JP3388503B2 - Epoxy resin composition and semiconductor encapsulation device - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an epoxy resin composition and a semiconductor encapsulation device which are excellent in moldability, high temperature storage property and flame retardancy.

[0002]

2. Description of the Related Art Epoxy resin compositions used for encapsulation of electronic and electric parts are extremely flammable as they are, and in order to have flame retardancy, they are generally brominated flame retardants and antimony compounds. Flame retardant aids are used. However, materials containing some halogen-based flame retardants are
There was an environmental problem because it was pointed out that a highly toxic dioxin compound might be generated during combustion. In addition to the fact that the antimony compound itself has been pointed out to be toxic, since the antimony compound easily dissolves in water,
The material containing it has a problem that it significantly affects the water quality environment.

For this reason, various flame retardants have been investigated, but even if a small amount of phosphorus-based flame retardant is added, it becomes a flame retardant material, but it still has a problem for the water quality environment, metal oxides and water. Inorganic flame retardants, such as oxides, have low flame retardance, so it was necessary to add a large amount. Further, when these flame retardants are used, there is a drawback that the long-term moisture resistance reliability is inferior to the conventional combination of brominated antimony compound.

[0004]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a flame-retardant epoxy resin composition having extremely low impact on the environment, excellent solder heat resistance, and high reliability of being left at high temperature after mounting, and its curing. An object of the present invention is to provide a semiconductor encapsulation device sealed with an object.

[0005]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies in order to achieve the above-mentioned object, and as a result, the following composition using a specific phenol curing agent has excellent moldability and high temperature storage reliability. It was found that a flammable epoxy resin composition can be obtained, and the present invention has been completed.

That is, the present invention provides (A) an epoxy resin, (B) a nitrogen-containing phenol resin having a nitrogen content of 10% or more, (C) triphenylphosphine, and (D) a silica powder having a maximum particle size of 100 μm or less. As an essential component, (D) maximum particle size of 100μ with respect to the entire resin composition
A flame-retardant epoxy resin composition containing 80 to 95% by weight of a silica powder of m or less and not using a brominated flame retardant , an antimony compound or a metal hydroxide, which is an epoxy resin (A). Is a flame-retardant epoxy resin composition which is one or more epoxy resins selected from the group consisting of o-cresol novolac type epoxy resins, biphenyl type epoxy resins, and epoxidized phenol xylene resins. The semiconductor encapsulation device of the present invention is a semiconductor encapsulation device characterized by being encapsulated with a cured product of the flame-retardant epoxy resin composition.

The present invention will be described in detail below.

The epoxy resin (A) used in the present invention may be of any kind as long as it is an epoxy resin having two or more epoxy groups, but from the viewpoint of moisture resistance reliability and the like, it is preferable that the epoxy resin represented by the general formula 1 A cresol novolac type epoxy resin, a biphenyl type epoxy resin represented by the general formula 2 or an epoxidized product of a phenol xylene resin represented by the general formula 3 is used. Specifically, for example,

[Chemical 4] (However, in the formula, n represents an integer of 1 or more)

[Chemical 5]

[Chemical 6]

[Chemical 7] (However, in the formula, n represents an integer of 1 or more) and the like, and these can be used alone or in combination of two or more kinds. In addition, other generally known epoxy resins such as bisphenol A type epoxy resin and bisphenol F type epoxy resin can be used in combination with this epoxy resin.

The nitrogen content (B) used in the present invention is 10%.
In the above nitrogen-containing phenol resin, the contained nitrogen may be present in any of the phenol resin structures. For example, the nitrogen may be provided by an amino group substituted on the phenol ring. Specific examples thereof include aminophenol resins.

However, the nitrogen-containing phenol resin as a preferred embodiment of the present invention is a co-condensation resin of a phenol compound, a guanamine compound and an aldehyde compound.

Examples of the phenol compound used therein include phenol, resorcin, and alkylphenol (cresol, xynol, etc.). Formaldehyde and the like are particularly preferable as the aldehyde compound. The guanamine compound can be represented by the following formula.

[0012]

[Chemical 8] (However, in the formula, R represents an amino group, a phenyl group, or an alkyl group such as a methyl group.) Specific examples include, for example, melamine, benzoguanamine, methylguanamine, and the like, which may be used alone or in combination of two kinds. The above can be mixed and used.

Such a co-condensation resin can be produced by reacting a phenol compound, an aldehyde compound and a guanamine compound in the presence of an acid catalyst (for example, oxalic acid, p-toluenesulfonic acid). In that case, the molar ratio of the aldehyde compound to the phenol compound is less than 1.0, preferably 0.5 to less than 1.0, and the primary amino group (-NH) of the guanamine compound.
₂ ) One mole of aldehyde compound (for example,
(3 mol formaldehyde for 1 mol melamine, 2 mol formaldehyde for 1 mol benzoguanamine)
Is preferably used.

As the (C) triphenylphosphine used in the present invention, those having a low impurity concentration are preferably used. This triphenylphosphine contains other known phosphorus-based curing accelerators, imidazole-based curing accelerators, DB
A U (diazabicycloundecene) -based curing accelerator and other curing accelerators may be used alone or in combination of two or more. The compounding ratio of (C) triphenylphosphine is preferably 0.01 to 5% by weight based on the entire resin composition. If the proportion is less than 0.01% by weight, the gel time of the resin composition is long and the production cycle of the semiconductor encapsulation device becomes long, which is not preferable. On the other hand, if it exceeds 5% by weight, the fluidity is extremely deteriorated, the filling property is deteriorated, and the moisture resistance reliability after mounting is deteriorated, which is not preferable.

(D) Maximum particle size 100 μm used in the present invention
As the following silica powder, silica powder having a low impurity concentration and an average particle diameter of 40 μm or less is preferably used.
The blending ratio of silica powder having a maximum particle size of 100 μm or less is
It is 80 to 95% by weight, preferably 84 to 92% by weight, based on the entire resin component. If the proportion is less than 80% by weight, the flame retardancy of the resin composition is low and the moisture resistance reliability after mounting is inferior. If it exceeds 95% by weight, the fluidity is extremely deteriorated and the filling property is deteriorated, which is not preferable.

The epoxy resin composition of the present invention comprises the above-mentioned epoxy resin, a nitrogen-containing phenol resin having a nitrogen content of 10% or more, triphenylphosphine and a maximum particle size of 1.
Silica powder having a particle size of 00 μm or less is an essential component, but as long as it does not deviate from the object of the present invention and, if necessary, a releasing agent such as natural waxes and synthetic waxes, a coloring agent such as carbon black, and rubber. A low-stress imparting agent for a system-based or silicone-based polymer, a coupling agent such as amine-modified and epoxy-modified silicone oil, and the like can be appropriately added and blended.

As a general method for preparing the epoxy resin composition of the present invention as a molding material, the above-mentioned epoxy resin, nitrogen-containing phenol resin having a nitrogen content of 10% or more, triphenylphosphine and maximum particle diameter are used. 10
Silica powder of 0 μm or less and other components are blended, sufficiently mixed by a mixer or the like, further subjected to heat melting and mixing treatment with a hot roll or a kneader, then cooled and solidified, and crushed to an appropriate size for molding. It can be a material. The molding material made in this way is used for sealing and coating electronic components such as semiconductor devices or electrical components.
When applied to insulation or the like, it is possible to impart characteristics such as excellent moldability and reliability.

Further, the semiconductor encapsulation device of the present invention is obtained by encapsulating a semiconductor chip by using the above molding material.
It can be easily manufactured. The semiconductor chip to be sealed is not particularly limited to, for example, an integrated circuit, a large scale integrated circuit, a transistor, a thyristor, a diode and the like. The most common method of sealing is transfer molding, but sealing by injection molding, compression molding, etc. is also possible, and if necessary vacuum molding can improve the filling property of the gap. it can. When sealing and heating after sealing to cure the resin, it is desirable to set the temperature to 150 ° C. or higher.

[0019]

The epoxy resin composition and the semiconductor encapsulation device of the present invention include the above-mentioned epoxy resin (particularly the epoxy resins specified in Chemical Formulas 1 to 3), nitrogen-containing phenol resin having a nitrogen content of 10% or more, and triphenylphosphine. And by using silica powder having a maximum particle size of 100 μm or less,
The flame retardancy can be maintained without using a brominated flame retardant or an antimony compound, and the deterioration at high temperature after mounting is reduced.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Next, the present invention will be specifically described with reference to Examples, but the present invention is not limited to these Examples.

Synthesis of nitrogen-containing phenol resin 235 parts by weight of benzoguanamine, 37% formalin 30
0.1 part by weight of oxalic acid was added to a mixture consisting of 0 part by weight and 87 parts by weight of phenol. The resulting mixture is 8
After reacting at 0 ° C. for 2 hours, it was dehydrated under reduced pressure. The resulting co-condensed resin contained 19% by weight nitrogen.

Example 1 Eighty-five parts by weight of fused spherical silica powder (average particle size 20 μm) having a maximum particle size of 100 μm or less was put in a mixer, and γ-phenylaminopropyltrimethoxysilane (0.1%) was added with stirring.
Surface treatment was carried out by adding 4 parts by weight. With this treated silica,
Chemical Formula 4 o-cresol novolac type epoxy resin 6.9
Parts by weight, 6.7 parts by weight of synthesized nitrogen-containing phenol resin (nitrogen content 19%), triphenylphosphine 0.4
Parts by weight, 0.3 parts by weight of ester wax, and 0.3 parts by weight of carbon black are mixed at room temperature, and then 70 to 1
The mixture was kneaded at 00 ° C., cooled and pulverized to produce a molding material.

Examples 2 to 3 and Comparative Examples 1 to 2 Molding materials having the compositions shown in Table 1 were produced in the same manner as in Example 1.

Examples 1 to 3 and Comparative Example 1 thus manufactured
1 by transfer molding machine using ~ 2 molding materials
Mold for 2 minutes in a mold heated to 75 ° C, then 175
After-curing at 4 ° C. for 4 hours, a test molded product and a semiconductor device were obtained. Various tests were carried out on them, and the results are shown in Table 2. The epoxy resin composition of the present invention can maintain flame retardancy without substantially using a brominated flame retardant or an antimony compound. The semiconductor device sealed with the resin composition was excellent in high temperature storage reliability after mounting, and the remarkable effect of the present invention could be confirmed.

[0025]

[Table 1]

[Table 2] * 1: Spiral flow measurement according to EMMI-I-66 was performed (175 ° C).

* 2: Measured by the hot plate method (175
C).

* 3: A test piece having an appropriate size was prepared and measured using a thermal analyzer.

* 4: Evaluated by the method according to UL-94 (0.8 mm thick test piece).

* 5: Using a molding material, a silicon chip having two or more aluminum wirings is formed into a normal 42
After bonding to an alloy frame and transfer molding at 170 ° C. for 4 minutes, post-curing was performed at 170 ° C. for 4 hours.
The molded product thus obtained was previously subjected to moisture absorption treatment at 30 ° C. and 60% for 100 hours, and then immersed in a solder bath at 250 ° C. for 10 seconds. After that, a high temperature storage test at 200 ° C is performed,
The open / short of the aluminum wiring was evaluated as a defect.

* 6: All test pieces burned out, V-0,
It did not belong to either V-1 or HB.

[0031]

As is clear from the above description and Table 2, the epoxy resin composition of the present invention can maintain flame retardancy without substantially using a brominated flame retardant or an antimony compound. The semiconductor device sealed with the resin composition has excellent moldability,
High-temperature storage reliability can be guaranteed for a long time after mounting.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI C08L 63/00 C08L 63/00 Z H01L 23/29 H01L 23/30 R 23/31 (58) Fields investigated (Int.Cl. ⁷ , DB name) C08G 59/24 C08G 59/32-59/38 C08G 59/40-59/66 C08L 63/00-63/10 H01L 23/29 H01L 23/31

Claims (4)

(57) [Claims] 1. An (A) epoxy resin, (B) a nitrogen-containing phenol resin having a nitrogen content of 10% or more, (C) triphenylphosphine and (D) a silica powder having a maximum particle size of 100 μm or less as essential components, (D) Maximum particle size of 100μ for the entire resin composition
A flame-retardant epoxy resin composition comprising 80 to 95% by weight of silica powder of m or less and not using a brominated flame retardant , an antimony compound or a metal hydroxide . 2. The (A) epoxy resin is an o-cresol novolac type epoxy resin represented by the following formula: (In the formula, n represents an integer of 1 or more.) A biphenyl type epoxy resin represented by the following formula: (Wherein, R ¹ represents a hydrogen atom or an alkyl group) and an epoxidized compound of a phenol xylene resin represented by the following formula: The flame-retardant epoxy resin composition according to claim 1, which is one or more epoxy resin selected from the group consisting of (wherein, n represents an integer of 1 or more). 3. The flame-retardant epoxy resin composition according to claim 1, wherein the nitrogen-containing phenol resin (B) is a co-condensation resin of a phenol compound, a guanamine compound and an aldehyde compound. 4. A semiconductor encapsulation device, wherein a semiconductor chip is encapsulated with a cured product of the flame-retardant epoxy resin composition according to any one of claims 1 to 3.