JPS60152522A - Sealing resin composition - Google Patents

Abstract

PURPOSE:A sealing resin composition excellent in laser markability and good in moisture resistance, heat resistance, and mechanical properties, prepared by mixing an epoxy resin with a novolak phenolic resin, an azo compound and an inorganic filler. CONSTITUTION:An epoxy resin (A) (e.g., bisphenol A-derived epoxy resin or novolak epoxy resin) is melt-blended with a novolak phenolic resin (B), a compound (C) having at least one azo group in the molecule (e.g., a compound of the formula), and an inorganic filler (D) (e.g., silica powder or alumina) in a kneader or the like. and the blend is solidified by cooling and ground. Here, the molar rario of the epoxy groups of component A to the phenolic hydroxyl groups of component B is about 0.1-10, the rate of component C (azo compound) to the total resin composition is 0.01-10wt%, and the rate of component D (inorganic filler) to the total is 29-90wt%.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a resin composition for sealing semiconductor devices, etc., and more specifically, a resin composition that has excellent laser mark properties and good moisture resistance, heat resistance, and mechanical properties. III to the sealing resin composition.

[Technical background of the invention and its problems] Conventionally, electronic components such as diodes, transistors, and integrated circuits have been sealed using thermosetting resin. This resin sealing is economically advantageous compared to hermetic sealing methods using glass, metal, or ceramic, and is therefore widely put into practical use.

Among thermosetting resin compositions, epoxy resin compositions are most commonly used as sealing resin compositions in terms of reliability and cost. Epoxy resin compositions use curing agents such as acid anhydrides, aromatic amines, and novolac-type phenolic resins. Among these, epoxy resin compositions using novolac type phenolic resin as a curing agent are
It is widely used as a semiconductor encapsulation material because it has excellent moldability and moisture resistance, is non-toxic, and is inexpensive compared to those using the hardening agent described above.

However, even epoxy resin compositions using a novolak type phenol resin as a curing agent have the disadvantage that they are not reliable enough in terms of moisture resistance and heat resistance, which are required as electronic parts become more densely densified. When a molded product using such a resin composition is subjected to a temperature/cold cycle test, bonding wire opens, resin cracks, and pellet cracks occur, making it unable to function as an electronic component. There was a problem that a similar phenomenon occurred and the function could no longer be fulfilled. Furthermore, in order to mark the product name and manufacturer's name on the surface of resin-sealed semiconductor products (diodes, transistors, integrated circuits), a method of stamping with thermosetting ink is currently generally employed. However, marks made with this ink have the disadvantage that they are relatively easily erased with organic solvents and are susceptible to friction. In order to compensate for these drawbacks and to improve the efficiency IL of the marking process, laser marking using a CO2 laser or the like has recently begun to be performed. However, when a laser mark is made with a conventional resin composition, the clarity of the mark is inferior to that of an ink marking method.

[Object of the Invention] The object of the present invention was to solve the above-mentioned drawbacks, and to provide a sealing resin composition that has excellent laser mark properties and good moisture resistance, heat resistance, and mechanical properties. This is what I am trying to do.

[Summary of the Invention] As a result of intensive research to achieve the above object, the present inventors have discovered that a resin composition containing a compound having one or more azo groups in the molecule exhibits excellent laser mark properties. It has been found that the resin composition has the following characteristics and also has good other properties, making it suitable for a sealing resin composition. That is, the present invention includes (A) an epoxy resin, (B) a novolac type phenolic resin, (C) a compound having one or more azo groups in the molecule, and (D) an inorganic filler as an essential component, and one or more azo groups in the molecule. 0.01 to 10% by weight of the above azo group-containing compound based on the resin composition and 25 to 90% of the above inorganic filler based on the resin composition.
This is a sealing resin composition characterized in that it is blended in a weight percent.

The epoxy resin (A) used in the present invention is not particularly limited in molecular structure, molecular weight, etc., as long as it is a compound having at least two epoxy groups in its molecule, and may broadly include commonly used ones. I can do it. Examples include aromatic resins such as bisphenol type, alicyclic resins such as cyclohexane M conductor, and epoxy novolak resins represented by the following general formula.

(In the formula, R1 represents a hydrogen atom, a halogen atom, or an alkyl group, R2 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 of two or more. You can also do it.

The (B) novolak type phenol resin used in the present invention includes a novolak type phenol resin obtained by reacting phenols such as phenol and alkylphenol with formaldehyde or var-laboraldehyde;
and modified resins thereof, such as epoxidized or butylated novolak type phenolic resins. The blending ratio of the novolak type phenolic resin is determined by the molar ratio of the epoxy I (a) of the (A) epoxy resin and the phenolic hydroxyl group (b) of the novolak type phenol resin (B) (
It is preferable that a/b) is within the range of 0.1 to 10. If the molar ratio 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 limited to the above range.

The compound (C) used in the present invention having one or more azo groups in its molecule is not particularly limited in molecular structure, molecular weight, etc., as long as it has one or more azo groups in its molecule, and is as follows: Compounds such as:

This compound is preferably one that does not contain a halogen atom such as chlorine or bromine in its molecule. The compounding ratio of the compound having one or more azo groups in the molecule is 0.00% of the resin composition.
The content is preferably 01 to 10% by weight. Blend amount is 0
．． If it is less than 0.01% by weight, it has no effect on laser mark properties,
If it exceeds 10% by weight, bulk will increase and moldability will be poor, making it unsuitable for practical use.

Furthermore, as the inorganic filler (D) used in the present invention,
Silica powder, alumina, antimony trioxide, talc, calcium carbonate, titanium white, clay, asbestos,
Examples include mica, red iron oxide, glass fiber, carbon iim, etc., and silica powder and alumina are particularly preferred. The blending ratio of the inorganic filler is 25 to 90% by weight of the resin composition.
It is preferable that If it is less than 25% by weight, it will have an effect on moisture resistance, heat resistance, mechanical properties, and moldability.
If it exceeds 0% by weight, bulk will increase and moldability will be poor, making it unsuitable for practical use.

The sealing resin composition of the present invention contains an epoxy resin, a novolac type phenol resin, a compound having an azo group, and an inorganic filler as essential components, and may optionally contain, for example, natural waxes and metal salts of straight chain fatty acids.

Release agents such as acid amides, esters, or paraffins, flame retardants such as chlorinated paraffin, bromotoluene, hexabromobenzene, and antimony trioxide, colorants such as carbon black and red iron, silane coupling agents, etc. There is no problem even if they are added and blended as appropriate.

A general method for preparing the encapsulating resin composition of the present invention as a molding material includes an epoxy resin, a novolac type phenol resin, a compound having one or more azo groups in the molecule, an inorganic filler, After mixing the other raw materials in a predetermined composition ratio sufficiently uniformly using a mixer, etc., they are further melted and mixed using heated rolls or mixed using a kneader, etc., and then cooled to solidify and pulverized to an appropriate size. A molding material can be obtained.

When the encapsulating resin composition according to the present invention is applied to encapsulating, coating, insulating, etc. electronic components and electrical components, excellent characteristics and reliability can be imparted.

[Effects of the Invention] The encapsulating resin composition of the present invention has good moisture resistance, good mechanical properties, high heat resistance, excellent laser mark properties, and good molding workability. Therefore, sufficient reliability can be obtained when used for sealing electronic and electrical components.

[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 the following Examples and Comparative Examples, "%" is replaced by "-"
% by weight.

Example 1 Talesol novolak epoxy resin (1i per epoxy
215) 18%, novolak type phenolic resin (phenol equivalent: 107%, 12%, and 69% silica powder were mixed at room temperature, and 90~
After kneading and cooling at 95°C, the mixture was pulverized to obtain 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. This molded product was tested for laser mark resistance, moisture resistance, and mechanical strength, and the results were evaluated in the first stage.
Shown in the table.

Example 2 Cresol novolac epoxy resin (epoxy equivalent weight 21
5) 16%, 13.5% of novolac type phenol resin (phenol equivalent: 107), 0.5%, and 70% of silica powder were used as a molding material in the same manner as in Example 1, and a molded article was obtained in the same manner.

The obtained molded article was tested for various properties similar to those in Example 1, and the results are shown in Table 1.

Comparative Example Cresol novolak epoxy resin (epoxy m2
15) 20% novolac type phenolic resin (phenol 11i 107) 10%, and silica powder 1
A molding material was obtained in the same manner as in Example 1, and a molded article was made using it. The properties of the obtained molded articles were similarly tested and are shown in Table 1.

Table 1 * 1 Embed a 25X 25X 3III11 copper plate on the bottom of a 30X 25X 5ml1 molded product, -
Place in constant temperature baths at 40℃ and +200℃ for 30 minutes each.
Resin cracks after 5 cycles were investigated.

*2 An electrical component having two aluminum wirings was transfer-molded at 170°C for 3 minutes using the sealing resin composition, and then cured at 180°C for 8 hours. The 100 sealed electrical components thus obtained were subjected to a moisture resistance test in high-pressure steam at 120° C., and the time required for 50% disconnection (defect occurrence) due to aluminum corrosion was evaluated.

*゛3 Using the sealing resin composition, an electrical component having two aluminum wirings was transfer-molded at 170°C for 3 minutes, and then cured at 180°C for 8 hours. A laser mark was made using a CO2 laser on the 100 sealed electrical components thus obtained, and the sharpness was visually evaluated.

It can be seen that the examples of the present invention have better laser mark properties than the comparative examples, and are not inferior in terms of moisture resistance and mechanical properties.

Claims (1)

[Claims] 1 (A) epoxy resin (B) novolac type phenol resin (C) compound having one or more azo groups in the molecule (D) an inorganic filler as an essential component; 0.01 to 10% by weight of the compound having at least 10 azo groups to the resin composition, and 25 to 90% of the inorganic filler to the resin composition.
A sealing resin composition characterized in that it is blended in a weight percent. 2 The molar ratio [(a)/(b)] between the epoxy group (a) of the epoxy resin and the phenolic hydroxyl group (b) of the novolac type phenolic resin is within the range of 0.1 to 10. A sealing resin composition according to claim 1.