JPH0656970A - Epoxy resin composition and semiconductor device sealed therewith - Google Patents

Abstract

PURPOSE:To provide an epoxy resin composition excellent in humidity resistance, corrosion resistance and mark legibility and a semiconductor device sealed therewith. CONSTITUTION:The resin composition essentially consists of an epoxy resin, a novolac resin, a carbon black colorant and an inorganic filler. The carbon black colorant has a particle diameter of 10-90nm, a pH of 10 or below and a halide ion constant of 100ppm or below and is used in an amount of 0.01-1wt.% based on the resin composition. The inorganic filler is used in an amount of 25-90wt.% based on the resin composition. The device is prepared by sealing a semiconductor chip with a cured product of this composition.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an epoxy resin composition excellent in moisture resistance, corrosion resistance and mark visibility and a semiconductor encapsulation device.

[0002]

2. Description of the Related Art Conventionally, diodes, transistors, I
Resin encapsulation has been performed to protect semiconductor elements such as C, LSI and VLSI from the external atmosphere and mechanical shock. The resin sealing method has been widely used because it is suitable for mass production as compared with the airtight sealing method using ceramics or the like.
This encapsulation method allows moisture to pass through the resin itself, or moisture can reach the element through the contact interface between the resin encapsulant and the semiconductor element, gold wires that electrically connect the element to the outside, and internal components such as lead frames. When it reaches, it causes deterioration of the element function such as deterioration of insulation and increase of leakage current. Furthermore, in the conventional epoxy resin molding material, due to manufacturing reasons, Cl
^- , Since it contains ionic impurities such as Na ⁺ , the absorbed moisture reacts with those ions, causing corrosion or disconnection of the semiconductor element, causing deterioration of the semiconductor element due to the material to be originally protected. There was a flaw. Since the resin is in direct contact with the semiconductor element, a method for synthesizing the epoxy resin, which is the main component of the encapsulating resin, and a method for cleaning ions, etc., are being studied, but it is difficult to avoid leaving a small amount of ions. Moisture absorption has also created a situation in which moisture reaches the element more easily than before, as semiconductor devices become lighter, thinner and smaller. On the other hand, if a large amount of ions or the like remains, the moisture resistance and the corrosion resistance are poor, and the mark visibility is poor.

[0003]

DISCLOSURE OF THE INVENTION The present invention has been made to solve the above-mentioned drawbacks, and is excellent in moisture resistance, corrosion resistance, and mark visibility, and there is no influence of moisture absorption or deterioration of insulation. It is an object of the present invention to provide an epoxy resin composition and a semiconductor encapsulation device which can guarantee long-term reliability without causing wire breakage due to electrode corrosion or leak current due to moisture.

[0004]

As a result of intensive studies to achieve the above object, the present inventor has found that the above object can be achieved by using a specific carbon black colorant. The invention has been completed.

That is, the present invention relates to (A) epoxy resin,
(B) novolac type phenol resin, (C) carbon black colorant and (D) inorganic filler are essential components, and the carbon black colorant of (C) has a particle size of 10 to 90.
nm, pH 10 or less, halogen ion content 100 ppm or less, 0.01 to 1% by weight relative to the resin composition, and the inorganic filler of the above (D) is 25 to 90% relative to the resin composition. The epoxy resin composition is characterized in that it is contained in a weight percentage. A semiconductor encapsulation device is obtained by encapsulating a semiconductor chip with a cured product of this epoxy resin composition.

The present invention will be described in detail below.

The (A) epoxy resin used in the present invention is not limited to its molecular structure, molecular weight, etc., as long as it is a compound having at least two epoxy groups in its molecule.
The commonly used ones can be widely used. Examples thereof include bisphenol type aromatic resins, alicyclic resins such as cyclohexane derivatives, and epoxy novolac resins represented by the following general formula.

[0008]

[Chemical 1] (In the formula, R ¹ represents a hydrogen atom, a halogen atom or an alkyl group, R ² represents a hydrogen atom or an alkyl group, and n represents an integer of 1 or more.) These epoxy resins may be used alone or in combination. You can

The novolak type phenolic resin (B) used in the present invention is a novolak type phenolic resin obtained by reacting phenols such as phenol and alkylphenol with formaldehyde or paraformaldehyde, and modified resins thereof, such as epoxidized or Butylated novolac type phenolic resin and the like can be used, and these can be used alone or in combination.
The compounding ratio of the novolac type phenol resin is the same as the above (A).
It is desirable that the molar ratio [(a) / (b)] of the epoxy group (a) of the epoxy resin of (1) and the phenolic hydroxyl group (b) of the novolak type phenolic resin of (B) be within the range of 0.1 to 10. . If the molar ratio is less than 0.1 or exceeds 10, the moisture resistance, molding workability and electrical properties of the cured product will deteriorate.
Either case is not preferable.

The carbon black colorant (C) used in the present invention has a particle size of 10 to 90 nm and a pH of 10 or less,
Use a halogen ion content of 100 ppm or less. If the particle size is less than 10 nm, the cost is increased because the yield is significantly poor in the production process of carbon black, and if it exceeds 90 nm, the original black color of the carbon black is lost and the mark visibility is poor, which is not preferable. If it exceeds pH 10, the resin composition is inferior in moisture resistance and corrosion resistance, and further, the dispersibility of carbon black in the resin is deteriorated, so that the strength is apt to be lowered. When the halogen ion content exceeds 100 ppm, the halogen ion causes corrosion of the semiconductor element, which is not preferable because it has no effect on the moisture resistance and the corrosion resistance. The carbon black colorant is preferably contained in an amount of 0.01 to 1% by weight based on the total resin composition. This formulation contains 0.01% by weight
If it is less than the above range, the coloring effect is poor, the appearance of the product is impaired, the light blocking effect is poor mechanically, and the characteristics of the LSI are deteriorated by light irradiation, which is not preferable. On the other hand, if it exceeds 1% by weight, the insulating property is lowered and the moisture resistance and the corrosion resistance are lowered, which is not preferable.

As the inorganic filler (D) used in the present invention, generally used ones are widely used. Examples of these inorganic fillers include silica powder, alumina, antimony trioxide, talc, calcium carbonate, titanium white, clay, red iron oxide, glass fiber, carbon fiber and the like, and silica powder and alumina are particularly preferably used. The blending ratio of the inorganic filler is preferably 25 to 90% by weight based on the total resin composition. If the proportion is less than 25% by weight, the resin composition has a high hygroscopicity and the moisture resistance after dipping in a solder bath is poor.
When the content is more than 10% by weight, the fluidity becomes extremely poor and the moldability is deteriorated, which is not preferable.

The epoxy resin composition of the present invention contains an epoxy resin, a novolac type phenolic resin, a carbon black colorant and an inorganic filler as essential components, but to the extent not deviating from the object of the present invention, and if necessary. , For example, natural waxes, synthetic waxes, metal salts of straight chain fatty acids, acid amides, esters, release agents such as paraffin,
Flame retardant such as antimony trioxide, silane coupling agent,
Various curing accelerators, rubber-based or silicone-based low stress imparting agents, and the like can be appropriately added and blended.

The general method for preparing the epoxy resin composition of the present invention as a molding material is to compound the above-mentioned specific epoxy resin, novolac type phenol resin, carbon black colorant and inorganic filler, and other components. After sufficiently homogeneously mixing with a mixer or the like, melt-mixing treatment with a hot roll or mixing treatment with a kneader or the like is further performed, followed by cooling and solidifying and pulverizing to an appropriate size to obtain a molding material. When the molding material thus obtained is applied to sealing, coating, insulation, etc. of electronic parts or electric parts such as semiconductor devices, excellent properties and reliability can be imparted. Further, the semiconductor encapsulation device of the present invention can be easily manufactured by encapsulating a semiconductor chip using the molding material described above. The semiconductor device 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 low pressure transfer molding, but injection molding,
Sealing by compression molding or casting is also possible. After sealing with a molding material, it is heated and cured, and finally a semiconductor sealing device sealed with this cured product is obtained. For curing by heating, it is desirable to heat and cure at 150 ° C or higher.

[0014]

In the epoxy resin composition and the semiconductor encapsulation device of the present invention, by using a specific carbon black colorant, the moisture resistance, corrosion resistance, and mark visibility of the resin composition are improved, and the insulation property by moisture is improved. There is no deterioration in the semiconductor device function due to deterioration or leakage current.

[0015]

EXAMPLES Next, the present invention will be described with reference to examples, but the present invention is not limited to these examples. In the following Examples and Comparative Examples, "%" means "% by weight".

Examples 1 to 4 The compositions shown in Table 1 were mixed at room temperature, further kneaded and cooled at 90 to 95 ° C., and then pulverized to obtain a molding material.

Comparative Examples 1 to 3 The compositions shown in Table 1 were mixed at room temperature in the same manner as in Examples, further kneaded and cooled at 90 to 95 ° C., and then pulverized to obtain molding materials.

The thus-prepared molding material was made into tablets, and by using the tablets, transfer injection into a mold heated to 170 ° C. and molding for 3 minutes were performed, and the integrated circuit was sealed and cured to manufacture a semiconductor sealing device. . Various tests were conducted on these semiconductor encapsulation devices, and the results are shown in Table 2. The epoxy resin composition and the semiconductor encapsulation device of the present invention are excellent in moisture resistance and the like, and thus the present invention is remarkable. I was able to confirm the effect.

[0019]

[Table 1] *: The amount of halogen ions was determined by measuring the atomic absorption spectrophotometry of the liquid that was extracted and filtered by stirring a mixed liquid of carbon black and distilled water for 20 hours at 95 ° C.

[0020]

[Table 2] * 1: Adhesion of an integrated circuit chip with aluminum wiring to a normal 42 alloy flare using a molding material, 170
After transfer molding at ℃ for 3 minutes, post-curing was performed at 175 ℃ for 8 hours. The molded product obtained in this way is heated at 127 ° C, 2.5
PCT was performed in saturated water vapor at atmospheric pressure, and the breakage due to corrosion of the aluminum wiring was evaluated as defective. * 2: Using a molding material, an aluminum wiring integrated circuit chip is bonded to a standard 42 alloy flare to form 170
After transfer molding at ℃ for 3 minutes, post-curing was performed at 175 ℃ for 8 hours. The molded product thus obtained is
Bias P at an applied voltage of 18 V in saturated steam of 2.5 atm
CT was performed, and disconnection due to corrosion of the aluminum wiring was evaluated as defective. * 3: After the UV curing mark ink was applied, UV curing was performed and the visibility of the mark was visually evaluated with a stereoscopic microscope. In the table, ◯: good, Δ: slightly unclear, ×: unclear.

[0021]

As is clear from the above description and Table 2, the epoxy resin composition and the semiconductor encapsulating device of the present invention are excellent in moisture resistance, corrosion resistance and mark visibility, and are not affected by moisture absorption. Further, there is no disconnection due to corrosion of the electrodes and no leak current due to moisture, and the reliability can be guaranteed for a long period of time.

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Claims (2)

[Claims] 1. An (A) epoxy resin, (B) novolac type phenol resin, (C) carbon black colorant and (D) inorganic filler are essential components, and the (C) carbon black colorant has a particle size. The content is 10 to 90 nm, the pH is 10 or less, the halogen ion content is 100 ppm or less, the content is 0.01 to 1% by weight with respect to the resin composition, and the inorganic filler of the above (D) is 25 with respect to the resin composition. An epoxy resin composition, characterized in that it is contained in a proportion of from 90 to 90% by weight. 2. The (A) epoxy resin, (B) novolac type phenol resin, (C) carbon black colorant and (D) inorganic filler are essential components, and the (C) carbon black colorant has a particle size. The content is 10 to 90 nm, the pH is 10 or less, the halogen ion content is 100 ppm or less, the content is 0.01 to 1% by weight with respect to the resin composition, and the inorganic filler of the above (D) is 25 with respect to the resin composition. A semiconductor encapsulation device, which is obtained by encapsulating a semiconductor chip with a cured product of an epoxy resin composition that is contained in a proportion of ˜90 wt%.