JPH10287796A - Epoxy resin composition and semiconductor device sealed therewith - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an epoxy resin composition freed from a problem of especially package cracking by subjecting the interface between an inorganic filler and the resin matrix to a firm treatment coping with surface mounting conditions and to provide a semiconductor device sealed therewith. SOLUTION: This invention provides an epoxy resin composition comprising an epoxy resin (A), a phenol resin (B) as a curing agent, 25-95 wt.%, based on the entire resin composition, inorganic filler (C) and a filler (D) obtained by surface-treating component (C) with a silane coupling agent essentially consisting of an aluminum chelate compound such as aluminum tris(acetylacetonate) and at least one dissolved compound selected from a diazabicycloalkene and its derivative and a semiconductor device sealed with a cured product thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-performance epoxy resin composition having improved surface treatment of an inorganic filler, and a semiconductor sealing device.

[0002]

2. Description of the Related Art As an encapsulating resin for a semiconductor device, an epoxy resin composition in which an epoxy resin using a phenol novolak resin or the like as a curing agent and an inorganic filler are used, and the cured product has moisture resistance Because of its excellent high-temperature electrical properties and moldability, it has become the mainstream of sealing resins.

[0003] In the case of a composite material comprising an epoxy resin and an inorganic filler, such as the above-mentioned sealing resin, the processing technology of the surface of the inorganic filler depends on the mechanical properties of the semiconductor device,
It is a very important factor that affects the electrical characteristics, moisture resistance, and the like.

Heretofore, it has been well known to use a silane-based, titanate-based, or aluminum-based coupling agent for the surface treatment of an inorganic filler such as silica or alumina.

[0005] In the surface treatment method using a coupling agent, for example, after a filler is dispersed in water or an organic solvent to form a slurry, the coupling agent is added, the mixture is stirred and allowed to stand, and the filler is settled. Separation and drying method, a method in which a filler is put into a blender and treated while spraying a coupling agent with air or nitrogen gas or the like while stirring, and then dried, and a resin and a filler are put into a mixer and stirred. There is a so-called integral blending method in which a coupling agent is added dropwise while doing so.

[0006] The resin composition using the inorganic filler subjected to the coupling treatment as described above is characterized in that the ease of mixing with the resin, the mechanical properties, the electrical properties, and the like use the inorganic filler which is not treated. It is certainly improved compared to the case where there was, and a certain effect is recognized.

[0007]

However, in recent years, due to the demand for high-density mounting of electronic equipment and automation of the assembling process,
The mounting method of the semiconductor device has shifted from the pin insertion type to the surface mounting type. When the surface treatment of the filler is performed by the above-mentioned conventional method, the chemical reaction between the coupling agent and the filler surface is not necessarily proceeding sufficiently, so it is satisfactory in the current situation where the process has shifted to the surface mount type. It cannot be said that this is an interface treatment method.

This is because, when soldering the substrate and the package by the surface mounting method, a method is used in which the cream solder on the substrate is heated with infrared rays or fluorocarbon vapor and connected to the package leads. At this time, the entire package is exposed to a high temperature of 215 to 260 ° C. This rapid heating may cause cracks in the package, causing an extreme decrease in the reliability of the device, and is currently one of the major problems in the surface mounting method. That is, the mechanism is that the moisture-absorbed resin is exposed to a high temperature, and the water inside the package evaporates and expands, so that the package expands, and the stress at that time causes the resin to break.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has provided a strong treatment for withstanding surface mounting conditions at an interface between an inorganic filler and a resin matrix, thereby improving the crack resistance of a package in particular. It is an object of the present invention to provide a high-performance epoxy resin composition, and a semiconductor encapsulation device resin-sealed using the same.

[0010]

Means for Solving the Problems As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that a silane coupling agent containing a compound which can easily react with an inorganic filler and / or a resin matrix is obtained. It has been found that the above-mentioned object can be achieved by using and surface-treating an inorganic filler, and the present invention has been completed.

That is, the present invention provides (A) an epoxy resin,
(B) a silane in which at least one compound selected from the group consisting of a phenolic resin as a curing agent, (C) an inorganic filler, and (D) (a) an aluminum chelate compound and (b) a diazabicycloalkene and a derivative thereof. A coupling agent is an essential component, and the inorganic filler of (C) surface-treated with the silane coupling agent of (D) is contained at a ratio of 25 to 95% by weight based on the whole resin composition. An epoxy resin composition characterized by the fact that,
A semiconductor sealing device characterized in that a semiconductor chip is sealed with a cured product of the epoxy resin composition.

Hereinafter, the present invention will be described in detail.

The epoxy resin (A) used in the present invention is not particularly limited as long as it has two or more epoxy groups in one molecule. Specific examples include phenol novolak epoxy resin, cresol novolak epoxy resin, naphthol novolak epoxy resin, bisphenol A novolak epoxy resin, bisphenol A glycidyl ether, and tri (hydroxyphenyl) alkane epoxide. Epoxy compounds of tetra (hydroxyphenyl) alkane, bishydroxybiphenyl-based epoxy resins, various brominated epoxy resins and the like can be mentioned.

The phenolic resin curing agent (B) used in the present invention may be any one having a phenolic hydroxyl group in the molecule, and may be a compound obtained by condensation of phenol or an alkylphenol with hydroxybenzaldehyde. For example, tris (hydroxyphenyl) methane, tris (hydroxymethylphenyl) methane, tris (hydroxyphenyl) propane, tris (hydroxyphenyl) methylmethane, etc.
In addition, various novolak type phenol resins, phenol aralkyl resins, terpene phenol resins, dicyclopentadiene phenol resins, naphthol resins and the like can be mentioned. In these resins, in order to ensure reliability, the concentration of free phenols contained in the resin is preferably 1% by weight or less.

The mixing ratio of the epoxy resin and the phenol resin is such that the ratio of the number of phenolic hydroxyl groups of the phenol resin as a curing agent to the number of epoxy groups of the epoxy resin (the number of phenolic hydroxyl groups / the number of epoxy groups) is in the range of 0.1 to 2.5. It is desirable to mix them. If the above value is less than 0.1, the curing reaction does not sufficiently occur, and if it exceeds 2.5, the properties of the cured product, particularly the moisture resistance, are likely to deteriorate.

A curing catalyst may be used to accelerate the curing reaction between the epoxy resin and the phenol resin. The curing catalyst is not particularly limited, but imidazoles such as 2-methylimidazole and 2-heptadecylimidazole, diazabicycloalkenes such as diazabicycloundecene and salts thereof, and organic phosphines such as triphenylphosphine, and the like. Organic metal compounds and the like can be mentioned.

The inorganic filler (C) used in the present invention may be any one as long as it is generally compounded with an epoxy resin matrix. For example, fused silica, crystalline silica, alumina, silicon nitride, nitrided Aluminum and the like. The amount of the inorganic filler is preferably 25 to 95% by weight based on the entire resin composition.

The (D) silane coupling agent used in the present invention may be any one as long as it is used for the surface treatment of an inorganic filler, and includes an alkoxy group bonded to a silicon atom, a glycidoxy group or an aminoalkyl group. A silane compound having a group is preferred.

In the present invention, the aluminum chelate compound (a) to be dissolved in (D) a silane coupling agent may be obtained by substituting a part or all of the RO groups of aluminum alcoholate with a chelating agent such as alkyl acetoacetate or acetylacetone. It is made by doing. Specific examples include aluminum ethyl acetoacetate diisopropylate, aluminum tris (ethyl acetoacetate), aluminum tris (acetylacetonate), and aluminum bisethylacetoacetate monoacetylacetonate.

In the present invention, the (b) diazabicycloalkene and its derivative which are dissolved in (D) a silane coupling agent include 1,8-diazabicyclo (5,4,0) undecene-7 (DBU), 6 -Butylamino-1,8-diazabicyclo (5,4,0) undecene-7 (6-butylamino-DB
U), 1,5-diazabicyclo (4,3,0) nonene-5 (DBN)
And the like.

These (a) compounds and / or (b)
A compound obtained by dissolving a compound in a silane coupling agent in advance is used as a filler treatment agent. (A) Compound and / or (b) for silane coupling agent of component (D)
The concentration of the compound is preferably 0.1 to 10% by weight. If it is less than 0.1 wt%, the effect of improving the surface treatment is poor.
If it exceeds 10 wt%, polymerization of the silane coupling agent itself occurs, and an appropriate surface treatment is not performed.

As the components constituting the resin composition of the present invention, in addition to the above essential components (A) to (D), a flame retardant auxiliary such as antimony trioxide; natural waxes and synthetic waxes , Release agents such as linear fatty acids and metal salts thereof, acid amides, esters, paraffins; pigments such as carbon black and titanium dioxide; silicone oils, silicone rubbers, various plastic powders, various engineering plastic powders, ABS resins A low-stressing agent such as a powder of MBS resin or the like may be appropriately added.

The epoxy resin composition of the present invention comprises the above-mentioned raw materials, ie, (A) an epoxy resin, (B) a phenolic resin curing agent, (C) an inorganic filler, and (D) (a) an aluminum chelate compound; (B) A silane coupling agent in which at least one of a diazabicycloalkene and a derivative thereof is dissolved, and other components are sufficiently mixed by, for example, a mixer such as a Henschel mixer, and further subjected to a melt treatment using a hot roll or a twin-screw extruder. It can be prepared by cooling and pulverizing after adding a melt-mixing treatment such as that described above.

The semiconductor encapsulation device of the present invention is manufactured by encapsulating a semiconductor chip with the epoxy resin composition for encapsulation. In this case, most commonly,
Although low-pressure transfer molding is used, sealing can also be performed by compression molding, injection molding, casting, or the like. The semiconductor chip sealed with the epoxy resin composition of the present invention is not particularly limited.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described more specifically based on embodiments.

Examples 1 to 3 and Comparative Examples 1 and 2 Resin compositions were prepared by blending the components shown in Table 1 in the respective amounts (parts by weight) shown in the table. That is, first, blend and mix each component with a Henschel mixer,
Next, knead with a heating roll at 60 to 130 ° C, cool it,
By pulverizing, sealing resin compositions of Examples 1 to 3 and Comparative Examples 1 and 2 were obtained.

The components indicated by the abbreviations in Table 1 are as follows. Epoxy resin A: ortho-cresol novolak epoxy resin (ESCN195XL, manufactured by Sumitomo Chemical Co., Ltd., epoxy equivalent: 197) Epoxy resin B: bisphenol A type brominated epoxy resin (AER-755, manufactured by Asahi Kasei Corporation, epoxy equivalent: 460)
Phenol resin: Phenol novolak resin (BRG)
-557, manufactured by Showa Polymer Co., Ltd., hydroxyl equivalent: 104) Curing accelerator: triphenylphosphine (PP360,
Release agent: Carnauba wax Inorganic filler: Fused silica powder having a maximum particle size of 100 μm or less Surface treatment agent A: DBU dissolved in γ-glycidoxypropyltrimethoxysilane (concentration: 3 wt. %) Surface treatment agent B: Dissolved aluminum tris (acetylacetonate) in γ-glycidoxypropyltrimethoxysilane (concentration: 3 wt%) Surface treatment agent C: γ-N-phenylaminopropyltrimethoxysilane DBU dissolved in water (concentration 3 wt.
%).

[0028]

[Table 1]

Next, each of the resin compositions was used at 180 ° C. for 3 hours.
A test piece was prepared by transfer molding under the condition of 1 minute, and after-cured at 180 ° C. for 8 hours. For these test pieces, glass transition temperature, coefficient of thermal expansion, bending strength,
The water absorption and the volume resistivity after moisture absorption were measured.

After the test device was sealed with each epoxy resin composition, after-curing was performed at 180 ° C. for 4 hours. For these test devices, a crack generation test and a freshener cooker test after the moisture absorption and high temperature treatment were performed. Table 2 summarizes the results obtained for the resin composition and the device.

As shown in Table 2, the resin compositions of Examples 1 to 3 had better mechanical properties, water resistance and electrical properties than those of Comparative Examples 1 and 2, and The semiconductor encapsulation device of (1) had better crack resistance at a high temperature and the reliability of the subsequent moisture resistance than those of Comparative Examples 1 and 2, and the effect of the present invention could be confirmed.

[0032]

[Table 2] * 1: Leave for 20H in a 2atm saturated steam atmosphere. * 2: Measured at 150 ° C after leaving for 20H in a 2atm saturated steam atmosphere. * 3: Twenty test devices were left in an atmosphere at a temperature of 85 ° C and a relative humidity of 85% for 72 hours to absorb moisture, and then exposed to a 240 ° C infrared lamp for 1 minute, causing cracks. The number of defective packages was checked. * 4: 8 to 20 test devices were left in a saturated steam atmosphere at 127 ° C, and the number of defects (leakage defects, open defects) generated in 100 to 500 hours was examined.

[0033]

As apparent from the above description and Table 2, the epoxy resin composition of the present invention is surface-treated with a silane coupling agent containing a compound which can easily react with an inorganic filler and / or a resin matrix. Because
The bond at the interface becomes strong, and the cured product has extremely good mechanical properties, water resistance, heat resistance and electrical properties. Furthermore, the semiconductor sealing device of the present invention sealed with this resin composition has extremely good crack resistance and high humidity resistance at high temperatures.

Claims (2)

[Claims] 1. An epoxy resin, (B) a phenol resin as a curing agent, (C) an inorganic filler, and (D)
At least one of (a) an aluminum chelate compound and (b) a diazabicycloalkene and a derivative thereof;
A silane coupling agent in which a kind of compound is dissolved is an essential component, and the inorganic filler (C) surface-treated with the silane coupling agent (D) is used in an amount of 25 to 95% by weight based on the whole resin composition. %. An epoxy resin composition, characterized in that it is contained in a proportion of 0.1%. 2. An epoxy resin, (B) a phenol resin as a curing agent, (C) an inorganic filler, and (D)
At least one of (a) an aluminum chelate compound and (b) a diazabicycloalkene and a derivative thereof;
A silane coupling agent in which a kind of compound is dissolved is an essential component, and the inorganic filler (C) surface-treated with the silane coupling agent (D) is used in an amount of 25 to 95% by weight based on the whole resin composition. %, Wherein a semiconductor chip is sealed with a cured product of an epoxy resin composition contained at a percentage of 0.1%.