JP3447615B2 - Resin composition for semiconductor encapsulation, semiconductor device using the same, and method of manufacturing semiconductor device - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a resin composition for semiconductor encapsulation excellent in flame retardancy, solder resistance, moisture resistance reliability, fluidity and releasability, a semiconductor device using the same, and a semiconductor device. It relates to the manufacturing method.

[0002]

2. Description of the Related Art Conventionally, semiconductor elements such as transistors, ICs, and LSIs have been encapsulated with ceramics or the like to be semiconductor devices, but recently, from the viewpoint of cost and mass productivity, resin-encapsulated type using plastics. Semiconductor devices have become mainstream. An epoxy resin composition has been conventionally used for this type of resin encapsulation, and has achieved good results. However, technological innovations in the semiconductor field have led to an increase in the degree of integration and an increase in the size of elements and miniaturization of wiring.
There is a tendency for packages to become smaller and thinner, and there is a demand for further improvement in the reliability of sealing materials.

On the other hand, it is essential for electronic parts such as semiconductor devices to comply with UL94 V-0, which is a standard of flame retardancy, and conventionally, a resin composition for encapsulating a semiconductor has a flame retarding effect. As a method of doing so, a method of adding a brominated epoxy resin and antimony oxide is generally used.

[0004]

However, there are two major problems with the above-mentioned flame retardancy imparting technology.

The first problem is that the harmfulness of antimony trioxide itself, the harmfulness to the human body due to the generation of hydrogen bromide, bromine gas, antimony bromide, etc. at the time of combustion and the corrosiveness of equipment are problems. ing.

A second problem is that when a semiconductor device employing the above flame retarding technology is left at high temperature for a long time, aluminum wiring on a semiconductor element corrodes due to the effect of liberated bromine, causing a failure of the semiconductor device. As a result, the high temperature reliability is deteriorated.

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

The first problem is that the semiconductor device tends to swell or crack during soldering. 2. Description of the Related Art In recent years, surface mounting has become a mainstream mounting method for semiconductor devices, and soldering methods such as solder dipping, infrared reflow, and vapor phase reflow are selected and used during soldering. Regardless of which treatment is adopted, the semiconductor device is exposed to a high temperature (usually 215 to 260 ° C.). Therefore, in the conventional semiconductor device by resin encapsulation using the resin composition to which the metal hydroxide is added, Due to the large water absorption of metal hydroxide,
There is a problem that the semiconductor device is swollen or cracked due to the rapid vaporization of the absorbed moisture, that is, the so-called solder resistance is lowered.

A second problem is that the reliability of the humidity resistance deteriorates in the semiconductor element function under a high temperature and high humidity environment of 80 to 200 ° C. and a relative humidity of 70 to 100%. Further, in a semiconductor device having a large amount of heat generation, a semiconductor device mounted around an engine of an automobile, or the like, a dehydration reaction occurs due to long-term use, which may cause a problem that moisture resistance reliability is deteriorated.

As described above, the conventional flame-retardant technique has the above-mentioned problems. Therefore, it is a safe material that does not generate a harmful gas at the time of burning, and is a metal hydroxide when soldering a semiconductor device. Development of flame-retardant technology that does not cause swelling or cracking of semiconductor devices due to dehydration of objects and does not cause corrosion of aluminum wiring on semiconductor elements or deterioration of moisture resistance reliability even if left in a high temperature and high humidity atmosphere for a long period of time Is strongly desired. Therefore, the present applicant proposes a thermosetting resin composition for semiconductor encapsulation in which a metal hydroxide and a metal oxide or a composite metal hydroxide thereof is used together with a thermosetting resin and a curing agent. The above problem was solved (Japanese Patent Application No. 7-507466). By using this thermosetting resin composition for semiconductor encapsulation, the effect of improving flame retardancy and moisture resistance reliability was certainly obtained, but a new problem occurred. That is, although semiconductor packages in recent years tend to be made thinner, moldability such as deformation of gold wires due to deterioration of fluidity of a resin composition as a sealing material during package molding such as transfer molding occurs. The problem is a significant decrease in

In order to solve the above problems, the present applicant proposes a resin composition for semiconductor encapsulation using a flame retardant having a special shape, that is, a polyhedral complex metal hydroxide. Has already filed an application to solve the above problem. However, it has been found that when the above-mentioned special complex metal hydroxide is used, the mold releasability tends to be poor.

The present invention has been made in view of the above circumstances, and is a resin composition for semiconductor encapsulation which is excellent not only in safety but also in moisture resistance reliability, flame retardancy and moldability, and also in releasability. An object is to provide an object, a semiconductor device using the same, and a method for manufacturing a semiconductor device.

[0013]

In order to achieve the above object, the first aspect of the present invention is a semiconductor encapsulating 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).

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 , IVa, Va, VIa, VII of the Periodic Table
It is a metal element belonging to a group selected from a, VIII, Ib, and IIb. In addition, m, n, a, b, c, d, and e are positive numbers, and may have the same value or different values. (D) At least one of a high acid value polyethylene wax and a long chain alkyl phosphate compound.

A second aspect of the present invention is a semiconductor device obtained by encapsulating a semiconductor element with the above-mentioned semiconductor encapsulating resin composition.

The present invention also provides a method of manufacturing a semiconductor device, in which a semiconductor element is resin-sealed by transfer molding using the above-mentioned resin composition for semiconductor sealing,
A third aspect of the present invention is a method for manufacturing a semiconductor device, in which a semiconductor device is manufactured by using a sheet-shaped sealing material made of the above resin composition for semiconductor sealing.

The polyhedral complexed metal hydroxide of the component (c) in the resin composition for semiconductor encapsulation of the present invention has a hexagonal plate shape as shown in FIG. 2, or It does not have a so-called thin plate-like crystal shape such as a scaly shape, but has large crystal growth in the thickness direction (c-axis direction) in both the vertical and horizontal directions. For example, a plate crystal has a thickness direction. A complex metal hydroxide having a granular crystal shape that has grown in the (c-axis direction) and is approximated to a more three-dimensional and spherical shape, for example, a dodecahedron, an octahedron, or a tetrahedron. , Usually a mixture of these. Of course, the above-mentioned polyhedron shape can be approximated to a more three-dimensional and spherical shape by changing the shape of the polyhedron by crushing or grinding in addition to the method of growing crystals. FIG. 1 shows an example of a scanning electron micrograph (magnification: 50,000 times) showing the crystal shape of the polyhedral composite metal hydroxide. As described above, in the present invention, by using the polyhedral composite metal hydroxide, a hexagonal plate having a conventional shape or a plate-like crystal shape such as a scale-like shape is used. It is possible to suppress a decrease in the fluidity of the resin composition as compared with the resin.

The shape of the composite metal hydroxide of the present invention will be described in more detail by taking 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 base surfaces on the upper and lower sides and six pyramidal surfaces on the outer periphery, and the pyramidal surfaces face upward and inclined. It has an octahedral shape in which inclined surfaces are alternately arranged.

More specifically, a conventional thin plate crystal having a thin plate shape has, for example, a hexagonal crystal structure as a crystal structure, as shown in FIG.
Upper and lower 2 represented by the (00.1) plane in the Bravais index
It is a hexagonal columnar shape whose outer periphery is surrounded by a base surface 10 of the surface and six square cylindrical surfaces 11 belonging to the {10.0} mold surface. And
Since there is little crystal growth in the [001] direction (c-axis direction), it has a thin hexagonal columnar shape.

On the other hand, the composite metal hydroxide of the present invention, as shown in FIG. 4, is obtained by controlling the crystal habit during crystal growth.
Two upper and lower base surfaces 12 represented by the (00 · 1) plane,
The outer periphery is surrounded by six pyramidal surfaces 13 belonging to the {10 · 1} mold surface. The pyramid surface 13 is (10.
It has an octahedral shape having a special crystal habit in which upwardly inclined surfaces 13a such as 1) surfaces and downwardly inclined surfaces 13b such as (10-1) surfaces are alternately arranged. Also, the crystal growth in the c-axis direction is larger than that of the conventional one. Although the shape shown in FIG. 4 is close to a plate shape, FIG. 5 shows that the crystal growth in the c-axis direction further progresses, and the crystal habit becomes prominent and isotropic. As described above, the composite metal hydroxide of the present invention also includes one having a shape close to a regular octahedron. That is, the ratio of the major axis diameter of the basal plane to the thickness between the basal planes (major axis diameter / thickness) is preferably 1 to 9. 7 is more preferable as the upper limit value of the ratio of the major axis diameter to the thickness. In addition, in the above-mentioned Miller-Brave index, "1 bar"
Is displayed as "-1".

As described above, in the composite metal hydroxide of the present invention, the six surfaces surrounding the outer periphery are pyramidal surfaces belonging to {10 · 1}, as can be seen from the following. That is, when the crystal of the composite metal hydroxide of the present invention is observed from the c-axis direction with a scanning electron microscope, the crystal exhibits three-fold rotational symmetry with the c-axis as the rotation axis. In addition, the (10 · 1) plane and the {1
The calculated value of the face-to-face angle with the mold surface of 0 · 1} substantially agrees with the measured value of the face-to-face angle in the scanning electron microscope observation.

Further, the composite metal hydroxide of the present invention is
Half-width B of peak of (110) plane in powder X-ray diffraction
₁₁₀And the half width B of the peak of the (001) plane₀₀₁Ratio with
(B_{11 0}/ B₀₀₁) Is 1.4 or more. This thing
In addition, the crystallinity in the c-axis direction is good and the thickness grows.
Can be confirmed. That is, 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 grows. Therefore (B₁₁₀/ B₀₀₁) Is
Get smaller. On the other hand, the composite metal hydroxide of the present invention
Then, since the crystallinity in the c-axis direction is good, the (001) plane
The peak is sharp and narrow, and the half width B₀₀₁Also becomes smaller.
Therefore (B₁₁₀/ B₀₀₁) Will increase in value
It

In order to obtain a resin composition for semiconductor encapsulation which is excellent in safety, solder resistance, moisture resistance reliability, flame retardancy and fluidity, and is also excellent in mold releasability. We conducted a series of studies. As a result, with the use of a polyhedral complexed metal hydroxide having a large crystal growth in the thickness direction along the length and width for the purpose of suppressing the decrease in the above-mentioned fluidity, it becomes a specific release agent, and the above high acid value. It has been found that use of at least one of polyethylene wax and long-chain alkyl phosphate compounds suppresses deterioration of fluidity of the resin composition and provides excellent mold releasability. Then, the specific release agent comes to also act as a dispersant, and finds that it is uniformly dispersed by suppressing the occurrence of secondary aggregation of the polyhedral complexed metal hydroxide. The invention was reached.

Further, when the average particle size of the special complex metal hydroxide having the above-mentioned crystal shape is in the above range, the excellent flame retardant effect and the deterioration of the fluidity thereof are further suppressed. Further improvement in moldability is realized.

When the aspect ratio of the composite metal hydroxide is 1 to 8, the effect of lowering the viscosity of the resin composition is exerted, and the moldability is further improved.
And, within the range of the aspect ratio from 1 to 8,
It is preferably 1 to 7.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION Next, embodiments of the present invention will be described in detail.

The semiconductor encapsulating resin composition according to the present invention is
Thermosetting resin (a component), curing agent (b component), and specific composite metal hydroxide having a polyhedral shape (c component)
And a specific release agent (dual component), which is usually in the form of a powder or a tablet formed by tableting. Alternatively, after melt-kneading the resin composition,
It is a sheet-shaped sealing material that is formed into a granular shape such as a substantially cylindrical shape, and is further formed into a sheet shape.

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

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

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

[0030]

[Chemical 3]

Of —H (hydrogen) or an alkyl group having 1 to 5 carbon atoms represented by R _{1 to} R ₄ in the general formula (2), the alkyl group is a methyl group, an ethyl group, Propyl group, isopropyl group, butyl group, isobutyl group,
Examples thereof include linear or branched lower alkyl groups such as sec-butyl group and tert-butyl group, particularly preferably methyl group, and R _{1 to} R ₄ may be the same or different. Among them, from the viewpoint of low hygroscopicity and reactivity, 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.

[0032]

[Chemical 4]

As the polymaleimide resin,
A conventionally known one is used without particular limitation,
It has two or more maleimide groups in one molecule. For example, N, N'-4,4'-diphenylmethane bismaleimide, 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, a conventionally known one such as phenol resin, acid anhydride or amine compound can be used. When an epoxy resin is used as the thermosetting resin, a phenol resin is preferably used. Examples of the phenol resin include phenol novolac, cresol novolac, bisphenol A type novolac,
Examples include naphthol novolac 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 the curing agent.

The curing agent used when the polymaleimide resin is used as the thermosetting resin is not particularly limited, and conventionally known ones can be used. Examples thereof include alkenylphenols and amines obtained by reacting the above epoxy resin curing agent with an allyl halide in the presence of an 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 both is 1 equivalent of epoxy group in the epoxy resin. The hydroxyl group in the phenol resin is preferably set to 0.7 to 1.3 equivalents, and particularly preferably set to 0.9 to 1.1 equivalents.

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

[0038]

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 , IVa, Va, VIa, VII of the Periodic Table
It is a metal element belonging to a group selected from a, VIII, Ib, and IIb. In addition, m, n, a, b, c, d, and e are positive numbers, and may have the same value or different values. ]

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

Q, which represents another metal element in the complex metal oxide represented by the above general formula (1), is selected from IVa, Va, VIa, VIIa, VIII, Ib and IIb of the periodic table. A metal that belongs to the selected family. 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.

The composite metal hydroxide having such a polyhedral crystal shape can be prepared, for example, by controlling various conditions in the production process of the composite metal hydroxide.
To obtain a complex metal hydroxide having a desired polyhedron shape in which crystal growth is large in the thickness direction (c-axis direction) in the vertical and horizontal directions, for example, a substantially dodecahedron, a substantially octahedron, a substantially tetrahedron, etc. You can

The polyhedral composite metal hydroxide used in the present invention shows, as an example, a polyhedral structure having a substantially octahedral crystal outer shape, and an aspect ratio of about 1 to 8, preferably 1 to 7, and particularly preferably. Is adjusted to 1 to 4,
For example, when the case of 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 magnesium hydroxide solution to prepare a partially composite metal hydroxide as a raw material. Then, this raw material, 800 ~ 1500
A composite metal oxide is produced by firing in the range of 1000C, more preferably in the range of 1000 to 1300C. This composite metal oxide is m (MgO) .n (Zn
O), but 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 by hydration reaction in the strong stirring 40 ° C. above the temperature in the system of aqueous medium coexisting ~6mol%, m (MgO) · n (ZnO) · cH represented by ₂ O, polyhedral shape of the present invention It is possible to produce a composite metal hydroxide having

In the above-mentioned production method, not only the partially composite metal hydroxide obtained by the above-mentioned method as a raw material but also the
For example, a complex 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. Further, stirring during the hydration reaction improves homogeneity and dispersibility, 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, etc. Therefore, strong stirring is preferable, and more powerful high shear stirring is more preferable. Such stirring is preferably carried out, for example, in a rotary blade type stirrer at a peripheral speed of the rotary blade of 5 m / s or more.

The above-mentioned carboxylic acid is not particularly limited, but preferable examples include monocarboxylic acid and 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, and examples of the oxycarboxylic acid (oxyacid) include glycolic acid, Lactic acid, hydroacrylic acid,
Examples include α-oxybutyric acid, glyceric acid, salicylic acid, benzoic acid and gallic acid. The metal salt of the carboxylic acid is not particularly limited, but magnesium acetate, zinc acetate and the like are preferable. The inorganic acid is not particularly limited, but nitric acid, hydrochloric acid and the like are preferable. The metal salt of the inorganic acid is not particularly limited, but magnesium nitrate, zinc nitrate and the like are preferable.

A typical representative example of the complexed metal hydroxide having the above polyhedral shape is 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. Among them, magnesium oxide / nickel oxide hydrate and magnesium oxide / zinc oxide hydrate are particularly preferably used.

As the complex metal hydroxide (ha component) having the above polyhedron shape, it is preferable to use one having an average particle size in the range of 0.5 to 10 μm by a laser particle sizer, more preferably 0. 6 to 6 μm. That is, when the average particle size of the composite metal hydroxide exceeds 10 μm and becomes large, the flame retarding effect tends to decrease.

The aspect ratio of the composite metal hydroxide (ha) component having the above polyhedral shape is usually 1 to 8,
It is preferably 1 to 7, and particularly preferably 1 to 4. The aspect ratio here is expressed by the ratio of the major axis and the minor axis of the composite metal hydroxide. That is, when the aspect ratio exceeds 8, the effect of decreasing the viscosity when the resin composition containing the complexed metal hydroxide is melted becomes poor. When used as a constituent 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, the conventional thin plate-shaped composite metal hydroxide can be used together with the polyhedral composite metal hydroxide which is the component (C). Then, from the viewpoint of decreasing the viscosity and exhibiting the effect of fluidity when the resin composition for semiconductor encapsulation of the present invention is melted, the total amount of the composite metal hydroxide used (including the conventional thin flat plate shape) is It is preferable to set the proportion of the polyhedral complex metal hydroxide in the range of 30 to 100% by weight. That is, when the proportion of the polyhedral complex metal hydroxide is less than 30% by weight, the effect of decreasing the viscosity of the resin composition and the effect of improving the fluidity become poor.

The content of the complex metal hydroxide containing the complex metal hydroxide (ha component) having the above polyhedron shape is 1 to 30% by weight, particularly 2 to 28% by weight of the whole resin composition.
It is preferable to set in the range of, and the excellent flame retarding effect can be exhibited within the range of this content. That is, when the content of the complexed metal hydroxide is less than 1% by weight, the flame retarding effect becomes insufficient, and when it exceeds 30% by weight, the chlorine ion concentration in the cured resin composition becomes high, so that the moisture resistance reliability is high. This is because there is a tendency of decreasing.

In addition, in the resin composition for semiconductor encapsulation according to the present invention, an inorganic filler can be used together with the above-mentioned components (a) to (c), and optionally a conventional thin plate-shaped composite metal hydroxide. . The inorganic filler is not particularly limited, and various conventionally known fillers can be used. For example, quartz glass powder, talc, silica powder,
Examples thereof 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 above-mentioned inorganic filler, silica powder is preferably used from the viewpoint that the linear expansion coefficient of the obtained cured product can be reduced. Among them, fused silica powder as silica powder,
It is particularly preferable to use spherical fused silica powder from the viewpoint of good fluidity of the resin composition. In addition, in the above inorganic filler, the average particle size is 10 to 70 μm.
The range is preferably, and more preferably 10 to 5.
It is 0 μm. That is, as described above, when the average particle size of the composite metal hydroxide is within the above range and the average particle size of the inorganic filler is within the above range, good fluidity of the resin composition is obtained. Is obtained. Further, as the above-mentioned silica powder, ground silica powder obtained by grinding the silica powder may be used depending on the case.

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

Further, the combined ratio of the composite metal hydroxide (x) containing the polyhedral composite metal hydroxide (c component) and the inorganic filler (y) is as follows:
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.

As the specific release agent (dual component) used together with the above components (a) to (c), a high acid value polyethylene wax or a long-chain alkyl phosphate compound is used.
These may be used alone or in combination. The specific release agent (dual component) has the function of a release agent,
It acts as a dispersant, and it is possible to suppress the occurrence of secondary aggregation of the polyhedral complex metal hydroxide (component (c)) and disperse it uniformly in the entire resin composition.

In the present invention, the "high acid value" in the high acid value polyethylene wax among the above specific release agents means an acid value of 50 or more. A polyethylene wax having an acid value of 100 or more is more preferable, and a polyethylene wax having an acid value of 150 or more is particularly preferable. That is, even if a polyethylene wax having a low acid value such as an acid value of less than 50 is used, the releasability is not improved, and the effect as a dispersant is not exerted, so that the above polyhedral composite metal hydroxide is obtained. The all-composite metal hydroxide containing the substance is inferior in dispersibility, and secondary aggregates are generated.

As the long-chain alkyl phosphate compound, a long-chain alkyl phosphate compound having a long-chain alkyl group moiety having 30 or more carbon atoms is used, and more preferably, the long-chain alkyl group moiety has carbon atoms. Is a long chain alkyl phosphate compound of 50 or more. That is, in the case of a long-chain alkyl phosphate compound having a carbon number of the long-chain alkyl group portion of less than 30, the compatibility with the resin component increases and the releasability from the molding die is poor.

The content ratio of the specific mold release agent (dual component) is 0.1 to 0.1% based on the total resin composition for semiconductor encapsulation.
It is preferably set in the range of 0.6% by weight, particularly preferably in the range of 0.3 to 0.45% by weight. That is, if the content ratio of the above-mentioned two components is too small, such as less than 0.1% by weight, it becomes difficult to obtain sufficient mold releasability, and conversely, if it exceeds 0.6% by weight, it becomes good. Although it exhibits releasability, the adhesive strength to the lead frame and the semiconductor element is impaired, and the moisture resistance reliability tends to be poor.

In the resin composition for semiconductor encapsulation of the present invention, the chlorine ion concentration in the extracted water extracted according to the following method is 20 per 1 g 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 thermosetting resin composition cured product and 50 cc of distilled water were placed in a dedicated extraction container, and this container was left in a dryer at 160 ° C. for 20 hours to extract water (pH 6.0-8. 0) is extracted. Then, the extracted water is subjected to ion chromatography analysis to measure the chlorine ion amount (α). This chloride ion amount (α)
Is a value obtained by diluting the amount of ions in the cured resin composition 10 times, and thus 1 g of the cured resin composition is calculated by the following formula.
Calculate the amount of chloride ion per unit. The pH of the extracted water is preferably in the range of 6.0 to 8.0. Furthermore, in the production of the thermosetting resin composition cured product, for example,
In the case of a cured epoxy resin composition, it is preferable that the cured product molding conditions are 175 ° C. × 2 minutes and post-curing is 175 ° C. × 5 hours.

[0058]

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

That is, when the concentration of chlorine ions contained in the extracted water of the cured resin composition is higher than 200 μg, the semiconductor element, the lead frame and the like are likely to be corroded and the moisture resistance tends to be deteriorated. Like

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

The above-mentioned curing accelerator is a conventionally known one, for example, 1,8-diaza-bicyclo (5,4,0).
Examples include tertiary aminos such as undecene-7 and triethylenediamine, imidazoles such as 2-methylimidazole, and phosphorus-based curing accelerators such as triphenylphosphine and tetraphenylphosphonium tetraphenylborate.

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

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

Further, in the resin composition for semiconductor encapsulation according to the present invention, when an organic flame retardant or a red phosphorus flame retardant is used in combination with the above components, the composite metal hydroxide having the above polyhedral shape is obtained. It is preferable because the amount of the complexed metal hydroxide containing (C) can be reduced. Examples of the organic flame retardant include nitrogen-containing organic compounds, phosphorus-containing organic compounds, phosphazene-based compounds, and the like, and nitrogen-containing organic compounds are particularly preferably used.

Examples of the nitrogen-containing organic compound include:
Examples thereof include compounds having a heterocyclic skeleton such as a melamine derivative, a cyanurate derivative, and an isocyanurate derivative.
These organic flame retardants may be used alone or in combination of two or more.

The above-mentioned organic flame retardant may be blended after being mechanically mixed with the above-mentioned composite metal hydroxide in advance, or the organic flame retardant may be dissolved in a solvent and added thereto. You may use the thing which added the thing and desolvated and surface-treated.

The content of the organic flame retardant is determined by the amount of the composite metal hydroxide used (polyhedral composite metal hydroxide and conventional thin plate composite metal used as the case may be). It is preferable to set it in the range of 1 to 10% by weight of the total amount of hydroxide). It is particularly preferably 1 to 5% by weight.

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

Then, in the resin composition for semiconductor encapsulation according to the present invention, suitable combinations of the respective components including the above-mentioned components (i)-(d) are as follows. That is, as the thermosetting resin (a component), an epoxy resin is preferable, and among them, a biphenyl epoxy resin is preferable from the viewpoint of good fluidity, and as the curing agent (b component), a viewpoint of its fluidity. Therefore, phenol aralkyl resin is preferable. Then, it is preferable to use fused silica powder as an inorganic filler together with the polyhedral composite metal hydroxide (component (c)). Furthermore, it is preferable to use at least one of a polyethylene wax having an acid value of 150 or more and a long-chain alkyl phosphate compound having a carbon number of the long-chain alkyl group portion of 50 or more as the specific release agent (dual component).

The resin composition for semiconductor encapsulation according to the present invention is
For example, it can be manufactured as follows. That is, a thermosetting resin (component a), a curing agent (component b), a polyhedral complex metal hydroxide (component c) and an inorganic filler, a specific release agent (component d) 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 this is cooled to room temperature. Then, the desired resin composition for encapsulating a semiconductor can be manufactured by a series of steps of pulverization by known means and tableting as necessary.

Alternatively, the mixture of the above-mentioned resin composition for semiconductor encapsulation is introduced into a kneading machine and kneaded in a molten state, and then the mixture is continuously molded into a substantially columnar granular body by a series of steps. The semiconductor encapsulating resin composition can be produced.

Further, a method of receiving a mixture of the above-mentioned resin composition for semiconductor encapsulation on a pallet and cooling it, followed by press rolling, roll rolling, or coating with a mixture of solvents to form a sheet, etc. Thus, a sheet-shaped resin composition for encapsulating a semiconductor can be manufactured.

The method for sealing a semiconductor element using the resin composition for semiconductor encapsulation (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-shaped resin composition for semiconductor encapsulation, for example, a semiconductor device by flip-chip mounting can be manufactured as follows. That is, the sheet-shaped semiconductor encapsulating resin composition is arranged on the electrode surface side of a semiconductor element having a bonding bump or on the bump bonding 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 bonding and sealing the both by resin sealing.

Next, examples will be described together with comparative examples.

First, the following materials were prepared.

[Epoxy Resin] Biphenyl epoxy resin represented by the above formula (3) [all R _{1 to} R ₄ in the formula (2) are methyl groups: epoxy equivalent 195]

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

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

[Phosphorus-Based Curing Accelerator] Triphenylphosphine

[Polyethylene Wax] Acid Value 160

[Polyethylene Wax] Acid Value 155

[Polyethylene Wax] Acid Value 20

[Long-Chain Alkyl Phosphate Compound] The long-chain alkyl group has 30 carbon atoms, an acid value of 65, and a carbon number of 3
0 carboxylic acid and phosphoric acid ester compounds

[Long-chain alkyl phosphate compound] Long-chain alkyl group having 50 carbon atoms, acid value of 50, and 5 carbon atoms
0 carboxylic acid and phosphoric acid ester compounds

[Long-Chain Alkyl Phosphate Compound] The long-chain alkyl group has 60 carbon atoms, an acid value of 30, and a carbon number of 6
0 carboxylic acid and phosphoric acid ester compounds

[Carnava wax] Acid value 2 to 10, purified carnauba wax

Next, prior to the examples, various composite metal hydroxides shown in Table 1 below were prepared. The composite metal hydroxides in Table 1 below were produced according to the above-described method for producing a polyhedral composite metal hydroxide.

[0089]

[Table 1]

[0090]

Examples 1 to 11 and Comparative Examples 1 to 5 Table 2 below
~ Each component shown in Table 4 is blended in the ratio shown in the same table, melt-kneaded with a mixing roll machine (temperature 100 ° C) for 3 minutes, cooled and solidified, and then pulverized to obtain a target powdery epoxy resin composition. Obtained.

[0091]

[Table 2]

[0092]

[Table 3]

[0093]

[Table 4]

Using the epoxy resin compositions of Examples and Comparative Examples thus obtained, the chloride ion concentration of the cured product was measured. The chlorine ion concentration was measured according to the method described above, and the molding conditions for the cured product were 175
C. × 2 minutes + post-curing 175 ° C. × 5 hours. Furthermore, a test piece having a thickness of 1/16 inch was molded using each epoxy resin composition, and flame retardancy was evaluated according to the method of UL94 V-0 standard. In addition, passing means 94-V0 passing. These measurement / evaluation results are shown in Tables 5 to 7 below.
Shown in.

Then, using each epoxy resin composition, the spiral flow value and the flow tester viscosity were measured according to the following methods.

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

[Flow Tester Viscosity] 2 g of each of the above epoxy resin compositions was precisely weighed and molded into a tablet. Then, put this in the pot of the Koka type flow tester, 1
The measurement was performed by applying a load of 0 kg. The melt viscosity of the sample was determined from the moving speed of the piston when the melted epoxy resin composition was extruded through a hole (diameter 1.0 mm × 10 mm) of a die.

Using the epoxy resin compositions obtained in the above Examples and Comparative Examples, semiconductor elements were transfer-molded (conditions: 175 ° C. × 2 minutes) and post-cured at 175 ° C. × 5 hours to give semiconductors. I got the device. This semiconductor device is an 80-pin QFP (quad flat package, size: 20 × 14 × 2 mm), and the die pad size is 8 × 8 mm.

With respect to the semiconductor device thus obtained, first, the occurrence of defects such as deformation of the gold wire was measured by observing a transmission image inside the package with a soft X-ray device. As a result of the measurement, the case where the deformation of the gold wire was confirmed was x, the case where the deformation of the gold wire was not confirmed and a good package was obtained was evaluated as o, and the following Tables 5 to 5 are given.
It shows in Table 7.

On the other hand, it was measured non-destructively with an ultrasonic flaw detector. After the measurement, the number of internal peeling (out of 10)
Was counted. After the above measurement, the non-defective product was subjected to the solder test shown below. That is, using a non-defective semiconductor device, after prebaking at 120 ° C. for 1 hour, it is baked at 85 ° C.
/ 85% RH x 168 hours, after absorbing moisture, V of 215 ° C
A 90-second evaluation test (solder crack resistance) was conducted by PS (vapor phase soldering). Then, the number of cracks (out of 10) was measured. The evaluation results are also shown in Tables 5 to 7 below.

Further, using the above semiconductor device, a pressure cooker bias test (PC
BT) was performed to measure the 50% failure occurrence time. The results are also shown in Tables 5 to 7 below. The above PCBT
The condition was set to 130 ° C. × 85% RH × 30 V (bias voltage).

Further, the mold releasability was measured and evaluated according to the following method. That is, first, a mold 15 including three stages of an upper stage 12, a middle stage 13, and a lower stage 14 as shown in FIG. 7A was prepared, and the mold surface of the mold 15 was washed with a cleaning resin. After that, the epoxy resin composition is passed through a filling passage (runner) 16 and a mold 15 is formed.
After filling the inside and transfer molding, a molded body 17 as shown in FIG. 6 (diameter c = 18 mm at the top surface, diameter d = at the bottom surface)
20 mm) was produced. Then, as shown in FIG. 7 (B), the middle stage 13 is taken out and inverted, and
And, as shown in (D), the load was placed on the support frame 19 and the push gauge 18 pushed the molded body 17 in the direction of the arrow A to measure the load when the molded body 17 was released from the middle stage 13. In FIG. 7, 19 is a support frame.

[0103]

[Table 5]

[0104]

[Table 6]

[0105]

[Table 7]

From Tables 5 to 7 above, it is clear that all of the examples have high flame retardancy levels, high spiral flow values, and low flow tester viscosities, and therefore are excellent in fluidity. Is. Further, since the gold wire was not deformed, it can be said that the gold wire has good formability. Moreover, good results were obtained regarding the moisture resistance reliability and the solder resistance of the obtained semiconductor device. Also, good results were obtained for all of the mold releasability.

On the other hand, in Comparative Examples 1, 2 and 3, there was no problem with respect to the flame retardancy level, but the spiral flow value was lower and the flow tester viscosity was remarkably higher than that of the Example product, so that the fluidity was low. It turns out that it is inferior to. This is also clear from the fact that deformation of the gold wire has been confirmed. Further, Comparative Example 3 using a normal metal hydroxide is also inferior in moisture resistance reliability and solder resistance of the obtained semiconductor device. Regarding mold releasability, there was no particular problem in Comparative Examples 1, 2 and 3, but in Comparative Examples 4 and 5, the releasability was remarkably lowered so as not to come off from the evaluation mold. showed that.

Further, as the epoxy resin component in the above Example 1, a biphenyl type epoxy resin in which R _{1 to} R ₄ in the formula (2) are all hydrogen and an R in the formula (2) are used.
_The biphenyl type epoxy resin in which _{1 to} R ₄ are all methyl groups was replaced with a mixed epoxy resin in which the weight ratio was 1: 1. Except for this, the epoxy resin composition was prepared by setting the same compounding ratio as in Example 1. Using this epoxy resin composition, the same measurement and evaluation as above were carried out, and as a result, good results substantially the same as those in the above-mentioned examples were obtained.

[0109]

INDUSTRIAL APPLICABILITY As described above, the present invention provides a high acid value polyethylene which serves as a specific mold release agent together with the polyhedral complexed metal hydroxide represented by the general formula (1). A resin composition for semiconductor encapsulation containing at least one of wax and a long-chain alkyl phosphate compound (dual component). As described above, the use of the above-mentioned special complex metal hydroxide imparts excellent flame retardancy and is free from the influence of bromine as compared with the conventional flame-retardant brominated epoxy resin, so that semiconductor elements and aluminum wiring can be obtained. Corrosion does not occur and the moisture resistance reliability is improved and the service life is extended. Furthermore, because it has the above-mentioned special polyhedron crystal shape instead of the conventional flat crystal shape, it has excellent fluidity and does not cause problems such as deformation of the gold wire when sealing the semiconductor package, improving moldability. To do. In addition to the effect of improving the flame retardancy and moldability, when the polyhedral composite metal hydroxide (component (c)) is used, the polyhedral composite metal hydroxide becomes a resin for encapsulating a semiconductor. Since it is uniformly dispersed in the composition, the flame retardancy equal to or higher than that of conventionally known flame retardants such as metal hydroxides can be obtained, so that the amount used thereof can be small. As a result, the amount of water absorption is reduced, and the solder characteristics are improved. Further, in the present invention, since the polyhedral complex metal hydroxide is used, compared to the case of using a conventional thin plate-shaped or scale-shaped complex metal hydroxide, it is possible to reduce the amount used, therefore, For example, when silica powder is used in combination, the amount of silica powder can be set relatively large, and in such a case, the linear expansion coefficient of the obtained semiconductor device can be lowered and the mechanical strength can be improved. Furthermore, by using at least one of the high acid value polyethylene wax and the long-chain alkyl phosphate ester-based compound (dual component), the mold release by using the polyhedral complex metal hydroxide (c component) is performed. It is possible to prevent deterioration of the workability, and it is possible to maintain good manufacturing workability.

Further, when the average particle size of the special complex metal hydroxide having the above-mentioned crystal shape is in a specific range, the excellent flame retardant effect and the deterioration of the fluidity are further suppressed. Further improvement in moldability is realized.

Further, when the aspect ratio of the composite metal hydroxide is 1 to 8, the effect of lowering the viscosity of the resin composition is exerted and the moldability is further improved.

Therefore, the semiconductor device encapsulated with the resin composition for semiconductor encapsulation of the present invention has a flame-retardant technique excellent in safety and the reliability of the semiconductor device is remarkably improved. Moreover, in the method of manufacturing a semiconductor device by transfer molding using the semiconductor encapsulating resin composition, or in the method of manufacturing a semiconductor device using the sheet-shaped semiconductor encapsulating resin composition, the moldability is also excellent. Therefore, among semiconductor devices, it is particularly effective for thin and large-sized semiconductor devices and has an extremely high industrial utility value.

[Brief description of drawings]

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

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

3A and 3B are explanatory views showing the outer shape of a conventional complexed 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, (a) is a plan view and (b) is a side view.

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

FIG. 6 is a perspective view of a molded body made of an epoxy resin composition, which is manufactured based on a method of evaluating releasability.

7 (A), (B), (C) and (D) are cross-sectional views showing a method of evaluating releasability using an epoxy resin composition.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ identification code FI H01L 23/31 (58) Fields investigated (Int.Cl. ⁷ , DB name) C08L 1/00-101/16

Claims (20)

(57) [Claims] 1. A resin composition for semiconductor encapsulation, which comprises 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 , IVa, Va, VIa, VII of the Periodic Table
It is a metal element belonging to a group selected from a, VIII, Ib, and IIb. In addition, m, n, a, b, c, d, and e are positive numbers, and may have the same value or different values. (D) At least one of a high acid value polyethylene wax and a long chain alkyl phosphate compound. 2. M representing the metal element in the complex metal hydroxide represented by the general formula (1) is aluminum, magnesium, calcium, nickel, cobalt, tin, zinc, copper, iron, titanium and The resin composition for semiconductor encapsulation according to claim 1, which is at least one metal selected from the group consisting of boron. 3. Q representing the 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 claim 1, which is one metal. 4. 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 any one of 1 to 3. 5. 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. . 6. The proportion of the complex metal hydroxide having the polyhedral shape represented by the general formula (1) in the whole complex 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 5. 7. 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 claim 1, wherein [0 <s <1, 0 <c ≦ 1]. 8. 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 claim 1, wherein [0 <s <1, 0 <c ≦ 1]. 9. The content of the complexed metal hydroxide represented by the general formula (1) is 1 to 30% by weight based on the whole resin composition.
The resin composition for semiconductor encapsulation according to any one of claims 1 to 8, wherein the resin composition is set in the range. 10. 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 9, wherein the resin composition is at most μg. 11. A cured product of a resin composition for semiconductor encapsulation,
In the UL94 combustion test with a thickness of 1/16 inch, V
The resin composition for semiconductor encapsulation according to claim 1, which exhibits a flame retardancy equivalent to −0. 12. The resin composition for semiconductor encapsulation according to claim 1, wherein the thermosetting resin as the component (a) is an epoxy resin. 13. The resin composition for semiconductor encapsulation according to claim 1, wherein the curing agent which is the component (b) is a phenol resin. 14. The total amount of the complex metal hydroxide containing the polyhedral complex metal hydroxide, which is the component (C), and the inorganic filler is 6% of the total amount of the resin composition for semiconductor encapsulation.
The resin composition for semiconductor encapsulation according to any one of claims 1 to 13, which is 0 to 92% by weight. 15. The total amount of the complex metal hydroxide containing the polyhedral complex metal hydroxide, which is the component (c), and the inorganic filler is 7 parts of the total resin composition for semiconductor encapsulation.
The resin composition for semiconductor encapsulation according to claim 1, which is 0 to 90% by weight. 16. The resin composition for semiconductor encapsulation according to claim 14, wherein the inorganic filler is silica powder. 17. The resin composition for semiconductor encapsulation according to any one of claims 1 to 16, which contains a nitrogen-containing organic compound. The resin composition for semiconductor encapsulation of. 18. A semiconductor device obtained by encapsulating a semiconductor element using the resin composition for encapsulating a semiconductor according to claim 1. 19. A semiconductor device manufactured by resin-sealing a semiconductor element by a transfer molding method using the resin composition for semiconductor encapsulation according to any one of claims 1 to 17. How to make the device. 20. A method of manufacturing a semiconductor device, which comprises manufacturing a semiconductor device using the sheet-shaped encapsulating material comprising the resin composition for encapsulating a semiconductor according to claim 1.