JP2002212450A - Sealing resin composition and semiconductor sealing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sealing resin composition having sufficient flame retardancy imparted by incorporating therein a new phosphorus/nitrogen based flame retardant containing neither a halogen (chlorine or bromine) compound nor antimony trioxide, excellent in moldability, continuous producibility, and reliability, and having high whiteness, reflectance and resistance to discoloration, and a semiconductor sealing device. SOLUTION: The sealing resin composition comprises essentially (A) an inorganic filler, (B) titanium oxide, (C) a cyclophosphazene compound and (D) a thermosetting resin, with the contents of the constituents (A), (B) and (C) respectively being 30-95 wt.%, 1-40 wt.% and 0.01-5 wt.%. The semiconductor sealing device is made by sealing a semiconductor chip with the cured material of the resin composition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a resin composition for sealing electronic parts such as semiconductors and a semiconductor sealing device.
More specifically, it is used for semiconductors such as photocouplers that are resin-sealed with a white encapsulant, has excellent flame retardancy without adding a halogen (chlorine, bromine) compound and antimony oxide, and further has resistance to Excellent discoloration, moldability,
The present invention relates to an epoxy resin composition excellent in high reliability and a semiconductor encapsulation device.

[0002]

2. Description of the Related Art Semiconductor and electronic components are sealed with a ceramic package or a resin package in order to protect them from the external environment. However, this sealing material is not filled with an inorganic material in terms of cost and productivity. The use of a synthetic resin composition containing an agent is widespread.

[0003] In a semiconductor encapsulation device, it is general that the encapsulating resin is provided with flame retardancy.
Halogen (chlorine, bromine) compounds and metal oxides alone or in combination exhibit a flame retardant effect. Specifically, a combination of a brominated epoxy resin and antimony trioxide is generally used. However, a brominated epoxy resin added to exhibit the flame retardant effect of the encapsulating resin composition, and a metal oxide added to assist the flame retardant effect, particularly antimony trioxide, are used in semiconductor encapsulation devices. However, there is a disadvantage that the reliability is lowered. More recently, it has also been pointed out that it has a negative impact on the environment.

[0004] Therefore, phosphorus-based flame retardants and metal hydrates have been widely studied as substitutes for brominated epoxy resins and antimony trioxide. However, many of the phosphorus-based flame retardants are coated phosphorus or phosphate ester-based ones, and even if a flame-retardant effect is obtained, the phosphoric acid generated by hydrolysis reduces the moisture resistance reliability of the semiconductor encapsulation device. This causes a reduction, and sufficient reliability cannot be secured. In particular, in the case of a white encapsulant, a phosphorus-based flame retardant cannot be used because the resin is likely to be colored, although it is desirable that the cured product after curing and after post-curing have high reflectance and little discoloration. In addition, not only the metal hydrate cannot ensure sufficient formability, but also its hygroscopicity deteriorates the reliability of the semiconductor sealing device significantly. For this reason, there has been a strong demand for development of a sealing resin which is excellent in moldability and reliability and does not contain a halogen (chlorine, bromine) compound and antimony trioxide.

[0005] In addition, when a flame retardant effect is imparted by a phosphorus-based flame retardant and a metal oxide, a large number of added parts are required if the compound is used alone, so that the properties of the resin composition are sufficiently improved. It is difficult to satisfy, and the additives used in this experiment are no exception.

The sealing resin composition is composed of a thermosetting resin such as an epoxy resin and an inorganic filler such as silica. However, these compositions have a small coefficient of thermal expansion and a good heat resistance. It is desirable that the conductive material, low moisture permeability, excellent mechanical properties, excellent storage stability, and low cost be used. In particular, in the case of a white sealing material, it is desirable that the cured product after curing and post-curing have high reflectance and little discoloration. Therefore, there has been a demand for a flame retardant for a white encapsulant that does not impair the characteristics conventionally solved.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned drawbacks and to meet the above-mentioned needs, and to provide a sufficient flame retardant without containing a halogen (chlorine, bromine) compound and antimony trioxide. While imparting properties, it is excellent in moldability, continuous productivity, reliability, high whiteness, high reflectance,
An object of the present invention is to provide a sealing resin composition and a semiconductor sealing device having discoloration resistance.

[0008]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above-mentioned object, and as a result, the use of a thermosetting resin having a composition described later has achieved the above object. The present invention has been completed.

That is, the present invention provides (A) an inorganic filler,
(B) titanium oxide, (C) a cyclophosphazene compound and (D) a thermosetting resin as essential components, and (A) the inorganic filler in an amount of 30 to 95% by weight based on the resin composition;
A sealing resin composition comprising (B) 1 to 40% by weight of titanium oxide and (C) 0.01 to 5% by weight of a cyclophosphazene compound. Further, there is provided a semiconductor encapsulating apparatus characterized in that a semiconductor chip is encapsulated with a cured product of the encapsulating resin composition.

Hereinafter, the present invention will be described in detail.

The resin composition of the present invention is obtained by blending an inorganic filler, titanium oxide and a cyclophosphazene compound with a thermosetting resin. The component (D) of the present invention is a thermosetting resin, and particularly comprises an epoxy resin and its curing agent.

Examples of the inorganic filler (A) used in the present invention include fine powders of inorganic compounds such as silica, calcium carbonate, and alumina. These can be used alone or in combination of two or more. The mixing ratio of the inorganic filler is desirably 30 to 90% by weight based on the entire resin composition. If this ratio is less than 30% by weight, the molded article has high moisture absorption, is inferior in moisture resistance after solder immersion, and
Exceeding the weight percentage is undesirable because the fluidity and moldability of the molding material are extremely deteriorated.

As the titanium oxide (B) used in the present invention, titanium oxide having a low impurity concentration is used, and its crystal form may be any of anatase type and rutile type. The mixing ratio of titanium oxide is 1 to 40 with respect to the entire resin composition.
Desirably, it is contained by weight. If this ratio is less than 1% by weight, the whiteness is not sufficient, and if it exceeds 40% by weight, the characteristics of the semiconductor device may be impaired.

The (C) cyclophosphazene compound used in the present invention is represented by the following structural formula.

[0015]

Embedded image (However, in the formula, R ¹ and R ² may be the same or different, and are not particularly limited because they are organic groups such as an alkoxy group, a phenoxy group, an amino group, an allyl group, and n is an integer of 3 to 10. These cyclophosphazene compounds can be used alone or in combination of two or more. Specific compounds include, for example,

Embedded image (Wherein, n represents an integer of 3 to 4) The compounding ratio of the cyclophosphazene compound is 0.05 to 1% by weight, preferably 0.1 to 0% by weight, based on the whole resin composition. .
It is desirable to adjust so that the content is 5% by weight. If it is less than 0.05% by weight, sufficient flame retardant effect cannot be obtained, and if it exceeds 1% by weight, moldability, moisture resistance and the like are deteriorated, which is not suitable for practical use.

As the thermosetting resin (D) used in the present invention, for example, urea resin, melamine resin, phenol resin, resorcinol resin, epoxy resin, polyurethane resin, vinyl acetate resin, polyvinyl alcohol resin, acrylic resin, vinyl urethane Resin, silicone resin, α
-Olefin maleic anhydride resin, polyamide resin, polyimide resin and the like, and these may be used alone or
A mixture of more than two kinds can be used, and among them, epoxy resins can be used industrially advantageously. The compounding ratio of the thermosetting resin is 5 to the entire resin composition.
It is desirable to contain 50% by weight. The compounding amounts of these thermosetting resins include the compounding amounts of the respective curing agents and catalysts.

In the present invention, the thermosetting resin composition comprises
The above-mentioned inorganic filler, titanium oxide, a cyclophosphazene compound and a thermosetting resin are used as essential components, but as long as the object of the present invention is not contradicted, and if necessary,
A solvent for adjusting viscosity, a coupling agent and other additives can be appropriately added and blended. Examples of the solvent include dioxane, solvent naphtha, industrial gasoline, cellosolve acetate, ethyl cellosolve, butyl cellosolve acetate, butyl carbitol acetate, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, and the like. It can be mixed and used.

As a general method for preparing the encapsulating resin composition of the present invention as a molding material, an inorganic filler, titanium oxide, a cyclophosphazene compound, additives and the like are mixed with the above-mentioned thermosetting resin. Usually, the mixture is heated and kneaded using a kneader, a roll mill, a mixer, or the like in a usual manner, cooled, and then pulverized to an appropriate size to obtain a molding material. The molding material thus obtained is used for encapsulation of electronic components or electric components including semiconductor devices,
When applied to coating, insulation and the like, excellent characteristics and reliability can be imparted.

The semiconductor sealing device of the present invention can be easily manufactured by sealing a semiconductor chip using the sealing resin obtained as described above. The semiconductor device for sealing is not particularly limited, for example, with an integrated circuit, a large-scale integrated circuit, a transistor, a thyristor, a diode, and the like. However, it is particularly effective for an optical circuit using a white sealing material. The most common sealing method is a low-pressure transfer molding method, but sealing by injection molding, compression molding, casting or the like is also possible. The sealing resin composition is heated and cured at the time of sealing, and finally a semiconductor sealing device sealed with a cured product of this composition is obtained. Curing by heating is desirably performed by heating to 150 ° C. or higher.

[0020]

The encapsulating resin composition and the semiconductor encapsulating apparatus of the present invention can obtain desired properties by using titanium oxide and a cyclophosphazene compound in addition to the resin component and the filler component. is there. That is, it is possible to mold an electronic component such as a semiconductor having a good filling property and workability, and significantly improved appearance and discoloration resistance of the cured resin.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described specifically with reference to examples, but the present invention is not limited to these examples.

Example 1 A fused silica filler (average particle size: 20 μm), a titanium oxide filler, a cyclophosphazene compound represented by the formula (2) (melting point: 100 ° C.), and an epoxy resin component were blended in the proportions shown in Table 1. Then, the mixture was kneaded with a roll mill and cooled and pulverized to produce epoxy resin compositions 1 and 2.

Comparative Example 1 Similarly, a fused silica filler, a titanium oxide filler, and an epoxy resin component were blended in the proportions shown in Table 1, kneaded by a roll mill, and cooled and pulverized to obtain an epoxy resin composition 3. ,
4 was produced.

Comparative Example 2 Similarly, a fused silica filler, a titanium oxide filler, an epoxy resin component containing a brominated epoxy, and antimony trioxide were blended in the proportions shown in Table 1 and kneaded with a roll mill. The resultant was cooled and pulverized to produce epoxy resin compositions 5 and 6.

In order to check the fluidity of the epoxy resin compositions obtained in Example 1 and Comparative Examples 1 and 2, the flow viscosity and light reflectance at 800 nm were measured, and the results are shown in Table 1. Each is shown. Table 1 also shows the results of the UL94 test.

From these results, the resin compositions 1 and 2 of Example 1 have the same fluidity as the resin compositions of the resin compositions 3 and 4 of Comparative Examples 1 and 2, and the discoloration resistance after post-curing. It was confirmed that the film had excellent properties. On the other hand, the flame retardancy of the resin composition of Example 1 maintained V-0 similar to that of Comparative Examples 1 and 2.

[0027]

[Table 1] * 1: Cresol novolak epoxy resin (softening point 80
C., an epoxy equivalent of 200) and a novolak phenol resin (softening point of 80 ° C., hydroxyl equivalent of 105) in an equal amount, and an organic phosphorus catalyst (triphenylphosphine, 0.1% in the resin).
* 2: Tetrabromobisphenol A type epoxy resin (epoxy equivalent: 400) * 3: 17 by Shimadzu Flow Tester CFT-500
* 4: Measured under the conditions of 5 ° C. and a load of 10 kg. * 4: The surface of the molded article molded under the curing conditions of 175 ° C. × 2 minutes was measured with an ultraviolet-visible spectrophotometer V-530 manufactured by JASCO Corporation * 5: * 4 Was subjected to post-curing at 175 ° C. for 8 hours, and the surface of the post-cured molded product was measured.

[0028]

As is apparent from the above description and Table 1, the sealing resin composition containing the inorganic filler and the cyclophosphazene compound of the present invention is used for sealing electronic parts such as semiconductors such as photocouplers. By using this, the flame retardancy can be maintained while maintaining the discoloration resistance of the white sealing material, and the load on the environment can be reduced.

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) H01L 23/29 H01L 23/30 R 23/31 F-term (Reference) 4J002 AA021 BB091 BE021 BF021 BG001 CC001 CC031 CC161 CC181 CD001 CK021 CL001 CM041 CP031 DE137 DE146 DE236 DJ016 EW158 GQ01 GQ05 4M109 AA01 BA01 CA21 EA02 EB02 EB07 EB08 EB12 EC20 GA01

Claims (3)

[Claims] 1. An inorganic filler (A), a titanium oxide (B), a cyclophosphazene compound (C) and a thermosetting resin (D) are essential components, and the resin composition is filled with the inorganic filler (A). A sealing resin comprising 30 to 95% by weight of an agent, (B) 1 to 40% by weight of titanium oxide, and (C) 0.01 to 5% by weight of a cyclophosphazene compound. Composition. 2. The sealing resin composition according to claim 1, wherein (D) the thermosetting resin comprises an epoxy resin and a curing agent thereof. 3. A semiconductor sealing device, wherein a semiconductor chip is sealed with a cured product of the sealing resin composition according to claim 1.