica having a particle size of 50 μm or more is contained in an amount of 5% by mass to 20% by mass. Furthermore, the ratio (D1) / (D2) of (D1) spherical silica having a particle size of less than 5 μm and (D2) spherical silica having a particle size of 5 μm or more and less than 50 μm is 0.15 or more and 0.50 or less, more preferably 0 It is preferably in the range of not less than 15 and not more than 0.45.

When the spherical silica of component (D) has a particle size distribution satisfying the above requirements, the resin composition exhibits good melting properties, and by using such a sealing resin composition, wire flow, resin leakage, etc. A semiconductor device free from defects can be obtained.
The content of spherical silica (D1) having a particle size of less than 5 μm is less than 15% by mass and the content of spherical silica (D3) having a particle size of 50 μm or more exceeds 20% by mass, or spherical particles having a particle size of less than 5 μm When the ratio (D1) / (D2) of the silica (D1) and the spherical silica (D2) having a particle size of 5 μm or more and less than 50 μm exceeds 0.50, the meltability of the resin composition increases, and the lower mold cavity There is a possibility that a so-called “resin leakage” is likely to occur when the heated and melted resin composition is scattered when being supplied inside or under reduced pressure.
Further, the content of spherical silica (D1) having a particle size of less than 5 μm exceeds 30% by mass and the content of spherical silica (D3) having a particle size of 50 μm or more is less than 50% by mass, or the particle size is 5 μm. When the ratio (D1) / (D2) of the spherical silica (D1) less than 5 μm and the spherical silica (D2) having a particle size of 5 μm or more and less than 50 μm is less than 0.15, the resin composition has low melting property, There is a possibility that the wire flowability becomes poor.

  (D) Although the compounding quantity of the spherical silica of a component is not specifically limited, The range of 80 mass% or more and 95 mass% or less is preferable with respect to the whole quantity of a composition, 85 mass% or more and 93 mass% or less. A range is more preferred. If it is less than 80% by mass, the coefficient of linear expansion increases and the dimensional accuracy, moisture resistance, mechanical strength, etc. of the molded product decreases. If it exceeds 95% by mass, the melt viscosity increases and the fluidity decreases. In addition, the moldability may be reduced.

  In the sealing resin composition of the present invention, in addition to the above components, inorganic fillers other than silica (for example, alumina) generally blended in this type of composition within a range not inhibiting the effects of the present invention. Coupling agents; mold release agents such as synthetic wax, natural wax, higher fatty acid, higher fatty acid and other metal salts; colorants such as carbon black and cobalt blue; silicone oil, Low stress imparting agents such as silicone rubber, hydrotalcites, ion scavengers and the like can be blended.

  As the coupling agent, an epoxy silane, amino silane, ureido silane, vinyl silane, alkyl silane, organic titanate, aluminum alcoholate, or the like is used. From the viewpoints of moldability, flame retardancy, curability, etc., aminosilane coupling agents are preferred, and in particular, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropylmethyldimethoxysilane. Γ-aminopropylmethyldiethoxysilane and the like are preferable.

  The amount of the coupling agent to be blended is preferably in the range of 0.01% by mass to 3% by mass and more preferably in the range of 0.1% by mass to 1% by mass of the entire composition. If it is less than 0.01% by mass of the whole composition, it is not very effective for improving moldability. Conversely, if it exceeds 3% by mass, foaming may occur during molding and voids or surface swelling may occur in the molded product. .

  In preparing the sealing resin composition of the present invention, (A) a biphenyl type epoxy resin, (B) a phenol resin curing agent, (C) a curing accelerator, (D) spherical silica, and the above-described necessity. The various components to be blended are sufficiently mixed (dry blended) with a mixer or the like, then melt-kneaded with a kneading apparatus such as a hot roll or a kneader, cooled, and pulverized to an appropriate size. The pulverization method is not particularly limited, and general pulverizers such as a speed mill, a cutting mill, a ball mill, a cyclone mill, a hammer mill, a vibration mill, a cutter mill, and a grinder mill can be used. A speed mill is preferable. The pulverized product can then be adjusted to a particle aggregate having a predetermined particle size distribution by sieving classification, air classification or the like.

In the sealing resin composition of the present invention, the degree of compression defined by the following formula is 12% or more and 19% or less, preferably 13% or more and 18% or less.
Compressibility (%) = {(tap bulk density−initial bulk density) / tap bulk density} × 100
In the above formula, the tap bulk density and the initial bulk density are values measured according to JIS R1628, respectively.
Here, the degree of compression of the resin composition depends on the particle size distribution of the resin composition, and in the particle size distribution measured by a standard sieving method using a Tyler sieve, 24 mesh passing particles are less than 25% by mass of the total, The degree of compression becomes less than 12%, and there is a possibility that a nest is generated on the surface of the molded product. On the other hand, if the 24 mesh particles exceed 50% by mass, the degree of compression may exceed 19%, and resin leakage tends to occur during molding.

The sealing resin composition of the present invention further satisfies at least one of the following conditions (i) to (iii) from the viewpoint of stable operation of the compression molding apparatus and resin moldability: To preferred. It is more preferable that two or more of the conditions (i) to (iii) are satisfied, and it is even more preferable that all of the conditions (i) to (iii) are satisfied.
(I) In the particle size distribution obtained by the standard sieving method using a Tyler sieve, each has one peak in the particle size range of more than 0.212 mm and 0.71 mm or less and in the particle size range of more than 0.71 mm and 1.4 mm or less. (Hereinafter, the peak in the particle size range of more than 0.212 mm and 0.71 mm or less is also referred to as “first peak”, and the peak in the particle size range of more than 0.71 mm and 1.4 mm or less is also referred to as “second peak”. ).
(Ii) In the particle size distribution obtained by the standard sieving method using a Tyler sieve, the particles constituting the first peak are 5% by mass or more and 30% by mass or less of the whole, and the particles constituting the second peak are 20% by mass of the whole. It is as follows. More preferably, the particles constituting the first peak are 10% by mass or more and 20% by mass or less of the whole, and the particles constituting the second peak are 5% by mass or more and 20% by mass or less of the whole.
(Iii) In the particle size distribution obtained by the standard sieving method using a Tyler sieve, the component having a particle size of 0.212 mm or less is less than 25% by mass, and the component having a particle size of more than 1.4 mm is less than 25% by mass. When the component having a particle size of 0.212 mm or less is 25% by mass or more of the whole, the particles are likely to rise when being supplied to the compression molding die, which may cause contamination by scattered particles, poor measurement, or the like. Moreover, there exists a possibility that defective filling parts, such as a void, may generate | occur | produce in hardened | cured material as a component with a particle size exceeding 1.4 mm is 25 mass% or more of the whole. More preferably, the component having a particle size of 0.212 mm or less is 0.1% by mass or more and 20% by mass or less, and the component having a particle size of 1.4 mm or more is 1.0% by mass or more and 15% by mass or less.

The semiconductor device of this invention can be manufactured by sealing a semiconductor element by compression molding using the said resin composition for sealing. Hereinafter, an example of the method will be described.
First, a substrate on which a semiconductor element is mounted is supplied to an upper mold of a compression molding mold, and then the sealing resin composition is supplied into a cavity of a lower mold. Next, the upper die and the lower die are clamped at a required clamping pressure to immerse the semiconductor element in the sealing resin composition heated and melted in the lower die cavity. Next, the heat-melted sealing resin composition in the lower mold cavity is pressed by the cavity bottom member, and compression molding is performed by applying a required pressure under reduced pressure. The molding conditions are preferably a temperature of 120 ° C. or more and 200 ° C. or less and a pressure of 2 MPa or more and 20 MPa or less.

Since the semiconductor device thus obtained is sealed with the sealing resin composition whose compression degree is set in the above-described range, the occurrence of wire flow during molding is suppressed, and the moldability is also good. As a result, a highly reliable semiconductor device can be obtained.
Furthermore, when the resin composition having the above particle size distribution is used as the sealing resin composition, the resin composition that is dispersed when the sealing resin composition is supplied to the lower mold cavity or heat-melted under reduced pressure is used. Since so-called “resin leakage” is suppressed, a semiconductor device with even higher reliability can be obtained.

  The semiconductor element to be sealed in the semiconductor device of the present invention is not particularly limited, and examples thereof include IC, LS, diode, thyristor, transistor, etc. The present invention is particularly useful in the case of a semiconductor element having a later thickness of 0.2 mm to 1.5 mm.

Next, the present invention will be described in more detail with reference to examples. In addition, this invention is not limited to these Examples at all. In the following description, “part” means “part by mass”. Furthermore, the compressibility of the obtained resin composition for encapsulating a semiconductor is measured by the following method.
[Compression degree]
Using a powder tester manufactured by Hosokawa Micron Co., Ltd., the initial bulk density (average value of n = 10) and tap bulk density (average value of n = 10) were measured in accordance with JIS R1628. ). In addition, the bottomed cylindrical container made from stainless steel (SUS304) and having a capacity of 100 cc was used as the measurement container. The tapping was performed under the conditions of a tap height of 20 mm, a tap speed of 60 times / minute, and a tap time of 3 minutes.

Example 1
Epoxy product of 3,3 ′, 5,5′-tetramethyl-4,4′-dihydroxybiphenyl as a biphenyl epoxy resin (trade name YX-4000HK, manufactured by Mitsubishi Chemical Corp .; epoxy equivalent 193, hydrolyzable chlorine content 450 ppm , Softening point 105 ° C.) 5.2 parts as a phenol resin, in general formula (1), R ¹ is a group represented by formula (1-1), R ² is a group represented by formula (1-4) , N is 1 to 2, nitrogen-containing phenol resin (trade name TAM-105 manufactured by Showa Denko KK; hydroxyl group equivalent 163, softening point 77 ° C .; expressed as phenol resin I) 4.0 parts, 2 as a curing accelerator -Phenyl-4-hydroxymethyl-5-methylimidazole (trade name 2P4MHZ manufactured by Shikoku Kasei Co., Ltd .; expressed as curing accelerator I), 0.25 parts, spherical silica (trade name MSR-8030 manufactured by Tatsumori Co., Ltd.) ; Uniform particle size 12 μm; Spherical silica I) 85 parts, Spherical silica (trade name SO-25R manufactured by Admatechs Co., Ltd .; average particle size 0.5 μm; Granular silica II) 5 parts, silane coupling agent 3-phenylaminopropyltrimethoxysilane (trade name Z-6883 manufactured by Toray Dow Corning Co., Ltd.) 0.30 part, and carbon black (trade name MA-100 manufactured by Mitsubishi Chemical Co., Ltd.) as a colorant. After mixing 25 parts at room temperature using a mixer, it was heat-kneaded at 120 ° C. using a hot roll. After cooling and pulverizing using a speed mill manufactured by Gohashi Seisakusho, 10 types of sieves (9 mesh, 10 mesh, 12 mesh, 20 mesh, 24 mesh, 28 mesh, 48 mesh, 65 mesh, and A resin composition for semiconductor encapsulation containing 40.9 wt% of 24 mesh passing particles was obtained by adjusting the amount of passing the 100 mesh sieve) as shown in Table 1. The compressibility of the obtained resin composition for encapsulating a semiconductor was 16.6%.

(Example 2)
Resin composition for semiconductor encapsulation containing 40.9% by weight of 24 mesh passing particles in the same manner as in Example 1 except that 80 parts of spherical silica (MSR-8030) and 10 parts of spherical silica (SO-25R) were used. I got a thing. The compressibility of the obtained resin composition for encapsulating a semiconductor was 16.6%.

(Example 3)
Resin composition for semiconductor encapsulation containing 40.9% by weight of 24 mesh passing particles in the same manner as in Example 1 except that 75 parts of spherical silica (MSR-8030) and 15 parts of spherical silica (SO-25R) were used. I got a thing. The compressibility of the obtained resin composition for encapsulating a semiconductor was 16.6%.

Example 4
A resin composition for encapsulating a semiconductor containing 27.5% by weight of 24 mesh passing particles was obtained in the same manner as in Example 2 except that the particle size distribution was changed to the particle size distribution shown in Table 1. The compressibility of the obtained resin composition for encapsulating a semiconductor was 12.8%.

(Example 5)
The blending amounts of 3,3 ′, 5,5′-tetramethyl-4,4′-dihydroxybiphenyl epoxidized product (YX-4000HK) and nitrogen-containing phenol resin (TAM-105) were 5.3 parts and 4. 1 part, and for semiconductor encapsulation containing 40.9% by weight of 24 mesh passing particles in the same manner as in Example 1 except that 0.10 parts of DBU (indicated as hardening accelerator II) was used as a hardening accelerator. A resin composition was obtained. The compressibility of the obtained resin composition for encapsulating a semiconductor was 16.6%.

(Example 6)
3,3 ′, 5,5′-tetramethyl-4,4′-dihydroxybiphenyl epoxidized product (YX-4000HK) and 2-phenyl-4-hydroxymethyl-5-methylimidazole (2P4MHZ) 6.1 parts and 0.20 parts respectively, and polyfunctional phenol resin as phenol resin (trade name MEH-7500 manufactured by Meiwa Kasei Co., Ltd .; hydroxyl group equivalent 97, softening point 109.6 ° C .; expressed as phenol resin II ) Was used in the same manner as in Example 2 except that 3.1 parts of a resin composition for semiconductor encapsulation containing 24. 9% by weight of 24 mesh particles was obtained. The compressibility of the obtained resin composition for encapsulating a semiconductor was 16.6%.

(Example 7)
Instead of using spherical silica (MSR-8030) and spherical silica (SO-25R), 90 parts of spherical silica (trade name ST7010-25 manufactured by Micron Corporation; average particle size 13.3 μm; expressed as spherical silica III) was used. Obtained a resin composition for encapsulating a semiconductor containing 40.9% by weight of 24 mesh passing particles in the same manner as in Example 1. The compressibility of the obtained resin composition for encapsulating a semiconductor was 12.0% .

(Comparative Example 1)
Except for changing the particle size distribution to the particle size distribution shown in Table 1, the particle size distribution was changed to the particle size distribution shown in Table 1 and in the same manner as in Example 2, 12.3 wt% A semiconductor sealing resin composition was obtained. The compressibility of the obtained resin composition for encapsulating a semiconductor was 9.3%.

(Comparative Example 2)
Except for changing the particle size distribution to the particle size distribution shown in Table 1, the particle size distribution was changed to the particle size distribution shown in Table 1 and in the same manner as in Example 2, 12.3 wt% A semiconductor sealing resin composition was obtained. The compressibility of the obtained resin composition for encapsulating a semiconductor was 10.5%.

(Comparative Example 3)
Except for changing the particle size distribution to the particle size distribution shown in Table 1, the particle size distribution was changed to the particle size distribution shown in Table 1, and in the same manner as in Example 2, the 24-mesh particles passed was 52.3 wt%. A semiconductor sealing resin composition was obtained. The compressibility of the obtained resin composition for encapsulating a semiconductor was 20.0%.

  About the resin composition for sealing obtained in each said Example and each comparative example, various characteristics were evaluated by the method shown below. The results are shown in Table 1 together with the composition and the like.

[Moldability (void, appearance)]
50 mm × 50 mm × 0.54 mm FBGA (Fine pitch Ball Grid Array) was compression molded using a sealing resin composition under conditions of a mold temperature of 175 ° C., a molding pressure of 8.0 PMa, and a curing time of 2 minutes. Thereafter, the occurrence of “nest” on the surface of the obtained molded product (FBGA) was visually observed and evaluated according to the following criteria.
○: No “nest” occurred △: “Nest” slightly generated ×: Many “nests” occurred [resin leakage]
FBGA of 50 mm × 50 mm × 0.54 mm was compression molded using a sealing resin composition under conditions of a mold temperature of 175 ° C., a molding pressure of 8.0 PMa, and a curing time of 2 minutes. The resin leakage was visually observed and evaluated according to the following criteria.
○: No resin leakage △: Slight resin leakage ×: Many resin leakages [Wire flow rate]
FBGA of 50 mm × 50 mm × 0.54 mm was compression molded using a sealing resin composition under conditions of a mold temperature of 175 ° C., a molding pressure of 8.0 PMa, and a curing time of 2 minutes, and then the obtained molded product (FBGA) The inside wire is observed with an X-ray observation apparatus (Pony Industry Co., Ltd.), and the wire flow rate of the maximum deformed portion (the maximum distance between the position of the wire before sealing and the position of the wire after sealing) Of the wire to the length of the wire (%)).

  As is clear from Table 1, the sealing resin compositions of Examples of the present invention having a degree of compression in the range of 12% to 19% all had good moldability, resin leakage, and wire flow rate. On the other hand, in Comparative Examples 1 and 2 with a compression degree of less than 12%, the moldability was poor, and in the Comparative Example with a compression degree exceeding 19%, many resin leaks occurred.

  Since the sealing resin composition of the present invention has an optimal compressibility, it exhibits good meltability and excellent moldability, and the wire flow during molding is reduced. Accordingly, a resin-encapsulated semiconductor device that is thin as a sealing material and is useful as a sealing material for a semiconductor element connected by a long and thin wire and having high reliability can be manufactured.

Claims (6)

(A) a biphenyl type epoxy resin, (B) a phenol resin curing agent, (C) a curing accelerator, and (D) a granular sealing resin composition containing spherical silica as essential components,
The degree of compression defined by the following formula is 12% or more and 19% or less,
In the particle size distribution obtained by the standard sieving method using a Tyler sieve, the particle size range is more than 0.212 mm and 0.71 mm or less, and more than 0.71 mm and 1.4 mm or less, each having one peak A sealing resin composition.
Compressibility (%) = {(tap bulk density−initial bulk density) / tap bulk density} × 100   The (D) spherical silica is (D1) 15% by mass to 30% by mass of spherical silica having a particle size of less than 5 μm, and (D2) 50% by mass to 80% by mass of spherical silica having a particle size of 5 μm to less than 50 μm, (D3) Ratio of spherical silica having a particle diameter of 50 μm or more and 5% by mass or more and 20% by mass or less and (D1) spherical silica having a particle diameter of less than 5 μm and (D2) spherical silica having a particle diameter of 5 μm or more and less than 50 μm ( 2. The sealing resin composition according to claim 1, wherein D1) / (D2) is in the range of 0.15 to 0.50. In the particle size distribution measured by a standard sieving method using a Tyler sieve, particles having a particle size of 25% by mass to 50% by mass and having a particle size of more than 0.212 mm and not more than 0.71 mm are 24%. The resin composition for sealing according to claim 1 or 2, wherein the content is from mass% to 30 mass%. 4. The sealing resin composition according to claim 1, wherein the (B) phenol resin curing agent includes a phenol resin represented by the following general formula (1). 5.

(In formula (1), R ¹ is a monovalent organic group having a phenolic hydroxyl group, R ² is a divalent organic group having a phenolic hydroxyl group, and n is an integer of 1 to 5)   5. The sealing resin composition according to claim 1, wherein the content of the (D) spherical silica is 80% by mass or more and 95% by mass or less of the entire composition. A method for manufacturing a semiconductor device , comprising: sealing a semiconductor element by compression molding using the sealing resin composition according to claim 1.