JP2000156438A - Resin composition for sealing semiconductor and semiconductor device using the same and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a solder resistance, moisture-resistance reliability, a flame retardation property, and fluidity by allowing a resin composition for sealing semiconductor to contain a thermosetting resin, a curing agent, a compound metal hydroxide in a specific polyhedron shape and a curing accelerator. SOLUTION: A resin composition for sealing semiconductor is allowed to contain a thermosetting resin, a curing agent, a compound metal hydroxide in a polyhedron shape that is expressed by an expression of m (MaOb).n(QdOe).cH2O (M and Q are mutually different metal elements, Q is a metal element that is selected from Iva, Va, Via, VIIa, VIII, Ib, and IIb in a periodic table, and m, n, and a-e are positive numbers), and one curing accelerator that is selected from a group consisting of tetra substitution phosphonium/tetra substitution boletol, diazabicycloalkene, and a tertiary amine expressed by a general expression. However, in the expression, R1 is an alkylene group, R2, R3, and R4 are an alkyl group, where R2-R4 are the same values or different values.

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, solder resistance, moisture resistance reliability and fluidity, a semiconductor device using the same, and a method for manufacturing a semiconductor device. is there.

[0002]

2. Description of the Related Art Conventionally, semiconductor devices such as transistors, ICs and LSIs have been sealed with ceramics and the like to form semiconductor devices. However, recently, from the viewpoint of cost and mass productivity, a resin-sealed type using plastic has been used. Semiconductor devices have become mainstream. Epoxy resin compositions have conventionally been used for this type of resin sealing and have achieved good results. However, due to technological innovation in the semiconductor field, the degree of integration has been improved, the element size has been increased, and the wiring has been miniaturized.
There is also a tendency for packages to be smaller and thinner, and accordingly, there is a demand for further improvement in reliability of sealing materials. Among them, a sealing material excellent in low stress property has been conventionally demanded, and various low stress agents are used.

On the other hand, electronic parts such as semiconductor devices are indispensable to comply with UL94 V-0, which is a standard for flame retardancy, and conventionally, a resin composition for encapsulating a semiconductor is provided with a flame retardant action. In general, a method of adding an antimony compound such as a brominated epoxy resin or antimony oxide is used.

[0004]

However, there are two major problems with the above flame-retarding technology.

The first problem is that the harmfulness of the antimony compound itself, the harmfulness to the human body due to the generation of hydrogen bromide, bromo-based gas, antimony bromide and the like during combustion, environmental pollution, and the like. Corrosion to the steel is a problem.

A second problem is that when a semiconductor device employing the above-described flame-retarding technology is left at a high temperature for a long period of time, the aluminum wiring on the semiconductor element is corroded by the effect of liberated bromine, resulting in failure of the semiconductor device. This causes a problem of deterioration in high-temperature reliability.

[0007] In order to solve the above problems, a method has been proposed in which a non-halogen / non-antimony metal hydroxide is added as an inorganic flame retardant as a flame retardant.
However, this method requires a large amount (for example, 40% by weight).
Metal hydroxides must be used, resulting in new problems.

[0008] The first problem is that the semiconductor device is liable to swell or crack during soldering. 2. Description of the Related Art In recent years, surface mounting has become the mainstream as a mounting method for semiconductor devices, and soldering methods such as solder immersion, infrared reflow, and vapor phase reflow are selected and used at the time of soldering. Regardless of which process is adopted, the semiconductor device is exposed to a high temperature (usually 215 to 260 ° C.). Therefore, in a conventional semiconductor device formed by resin sealing using a resin composition to which a metal hydroxide is added, Due to the high water absorption of metal hydroxide,
There is a problem in that the semiconductor device swells or cracks due to rapid vaporization of the absorbed moisture, which is a so-called decrease in solder resistance.

A second problem is that the semiconductor element functions under a high-temperature and high-humidity environment of 80 to 200 ° C. and a relative humidity of 70 to 100% with respect to the moisture resistance reliability deteriorates. In addition, in a semiconductor element that generates a large amount of heat or a semiconductor device mounted around an engine of an automobile, a dehydration reaction occurs when used for a long period of time, so that there is a possibility that a problem that the moisture resistance reliability is reduced may occur.

As described above, in the conventional flame retarding technology, since the above-mentioned problem occurs, it is a safe material which does not generate harmful gas during combustion, and is a metal hydroxide at the time of soldering a semiconductor device. Development of flame-retardant technology that does not cause swelling or cracking of semiconductor devices due to dehydration of materials, and does not cause corrosion of aluminum wiring on semiconductor elements or decrease in moisture resistance reliability even if left in a high-temperature, high-humidity atmosphere for a long period of time Is strongly desired. Accordingly, the present applicant has proposed a thermosetting resin composition for semiconductor encapsulation using a metal hydroxide and a metal oxide, or a composite metal hydroxide thereof in combination with a thermosetting resin and a curing agent. Then, the above-mentioned problem was solved (Japanese Patent Application No. 7-507466). Although the use of this thermosetting resin composition for encapsulating a semiconductor could certainly improve flame retardancy and humidity resistance, it caused a new problem. That is, although semiconductor packages in recent years tend to be thinner, moldability such as deformation of a gold wire due to a decrease in fluidity of a resin composition serving as a sealing material during package molding such as transfer molding or the like occurs. Has become a problem.

On the other hand, in reality, it is desired that the above-mentioned problems be solved and further improved moisture resistance reliability be improved.

The present invention has been made in view of such circumstances, and a semiconductor sealing resin composition excellent in solder resistance, moisture resistance reliability, flame retardancy and fluidity, a semiconductor device using the same, and a semiconductor device using the same. It is intended to provide a method for manufacturing a semiconductor device.

[0013]

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) thermosetting resin. (B) Curing agent. (C) A polyhedral complex metal hydroxide represented by the following general formula (1).

## STR3 ## _{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 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) at least one curing accelerator selected from the group consisting of the following (a) to (c): (A) Tetra-substituted phosphonium / tetra-substituted borate. (B) diazabicycloalkenes. (C) Tertiary amine represented by the following general formula (X).

Embedded image

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

Further, the present invention provides a method of manufacturing a semiconductor device by manufacturing a semiconductor device by resin-sealing a semiconductor element by a transfer molding method using the above resin composition for semiconductor sealing.
A third aspect of the present invention is a method of manufacturing a semiconductor device by manufacturing a semiconductor device using a sheet-shaped sealing material made of the resin composition for semiconductor encapsulation.

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 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. 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 thin plate 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 addition,
In the Miller-Brabé index, “1 bar” is
"-1" was displayed.

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 resin composition for semiconductor encapsulation having excellent solder resistance, moisture resistance reliability, flame retardancy and fluidity. As a result, in place of the conventionally used flame retardant, a polyhedral composite metal hydroxide having a large crystal growth in the thickness direction as well as in the vertical and horizontal directions is used for the purpose of suppressing the decrease in the fluidity. With the use of a curing accelerator, release of chloride ions and the like can be suppressed, and as a result, excellent moisture resistance as well as excellent moldability and flame retardancy due to the use of the composite metal hydroxide can be obtained. And arrived at the present invention.

By using a composite metal hydroxide having the above-mentioned specific particle size distribution and a fine particle diameter as the composite metal hydroxide having the above-mentioned polyhedral shape, a very excellent reduction in fluidity is obtained. It was found that the suppression was performed, no problems occurred during transfer molding, and the improvement of moldability was realized.

When the composite metal hydroxide has an aspect ratio of 1 to 8, the effect of lowering the viscosity of the resin composition is exhibited, and the moldability is further improved.
And the above aspect ratio is in the range of 1 to 8,
Preferably it is 1-7.

[0026]

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

The resin composition for semiconductor encapsulation of the present invention comprises a thermosetting resin (component (a)), a curing agent (component (b)), a polyhedral composite metal hydroxide (component (c)), It is obtained by using a curing accelerator (two components) and is usually in the form of a powder or a tablet obtained by compressing the powder.
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.

Examples of the thermosetting resin (component (a)) include an epoxy resin, a polymaleimide resin, an unsaturated polyester resin, and a phenol resin. Particularly, in the present invention, it is preferable to use an epoxy resin or a polymaleimide resin.

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

The biphenyl type epoxy resin among the above epoxy resins is represented by the following general formula (2).

[0031]

Embedded image

Of the alkyl groups having 1 to 5 carbon atoms represented by R _{1 to} R ₄ in the general formula (2), the alkyl groups include a methyl group, an ethyl group, Propyl, isopropyl, butyl, isobutyl,
Examples thereof include a linear or branched lower alkyl group such as a sec-butyl group and a tert-butyl group. A methyl group is particularly preferable, and R _{1 to} 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.

[0033]

Embedded image

Further, the above-mentioned polymaleimide resin includes:
It is not particularly limited and conventionally known ones are used.
It has two or more maleimide groups in one molecule. For example, N, N'-4,4'-diphenylmethanebismaleimide, 2,2-bis- [4- (4-maleimidophenoxy) phenyl] propane and the like can be mentioned.

As the curing agent (component (b)) used together with the thermosetting resin (component (a)), for example, conventionally known ones such as phenol resins, acid anhydrides and amine compounds are used. When an epoxy resin is used as the thermosetting resin, a phenol resin is preferably used. Examples of the phenol resin include phenol novolak, cresol novolak, bisphenol A type novolak,
Examples include naphthol novolak and phenol aralkyl resin. When a biphenyl type epoxy resin is used as the epoxy resin, it is preferable to use a phenol aralkyl resin as a curing agent.

The curing agent when using a polymaleimide resin as the thermosetting resin is not particularly limited, and a conventionally known curing agent is used. Examples thereof include alkenylphenols and amines obtained by reacting the above-mentioned curing agent for epoxy resin with allyl halide in the presence of alkali.

When the thermosetting resin (component (a)) is an epoxy resin and the curing agent (component (b)) is a phenol resin, the content ratio of the two is per 1 equivalent of epoxy group in the epoxy resin. The hydroxyl group in the phenol resin is preferably set to be 0.7 to 1.3 equivalents, and particularly preferably set to be 0.9 to 1.1 equivalents.

The composite metal hydroxide (component (c)) used together with the thermosetting resin (component (a)) and the curing agent (component (b)) is represented by the following general formula (1) and has a polyhedral crystal shape. It has a shape.

[0039]

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 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. ]

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, iron, cobalt, nickel, palladium, copper, zinc and the like can be mentioned, and they are selected alone or in combination of two or more.

Such a composite metal hydroxide having 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, such as a substantially dodecahedral, a substantially octahedral, or a 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 an example, a polyhedral structure having an approximately octahedral crystal outer shape and an aspect ratio of about 1 to 8, preferably 2 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, 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, an oxycarboxylic acid (oxyacid) and the like. 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 and hydrates of magnesium oxide / zinc oxide are particularly preferably used.

The composite metal hydroxide having the polyhedral shape (component (c)) preferably has the following particle size distributions (A) to (C). In addition, a laser type particle size analyzer is used for the measurement of the particle size distribution shown below. (A) 10 to 35% by weight having a particle size of less than 1.3 μm. (B) 50 to 65 particles having a particle size of less than 1.3 to 2.0 μm.
weight%. (C) 10 to 30% by weight of particles having a particle size of 2.0 μm or more.

In the above particle size distribution, when the particle size distribution (A) having a particle size of less than 1.3 μm is less than 10% by weight,
If the flame retardant effect is poor, and if it exceeds 35% by weight, the flowability tends to be impaired. Further, those having a particle size distribution (C) of 2.0 μm or more
If the amount is less than 0% by weight, the fluidity tends to decrease, while 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 (A) is 0.1 μm, and the normal upper limit of the particle size in the particle size distribution (C) is 15 μm.

In the polyhedral composite metal hydroxide as the component (c), the particle size distribution (A)
In addition to (C), 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 composite 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 the BET adsorption method.

The composite metal hydroxide having the polyhedral shape (component (c)) has an aspect ratio of usually 1 to 8,
It is preferably from 1 to 7, particularly preferably from 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.

In the present invention, a conventional composite metal hydroxide having a thin plate shape 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 above-mentioned polyhedral shape (component (c)) is 1 to 30% by weight, particularly 2 to 28% by weight of the whole resin composition.
It is preferable to set the content within the range, and within this range of the content, the excellent flame retardant effect can be exhibited. That is, if the composite metal hydroxide is less than 1% by weight, the flame retarding effect becomes insufficient, and if it exceeds 30% by weight, the chlorine ion concentration in the cured resin composition increases, so that the moisture resistance reliability is increased. Is a tendency to decrease.

In the resin composition for encapsulating a semiconductor according to the present invention, an inorganic filler can be used together with the above-mentioned components (a) to (c) and, if necessary, a conventional composite metal hydroxide having a thin plate shape. . The inorganic filler is not particularly limited, and includes various known fillers. For example, quartz glass powder, talc, silica powder,
Examples include alumina powder, calcium carbonate, boron nitride, silicon nitride, and carbon black powder. These may be used alone or in combination of two or more. And
As the inorganic filler, it is preferable to use silica powder from the viewpoint that the coefficient of linear expansion of the obtained cured product can be reduced. Among them, fused silica powder as silica powder,
In particular, it is particularly preferable to use spherical fused silica powder from the viewpoint of good fluidity of the resin composition. In the above-mentioned inorganic filler, the average particle size is 10 to 70 μm.
And more preferably 10 to 5
0 μm. That is, as described above, when the composite metal hydroxide has the particle size distributions (A) to (C) and the average particle size of the inorganic filler is within the above range,
Good fluidity of the resin composition is obtained. Further, as the above-mentioned silica powder, a crushed silica powder obtained by optionally crushing a silica powder can also be used.

With respect to the content of the above-mentioned inorganic filler, a composite metal hydroxide (a composite metal hydroxide having a polyhedral shape and a conventional thin plate-shaped composite metal used in some cases) may be added to the inorganic filler. (Hydroxide), the total amount of the whole inorganic substance is 60% of the whole resin composition for semiconductor encapsulation.
It is preferable to set to be about 92% by weight. Particularly preferably, it is 70 to 90% by weight. That is, if the total amount of the inorganic substances is less than 60% by weight, the flame retardancy tends to decrease.

Further, when the composite metal hydroxide (x) containing the polyhedral composite metal hydroxide (component (c)) is used in combination with the inorganic filler (y),
The weight ratio (x / y) is preferably set in the range of x / y = 0.01 / 1 to 1/1, more preferably x / y.
= 0.01 / 1 to 0.75 / 1.

Specific curing accelerators (two components) used together with the above-mentioned components (a) to (c) and the inorganic filler include tetra-substituted phosphonium / tetra-substituted borate (a), diazabicycloalkenes (b), and And a tertiary amine (c) represented by the general formula (X).
These may be used alone or in combination of two or more.

[0058]

Embedded image

The tetra-substituted phosphonium / tetra-substituted borate (a) includes, for example, tetraphenylphosphonium / tetraphenyl borate represented by the following structural formula.

[0060]

Embedded image

The diazabicycloalkenes (b) include, for example, 1,8-diazabicyclo (5,4,0) undecene-7 (hereinafter referred to as “DB”) represented by the following structural formula.
U "), 1,5-diazabicyclo (4,3,0) nonene-5 (hereinafter" DBN ") represented by the following structural formula
And the like). These may be used alone or in combination of two or more.

[0062]

Embedded image

[0063]

Embedded image

In the tertiary amine (c) represented by the general formula (X), R ₁ in the formula (X) is specifically an alkylene group having 1 to 4 carbon atoms. Particularly preferred is a methylene group. Further, as R ₂ and R ₃ in the formula (X), preferably, an alkyl group having 1 to 4 carbon atoms is used, and particularly preferably, both R ₂ and R ₃ are methyl groups. Further, as R ₄ in the formula (X),
Specific examples include a hydroxyl group and an alkyl group having 1 to 4 carbon atoms, and a hydroxyl group is particularly preferred. As the tertiary amine represented by the general formula (X), 2,4,6-trisdimethylaminomethylphenol represented by the following structural formula is particularly preferably used.

[0065]

Embedded image

The mixing ratio of the specific curing accelerator (d component) is 100 parts by weight (hereinafter referred to as "parts") of the curing agent (d).
) Is preferably set in the range of 1 to 8 parts. More specifically, in consideration of the type [(a) to (c)] of the curing accelerator and the like, it is preferable to set as follows. For example, among the specific curing accelerators, when the above-mentioned tetra-substituted phosphonium / tetra-substituted borate (a) is used, the above-mentioned curing agent (b component) 1
More preferably, the amount is set in the range of 1 to 8 parts with respect to 00 parts, particularly preferably 3 to 5 parts. When the diazabicycloalkenes (b) are used, the content is more preferably set to 1 to 4 parts, more preferably 2 to 3 parts, per 100 parts of the curing agent (b). is there. Further, when the specific tertiary amine (c) is used, 1 to 4 parts per 100 parts of the curing agent (b) is used.
The amount is more preferably set in the range of parts, and particularly preferably 2 to 3 parts. That is, when the proportion of the specific curing accelerator (d component) is less than the above range, it is difficult to exhibit a sufficient curing accelerating action, and there is a tendency to cause poor curing which impairs molding workability. If the ratio exceeds the above range, the curing reaction becomes extremely fast, and there is a tendency to cause molding defects such as wire flow during molding.

For example, when imidazoles conventionally used are used, it is presumed that chlorine ions are easily generated in the cured resin composition. By using the specific curing accelerator (two components), it is possible to suppress the release of chloride ions in the cured resin composition, and as a result, the chlorine ion concentration is reduced and the moisture resistance reliability is improved. This has the effect of doing so.

In the resin composition for encapsulating a semiconductor of the present invention, the concentration of chloride ions in the extraction water extracted according to the following method is 20 per gram of the cured product of the resin composition.
It is preferably 0 μg or less. That is, 5 g of the powdered product of the cured thermosetting resin composition and 50 cc of distilled water are placed in a dedicated extraction container, and this container is left in a dryer at 160 ° C. for 20 hours to extract water (pH 6.0 to 8.0). 0) is extracted. Then, the extracted water is subjected to ion chromatography analysis to measure the amount of chloride ions (α). This chlorine ion amount (α)
Is a value obtained by diluting the amount of ions in the cured resin composition by 10 times, so that 1 g of the cured resin composition is obtained by the following formula.
Calculate the amount of chloride ions per unit. In addition, the pH of the said extraction water has the preferable range of 6.0-8.0. Further, in producing the thermosetting resin composition cured body, for example,
In the case of a cured epoxy resin composition, the cured body is molded under heat at 175 ° C. for 2 minutes.
It is preferable to set the post-curing at 75 ° C. for 5 hours.

[0069]

## EQU1 ## Chlorine ion amount (μg) per 1 g of the cured resin composition = α × (50/5)

That is, when the concentration of chloride ions contained in the extraction water of the cured resin composition is higher than 200 μg, there is a tendency that corrosion of semiconductor elements, lead frames, etc. occurs, and that the moisture resistance is deteriorated. Become like

The resin composition for encapsulating a semiconductor according to the present invention requires a pigment, a release agent, a surface treatment agent, a flexibility-imparting agent, etc. in addition to the above components (a) to (d) and the inorganic filler. They can be added as appropriate.

Examples of the pigment include carbon black and titanium oxide. Further, as the release agent,
Polyethylene wax, paraffin and fatty acid esters,
Fatty acid salts and the like.

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

In the resin composition for encapsulating a semiconductor according to the present invention, when an organic flame retardant or a red phosphorus flame retardant is used in addition to the above components, the composite metal hydroxide having the polyhedral shape is obtained. It is preferable because the amount of the composite metal hydroxide containing (c) can be reduced. Examples of the organic flame retardant include a nitrogen-containing organic compound, a phosphorus-containing organic compound, a phosphazene-based compound, and the like. In particular, a nitrogen-containing organic compound is 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.

The content of the organic flame retardant is determined by the amount of the composite metal hydroxide used (the polyhedral composite metal hydroxide and the conventional thin plate-shaped composite metal hydroxide optionally used). (Total amount of hydroxide) is preferably set in the range of 1 to 10% by weight. Particularly preferably, it is 1 to 5% by weight.

On the other hand, examples of the red phosphorus-based flame retardant include red phosphorus powder and red phosphorus powder whose red phosphorus powder surface is protectively coated with various organic and inorganic substances. The content of the red phosphorus-based flame retardant is the same as in the case of the organic flame retardant, and the amount of the composite metal hydroxide used (conventionally used with the polyhedral composite metal hydroxide) (The total amount of the composite metal hydroxide in the form of a thin plate) is preferably set in the range of 1 to 10% by weight, particularly preferably 1 to 5% by weight.

In the resin composition for encapsulating a semiconductor according to the present invention, preferred combinations of the components including the components (a) to (d) are as follows. That is, the thermosetting resin (component (a)) is preferably an epoxy resin, and among them, a biphenyl-based epoxy resin is preferable because of its good fluidity, and the curing agent (component (b)) is preferable from the viewpoint of its fluidity. And phenol aralkyl resins are preferred. Then, together with the polyhedral complex metal hydroxide (component (c)), as the specific curing accelerator, for example, tetraphenylphosphonium / tetraphenylborate, DBU, DBN, and 2,
It is preferred to use 4,6-trisdimethylaminomethylphenol. Further, when the above-mentioned composite metal hydroxide is used in addition to these components, the releasability tends to decrease, so that waxes, especially an acid value of 30 or more (normal upper limit value) It is preferable to use a polyethylene wax or ester wax having a high acid value of 200).

The resin composition for encapsulating a semiconductor according to the present invention comprises:
For example, it can be manufactured as follows. That is, a thermosetting resin (component (a)), a curing agent (component (b)), a polyhedral composite metal hydroxide (component (c)), a specific curing accelerator (component (d)), an inorganic filler, and if necessary. Other additives are blended in a predetermined ratio. Next, this mixture is melt-kneaded in a heated state using a kneading machine such as a mixing roll machine, and the mixture is cooled to room temperature. Then, the desired resin composition for semiconductor encapsulation can be produced by a series of steps of pulverization 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, cooled, and then rolled by press rolling, roll rolling, or a mixture of solvents to form a sheet. Thereby, a sheet-like resin composition for semiconductor encapsulation can be manufactured.

The method for encapsulating a semiconductor device using the thus obtained resin composition for encapsulating a semiconductor (powder, tablet, granule, etc.) 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, a semiconductor device by flip-chip mounting can be manufactured, for example, 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 a] Cresol novolak type epoxy resin (epoxy equivalent: 200)

[Epoxy resin b] A biphenyl-based epoxy resin represented by the formula (3) [R _{1 to} R ₄ in the formula (2)
Are all methyl groups: epoxy equivalent 195]

[Phenol resin c] Phenol novolak resin (hydroxyl equivalent 107)

[Phenol resin d] Phenol aralkyl resin (hydroxyl equivalent 174)

[Silica powder] Fused silica powder having an average particle size of 30 μm

[Curing accelerator] Tetraphenylphosphonium / tetraphenylborate

[Curing accelerator] DBN

[Curing accelerator] DBU

[Curing accelerator] 2,4,6-trisdimethylaminomethylphenol represented by the above structural formula

[Curing accelerator] 2-methylimidazole

[Ester wax] Carnauba wax (acid value 2 to 10)

[Olefin wax] Polyethylene wax (acid value 160)

Next, prior to the examples, various composite metal hydroxides shown in Tables 1 and 2 below were prepared. The composite metal hydroxides in Tables 1 and 2 below are:
It was produced according to the method for producing a polyhedral composite metal hydroxide described above.

[0100]

[Table 1]

[0101]

[Table 2]

[0102]

Examples 1 to 19 and Comparative Examples 1 to 6
The components shown in Table 7 are blended in the proportions shown in the same table, melt-kneaded in a mixing roll machine (temperature 100 ° C.) for 3 minutes, cooled and solidified, and then pulverized to obtain a desired powdery epoxy resin composition. Obtained.

[0103]

[Table 3]

[0104]

[Table 4]

[0105]

[Table 5]

[0106]

[Table 6]

[0107]

[Table 7]

Using the thus obtained epoxy resin compositions of Examples and Comparative Examples, the cured products were measured for chloride ion concentration. The method for measuring the chloride ion concentration was in accordance with the method described above, and the molding conditions for the cured product were 17
The setting was 5 ° C. × 2 minutes and the post-curing was 175 ° C. × 5 hours. Further, a test piece having a thickness of 1/16 inch was molded using each epoxy resin composition, and the flame retardancy was evaluated according to the method of UL94 V-0 standard. In addition, pass means 94-V0 pass. The results of these measurements and evaluations are shown in Tables 8 to 12 below.

Next, a spiral flow value and a flow tester viscosity were measured for each epoxy resin composition according to the following methods.

[Spiral Flow Value] EMMI 1-6 at 175 ± 5 ° C. using a spiral flow measurement mold.
The spiral flow value was measured according to 6.

[Flow Tester Viscosity] Each of the above epoxy resin compositions was precisely weighed in an amount of 2 g and molded into tablets. Then, put this in the pot of the Koka type flow tester,
The measurement was performed with a load of 0 kg. The melt viscosity of the sample was determined from the moving speed of the piston when the molten epoxy resin composition was extruded through a die hole (diameter 1.0 mm × 10 mm).

Further, the semiconductor element was subjected to transfer molding (condition: 175 ° C. × 2 minutes) using the epoxy resin compositions obtained in the above Examples and Comparative Examples, and post-cured at 175 ° C. × 5 hours to obtain a semiconductor device. The device was obtained. This semiconductor device has an 80-pin QFP (quad flat package, size: 20 × 14 × 2 mm) and a die pad size of 8 × 8 mm. Further, regarding the semiconductor device, first, observation of a transmission image inside the package with a soft X-ray device was performed to confirm occurrence of a defect such as deformation of a gold wire. As a result, those in which the deformation of the gold wire was confirmed were evaluated as x, those in which the deformation of the gold wire was not confirmed and a good package was obtained were evaluated as ○, and Tables 8 to 1 described below.
It is shown in FIG.

On the other hand, using the semiconductor device manufactured in this way, the measurement was performed nondestructively by an ultrasonic flaw detector. After the measurement, the number (out of 10) where internal peeling occurred was counted. Then, after the above measurement, non-defective products were subjected to the following solder test. That is, using a good semiconductor device,
After pre-baking at 20 ° C x 1 hour, this is baked at 85 ° C / 85%
After absorbing moisture for RH × 168 hours, an evaluation test (solder crack resistance) for 90 seconds was performed by VPS (vapor phase soldering) at 215 ° C. Then, the number of cracks (out of 10) was measured. The evaluation results are shown in Tables 8 to 12 below.

Further, using the above semiconductor device, a pressure cooker bias test (PC
BT) to measure the 50% failure occurrence time. The results are shown in Tables 8 to 12 below. The above PCB
The condition of T was 130 ° C. × 85% RH × 30 V (bias voltage).

[0115]

[Table 8]

[0116]

[Table 9]

[0117]

[Table 10]

[0118]

[Table 11]

[0119]

[Table 12]

From the above Tables 8 to 12, it is clear that all Examples have high flame retardancy levels, high spiral flow values, and low flow tester viscosities, and therefore have excellent fluidity. It is. In addition, since no deformation of the gold wire occurred, it can be said that the metal wire has good moldability. Good results were also obtained with respect to the moisture resistance reliability and the solder resistance of the obtained semiconductor device.

On the other hand, Comparative Examples 1 and 2
In the case of the 3, 5, and 6 products, it was found that the evaluation of the deformation of the gold wire was poor and the fluidity was reduced. Comparative Examples 3, 4, 5, 6
The product has a high chlorine ion concentration and a short failure occurrence time in the PCBT, indicating that the product is inferior in moisture resistance.

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 epoxy resin component 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.

[0123]

As described above, the present invention contains the specific hardening accelerator (d component) together with the polyhedral complex metal hydroxide (c component) represented by the general formula (1). It is a resin composition for semiconductor encapsulation. As described above, the use of the above-mentioned special complexed metal hydroxide imparts excellent flame retardancy and has no influence of bromine as compared with the use of a brominated epoxy resin or an antimony compound which is a conventional flame retardant. Corrosion of the semiconductor element and the aluminum wiring does not occur, so that the moisture resistance reliability is improved and the life is extended, and problems such as environmental pollution do not occur. Furthermore, since it has the special polyhedral crystal shape instead of the conventional plate-like crystal shape, it has excellent fluidity and improves moldability. In addition to the above-mentioned flame retardancy, moldability, and effect of preventing the occurrence of environmental pollution, when the above-mentioned polyhedral complex metal hydroxide (C component) is used, the polyhedral complex metal hydroxide becomes a semiconductor. Since it is uniformly dispersed in the encapsulating resin composition, flame retardancy equal to or higher than that of a conventionally known flame retardant such as a metal hydroxide can be obtained, so that the amount used is small. As a result, the amount of water absorption is reduced, so that the solder characteristics are improved. Further, in the present invention, in order to use the polyhedral complex metal hydroxide, compared to the case of using a conventional thin plate-like or scale-like complex metal hydroxide, the amount of use can be reduced, therefore, For example, when using silica powder in combination,
Because the amount of silica powder can be set relatively large,
In such a case, the linear expansion coefficient of the obtained semiconductor device can be reduced and the mechanical strength is improved. Further, by using the above-mentioned specific curing accelerator (two components), in addition to the above-mentioned effects, a product having more excellent moisture resistance reliability can be obtained.

Further, when the special composite metal hydroxide having the above crystal shape has a specific particle size distribution,
With excellent flame retardant effect, extremely excellent suppression of decrease in fluidity is achieved, and no problem occurs during transfer molding and the like, and further improvement in moldability is realized.

When the composite metal hydroxide has an aspect ratio of 1 to 8, the effect of lowering the viscosity of the resin composition is exhibited, and the moldability is further improved.

Therefore, the semiconductor device encapsulated with the resin composition for encapsulating a semiconductor of the present invention is a flame-retardant technology excellent in safety and the reliability of the semiconductor device is remarkably improved. In addition, the method for producing a semiconductor device by transfer molding using the resin composition for semiconductor encapsulation or the method for producing a semiconductor device using the resin composition for semiconductor encapsulation in a sheet form is excellent in moldability. Therefore, among semiconductor devices, the semiconductor device is particularly effective for a thin and large semiconductor device, and has extremely high industrial utility value.

[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.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08L 61/00 C08L 63/00 63/00 101/00 101/16

Claims (21)

[Claims] 1. A resin composition for encapsulating a semiconductor, comprising the following components (a) to (d): (A) thermosetting resin. (B) Curing agent. (C) A polyhedral complex 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) at least one curing accelerator selected from the group consisting of the following (a) to (c): (A) Tetra-substituted phosphonium / tetra-substituted borate. (B) diazabicycloalkenes. (C) Tertiary amine represented by the following general formula (X). Embedded image 2. The resin composition for semiconductor encapsulation according to claim 1, wherein the component (c) has the following particle size distributions (A) to (C). (A) 10 to 35% by weight having a particle size of less than 1.3 μm. (B) 50 to 65 particles having a particle size of less than 1.3 to 2.0 μm.
weight%. (C) 10 to 30% by weight of particles having a particle size of 2.0 μm or more. 3. A metal element in the composite metal hydroxide represented by the general formula (1), wherein M represents aluminum, magnesium, calcium, nickel, cobalt, tin, zinc, copper, iron, titanium and The resin composition for semiconductor encapsulation according to claim 1, wherein the resin composition is at least one metal selected from the group consisting of boron. 4. Q representing a metal element in the composite metal hydroxide represented by the general formula (1) is at least one selected from the group consisting of iron, cobalt, nickel, palladium, copper and zinc. The resin composition for semiconductor encapsulation according to any one of claims 1 to 3, which is a single metal. 5. The composite metal hydroxide represented by the general formula (1) has an average particle size of 0.5 to 10 μm.
The resin composition for semiconductor encapsulation according to the above. 6. The resin composition for semiconductor encapsulation according to claim 1, wherein the composite metal hydroxide represented by the general formula (1) has an aspect ratio of 1 to 8. . 7. The proportion of the composite metal hydroxide having a polyhedral shape represented by the general formula (1) in the entire composite metal hydroxide is in the range of 30 to 100% by weight. The resin composition for semiconductor encapsulation according to any one of 1 to 6. 8. The composite metal hydroxide represented by the general formula (1) is sMgO. (1-s) NiO.cH ₂ O
The resin composition for semiconductor encapsulation according to any one of claims 1 to 7, wherein [0 <s <1, 0 <c ≦ 1]. 9. The composite metal hydroxide represented by the general formula (1) is sMgO. (1-s) ZnO.cH ₂ O.
The resin composition for semiconductor encapsulation according to any one of claims 1 to 7, wherein [0 <s <1, 0 <c ≦ 1]. 10. The resin composition according to claim 1, wherein the content of the composite metal hydroxide represented by the general formula (1) is set in a range of 1 to 30% by weight of the whole resin composition. The resin composition for semiconductor encapsulation according to claim 1. 11. The pH of the extract of the cured resin composition for semiconductor encapsulation is in the range of 6.0 to 8.0, and the chloride ion concentration is 200 per 1 g of the cured resin composition.
The resin composition for semiconductor encapsulation according to any one of claims 1 to 10, wherein the amount is not more than μg. 12. A cured product of the resin composition for encapsulating a semiconductor,
In a UL94 combustion test with a 1/16 inch thickness, V
The resin composition for semiconductor encapsulation according to any one of claims 1 to 11, which exhibits flame retardancy equivalent to -0. 13. The resin composition for semiconductor encapsulation according to claim 1, wherein the thermosetting resin as the component (a) is an epoxy resin. 14. The resin composition for semiconductor encapsulation according to claim 1, wherein the curing agent as the component (b) is a phenol resin. 15. The total amount of the composite metal hydroxide containing the polyhedral composite metal hydroxide as the component (c) and the inorganic filler is 6% of the total of the resin composition for semiconductor encapsulation.
The resin composition for semiconductor encapsulation according to any one of claims 1 to 14, which is 0 to 92% by weight. 16. The total amount of the composite metal hydroxide containing the polyhedral composite metal hydroxide as the component (c) and the inorganic filler is 7% of the whole resin composition for semiconductor encapsulation.
The resin composition for semiconductor encapsulation according to any one of claims 1 to 14, which is 0 to 90% by weight. 17. The resin composition according to claim 15, wherein the inorganic filler is a silica powder. 18. The resin composition for semiconductor encapsulation according to any one of claims 1 to 17, wherein the resin composition contains a nitrogen-containing organic compound. A resin composition for encapsulating a semiconductor. 19. A semiconductor device comprising a semiconductor element encapsulated with the resin composition for semiconductor encapsulation according to claim 1. Description: 20. A semiconductor device, wherein the semiconductor element is resin-sealed by transfer molding using the resin composition for semiconductor encapsulation according to claim 1 to manufacture a semiconductor device. Equipment manufacturing method. 21. A method for manufacturing a semiconductor device, comprising manufacturing a semiconductor device using a sheet-shaped sealing material comprising the resin composition for semiconductor encapsulation according to claim 1. Description: