JPH01188518A - Epoxy resin composition and resin-sealed semiconductor device produced by using same - Google Patents

Abstract

PURPOSE:To provide the subject composition composed of an epoxy resin, a phenolic resin hardener, a cure accelerator, a specific maleimide compound and a specific amount of an inorganic filler, giving a cured product having excellent thermal shock resistance and moldability and useful for the sealing of semiconductor. CONSTITUTION:The objective composition is composed of (A) an epoxy resin (e.g., bisphenol A epoxy resin), (B) a phenolic resin hardener (e.g., phenolic novolak resin), (C) a cure accelerator (e.g., 2-methylimidazole), (D) a univalent maleimide compound of formula (X is H, halogen, OH, alkoxy or carboxyl; n is 1-5) (preferably phenylmaleimide) and (E) 50-75vol.% of an inorganic filler (preferably silica powder). A semiconductor device is sealed with the composition.

Description

Detailed Description of the Invention [Object of the Invention] (Industrial Application Field) The present invention provides an epoxy resin composition for semiconductor encapsulation that provides a cured product having excellent thermal shock resistance and moldability, and the resin composition. The present invention relates to a resin-sealed semiconductor device that is sealed with a material.

(Prior Art) In recent years, in the field of encapsulation of semiconductor devices, as semiconductor devices have become highly integrated, various functional units on devices have become finer and device pellets themselves have become larger.

Due to these changes in element pellets, conventional sealing resins are no longer able to satisfy requirements such as thermal shock resistance. Epoxy resin compositions cured with phenol novolac resins, which have been traditionally used as encapsulating resins for semiconductor devices, have excellent hygroscopicity, high-temperature electrical properties, and moldability, and have become the mainstream for molding. .

However, when this type of resin composition is used to seal a device pellet that is large and has a fine surface structure, phosphosilicate glass (PSG), which is a coating material to protect the aluminum (AQ) pattern on the surface of the device pellet, is sealed. ) film or silicon nitride (NiN) film, or the element pellet. This tendency is particularly significant when a thermal cycle test is performed. As a result, defects in device characteristics due to pellet cracking and defects due to corrosion of the AN pattern caused by the film cracking occur.

As a countermeasure, the stress on the internal sealing resin is reduced, and the PSG film or SiN film on the sealing resin and the element is
It is necessary to increase the adhesion with glass films such as membranes.

For example, in order to reduce the stress on the internal encapsulation of the sealing resin, a method has been adopted in which the coefficient of thermal expansion of the resin is reduced by increasing the amount of filler. However, in this case, there is a problem in that the use of a large amount of filler causes a significant increase in viscosity at the melting point, impairing the moldability of the resin.

Furthermore, along with these changes in the element pellet, there is a problem of reduced reliability, which is thought to be caused by the extreme stress of the resin and filler on the chip.To avoid this, it is necessary to cut the coarse particles of the crushed filler. This is considered to be effective. Further, when the package is small and thin, the gate of the molding die is narrower than usual, so the presence of large crushed filler particles is also undesirable in this case. However, even when the average particle size of the filler is reduced for these purposes, the melt viscosity of the resin increases, which may cause unfilling or deformation of the bonding wire.

Conventionally, measures have been taken to suppress such an increase in melt viscosity, such as reducing the molecular weight of the matrix resin or adding components that have a low viscosity at 1°C of the resin molding temperature. However, in many cases, there are drawbacks such as a decrease in the glass transition temperature, which impairs the heat resistance of the molded product, or a significant decrease in strength, so a satisfactory solution has not yet been found.

(Problem to be solved by the invention) As mentioned above, increasing the amount of filler or making it finer to improve thermal shock resistance leads to an increase in melt viscosity, and measures to suppress this have not yet been sufficiently studied. Not yet.

An object of the present invention is to provide an epoxy resin composition for semiconductor encapsulation that solves the above problems and provides a cured product having excellent thermal shock resistance and moldability.

In order to achieve the above object, the present inventors have conducted extensive research and found that by blending a monovalent maleimide compound into a resin composition, the melt viscosity of the composition can be increased without impairing other properties, especially heat resistance. The present inventors have discovered that it is possible to reduce the amount of carbon dioxide, and have completed the present invention.

That is, the epoxy resin composition for encapsulating a semiconductor device and the resin-encapsulated semiconductor device of the present invention contain: (A) epoxy resin CB) phenolic resin curing agent (C) curing accelerator (D) - Shipman (in the formula, or hydrogen, a halogen atom, a hydroxyl group, an alkoxy group, or a carboxyl group, and n is 1 to 5
A monovalent maleimide compound (E) represented by (representing an integer of
An epoxy resin composition for encapsulating a semiconductor, characterized in that the amount is 50 to 75% by volume based on the total amount of (E), and a resin-encapsulated semiconductor device encapsulated with the same.

The epoxy resin which is the component (A) of the present invention may be any resin as long as it contains at least two epoxy groups in one molecule. For example, bisphenol A
Examples include type epoxy resins, novolac type epoxy resins, alicyclic type epoxy resins, and glycidyl ester type epoxy resins, and these can be used alone or in a mixture of two or more types.

The phenolic resin curing agent, which is component (B) of the present invention, may be any one that is generally known as a curing agent for epoxy resins, such as phenol novolac resins, cresol novolac resins, etc. Novolak type phenolic resins having two or more hydroxyl groups are mentioned.

The blending amount of component (B) is usually 30 to 150 parts by weight per 100 parts by weight of component (A). If it is less than 30 parts by weight, curing will be insufficient, and if it exceeds 150 parts by weight, moisture resistance will be poor. Preferably it is 50 to 100 parts by weight.

The curing accelerator which is component (C) of the present invention may be any curing accelerator known to be used as a curing accelerator when curing epoxy resin using phenolic resin. good. Specific examples of component (C) include imidazole compounds such as 2-methylimidazole, 2-ethyl-4-methylimidazole, and 1-cyanoethyl-2-ethyl-methylimidazole; benzyldimethylamine, trisdimethylaminomethylphenol, etc. tertiary amine compound; triphenylphosphine.

Organic phosphine compounds such as tricyclohexylphosphine, tributylphosphine, methyldiphenylphosphine; 1,8-diaza-bicyclo(5,4゜0)undecene-7 or its salts; these may be used alone or in combination of two or more. used in the system.

The amount of component (C) to be blended is usually 0.01 parts by weight to 10 parts by weight per 100 parts by weight of component (A).

If the amount is less than 0.01 parts by weight, the curability will be poor, and if it exceeds 10 parts by weight, the moisture resistance will decrease.

The monovalent maleimide compound which is component (D) of the present invention is:
It may be of any type as long as it is represented by the above-mentioned general formula, but preferably phenylmaleimide in which X is hydrogen. The blending amount of this component (D) is (A)
The amount is 1 to 1 part by weight per 100 parts by weight of the ingredients. When the amount is less than 1 part by weight, it is not sufficient to lower the melt viscosity, and when it is 50 parts by weight or more, the curability is poor.

The inorganic filler which is component (E) of the present invention may be any inorganic powder commonly used as a fabric filler, but preferably silica powder. The silica powder may be fused or crystalline, and may be a mixture thereof, but fused silica powder is preferable. Moreover, the shape is not particularly limited. Further, in order to avoid local stress concentration on the encapsulated element, the maximum particle size of the filler is preferably 75 I# or less.

The amount of component (E) is 50 to 75% by volume based on the total amount of components (A), (B), (C), (D), and (E).

If the amount is less than 50% by volume, the resulting cured product will not have sufficient thermal shock resistance, and if it exceeds 75% by volume, the melt viscosity will increase and moldability will decrease.

The composition of the present invention may optionally contain surface treatment agents such as γ-glycidoxypropyltrimethoxysilane, mold release agents such as higher fatty acids and waxes, and known agents containing antimony, phosphorus compounds, bromine and chlorine. Flame retardants may also be added, such as polystyrene, polymethyl methacrylate, and polyvinyl acetate.

Alternatively, various thermoplastic resins such as copolymers of these, silicone oil, silicone rubber, etc. may be added.

Further, the resin-sealed semiconductor device of the present invention may be any semiconductor device as long as it can be sealed with the above-mentioned epoxy resin.

EXAMPLES The present invention will be explained in more detail below with reference to Examples. It should be noted that all values in the table represent weight % unless otherwise specified.

(Example) Examples 1 to 3 Compositions of the present invention were obtained using the components shown in Table 1. The above composition is first mixed in a Henschel mixer.
After treating the filler with a surfactant, the remaining components were mixed in a mixer, kneaded with heated rolls at 60 to 110°C, cooled, and pulverized.

The composition of the present invention can be prepared by mixing the above-mentioned components using a special mixer such as melt blending using a heating roll, melt blending using a kneader, melt kneading using an extruder, pulverization, or an appropriate combination of these methods. can be manufactured.

In addition, each resin in Table 1 is an octocresol novolac type epoxy resin (epoxy equivalent: 196, softening point: 76°C)
, flame-retardant epoxy resin (epoxy equivalent: 270°, softening point: 8
4°C), and a phenol novolak resin (phenol equivalent: 106, softening point: 84°C) was used.

Comparative Examples 1 to 3 Each component of the composition shown in Table 1 was treated in the same manner as in the example. This was used as a comparative example.

(The following is a blank space) 111= The following experiments were conducted on the compositions obtained in Examples 1 to 3 and Comparative Examples 1 to 3 above. The results are shown in Table 2.

First, in order to evaluate the fluidity of the composition, the melt viscosity at 175°C was measured using a Koka type flow tester.

Regarding the cured product, the linear expansion coefficient and glass transition temperature were measured for samples molded by low-pressure transfer molding.

Furthermore, using the same composition, a large pellet evaluation element having a PSG layer on the surface was sealed by low-pressure transfer molding.

In order to evaluate the thermal shock resistance of the obtained sample element, a thermal shock test (cooling/heating cycle test from -65°C to 150°C) was conducted to measure property defects.

As is clear from Table 2, the products of the present invention in Examples are superior in thermal shock resistance as compared to comparative products, and have a moderate viscosity while maintaining sufficient heat resistance.

〔Effect of the invention〕

The epoxy resin composition for semiconductor encapsulation of the present invention has good moldability without impairing heat resistance and provides a cured product with excellent thermal shock resistance, so it is useful as a packaging material for semiconductor electronic components. Yes, and its industrial value is extremely large.

Agent: Patent Attorney Noriyuki Chika Same as Mitsuyuki Matsuyama

Claims (2)

[Claims] (1) (A) Epoxy resin (B) Phenolic resin curing agent (C) Curing accelerator (D) General formula ▲ Numerical formulas, chemical formulas, tables, etc. are available ▼ (In the formula, X is hydrogen, halogen atom, hydroxyl group, alkoxy group, carboxyl group, and n is 1 to 5
(representing an integer of ) consisting of a monovalent maleimide compound (E) inorganic filler represented by
An epoxy resin composition characterized in that the amount is 50 to 75% by volume based on the total amount of (E). (2) (A) Epoxy resin (B) Phenolic resin curing agent (C) Curing accelerator (D) General formula ▲ Numerical formulas, chemical formulas, tables, etc. are available ▼ (In the formula, X is hydrogen, halogen atom, hydroxyl group, alkoxy group, carboxyl group, and n is 1 to 5
(representing an integer of ) consisting of a monovalent maleimide compound (E) inorganic filler represented by
A resin-sealed semiconductor device, characterized in that it is encapsulated with an epoxy resin composition in an amount of 50 to 75% by volume based on the total amount of (E).