JPS62100523A - Epoxy resin composition for sealing semiconductor element - Google Patents

Abstract

PURPOSE:The titled epoxy resin composition capable of forming a plastic package having improved reliability of water-vapor resistance, comprising an epoxy resin of novolak type having a fixed softening point, a phenolic resin having the fixed softening point and a specific water repellent. CONSTITUTION:The aimed composition obtained by blending (A) an epoxy resin of novolak type (e.g., cresol novolak type epoxy resin) having 50-130 deg.C softening point with (B) a phenolic resin of novolak type (e.g., phenolic novolak, etc.,) having 50-130 deg.C softening point and (C) a water repellent comprising a polyethylene having >=10,000 molecular weight as a main component. The amount of the component C used is preferably 0.3-0.7wt% based on the total amount of the epoxy resin composition.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an epoxy resin composition for encapsulating a half body that can be formed into a plastic package with excellent moisture resistance and reliability. .

[Conventional technology]

Semiconductors such as transistors, ICs, and LSIs are sealed using ceramics and resins from the viewpoint of mechanical strength and moisture resistance. The ceramic package described above has excellent heat resistance and moisture permeation resistance of its constituent materials, so it is capable of extremely reliable sealing. However, in recent years, sealing with resin has become less popular due to the comparatively expensive constituent materials and poor V productivity.

[Problem that the invention seeks to solve]

Among these, epoxy resin compositions are often used, but as packages have become smaller and thinner in recent years, it has become easier for moisture to penetrate into the packages.

In addition, when mounting packages, surface mounting is now performed, and the entire package is immersed in solder, or it is heated by infrared rays in a solder reflow oven, which causes the package to receive a large thermal shock. 'A gap is created at the interface between the cage and the lead frame, and the intrusion of moisture through the gap cannot be ignored. With this moisture intrusion,
Impurity ions in the sealing resin are activated and cause corrosion to the wiring portions on the surface of the semiconductor element, creating a need to further improve the moisture resistance of the resin-sealed semiconductor.

The present invention was made in view of the above circumstances, and an object of the present invention is to provide an epoxy resin composition for encapsulating a semiconductor element that can achieve encapsulation with even higher moisture resistance.

[Means for solving problems]

In order to achieve the above object, the epoxy resin composition for semiconductor device encapsulation of the present invention is an epoxy resin composition containing the following components (A) to (C), in which the following component (C) is a molecule. The structure uses a water repellent whose main component is polyethylene of 110,000 or more.

(A) Novolac type epoxy resin with a softening point of 50 to 130°C.

(B) 7 novolak type phenolic resin with a softening point of 50-130°C.

(C) Water repellent.

In other words, the inventors have conducted a series of researches in order to meet the demand for the above-mentioned resin material 1: improving the moisture resistance reliability of semiconductors, and as a result, they have developed an iG solution that has polyethylene as a main component with a molecular weight of 10,000 or more. When this is combined with a novolac-type epoxy resin and a novolac-type phenol resin having the above-mentioned specific softening points, the adhesiveness of the resulting cured epoxy resin composition for sealing to the semiconductor element becomes extremely high, and it becomes heat-resistant. Even if subjected to impact, etc., no gap will be formed at the interface between the package and the lead frame, and even if a gap does occur, the polyethylene water repellent in the composition will cover the entire element and protect it through heating during element sealing. Because it is in a state of water repellency, it prevents moisture from entering.
F, and as a result, the moisture resistance of the semiconductor device was found to be significantly improved, and the present invention was achieved.

The epoxy resin composition of this invention has a softening point of 50 to 130.
°C novolac type epoxy resin (component A) and softening point 5
Novolac type phenolic resin (B component) at 0 to 130°C
It is obtained using a TA solution (component C) whose main component is polyethylene with a molecular size of 1ioooo or more, and is usually in the form of a powder or a tablet formed by compressing it.

The novolak type epoxy resin serving as the above-mentioned component A is not particularly limited as long as it has a softening point of 50 to 130°C, and cresol novolak, phenol novolak, etc. can be appropriately selected and used. However, preferred are those based on cresol novolacs. These materials preferably have an epoxy equivalent weight within the range of 180 to 250.

The novolac type phenolic resin of component B used as a curing agent for the above epoxy resin has a softening point of 50 to 130.
Phenol novolaks and cresol novolacs of "C" are preferred.

The water repellent as component C is mainly composed of polyethylene with a molecular weight of 110,000 or more.
An IΩ solution containing polyethylene as a main component of 0000 to 100ooo gives good results. Here, the term "main component" is meant to include cases where the entire component is made of the main component. If the main component is polyethylene having a molecular weight of 110,000 or more, the moisture resistance of the resin-sealed semiconductor will not be sufficiently improved, and the object of the present invention cannot be achieved. Here, the above molecular weight indicates the weight average molecular weight determined by gel permeation chromatography using polystyrene as a reference material and tetrahydrofuran as a developing solvent.

It is preferable that the amount of water repellent used as the Biped C component is set at 0.1 to 1.5% by weight (hereinafter abbreviated as "-%") of the entire epoxy resin composition. The preferred value is 0.
It is within the range of 3 to 0.7%. The amount of tΩ solution used is 0.
If it is less than 1%, the moisture resistance of the resin-sealed 1F half-m body will not be sufficiently improved, and on the other hand, if it exceeds 1.5%, the appearance of the resin-sealed body will deteriorate and at the same time it will be difficult to print on the surface. Power (power seen) et al.

In addition, the epoxy resin 3 of this invention, the acid compound, is generally r'
6. In addition to the above components, various conventionally used curing accelerators may be used alone or in combination. As this type of curing accelerator: 1. Suitable examples include the following tertiary amines, quaternary ammonium salts, imidazoles, and boron compounds.

Tertiary amine triethanolamine, tetramethylhexanediamine, triethylenediamine, dimethylaniline, dimethylaminoethanol, diethylaminoethanol, 2,4
．． 6- (dimethylaminomethyl)phenol, N, N
'-dimethylpiperazine, pyridine, picoline, 1.8
-Diaza-bicyclo(5,4,0)undecene-7, benzyldimethylamine, 2-(dimethylamino)methylphenol quaternary ammonium salt Topdyltrimethylammonium iodide, cetyltrimethylammonium chloride, hensyldimethyltetrabutylammonium chloride , stearyltrimethylammonylammonium chloride 1 colloid imidazole 2-methylimidazole, 2-undecylimidazole, 2-ethylimidazole, 1-benzyl-2-methylimidazole, ■-cyanoethyl-2-undecylimidazole boron compound tetraphenylboron 1 , tetraphenylborate, N
-Methylmorpholinetetraphenylbore 1. Also, if necessary, -[In addition to the component raw materials listed in -,

Inorganic fillers, antimony trioxide, flame retardants such as phosphorus compounds, pigments, and coupling agents such as silane coupling agents can be used. 9 The above-mentioned inorganic filler is not particularly limited, and commonly used quartz glass powder, talc, silica powder, alumina powder, etc. can be used as appropriate.

The epoxy resin composition used in this invention is produced by a conventionally known method, and in more detail, it contains a novolac type epoxy resin, a novolac type phenolic resin, a water repellent, and optionally an inorganic filler. agent,
Other additives such as pigments, coupling agents, mold release agents, etc. are appropriately blended, and this mixture is kneaded in a heated state using a kneading machine such as a mixing roll machine to obtain a semi-cured resin composition.
After cooling this to room temperature, it is crushed by known means,
It can be obtained by tabletting if necessary.

The encapsulation of a semiconductor element using such an epoxy resin composition is not particularly limited, and can be carried out by a conventional method, for example, a known molding method such as transfer molding.

The semiconductor device thus obtained is 1. It has excellent moisture resistance and reliability.

〔Effect of the invention〕

The epoxy resin composition for encapsulating semiconductor elements of the present invention comprises 1
As a water-combining agent, we use a material whose main component is polyethylene with a molecular weight of 110,000 or more, and we combine this with a novolak-type epoxy resin and a novolak-type phenol resin that have a specific softening point, as mentioned earlier.
), the adhesion of the cured product to semiconductor elements is significantly improved. Therefore, even if subjected to thermal shock or the like, no interfacial peeling occurs between the plastic package obtained by curing the composition and the element. Furthermore, the polyethylene water repellent in the composition melts when heated during resin sealing, coating and protecting the surface of the element, so even if a gap occurs between the package and the element, the water repellent will remain intact. 18 Water intrusion is prevented by water curing. In other words, due to the above effects, the epoxy resin composition of the present invention can achieve extremely high moisture resistance reliability when a semiconductor element is temporarily stopped, and can be used to reduce the size and thickness of plastic packages. This is sufficient to withstand thermal shock during surface mounting of the package.

Next, examples will be explained together with comparative examples.

[Examples 1 to 4, Comparative Examples 1 to 3] First, each raw material was blended with the composition shown in Table 1 below, and this blend was kneaded for 5 minutes with a hot roll at 120 ° C. After cooling, it was pulverized. It was made into a powdered composition.

Next, using the obtained powder composition, a semiconductor element consisting of a silicon chip having aluminum wiring attached to the surface was transfer-molded under the conditions of a pressure cuff of 0 kg/cJ and a temperature of 180°C for 1 hour and 2 minutes. , a semiconductor device was obtained.

(Left below) [Test] Examples 1 to 4 and Comparative Examples 1 to 4 thus obtained
Fifty semiconductor devices of No. 3 were each prepared, and a moisture resistance test was conducted in the following manner. That is, first, the resistance value of the aluminum wiring on the chip of the semiconductor device was measured, and then the semiconductor device was heated to 121°C.

After leaving it in a pressurized steam sealed container at 2 atmospheres for a certain period of time, take it out and repeat step 1. The resistance of the aluminum wiring was measured.

A product whose resistance value after being left is 150% or more of the resistance value before being left was determined to be a defective product, and the number of defective products per 50 samples was used as a measure of moisture resistance. The results are shown in Table 2.

(The following is a blank space) 1-2 ----Person From the results in Table 2, it can be seen that according to the epoxy resin composition of the example, a resin pair 1: having excellent moisture resistance can be produced.

In contrast to the above examples, Comparative Example 1.2 uses polyethylene with a small molecular weight (θ water agent), which is outside the scope of the present invention, so the results are not good. The results were the worst when using water medications.

(Left white)

Claims (2)

[Claims] (1) An epoxy resin composition containing the following components (A) to (C), in which the following component (C) has a molecular weight of 10
1. An epoxy resin composition for encapsulating a semiconductor device, characterized in that a water repellent having a polyethylene of 000 or more as a main component is used. (A) Novolac type epoxy resin with a softening point of 50 to 130°C. (B) Novolac type phenolic resin with a softening point of 50 to 130°C. (C) Water repellent. (2) Polyethylene has a molecular weight of 10,000 to 10,000
1. The epoxy resin composition for encapsulating a semiconductor device according to claim 1, which has the following properties.