JPH0468329B2 - - Google Patents

Description

[Detailed description of the invention]

[Technical Field of the Invention] The present invention relates to a sealing resin composition that is low in stress and has excellent moisture resistance and laser mark properties. [Technical Background of the Invention and Problems thereof] In recent years, methods have been used to seal electronic components such as diodes, transistors, and integrated circuits using thermosetting resins. This resin sealing method is economically advantageous compared to hermetic sealing methods using glass, metal, or ceramic, and is therefore widely put into practical use. Thermosetting resins are used as the sealing resin, and among them, epoxy resin compositions are most commonly used in terms of reliability, cost, etc. Acid anhydrides, aromatic amines, novolac type phenolic resins, etc. are used as curing agents for epoxy resins, but epoxy resin compositions using novolac type phenolic resins as curing agents are similar to those using other curing agents. Formability compared to
Because it has excellent moisture resistance, is nontoxic, and is inexpensive, it is most preferred and widely used as a material for semiconductor encapsulation. However, conventional epoxy resin compositions using a novolak type phenolic resin as a curing agent have the disadvantage that they shrink during molding and curing, applying stress to the element, resulting in poor reliability of the encapsulated molded product. In other words, when a hot/cold cycle test is performed on a molded product using the above-mentioned resin composition, bonding wire breakage,
Resin cracks and element cracks occur, making it impossible to function as an electronic component. In particular, when used for sealing large device sizes (5 mm x 5 mm or larger) such as CPUs and gate arrays, the above phenomenon occurs significantly. Furthermore, in order to mark the product name or manufacturer's name on the surface of a resin-sealed semiconductor product, a method of stamping with thermosetting ink is currently generally employed. However, the disadvantage of this ink stamp is that it is relatively easily erased by organic solvents and is susceptible to friction. In order to compensate for this drawback and to improve the efficiency of the marking process, laser marking using a laser such as carbon dioxide gas has recently begun to be performed.
However, when making laser marks on conventional epoxy resin compositions, there was a drawback that the mark clarity was inferior to that of the ink marking method. [Object of the Invention] The object of the present invention was made to eliminate the above-mentioned drawbacks, and it has low stress, excellent moisture resistance, and laser mark property, and has the inherent heat resistance of an epoxy resin composition. The object of the present invention is to provide a sealing resin composition that maintains mechanical properties and moldability. [Summary of the Invention] As a result of intensive studies to achieve the above object, the present inventors have formulated an organic dye having at least one metal atom or metal ion in the molecule and an ethylene-vinyl alcohol copolymer. It was discovered that by doing so, a sealing resin composition with low stress and excellent moisture resistance and laser mark properties could be obtained, and the present invention was completed. That is, the present invention provides (A) an epoxy resin, (B) a novolac type phenolic resin, (C) an organic dye having at least one metal atom or metal ion in the molecule, and (D) an ethylene-vinyl alcohol copolymer. (E) A sealing resin composition characterized by containing an inorganic filler. Then, to this resin composition, (C) 0.01 to 10% by weight of an organic dye having at least one metal atom or metal ion in the molecule, (D) ethylene-
0.1-20% by weight of vinyl alcohol copolymer, (E)
Each contains 25 to 90% by weight of inorganic filler,
Or (A) the epoxy group of the epoxy resin (a) and (B) the phenolic hydroxyl group of the novolac type phenolic resin (b)
A sealing resin composition having a molar ratio [(a)/(b)] of 0.1 to 10 is particularly suitable. As long as the epoxy resin (A) used in the present invention is a compound having at least two or more epoxy groups in its molecule, there are no particular restrictions on its molecular structure or molecular weight, and it broadly includes commonly used epoxy resins. can do. Examples include aromatic bisphenol type resins, alicyclic resins such as cyclohexane derivatives, and epoxy novolac type resins represented by the following general formula, and these resins may be used alone or in combination of two or more types. (In the formula, R ¹ is a hydrogen atom, a halogen atom, or an alkyl group, R ² is a hydrogen atom or an alkyl group,
(n each represents an integer of 1 or more) The novolac type phenolic resin (B) used in the present invention includes novolac type phenolic resins obtained by reacting phenols such as phenol and alkylphenol with formaldehyde or paraformaldehyde, and these. Examples of modified resins include epoxidized or butylated novolak type phenolic resins, which may be used alone or in combination of two or more. The blending ratio of the novolak type phenolic resin is the molar ratio of the epoxy group (a) of the epoxy resin (A) and the phenolic hydroxyl group (b) of the novolak type phenolic resin (B) [(a)/(b)] is 0.1
It is preferably within the range of ~10. The molar ratio
If it is less than 0.1 or more than 10, the moisture resistance, molding workability, and electrical properties of the cured product will deteriorate, and either case is unfavorable. Therefore, it is better to limit it to the above range. As long as the organic dye having at least one metal atom or metal ion in the molecule (C) used for this application has the above-mentioned conditions, the molecular structure,
There are no particular restrictions on molecular weight, etc. As a specific compound, These may be used alone or in combination of two or more. And especially these organic dyes,
It is preferable that the molecule does not contain halogen atoms such as chlorine or bromine. The blending ratio of the organic dye is preferably 0.01 to 10% by weight based on the resin composition. If the amount is less than 0.01% by weight, there is no effect on laser mark properties, and if it exceeds 10% by weight, the bulk will increase and the moldability will be poor, making it unsuitable for practical use. The (D) ethylene-vinyl alcohol copolymer used in the present invention contains (In the formula, m and n represent integers of 1 or more.) As long as it has this group, there are no particular restrictions on the molecular structure, molecular weight, etc., and commonly used ones can be widely used. can be included. The content of the ethylene-vinyl alcohol copolymer is preferably 0.1 to 20% by weight based on the resin composition. If the amount is less than 0.1% by weight,
It has no effect on low stress, and when it exceeds 20% by weight,
It is bulky and has poor moldability, making it unsuitable for practical use. Furthermore, the inorganic filler (E) used in the present invention includes silica powder, alumina, antimony trioxide,
Examples include inorganic fibers such as talc, calcium carbonate, titanium white, clay, asbestos, mica, red iron, glass fiber, and carbon fiber, and these may be used alone or in combination of two or more. Among these fillers, silica powder and alumina are particularly preferred. The blending ratio of the inorganic filler is preferably 25 to 90% by weight based on the resin composition. If the amount is less than 25% by weight, it will have no effect on moisture resistance, heat resistance, mechanical properties, or moldability, and if it exceeds 90% by weight, it will be bulky and have poor moldability, making it unsuitable for practical use. The sealing resin composition of the present invention includes an epoxy resin,
Novolac type phenolic resin, organic dye having at least one metal atom or metal ion in the molecule, ethylene-vinyl alcohol copolymer,
Contains inorganic fillers, but if necessary, for example, natural waxes, metal salts of straight chain fatty acids, acid amides, etc.
Mold release agents such as esters and paraffins, flame retardants such as chlorinated paraffin, bromotoluene, hexabromobenzene, and antimony trioxide, colorants such as carbon black and red iron, and silane coupling agents may be added as appropriate. I can't help it. As a general method for using the encapsulating resin composition of the present invention as a molding material, the above-mentioned components selected at a predetermined composition ratio are sufficiently uniformly mixed using a mixer, etc., and then further heated using a hot roll. A molding material can be produced by performing melt mixing treatment or mixing treatment using a kneader or the like, then cooling and solidifying, and pulverizing into an appropriate size. When the encapsulating resin composition according to the present invention is applied to encapsulating, coating, insulating, etc. electronic/electrical components, excellent characteristics and reliability can be imparted. [Effects of the Invention] The encapsulating resin composition of the present invention has a low Since it is a stress, it does not shrink during molding and hardening and does not apply stress to the element, and has excellent moisture resistance, preventing bonding wire breakage, resin cracks, etc. in hot and cold cycle tests.
No element cracks occur. Furthermore, it has excellent laser marking properties, and marks with good clarity can be obtained. Of course, since it maintains the heat resistance, mechanical properties and workability of the epoxy resin composition, sufficient reliability can be obtained when this composition is used for sealing electronic and electrical parts. [Examples of the Invention] The present invention will be specifically explained with reference to Examples, but the present invention is not limited to the following Examples.
In Examples and Comparative Examples, "%" means "% by weight". Example 16% of cresol novolak epoxy resin (epoxy equivalent: 215), 9% of novolak type phenolic resin (phenol equivalent: 107), organic dye of the following formula 1%, ethylene-vinyl alcohol copolymer 5%
and 69% silica powder are mixed at room temperature, then 90%
After kneading and cooling at ~95°C, the mixture was pulverized to produce a molding material. The obtained molding material was made into a tablet, preheated, injected into a mold heated to 170°C by transfer molding, and cured to obtain a molded product (sealed product). This molded article was tested for mechanical properties, glass transition point, temperature and cold cycles, moisture resistance, and laser mark properties, which are shown in Table 1. Comparative example: 20% cresol novolac epoxy resin (epoxy equivalent 215), 10% novolac type phenolic resin (phenol equivalent 107), and 70% silica powder.
% was processed in the same manner as in the Examples to produce a molding material, which was used to form a molded article, and this molded article was tested for the same properties as in the Examples. The results are shown in Table 1.

【table】

[Table] The present invention was superior in low stress, moisture resistance, and laser mark property compared to the comparative example, and the remarkable effects of the present invention were recognized.

Claims (1)

[Claims] 1. (A) Epoxy resin, (B) Novolac type phenolic resin, (C) Organic dye having at least one metal atom or metal ion in the molecule, (D) Ethylene-vinyl alcohol co-organic. A sealing resin composition comprising a polymer and (E) an inorganic filler. 2 Based on the resin composition, 0.01 to 10% by weight of the organic dye having at least one metal atom or metal ion in the molecule (C) and 0.1 to 10% by weight of the ethylene-vinyl alcohol copolymer (D) 20% by weight, said
(E) The sealing resin composition according to claim 1, each containing 25 to 90% by weight of an inorganic filler. 3. A patent claim in which the molar ratio [(a)/(b)] between the epoxy group (a) of the epoxy resin (A) and the phenolic hydroxyl group (b) of the novolak type phenolic resin (B) is in the range of 0.1 to 10. The sealing resin composition according to item 1 or 2.