JP2000195993A - Semiconductor sealing resin-composition and semiconductor device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve flame resistance, wet-resistance reliability, and fluidity of a semiconductor sealing resin composition, by making it contain an epoxy resin, a phenol resin, a polyhedron- form composite metal hydroxide represented by a specific formula, and a red-phosphorous based flame-resistant agent. SOLUTION: As epoxy resin (A component), various kinds of epoxy resins, e.g. a biphenyl- type epoxy resin are preferable. A phenol resin (B component), used together with the A component is used as the hardening agent of the epoxy resin, and a phenol aralkyl resin is preferable. With respect to a composite metal hydroxide, a polyhedron-form composite metal hydroxide (C component) represented by a general formula of m(MaOb).n(QdOe).cH2 O[where M, Q different metal elements from each other is used, and Q is a metal element selected from among IVa-VIIIa, Ib, IIb of the periodic table, and further, m, n, a to e are integers]. As the metal element M, Al, Mg, Ca, Ni, Co, Sn, Zn, etc., are exemplified, and as the other metal; element Q, e.g. Fe, Co, Ni, Pd, Cu, etc. Can be cited to be selected as their kind solely or as two or more kinds of them concurrently. As a red-phosphorous based flame-resistant agent (D component) used together with the A-C components, the red phosphorous having its surface coated with a shell portion is used. The foregoing respective components are forced to be contained in a semiconductor sealing resin-composition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition for semiconductor encapsulation having excellent flame retardancy, moisture resistance reliability and fluidity, and a semiconductor device using the same.

[0002]

2. Description of the Related Art Semiconductor elements such as transistors, ICs, and LSIs have conventionally been sealed with an epoxy resin composition to form electronic parts. It is indispensable that this electronic component complies with UL94 V-0, which is a standard of flame retardancy, and until now, in order to impart its flame retardant action, antimony compounds such as brominated epoxy resin and antimony oxide have been used. Has been adopted.

However, recently, from the viewpoint of environmental protection, a flame-retardant epoxy resin composition having a flame retardancy without using a halogen-based flame retardant or antimony oxide has been demanded.
In response to this requirement, for example, the use of metal hydroxides, boron compounds, red phosphorus compounds, and the like as flame retardants has been studied. However, many of these compounds have reduced moisture resistance due to a large amount of impurities, It has not been put to practical use due to poor moldability due to reduced fluidity.

[0004]

SUMMARY OF THE INVENTION Among the above compounds,
Regarding metal hydroxides, the present applicant has proposed an epoxy resin composition for semiconductor encapsulation using a combination of a metal hydroxide and a metal oxide or a composite metal hydroxide thereof (Japanese Patent Application No. Hei 7 (1994) -207). 507466). Further, the applicant has
The above proposal proposes an epoxy resin composition for semiconductor encapsulation that solves the problem of fluidity (Japanese Patent Application No. 9-1036).
No. 46). However, the epoxy resin composition for encapsulating a semiconductor having a high content of the flame retardant has good fluidity as compared with the conventional one due to a large amount of the additive, but still has a slight fluidity. Tended to cause a drop in gender.

[0005] The above-mentioned red phosphorus compound is useful because it exhibits a flame-retardant effect even with a small amount of addition, but has the problem that impurities such as phosphine and phosphoric acid are generated and the reliability is reduced. It was not useful as a stopping material. Therefore, in order to solve such a problem, a method using red phosphor coated with a metal hydroxide and a phenol resin has been proposed (Japanese Patent Application No. 6-295252).
However, when this coated red phosphorus is used, it must be added in a large amount, so that a large amount of phosphoric acid is still extracted as an impurity, and as a result, there is a problem that the moisture resistance is reduced.

The present invention has been made in view of such circumstances, and a resin composition for semiconductor encapsulation having excellent flame retardancy, fluidity, and moisture resistance reliability, and a highly reliable semiconductor obtained by using the same. The purpose is to provide the device.

[0007]

In order to achieve the above object, the present invention provides, as a first gist, a semiconductor sealing resin composition containing the following components (A) to (D).

(A) Epoxy resin. (B) a phenolic resin. (C) A polyhedral composite metal hydroxide represented by the following general formula (1).

## STR2 ## in _{m (M a O b) ·} n (Q d O e) · cH 2 O ... (1) [In formula (1), M and Q are different metal elements from each other, Q is the period IVa, Va, VIa, VII of the Ritsu table
a, VIII, Ib, IIb. Further, m, n, a, b, c, d, and e are positive numbers, and may have the same value or different values. (D) Red phosphorus flame retardant.

A second aspect of the present invention provides a semiconductor device in which a semiconductor element is sealed using the above resin composition for semiconductor sealing.

The polyhedral composite metal hydroxide of the component (C) in the resin composition for semiconductor encapsulation of the present invention may be a compound having a hexagonal plate shape as shown in FIG. It does not have a so-called thin plate-like crystal shape such as a scaly shape, but has a large crystal growth in the thickness direction (c-axis direction) both vertically and horizontally. A composite metal hydroxide having a granular crystal shape which is more three-dimensionally and spherically formed by growing crystals in the (c-axis direction), for example, a substantially dodecahedral, a substantially octahedral, or a substantially tetrahedral shape. , Usually a mixture of these. Of course, in addition to crystal growth, the shape of the polyhedron changes due to pulverization, grinding, and the like, and the polyhedron can be approximated more three-dimensionally and spherically. FIG. 1 shows an example of a scanning electron microscope photograph (magnification: 50,000 times) showing the crystal shape of the polyhedral composite metal hydroxide. Thus, in the present invention, by using the composite metal hydroxide of the polyhedral shape, a hexagonal plate shape as in the related art, or a plate-like crystal shape such as a flake shape Compared with the resin composition, it is possible to suppress a decrease in the fluidity of the resin composition.

The shape of the composite metal hydroxide of the present invention will be described in more detail with reference to a substantially octahedral shape as an example. That is, an octahedral shape which is an example of the composite metal hydroxide of the present invention is composed of two parallel upper and lower base surfaces and six outer peripheral pyramid surfaces, and the pyramid surface is directed upward and downward. It has an octahedral shape in which inclined surfaces are alternately arranged.

More specifically, a conventional thin plate-shaped crystal having a flat crystal shape has a hexagonal crystal structure, for example, as shown in FIG.
Upper and lower 2 represented by (00 · 1) plane in the Bravais index
It has a hexagonal prism shape whose outer periphery is surrounded by a base surface 10 of the surface and six square cylinder surfaces 11 belonging to a {10.0} mold surface. And
Since there is little crystal growth in the [001] direction (c-axis direction), it has a thin hexagonal column shape.

On the other hand, as shown in FIG. 4, the composite metal hydroxide of the present invention can be controlled by controlling the crystal habit during crystal growth.
A base surface 12 of two upper and lower surfaces represented by a (00 · 1) plane;
The outer circumference is surrounded by six pyramidal surfaces 13 belonging to the {10 · 1} mold surface. The pyramidal surface 13 is (10 ·
An octahedral shape having a special crystal habit in which an upwardly inclined surface 13a such as a (1) plane and a downwardly inclined surface 13b such as a (10-1) plane are alternately arranged. Further, the crystal growth in the c-axis direction is larger than that of the conventional one. FIG. 4 shows a plate-like shape, but FIG. 5 shows that the crystal growth in the c-axis direction further progressed and the crystal habit became remarkable and became isotropic. As described above, the composite metal hydroxide of the present invention includes those having a shape close to a regular octahedron. That is, the ratio (major axis diameter / thickness) of the major axis diameter of the basal plane to the thickness between the basal planes is preferably 1 to 9. 7 is more preferable as the upper limit of the ratio between the major axis diameter and the thickness. In the Miller-Bravey index, "1 bar"
Is indicated as "-1".

As described above, it can be understood from the following facts that the composite metal hydroxide of the present invention has six surfaces surrounding the outer periphery which are pyramidal surfaces belonging to {10 · 1}. That is, when the crystal of the composite metal hydroxide of the present invention is observed with a scanning electron microscope from the c-axis direction, the crystal exhibits three-fold rotational symmetry with the c-axis as a rotation axis. Also, the (10 · 1) plane using the measured value of the lattice constant by powder X-ray diffraction and ｛1
The calculated value of the inter-plane angle with the mold surface of 0.1 ° almost coincides with the measured value of the inter-plane angle in scanning electron microscope observation.

Further, the composite metal hydroxide of the present invention comprises:
Half width B of peak at (110) plane in powder X-ray diffraction
₁₁₀And the half width B of the peak of the (001) plane₀₀₁And the ratio
(B_{11 0}/ B₀₀₁) Is 1.4 or more. This thing
Also, the crystallinity in the c-axis direction is good, and the thickness grows.
Can be confirmed. That is, the conventional hydroxide mug
In crystals such as nesium, crystals grow in the c-axis direction.
The peak of the (001) plane is broad and the half width B₀₀₁
Also increases. Therefore, (B₁₁₀/ B₀₀₁)
Become smaller. In contrast, the composite metal hydroxide of the present invention
Then, the crystallinity in the c-axis direction is good, so that the (001) plane
Peak is sharp and narrow, half width B₀₀₁Is also smaller.
Therefore, (B₁₁₀/ B₀₀₁) Will increase in value
You.

That is, the present inventors have conducted a series of studies to obtain a sealing material having not only flame retardancy but also excellent fluidity and moisture resistance reliability. As a result, when the composite metal hydroxide having the polyhedral shape and the red phosphorus-based flame retardant are used in combination, the respective addition amounts for imparting the flame retardancy can be suppressed, and the adverse effects caused by using only one of them, For example, by using only a polyhedral composite metal hydroxide, it is possible to suppress a decrease in fluidity due to a large amount of the addition of the flame retardant, and a red phosphorus-based flame retardant It has been found that the use of only Nb reduces the amount of impurities such as phosphoric acid and can suppress a decrease in moisture resistance. further,
Since the composite metal hydroxide having the polyhedral shape has an ion capturing action, it becomes possible to capture impurities such as phosphoric acid caused by the red phosphorus-based flame retardant and reduce the amount of impurities in the entire system, It has been found that the effect of further improving the moisture resistance can be obtained, and that the above problem can be solved together with excellent flame retardancy, and the present invention has been achieved.

When a red phosphorus-containing flame retardant coated with red phosphorus using a metal hydroxide and a phenol resin is used, oxidation of the red phosphorus is prevented, and stability is improved because of stability. Become.

By setting the polyhedral complex metal hydroxide and the red phosphorus-based flame retardant to specific ranges, fluidity and moisture resistance can be further improved.

[0019]

Next, embodiments of the present invention will be described in detail.

The resin composition for encapsulating a semiconductor of the present invention comprises an epoxy resin (A component), a phenol resin (B component),
It is obtained by using a polyhedral complex metal hydroxide (component (C)) and a red phosphorus-based flame retardant (component (D)).
It is in the form of a powder or a tablet obtained by compressing it. Alternatively, it is a sheet-like sealing material obtained by melting and kneading the resin composition and then forming into a substantially columnar or other granule, and further into a sheet.

The epoxy resin (component (A)) is not particularly limited, and various conventionally known epoxy resins can be used. For example, bisphenol A type epoxy resin, phenol novolak type epoxy resin, cresol novolak type epoxy resin, biphenyl type epoxy resin and the like can be mentioned.

It is preferable to use a biphenyl type epoxy resin among the above epoxy resins. For example, a biphenyl type epoxy resin represented by the following general formula (2) is used.

[0023]

Embedded image

Of the alkyl groups having 1 to 5 carbon atoms represented by R _{1 to} R ₄ in the general formula (2), examples of the alkyl group include a methyl group, an ethyl group, n
- propyl group, an isopropyl group, n- butyl group, isobutyl group, sec- butyl group, a linear or branched lower alkyl group such as a tert- butyl group are exemplified, particularly preferably a methyl group, the R ₁ ~ R ₄ may be the same or different. Among them, it is particularly preferable to use a biphenyl-type epoxy resin having a structure represented by the following formula (3) in which all of R _{1 to} R ₄ are methyl groups, from the viewpoint of low hygroscopicity and reactivity.

[0025]

Embedded image

The phenol resin (component B) used together with the epoxy resin (component A) acts as a curing agent for the epoxy resin, and is not particularly limited, and a conventionally known one can be used. Examples include phenol novolak, cresol novolak, bisphenol A type novolak, naphthol novolak, and phenol aralkyl resin. Especially, when a biphenyl type epoxy resin is used as the epoxy resin (component A), it is preferable to use a phenol aralkyl resin represented by the following general formula (4) as the phenol resin.

[0027]

Embedded image

The mixing ratio of the epoxy resin (component A) and the phenol resin (component B) is such that the hydroxyl group in the phenol resin is 0.7 to 1.3 equivalent per equivalent of epoxy group in the epoxy resin. It is preferable to set so that it becomes, and it is especially preferable to set so that it may become 0.9 to 1.1 equivalent.

The polyhedral complex metal hydroxide (component C) used together with the components A and B is as follows:
It is represented by the following general formula (1), and has a polyhedral crystal shape.

[0030]

Embedded image m (M _a O _b ) · n (Q _d O _e ) · cH ₂ O (1) [In the above formula (1), M and Q are different metal elements, and Q is a period. IVa, Va, VIa, VII of the Ritsu table
a, VIII, Ib, IIb. Further, m, n, a, b, c, d, and e are positive numbers, and may have the same value or different values. ]

Regarding the composite metal hydroxide represented by the general formula (1), M representing the metal element in the formula (1) is represented by Al, Mg, Ca, Ni, Co, Sn, Zn, C
u, Fe, Ti, B and the like.

Q representing another metal element in the composite metal hydroxide represented by the general formula (1) is IVa, Va, VIa, VIIa, VIII, Ib, IIb in the periodic table. Metals belonging to the group selected from For example, Fe, C
o, Ni, Pd, Cu, Zn, etc., and are selected alone or in combination of two or more.

The composite metal hydroxide having such a polyhedral crystal shape can be obtained, for example, by controlling various conditions in the production process of the composite metal hydroxide.
Obtaining a composite metal hydroxide having a desired polyhedral shape, for example, a substantially dodecahedral, substantially octahedral, or substantially tetrahedral shape, in which crystal growth in the thickness direction (c-axis direction) is large both vertically and horizontally. Can be.

The polyhedral complex metal hydroxide used in the present invention has, as one example, a polyhedral structure having an approximately octahedral crystal outer shape and an aspect ratio of about 1 to 8, preferably 1 to 7, and particularly preferably. Is adjusted to 1-4,
For example, when the case where M = Mg and Q = Zn in the formula (1) is described, it can be manufactured as follows. That is, first, a zinc nitrate compound is added to an aqueous solution of magnesium hydroxide to prepare a partially complexed metal hydroxide as a raw material. Then, this raw material is 800-1500
The composite metal oxide is produced by firing at a temperature in the range of 1000C, more preferably in the range of 1000 to 1300C. This composite metal oxide has m (MgO) · n (Zn
O), at least one selected from the group consisting of a carboxylic acid, a metal salt of a carboxylic acid, an inorganic acid and a metal salt of an inorganic acid is added in an amount of about 0.1 to the composite metal oxide. The polyhedral shape of the present invention represented by m (MgO) · n (ZnO) · cH ₂ O by performing a hydration reaction at a temperature of 40 ° C. or more while strongly stirring in a system in an aqueous medium coexisting with ６6 mol% Can be produced.

In the above-mentioned production method, the raw materials include not only the partially complexed metal hydroxide obtained by the above-mentioned method, but also
For example, a composite metal hydroxide obtained by a coprecipitation method,
A mixture of magnesium hydroxide and Zn, a mixture of magnesium oxide and Zn oxide, a mixture of magnesium carbonate and Zn carbonate, and the like can also be used. In addition, stirring during the hydration reaction improves uniformity and dispersibility, and improves contact efficiency with at least one selected from the group consisting of carboxylic acids, metal salts of carboxylic acids, inorganic acids and metal salts of inorganic acids. Therefore, strong stirring is preferable, and more powerful high shear stirring is more preferable. Such stirring is preferably performed, for example, with a rotary blade type stirrer at a peripheral speed of the rotary blade of 5 m / s or more.

The carboxylic acid is not particularly limited, but preferably includes a monocarboxylic acid and an oxycarboxylic acid (oxyacid). Examples of the monocarboxylic acid include formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, acrylic acid, crotonic acid, and the like. Examples of the oxycarboxylic acid (oxyacid) include glycolic acid, Lactic acid, hydroacrylic acid,
α-oxybutyric acid, glyceric acid, salicylic acid, benzoic acid, gallic acid and the like. The metal salt of the carboxylic acid is not particularly limited, but preferably includes magnesium acetate, zinc acetate and the like. The inorganic acid is not particularly limited, but preferably includes nitric acid, hydrochloric acid, and the like. The inorganic acid metal salt is not particularly limited, but preferably includes magnesium nitrate, zinc nitrate and the like.

As a specific representative example of the composite metal hydroxide having the polyhedral shape, sMgO. (1-s) N
iO · cH ₂ O [0 <s <1, 0 <c ≦ 1], sMgO
· (1-s) ZnO · cH ₂ O [0 <s <1, 0 <c ≦
1], sAl ₂ O _3. (1-s) Fe ₂ O ₃ .cH ₂ O
[0 <s <1, 0 <c ≦ 3] and the like. Of these, hydrates of magnesium oxide / nickel oxide, hydrates of magnesium oxide / zinc oxide, and hydrates of magnesium oxide / copper oxide are particularly preferably used.

The composite metal hydroxide having the polyhedral shape (component C) preferably has the following particle size distributions (c1) to (c3). In addition, a laser type particle size analyzer is used for the measurement of the particle size distribution shown below. (C1) 10 to 35% by weight having a particle size of less than 1.3 μm. (C2) 50 to 6 particles having a particle size of less than 1.3 to 2.0 μm
5% by weight. (C3) 10 to 30% by weight having a particle size of 2.0 μm or more.

In the above particle size distribution, the particle size distribution (c1)
If the particle size is less than 1.3 μm is less than 10% by weight, the effect of flame retardancy is poor, and if it exceeds 35% by weight, the fluidity tends to be impaired. If the particle size distribution (c3) of 2.0 μm or more is less than 10% by weight, the fluidity is reduced, and if it exceeds 30% by weight, the effect of flame retardancy tends to be poor. The normal lower limit of the particle size in the particle size distribution (c1) is 0.1 μm, and the particle size distribution (c1)
The normal upper limit of the particle size in 3) is 15 μm.

In the polyhedral composite metal hydroxide as the component (C), the particle size distribution (c1)
In addition to (c3), the maximum particle size is preferably 10 μm or less. Particularly preferably, the maximum particle size is 6 μm or less. That is, when the maximum particle size exceeds 10 μm, a large amount tends to be required to have flame retardancy.

Further, the specific surface area of the polyhedral complex metal hydroxide as the component (C) is 2.0 to 4.0 m ^2.
/ G is preferable. The specific surface area of the component (C) is measured by a BET adsorption method.

The aspect ratio of the composite metal hydroxide (component C) having the polyhedral shape is usually 1 to 8, preferably 1 to 7, and particularly preferably 1 to 4. The term “aspect ratio” as used herein refers to the ratio of the major axis to the minor axis of the composite metal hydroxide. That is, if the aspect ratio exceeds 8, the effect of lowering the viscosity when the resin composition containing the composite metal hydroxide is melted becomes poor. When used as a component of the resin composition for semiconductor encapsulation of the present invention, those having an aspect ratio of 1 to 4 are generally used.

In the present invention, a conventional thin plate-shaped composite metal hydroxide can be used together with the polyhedral composite metal hydroxide as the component (C). In view of the reduction in viscosity and the effect of fluidity when the resin composition for semiconductor encapsulation of the present invention is melted, the entire composite metal hydroxide used (including the conventional thin plate shape) is used. It is preferable to set the ratio of the polyhedral composite metal hydroxide in the range of 30 to 100% by weight. That is, when the ratio of the polyhedral composite metal hydroxide occupies less than 30% by weight, the effect of decreasing the viscosity of the resin composition and the effect of improving the fluidity are poor.

The content of the composite metal hydroxide containing the composite metal hydroxide having the polyhedral shape (component C) is 1 to 30% by weight, particularly 3 to 25% by weight of the whole resin composition.
Is preferably set in the range. That is, if the composite metal hydroxide is less than 1% by weight, the flame retardant effect of the combined use with the red phosphorus-based flame retardant is insufficient, so that it is necessary to use a large amount of the red phosphorus-based flame retardant. And as a result,
There is a tendency to cause a decrease in moisture resistance. Also, 30
If the content exceeds% by weight, the fluidity tends to decrease, and a tendency such as wire flow or the like tends to occur.

The red phosphorus-based flame retardant (component D) used together with the above components A to C includes those composed of red phosphorus alone.
This red phosphorus alone is liable to be oxidized, and has a difficulty in handling due to its instability. For this reason, it is preferable to use at least one of the metal hydroxide and the phenol resin whose red phosphorus surface is coated in advance. Examples of the metal hydroxide serving as the coating material include magnesium hydroxide and aluminum hydroxide. In addition, the phenol resin is not particularly limited, and includes various conventionally known phenol resins. The content of red phosphorus in the red phosphorus flame retardant thus coated is preferably 45 to 95% by weight, particularly preferably 70 to 95% by weight.
% By weight. That is, if the content of red phosphorus is less than 45% by weight, it is difficult to obtain the desired flame retardancy unless the red phosphorus-based flame retardant itself is added in a large amount. This is because there is a tendency to decrease and cause problems in stability and purity.

Further, as the above-mentioned red phosphorus-based flame retardant, it is preferable to use those having an average particle diameter of 5 to 70 μm, more preferably 10 to 45 μm, by a laser particle size analyzer.
μm. That is, when the average particle size of the red phosphorus-based flame retardant exceeds 70 μm, the dispersibility of the red phosphorus-based flame retardant tends to decrease, and when the average particle diameter is less than 5 μm, the flowability tends to decrease. It is.

The content of the red phosphorus-based flame retardant (component D) is preferably set in the range of 0.1 to 2% by weight in the whole resin composition, and particularly preferably in the range of 0.1 to 1%. .
0% by weight. That is, when the content is less than 0.1% by weight, the amount of the composite metal hydroxide (component C) relatively increases in order to obtain the desired flame retardancy, and the flowability tends to decrease. When the content exceeds 2% by weight, impurities such as phosphoric acid increase to cause a decrease in moisture resistance, and at the same time, when added in a large amount, a tendency to show no flame retardancy is observed.

In the resin composition for semiconductor encapsulation of the present invention, an inorganic filler can be used together with the above-mentioned components A to D and, if necessary, a conventional composite metal hydroxide having a thin plate shape. The inorganic filler is not particularly limited and includes various conventionally known fillers, for example, quartz glass powder, talc, silica powder, alumina powder, aluminum nitride powder, silicon nitride powder and the like. These may be used alone or in combination of two or more. It is preferable to use silica powder as the inorganic filler from the viewpoint that the coefficient of linear expansion of the obtained cured product can be reduced. Among them, it is particularly preferable to use a fused silica powder, particularly a spherical fused silica powder, as the silica powder from the viewpoint of good fluidity of the resin composition. The average particle size of the inorganic filler is preferably in the range of 10 to 70 μm, more preferably 10 to 50 μm. That is, as described above, the composite metal hydroxide has a particle size distribution (c1) to
When the resin composition has (c3) and the average particle size of the inorganic filler is within the above range, good fluidity of the resin composition can be obtained. Further, as the above-mentioned silica powder, a crushed silica powder obtained by optionally crushing a silica powder can also be used.

The content of the inorganic filler is preferably set so as to be 60 to 95% by weight of the whole resin composition for semiconductor encapsulation.

The resin composition for encapsulating a semiconductor according to the present invention contains, in addition to the components A to D and the inorganic filler, a curing accelerator, a pigment, a release agent, a surface treatment agent, and a flexibility-imparting agent. And the like can be appropriately added as needed.

The curing accelerator is not particularly limited as long as it promotes the reaction between the epoxy group and the hydroxyl group. For example, 1,8-diazabicyclo (5,
(4,0) diazabicycloalkene compounds such as undecene-7, tertiary amines such as triethylenediamine,
Imidazoles such as methylimidazole; and phosphorus-based compounds such as triphenylphosphine. These compounds are used alone or in combination of two or more.

Examples of the pigment include carbon black and titanium oxide. Further, as the release agent,
Carnauba wax, polyethylene wax, paraffin, fatty acid ester, fatty acid salt and the like can be mentioned.

Further, examples of the surface treatment agent include a coupling agent such as a silane coupling agent. Examples of the flexibility imparting agent include various silicone compounds and butadiene-acrylonitrile rubber.

In the resin composition for encapsulating a semiconductor according to the present invention, an organic flame retardant may be used in addition to the above components. Examples of the organic flame retardant include a nitrogen-containing organic compound and a phosphazene-based compound, and a nitrogen-containing organic compound is particularly preferably used.

Examples of the nitrogen-containing organic compound include, for example,
Compounds having a heterocyclic skeleton such as a melamine derivative, a cyanurate derivative, and an isocyanurate derivative are exemplified.
These organic flame retardants are used alone or in combination of two or more.

The organic flame retardant may be blended after being mechanically mixed with the composite metal hydroxide in advance, or the organic flame retardant may be dissolved in a solvent and mixed with the composite metal hydroxide. A material which has been subjected to a surface treatment by adding a substance to remove the solvent may be used.

In the resin composition for semiconductor encapsulation according to the present invention, preferred combinations of the components including the components A to D are as follows. That is, among the epoxy resins (component A), a biphenyl-based epoxy resin is preferred from the viewpoint of good fluidity, and the phenol resin (component B) is preferably a phenol aralkyl resin from the viewpoint of fluidity. Then, it is preferable to use a red phosphorus powder whose surface is coated with a metal hydroxide and a phenol resin as the red phosphorus flame retardant (D component). Further, it is preferable to use a fused silica powder as an inorganic filler together with the polyhedral composite metal hydroxide (component C). Furthermore, in the case where a composite metal hydroxide as described above is used in addition to each of these components, wax tends to be used, so that it is preferable to use waxes.

The resin composition for encapsulating a semiconductor according to the present invention comprises:
For example, it can be manufactured as follows. That is, an epoxy resin (A component), a phenol resin (B component), a polyhedral composite metal hydroxide (C component), a red phosphorus-based flame retardant (D component), and an inorganic filler, if necessary. The additives are blended in a predetermined ratio. Next,
This mixture is melted and kneaded in a heated state using a kneading machine such as a mixing roll machine, and the mixture is cooled to room temperature. And
The desired resin composition for encapsulating a semiconductor can be produced by a series of steps of pulverizing by known means and tableting as necessary.

Alternatively, the mixture of the resin composition for semiconductor encapsulation is introduced into a kneader, kneaded in a molten state, and then continuously formed into substantially columnar granules. Can be produced.

Further, the mixture of the above resin composition for semiconductor encapsulation is received on a pallet, and after cooling, press rolling, roll rolling, or coating with a mixture of solvents to form a sheet is performed. Thereby, a sheet-like resin composition for semiconductor encapsulation can be manufactured.

The method for encapsulating a semiconductor device using the resin composition for encapsulating a semiconductor (powder, tablet, granule, etc.) thus obtained is not particularly limited.
It can be performed by a known molding method such as ordinary transfer molding.

Using the sheet-like resin composition for semiconductor encapsulation, for example, a semiconductor device can be manufactured by flip chip mounting as follows. That is, the sheet-shaped resin composition for semiconductor encapsulation is disposed on the electrode surface side of a semiconductor element having a bonding bump or on the bump bonding portion side of a circuit board, and the semiconductor element and the circuit board are bumped. The semiconductor device can be manufactured by flip-chip mounting by joining and bonding the two together by resin sealing.

Next, examples will be described together with comparative examples.

First, the following materials were prepared.

[Epoxy resin] 4,4'-bis (2,3
-Epoxypropoxy) -3,3 ', 5,5'-tetramethylbiphenyl

[Phenol resin] A phenol aralkyl resin represented by the above formula (4) (softening point 70 ° C., hydroxyl equivalent 175)

[Red Phosphorus Flame Retardant] Red phosphorus powder surface coated with magnesium hydroxide and phenol resin (red phosphorus content: 93% by weight, average particle size: 30 μm: Nova Excel, manufactured by Rin Kagaku Kogyo Co., Ltd.)

[Silica powder] Fused silica powder (spherical, average particle size 25 μm, specific surface area 1.4 m ² / g)

[Silane coupling agent] β- (3,4-
Epoxycyclohexyl) ethyltrimethoxysilane

[Curing accelerator] Triphenylphosphine

[Composite Metal Hydroxide] Next, prior to the examples, polyhedral composite metal hydroxides shown in Tables 1 and 2 below were prepared. The polyhedral complex metal hydroxide was prepared according to the method for producing a polyhedral complex metal hydroxide described above.

[0072]

[Table 1]

[0073]

[Table 2]

[0074]

Examples 1 to 8 and Comparative Examples 1 to 3
The components shown in Table 4 were blended in the proportions shown in the same table, and melt-kneaded for 3 minutes with a mixing roll machine (temperature: 100 ° C.)
After cooling and solidifying, the mixture was pulverized to obtain a desired powdery epoxy resin composition.

[0075]

[Table 3]

[0076]

[Table 4]

Using the thus obtained epoxy resin compositions of Examples and Comparative Examples, tablets were formed, and test pieces for flame retardancy were molded under molding conditions of 175 ° C. × 70 kg / cm ² × 120 seconds. In addition, L in TOWA automatic molding machine
A package of QFP-114 (size: 20 mm × 20 mm × thickness 1.4 mm) was formed. Using these test pieces for flame retardancy and the package, flame retardancy, wire flow and moisture resistance were measured and evaluated. Further, after the test piece was pulverized, phosphate ions were extracted under extraction conditions of 160 ° C. × 20 hours, and the amount of the ions was measured by ion chromatography analysis. The results are shown in Tables 5 and 6 below.

[Flame retardancy] Flame retardancy was evaluated according to the method of UL94 V-0 standard. In addition, pass means 94-V0 pass.

[Wire Flow] First, the occurrence of defects such as deformation of the gold wire was measured by observing a transmission image inside the package using a soft X-ray apparatus. As a result of the measurement, those in which the deformation of the gold wire was confirmed were evaluated as x, and those in which the deformation of the gold wire was not confirmed and a good package was obtained were evaluated and indicated as ○.

[Moisture Resistance] A pressure cooker test (PCT test) was performed by applying a bias to the semiconductor device manufactured as described above (condition: 130 ° C./8).
5% RH, 30V bias). In the failure mode, a leakage failure and an open failure were measured, and the time until the failure occurred was determined.

[0081]

[Table 5]

[0082]

[Table 6]

From the results shown in Tables 5 and 6, the products of the Examples show not only excellent flame retardancy, but also no problem in wire flow, and the amount of phosphate ions is compared with the use of red phosphorus-based flame retardant alone. Compared with the product of Example 1, the result was very small, and good results were also obtained in terms of moisture resistance. From these facts, it can be seen that the flame retardancy, fluidity and moisture resistance are all excellent. On the other hand, the product of Comparative Example 1 was a system using only a red phosphorus-based flame retardant, and good results were obtained in terms of flame retardancy and fluidity, but the amount of phosphate ions was large and the moisture resistance was poor. Comparative Example 2 was a composite metal hydroxide alone system, had good fluidity, had a small amount of phosphate ions and had no problem with moisture resistance, but failed the flame retardancy test. The product of Comparative Example 3 is a composite metal hydroxide alone system, but has a good flame retardancy because the amount of the composite metal hydroxide is set to be larger than that of the product of Comparative Example 2. In addition, there was no problem with respect to moisture resistance because the amount of phosphate ions was small, but it was found that the flowability was poor because a problem occurred in the wire flow.

Further, in Example 1, the epoxy resin component was a biphenyl type epoxy resin in which all of R _{1 to} R ₄ in the above formula (2) were hydrogen, and the R in the above formula (2).
_The mixture was replaced with a mixed epoxy resin in which biphenyl type epoxy resins in which all of _{1 to} R ₄ are methyl groups were blended so that the weight ratio became 1: 1. Otherwise, the same blending ratio as in Example 1 was set to produce an epoxy resin composition. The same measurement and evaluation as described above were performed using this epoxy resin composition, and as a result, almost the same good results as those in the above example were obtained.

[0085]

As described above, the present invention provides a polyhedral complex metal hydroxide (C) represented by the general formula (1).
And a red phosphorus-based flame retardant (component (D)). As described above, since the polyhedral complex metal hydroxide and the red phosphorus-based flame retardant are used in combination as the flame retardant component, the amounts of the individual components C and D for imparting flame retardancy are suppressed. can do. That is, the harmful effects of using only one of them, such as the use of only a polyhedral composite metal hydroxide, a decrease in fluidity due to a large amount of the added metal in imparting flame retardancy,
When only the red phosphorus-based flame retardant is used, the amount of impurities such as phosphoric acid is large and the moisture resistance is reduced. However, the decrease in fluidity and the decrease in moisture resistance can be suppressed. Furthermore, the impurities such as phosphoric acid are reduced due to the ion capturing effect of the polyhedral complex metal hydroxide, and the effect of suppressing a decrease in moisture resistance becomes more effective.
Therefore, a material having excellent fluidity and moisture resistance reliability as well as excellent flame retardancy can be obtained.

When the red phosphorus-based flame retardant (component D) is coated with red phosphorus with a metal hydroxide and a phenol resin, the oxidation of the red phosphorus is prevented, and the red phosphorus is stable. The property becomes good.

By setting the contents of the polyhedral complex metal hydroxide (component C) and the red phosphorus-based flame retardant (component D) to specific ranges, respectively, more excellent fluidity and moisture resistance can be obtained. Property is obtained.

[Brief description of the drawings]

FIG. 1 is a scanning electron microscope photograph (magnification: 50,000 times) showing an example of the crystal shape of a polyhedral complex metal hydroxide used in the present invention.

FIG. 2 is a perspective view showing a hexagonal plate shape which is one of the crystal shapes of a conventional composite metal hydroxide.

FIGS. 3A and 3B are explanatory views showing the outer shape of a conventional composite metal hydroxide, wherein FIG. 3A is a plan view and FIG. 3B is a side view.

FIG. 4 is an explanatory view showing an example of the outer shape of the composite metal hydroxide of the present invention, wherein (a) is a plan view and (b) is a side view.

5 is an explanatory view showing another example of the outer shape of the composite metal hydroxide of the present invention, wherein (a) is a plan view and (b) is a side view. FIG.

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) // (C08K 3/00 3:22 3:02)

Claims (7)

[Claims] 1. A resin composition for encapsulating a semiconductor, comprising the following components (A) to (D): (A) Epoxy resin. (B) a phenolic resin. (C) A polyhedral composite metal hydroxide represented by the following general formula (1). Embedded image m (M _a O _b ) · n (Q _d O _e ) · cH ₂ O (1) [In the above formula (1), M and Q are different metal elements, and Q is a period. IVa, Va, VIa, VII of the Ritsu table
a, VIII, Ib, IIb. Further, m, n, a, b, c, d, and e are positive numbers, and may have the same value or different values. (D) Red phosphorus flame retardant. 2. The red phosphorus flame retardant as the component (D),
The resin composition for semiconductor encapsulation according to claim 1, wherein red phosphorus is coated with a metal hydroxide and a phenol resin. 3. The content of the polyhedral complex metal hydroxide as the component (C) is 1 to 30 of the whole resin composition.
The resin composition for semiconductor encapsulation according to claim 1 or 2, which is in terms of% by weight. 4. The semiconductor according to claim 1, wherein the content of the red phosphorus-based flame retardant as the component (D) is 0.1 to 2% by weight of the whole resin composition. A resin composition for sealing. 5. The polyhedral composite metal hydroxide as the component (C) has a particle size distribution (c1) to (c) shown below.
The resin composition for semiconductor encapsulation according to any one of claims 1 to 4, having 3). (C1) 10 to 35% by weight having a particle size of less than 1.3 μm. (C2) 50 to 6 particles having a particle size of less than 1.3 to 2.0 μm
5% by weight. (C3) 10 to 30% by weight having a particle size of 2.0 μm or more. 6. The resin composition for semiconductor encapsulation according to any one of claims 1 to 5, wherein the resin composition contains a nitrogen-containing organic compound. A resin composition for semiconductor encapsulation. 7. A semiconductor device in which a semiconductor element is encapsulated with the resin composition for encapsulating a semiconductor according to any one of claims 1 to 6.