JPH0739470B2 - Sealing resin composition and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a resin composition for sealing electronic or electric parts, which is free from variations in low stress characteristics and has excellent moisture resistance, and its production. Regarding the method.

(Prior Art) Conventionally, a method of encapsulating an electronic component such as a diode, a transistor, an integrated circuit using a thermosetting resin has been performed. This resin encapsulation has been widely put into practical use because it is economically advantageous as compared with the hermetic sealing method using glass, metal, or ceramic. Among thermosetting resins used for resin encapsulation, epoxy resin compositions are most commonly used. Curing agents such as acid anhydrides, aromatic amines and novolac type phenolic resins are used in the epoxy resin composition, but the epoxy resin composition using the novolac type phenolic resin as a curing agent is different from other curing agents. It is widely used as a semiconductor encapsulating material because it has superior moldability and moisture resistance, is less toxic, and is less expensive than the one using.

(Problems to be Solved by the Invention) However, an epoxy resin composition using a novolac-type phenol resin as a curing agent has a drawback that it shrinks during molding and curing, stress is applied to a semiconductor element, and the reliability of the element is deteriorated. is there. When a cold cycle test of a molded product using such a resin composition is performed, opening of a bonding wire, resin crack, pellet crack, etc. occur,
There was a problem that the function as an electronic component could not be fulfilled. In addition, there is a method of adding a third component in order to reduce the stress of the resin composition, but the third component forms a secondary aggregate and cannot be uniformly dispersed in the resin composition, which results in low stress characteristics. There was a drawback that there was variation.

The present invention has been made in order to eliminate these drawbacks, there is no variation in low stress characteristics, moisture resistance, excellent cold and cold cycle property, and reliability of maintaining the characteristics of conventional epoxy resin composition. It is intended to provide a high sealing resin composition and a method for producing the same.

[Structure of the Invention] (Means for Solving Problems) As a result of earnest studies to achieve the above object, the present inventor has found that a polyamide resin is a resin obtained by uniformly dispersing and mixing the polyamide resin in a novolac-type phenol resin. It was found that the variation of low stress characteristics disappears by using
The present invention has been completed.

That is, the first invention is a resin [(A) + (B)] in which (B) polyamide resin is uniformly dispersed and mixed in (A) novolac type phenol resin, (C) epoxy resin and (D) inorganic substance. A resin composition for encapsulation, which comprises a filler as an essential component. A second invention is a resin [(A) + (B)] in which (A) a novolac type phenolic resin is melted, and (B) a polyamide resin is added and uniformly mixed therein (C). Manufacture of a resin composition for encapsulation, which comprises crushing with an epoxy resin, then adding (D) an inorganic filler and, if necessary, other components, mixing, and further heat kneading, followed by cooling, solidifying and crushing. Is the way.

Examples of the (A) novolak type phenolic resin used in the present invention include novolak type phenolic resins obtained by reacting phenols such as phenol and alkylphenol with formaldehyde or paraformaldehyde, and modified resins thereof such as epoxidized or butylated novolaks. Type phenolic resin. The blending ratio of the novolac type phenol resin is the molar ratio [(c) / (a)] of the epoxy group (c) of the epoxy resin and the phenolic hydroxyl group (a) of the novolac type phenol resin described below.
Is preferably in the range of 0.1 to 10. If this molar ratio is less than 0.1 or exceeds 10, the moisture resistance, the molding workability, and the electrical properties of the cured product deteriorate, which is not preferable in any case. Therefore, it is preferable to limit it to the above range.

The (B) polyamide-based resin used in the present invention is a polycondensation product of a diamine and a dicarboxylic acid, and a molecular weight, if it is synthesized from an ω-aminocarboxylic acid or a corresponding lactam by polycondensation or ring-opening polymerization. There is no limitation on the molecular structure and the like and it can be widely used, and these are used alone or in combination of two or more kinds.

The mixing ratio of the polyamide resin is preferably 0.1 to 90% by weight based on the resin [(A) + (B)] in which the polyamide resin is uniformly dispersed and mixed in the epoxy type phenol resin. If the proportion is less than 0.1% by weight, there is no effect of withstanding low stress and warm and cold cycles, and 90% by weight.
When it exceeds, it is not preferable because uniform dispersion and mixing cannot be carried out in the novolac type phenol resin. The method of uniformly dispersing and mixing the polyamide-based resin in the novolac-type phenol resin is to put the novolac-type phenol resin in a device (container) that can be heated to a temperature above the melting point of the novolak-type phenol resin, and to add the temperature above the melting point. After warming to a completely molten liquid, a polyamide resin is added, and the mixture is stirred at preferably 150 ° C. or higher for 20 minutes or longer, and uniformly dispersed and mixed. The resin [(A) + (B)] in which a polyamide resin is dispersed and mixed in a novolac type phenol resin is preferably contained in an amount of 1 to 30% by weight based on the entire resin composition. If the proportion is less than 1% by weight, the low stress is not effective, and if it exceeds 30% by weight, the moisture resistance is deteriorated, which is not preferable.

The (C) epoxy resin used in the present invention is not particularly limited in terms of molecular structure, molecular weight, etc., as long as it is a compound having at least two epoxy groups in its molecule, and those used for general encapsulating materials are Can be broadly included. Examples thereof include bisphenol type aromatic resins, alicyclic resins such as cyclohexane derivatives, and epoxy novolac resins represented by the following general formula.

(However, 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 are used alone or as a mixed system of two or more kinds.

Examples of the inorganic filler (D) used in the present invention include silica powder, alumina, antimony trioxide, talc, calcium carbonate, titanium white, clay, mica, red iron oxide, glass fiber, carbon fiber and the like, which may be used alone or Mix and use two or more types. Among these, silica powder and alumina are particularly preferably used. The blending ratio of the inorganic filler is 25 to 90 with respect to the entire resin composition.
It is desirable that the content be wt%. If the proportion is less than 25% by weight, the moisture resistance, heat resistance, mechanical properties and moldability are not effective, and if it exceeds 90% by weight, the dryness becomes large and the moldability is poor and it is not suitable for practical use.

The encapsulating resin composition of the present invention contains a novolac-type phenol resin, a polyamide resin, an epoxy resin and an inorganic filler as essential components, but if necessary, for example, natural waxes, synthetic waxes, straight-chain fatty acids, etc. Release agent for metal salts, acid amides, esters, paraffins, chlorinated paraffins, bromotoluene, hexabromobenzene,
A flame retardant such as antimony trioxide, a silane coupling agent, various curing accelerators and the like can be appropriately added.

The method for producing the encapsulating resin composition of the present invention may be carried out by heating and mixing a polyamide resin in a novolac type phenolic resin, and a resin obtained by uniformly dispersing and mixing it may be used, and is not particularly limited to the production method. Absent. However, it is usually manufactured as follows. Using a device (container) capable of heating to a temperature above the melting point of the novolac type phenolic resin, such as a universal mixer, a strong kneader, a heating reaction kettle, etc., charge the novolac type phenolic resin into it, and heat it above the melting point. , After completely melting, add polyamide resin,
Stir at 150 ° C or above for 20 minutes or more to uniformly disperse and mix. A novolac-type phenol resin in which a polyamide resin is uniformly dispersed and mixed, and an epoxy resin are crushed, and then a raw material composition in which an inorganic filler and other components are selected to have a predetermined composition ratio is sufficiently mixed by a mixer or the like. After that, the mixture is further heated and kneaded by a hot roll, an extruder, a kneader, or the like, and then cooled and solidified, and then crushed to an appropriate size to produce a sealing resin composition. As described above, the production method in which the polyamide resin is dispersed and mixed in the novolac type phenol resin, and then the other components are blended is explained.
In the production process of novolac type phenolic resin, a resin is prepared by uniformly dispersing and mixing polyamide resin,
You may mix and knead a necessary amount with other components as needed. The encapsulating resin composition of the present invention produced in this manner can be applied to encapsulation, coating, insulation and the like of electronic or electric parts.

(Function) By uniformly dispersing and mixing the polyamide-based resin in the novolac-type phenol resin (including making it into a fibrous form), it is possible to reduce the formation of secondary aggregates and eliminate the variation in low stress characteristics. . By simply mixing and kneading the epoxy resin, novolac type phenol resin, polyamide resin, inorganic filler and other components, the polyamide resin particles produce secondary aggregates having a particle size of several hundreds of μm, which results in low stress characteristics. As a result, there is a decrease or variation in low stress characteristics occurs, resulting in a loss of reliability. Therefore, if you disperse and mix it in the novolac type phenolic resin in advance,
The generation of secondary aggregates is small, and also decreases, the particle size of the polyamide resin is fine, and it is dispersed in a fibrous form.
It is confirmed that the low stress characteristics are excellent and variations are eliminated. The dispersion state of the polyamide-based resin can be arbitrarily adjusted by adjusting the particle size according to the mixing conditions (temperature, time, etc.), but the dispersion state is preferably 0.1 to 100.
It is preferably within the range of μm.

(Examples) The present invention will be specifically described with reference to Examples.
The present invention is not limited to the examples below. In the following Examples and Comparative Examples, "%" means "% by weight"
Means

Resin production 70% of novolac epoxy resin (phenol equivalent 1078) is put into a universal mixer and heated to 150 ° C. 30% of nylon 6/12 after novolac type phenolic resin is completely melted
Was added, and the mixture was heated and stirred for 1 hour to prepare a resin (hereinafter referred to as PA resin) in which nylon 6/12 was uniformly dispersed and mixed.

Example 1 10% of PA resin and 18% of cresol novolac epoxy resin (epoxy equivalent of 215) were used as a screen 2 of a yarder grinder.
Milled with mm, fused silica powder 65% and other components 5%
Were mixed at room temperature, further kneaded at 90 to 100 ° C., cooled, and then pulverized to produce a sealing resin composition. This resin composition was transfer-injected into a mold heated to 175 ° C. and cured to form a molded product (sealed product). The molded article was tested for moisture resistance, strain, particle size of polyamide resin, and other tests. The results are shown in Table 1.
The polyamide resin was well dispersed in the encapsulating resin composition of the present invention, and it was excellent in hot and cold cycles, moisture resistance, and low stress characteristics, and the remarkable effects of the present invention were recognized.

Example 2 PA-A resin 10% and cresol novolac epoxy resin (epoxy equivalent 215) 20% were used as a screen 2 of a yaiya crusher.
Milled with mm, fused silica powder 65% and other components 5%
Was added to prepare a sealing resin composition in the same manner as in Example 1. Further, a molded product was prepared in the same manner and the same various tests were conducted. The results are shown in Table 1. Similar to Example 1, the remarkable effect of the present invention was recognized.

Comparative Example 1 Cresol novolac epoxy resin (epoxy equivalent 21
5) Novolac type phenolic resin (phenol equivalent 107) 9%, nylon 6/12 2.5%, fused silica powder to 18.5%
65% and 5% of other ingredients are mixed at room temperature and then 90-
The mixture was kneaded at 100 ° C., cooled, and then pulverized to produce a sealing resin composition. Next, a molded product was made using this resin composition, and various properties were tested in the same manner as in Examples. The results are shown in Table 1.

Comparative Example 2 Cresol novolac epoxy resin (epoxy equivalent 21
5) 20%, novolac type phenol resin (phenol equivalent 107) 10%, fused silica powder 65% and other components 5% were prepared in the same manner as in Comparative Example 1 to produce a resin composition for encapsulation. Was prepared and various properties were tested in the same manner. The results are shown in Table 1.

[Effects of the Invention] As is clear from the above description and Table 1, according to the encapsulating resin composition and the method for producing the same of the present invention, the polyamide resin is heated and mixed uniformly in the novolac type phenol resin. By mixing, secondary agglomerates are also small, low stress characteristics are excellent, there is no variation, good moisture resistance,
In addition, a product having the characteristics of the conventional epoxy resin composition was obtained. Excellent reliability can be imparted to an electronic component or an electrical component using this resin composition.

Claims (6)

[Claims] 1. In (A) novolak type phenolic resin,
(B) Resin [(A) + (B)] in which polyamide resin is uniformly dispersed and mixed, (C) epoxy resin and (D)
A resin composition for encapsulation, which comprises an inorganic filler as an essential component. 2. A polyamide-based resin (B) is used as a resin [(A)].
+ (B)] 0.1 to 90% by weight of the sealing resin composition according to claim 1. 3. A resin composition containing the resin [(A) + (B)] in an amount of 1 to 30% by weight based on the total resin composition.
Item 2. The encapsulating resin composition according to Item 2 or Item 2. 4. The encapsulating resin composition according to any one of claims 1 to 3, wherein the inorganic filler (D) is contained in an amount of 25 to 90% by weight based on the entire resin composition. 5. A molar ratio [(c) / (a)] of the epoxy group (c) of the epoxy resin and the phenolic hydroxyl group (a) of the novolac type phenol resin is in the range of 0.1 to 10. 5. The encapsulating resin composition according to any one of claims 1 to 4. 6. A resin [(A) + (B)] in which (A) a novolac type phenolic resin is melted, and (B) a polyamide resin is added thereto and uniformly dispersed and mixed, and (C) an epoxy resin. And (D) an inorganic filler and optionally other components are added and mixed, and the mixture is further heated and kneaded, followed by cooling, solidifying and pulverizing, and a method for producing a resin composition for encapsulation.