JPH10168283A - Epoxy resin molding material for sealing electronic component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a resin molding material which can give a cured product markedly reduced in water absorptivity and having on excellent heat resistance by mixing an epoxy resin with a curing agent being a compound having an active ester group, a cure accelerator and an inorganic filler. SOLUTION: This material comprises an epoxy resin (A) having at least two epoxy groups in the molecule and generally used for sealing electronic components, a curing agent being a compound (B) having at least one active ester group in the molecule, a cure accelerator (C) and 60-85vol.% inorganic filler. Component B is desirably a compound prepared by esterifying a polyhydric phenol such as a phenol novolac resin or a phenol addition polybutadiene resin and is used in an amount of 50-200 pts.wt. per 100 pts.wt. component A. Component C functions as a curing agent for an epoxy resin and is a pyridine homologue, imidazole or the like and is used in amount of 0.1-10 pts.wt., per 100 pts.wt., in total, components A and B and other curing agents.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an epoxy resin molding material for encapsulating electronic components, which is excellent in reflow crack resistance and is suitable as a molding material for encapsulating electronic components, particularly, plastic package ICs for surface mounting.

[0002]

2. Description of the Related Art Conventionally, epoxy resin molding materials having excellent electrical properties, moisture resistance, heat resistance, mechanical properties, and adhesiveness to inserts have been used as molding materials for sealing electronic components such as transistors and ICs. ing. Particularly, in the molding material for IC encapsulation, since high heat resistance is required, an epoxy resin molding material obtained by curing an O-cresol novolak type epoxy resin which is a polyfunctional epoxy resin with a phenol novolak resin which is a polyhydric phenol compound is used. Widely used.

In recent years, as the density of printed wiring boards has been increased, the package of electronic components has become the mainstream from the conventional pin insertion type to the surface mounting type. Furthermore, surface mount type IC
In order to increase the density and reduce the mounting height, packages have become smaller and thinner year by year, the occupied volume of elements in the package has become relatively large, and the thickness of the package has become very thin. I have.

In a conventional pin insertion type package,
The package was not directly exposed to high temperature because it was soldered from the back side of the wiring board after it was inserted into the wiring board. However, for surface mount ICs, after being temporarily fixed to the wiring board surface, a solder bath or solder reflow device was used. Etc., the package is directly exposed to the high soldering temperature. As a result, in the case of the surface mount type IC, when the IC package absorbs moisture, the moisture absorption expands rapidly at the time of soldering to cause a crack in the package, which is a major problem of the surface mount type IC. I have.

In order to prevent package cracking during solder reflow, there have been proposed methods of protecting the IC with moisture-proof packing and drying the IC sufficiently before mounting it on a wiring board. However, all of them have a problem that the cost is increased, and there has been a demand for the development of an epoxy resin molding material for surface mounting IC encapsulation having low moisture absorption and good crack resistance.

In order to meet this demand, the following proposals have been made to improve the hygroscopicity and crack resistance of an epoxy resin molding material for sealing electronic parts.

More specifically, an epoxy resin molding material containing a superabsorbent resin (see Japanese Patent Application Laid-Open No. 62-100522) and a product using a fluorine-containing phenol (see Japanese Patent Application Laid-Open No.
No. 118524), using highly alkylated epoxy resin and novolak resin (Japanese Patent Laid-Open No. 3-1).
No. 28918), those using a specific trifunctional phenol resin (see JP-A-3-243616),
Those using a highly hydrophobic curing agent such as cyclopentadienyl-modified novolak resin (see JP-A-4-139210).

Further, those using a naphthalene-modified epoxy resin and novolak resin (see JP-A-3-43412), those using an epoxy resin made of a naphthol polymer as a raw material (see JP-A-4-337314), A resin using a resin composition having a naphthalene structure introduced into a resin skeleton, such as a bisnaphthylmethane-type polyvalent epoxy resin (see Japanese Patent Application Laid-Open No. 4-337316), has also been proposed.

[0009]

However, as disclosed in Japanese Patent Application Laid-Open No. Sho 62-100522, when a highly water-absorbing resin is added to an epoxy resin molding material, the heat resistance of the epoxy resin molding material is reduced. There is a problem.

Further, those using highly alkylated epoxy resins and novolak resins disclosed in JP-A-3-128918 and those using fluorine-containing phenols disclosed in JP-A-1-118524. JP-A-3-243616, those using a specific trifunctional phenol resin, and JP-A-4-1392.
In the case of using a cyclopentadienyl-modified novolak resin or the like as a curing agent disclosed in Japanese Patent Application Laid-Open No. 10-210, although the hygroscopicity of a package is slightly improved by imparting hydrophobicity to an epoxy resin, cracking during solder reflow is difficult. Was not enough to prevent

Further, JP-A-3-43412, JP-A-4-337314 and JP-A-4-337316.
As disclosed in Japanese Patent Application Laid-Open Publication No. H10-209, even a composition in which a naphthalene structure is introduced into the resin skeleton of the composition is insufficient to prevent cracks during solder reflow.

The present invention has been made in view of such circumstances, and has been made to improve the hygroscopicity of an IC package without impairing the heat resistance of a conventional epoxy resin molding material, and to provide an electronic device that does not generate cracks during solder reflow. It is an object of the present invention to provide an epoxy resin molding material for sealing parts.

[0013]

Means for Solving the Problems The present inventors have conducted intensive studies in order to solve the above-mentioned problems, and as a result, when a compound having an active ester group is used as a curing agent for an epoxy resin, the obtained resin curing agent is hardened. It has been found that the water absorption of the product significantly decreases, and an epoxy resin having two or more epoxy groups in the molecule, a polyhydric phenol compound obtained by arylesterification of a phenolic hydroxyl group, and an inorganic filler are essential components. Invented an epoxy resin molding material for encapsulating electronic parts (Japanese Patent Application Laid-Open No. 7-53675).

By mixing a compound having a specific active ester group into an epoxy resin molding material for encapsulating an electronic component, the present inventors can obtain a cured resin having excellent water absorption properties and heat resistance. And found that the present invention was completed.

That is, the epoxy resin molding material for electronic component encapsulation of the present invention comprises: (A) an epoxy resin having two or more epoxy groups in one molecule; and (B) an epoxy resin in one molecule. (C) A curing accelerator (D) An epoxy resin for sealing electronic parts, comprising 60 to 85% by volume of an inorganic filler. A molding material is provided. Further, the present invention provides the above (A) to
An epoxy resin molding material for encapsulating electronic components, which comprises (E) a compound having two or more phenolic hydroxyl groups in one molecule in addition to (D).

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION (A) An epoxy resin having two or more epoxy groups in one molecule, which is used for the epoxy resin molding material for sealing electronic parts of the present invention, is generally used for sealing electronic parts. Epoxy resin can be used as it is. Specific examples of the epoxy resin (A) include a phenol novolak epoxy resin, a cresol novolak epoxy resin, a biphenyl epoxy resin, a naphthol-modified novolak epoxy resin, a bisphenol A epoxy resin, and a brominated bisphenol A epoxy resin. , A brominated phenol novolak type epoxy resin, a glycidylamine type epoxy resin made from a polyamine such as diaminodiphenylmethane, a triglycidyl isocyanurate type epoxy resin, and a mixture thereof. To obtain heat resistance, phenol novolak type epoxy resin with epoxy equivalent of 230 or less, cresol novolak type epoxy resin, biphenyl type epoxy resin, naphthol modified novolak type epoxy resin, bromination Scan phenol A type alone or a mixture of two or more epoxy resins and epoxy resin selected from a brominated phenol novolak type epoxy resin is preferable. Regarding the purity of the epoxy resin of the present invention, the smaller the amount of hydrolyzable chlorine causing corrosion of aluminum wiring on an element such as an IC, the better, and in order to obtain an epoxy resin molding material for sealing electronic parts having good moisture resistance. Has 500
It is preferably at most ppm, but is not particularly limited.

A feature of the present invention resides in that (B) a compound having one or more active ester groups in one molecule is used as a curing agent for an epoxy resin. The compound (B) of the present invention having one or more active ester groups in one molecule can be obtained by converting a compound having a phenolic hydroxyl group into an organic acid, an acid chloride, or a non-catalyst under a basic catalyst, an acid catalyst, or a non-catalyst.
It is obtained by acylation using any of acid anhydrides. For example, using a polyhydric phenol compound, an active ester group compound can be obtained by benzoylation with benzoyl chloride or acetylation with acetic anhydride.

The compounds used as raw materials for the active ester group compounds include, in addition to monomer compounds such as catechol, resorcin, hydroquinone, pyrogallol and bisphenols,
Condensed resins of phenols and aldehydes, phenol / aralkyl resins, polymers having a hydroxyphenyl group, and the like can be used.

Examples of the condensation resin of phenol and aldehyde used as the raw material of the active ester group compound include phenols such as phenol, cresol, xylenol, catechol, resorcin, bisphenol A, bisphenol F, α-naphthol, β- Resins obtained by condensing or co-condensing naphthols such as naphthol and dihydroxynaphthalene with aldehydes such as formaldehyde, acetaldehyde, propionaldehyde, benzaldehyde and saltyl aldehyde in the presence of an acidic catalyst. In addition, as phenol aralkyl resin,
Examples include a condensation resin of a phenol resin and dimethoxylated para-xylene, a dicyclopentazine-modified phenol resin, and a tetrahydroindene-modified phenol resin. Furthermore, examples of the polymer having a phenolic hydroxyl group include a paravinylphenol polymer and a phenol-added polybutadiene resin.

As the active ester group compound (B),
Compounds obtained by esterifying a polyhydric phenol compound such as a phenol novolak resin, a cresol novolak resin, a dicyclopentadiene-modified phenol resin, and a phenol-added polybutadiene resin are preferable. (B) 1
Specific examples of compounds having one or more active ester groups in the molecule include:

[0021]

Embedded image

Wherein R 1 and R 2 are hydrogen, halogen or a lower alkyl group, which may be the same or different, and R 3 is an alkyl group having 1 to 4 carbon atoms. And n and m represent positive integers), and a fatty acid esterified phenolic novolak resin represented by the formula: Specific examples include acetylated phenol novolak resin, propionylated phenol novolak resin, butyrylated phenol novolak resin, acetylated cresol novolak resin, propionylated cresol novolak resin, and butyrylated cresol novolak resin. As shown in (Chemical Formula 1), all of the phenolic hydroxyl groups may be left without being esterified, or a non-esterified polyhydric phenol compound may remain. These active ester group compounds are used alone or as a mixture.

The amount of the active ester group compound varies depending on the content of the ester group and the content of the phenolic hydroxyl group remaining without being esterified. That is, it is considered that the active ester group compound reacts with the epoxy group of the epoxy resin in both the arylate group and the remaining phenolic hydroxyl group, and the equivalent derived from the content of both is equivalent to the equivalent as the curing agent. Therefore, the compounding amount of the active ester group compound is preferably 0.6 to 1.4 equivalent ratio with respect to the epoxy equivalent of the epoxy resin, similarly to the case of the non-esterified polyhydric phenol compound. It is desirable to mix the active ester group compound in an amount of 50 to 200 parts by weight with respect to parts by weight. If the amount of the active ester group compound is 50 parts by weight or less or 200 parts by weight or more, it is difficult to obtain a cured product having sufficient strength and heat resistance.

Along with the active ester group compound, if necessary, a phenolic curing agent such as phenol novolak which has been conventionally used as a curing agent for epoxy resins, an amine curing agent such as diethylenetriamine or diaminodiphenylmethane, tetrahydrophthalic anhydride, etc. Acid anhydride-based curing agents, guanidine-based curing agents such as dicyandiamide, and guanamine-based curing agents such as benzoguanamine. However, in order to keep the water absorption of the resin low, the curing agent other than the active ester group compound is desirably 50 parts by weight or less based on 100 parts by weight of the epoxy resin.

In the epoxy resin molding material of the present invention, a curing accelerator (C) is used to promote the curing reaction between the active ester group compound and the epoxy resin and reduce the water absorption of the resin. Most of the curing accelerators conventionally used for the curing reaction between an epoxy resin and various curing agents also promote the curing reaction between the active ester group compound of the epoxy resin molding material of the present invention and the epoxy resin. Has been confirmed. Specific examples of such a curing accelerator include 1,8-diazabicyclo [5,4,0] undecene-7 and 1,5-diazabicyclo [4,3,0] -5.
Basic catalysts such as -nonene, pyridine, N-dimethylaminopyridine, 4-benzylpyridine, 2,5-dimethylpyrazine, pyridine homologs such as 4-methylpyrimidine,
Tertiary amines such as triethylenediamine, dimethylbenzylamine and tris (dimethylaminomethyl) phenol, imidazoles such as 1-methylimidazole, 2-methylimidazole, 2-phenylimidazole and 2-phenyl-4-methylimidazole, and derivatives thereof; Organic phosphines such as tributylphosphine, methyldiphenylphosphine and triphenylphosphine, methyldiphenylphosphonium tetraphenylborate, 2-ethyl-4-methylimidazole tetraphenylborate,
Examples thereof include tetraphenylboron salts such as N-methylmorpholine tetraphenylborate, tetraphenylphosphoniumethyltriphenylborate, and tetrabutylphosphonium tetrabutylborate, and phosphonium boron salts. Of these, 1,8-diazabicyclo [5,4,
0] One or a mixture of two or more curing accelerators selected from undecene 7, 1-methylimidazole, 2-methylimidazole and N-dimethylaminopyridine is preferred because of its high curing acceleration effect. The curing accelerator is used in an amount of 0.1 to 10.0 parts by weight based on 100 parts by weight of the total weight of the epoxy resin, the compound having an active esterified phenol group, and other curing agents.

The compound (E) having two or more phenolic hydroxyl groups in one molecule is a phenol novolak resin,
Polyhydric phenols such as cresol novolak resin, phenol or cresol-based trifunctional resin curing agent, resin curing agent by phenol and aralkyl ether polycondensate, and phenol resin curing agent having naphthalene skeleton or dicyclopentadiene skeleton are preferable. It is desirable that the amount of this compound be 0.6 to 1.4 equivalents in total with (B) based on the epoxy groups of the epoxy resin having two or more epoxy groups in one molecule of (A). If the amount is less than 0.6 equivalent relative to the epoxy group, the epoxy resin will not be completely cured, resulting in poor heat resistance, moisture resistance, and electrical properties. The hydroxyl group of the agent is present, and the electrical properties and moisture resistance are reduced.

In the epoxy resin molding material for sealing electronic parts of the present invention, (D) 60-
85% by volume of inorganic filler is used. As the inorganic filler, crystalline silica, fused silica, alumina, zircon,
Powders of calcium silicate, calcium carbonate, silicon carbide, silicon nitride, boron nitride, magnesia, zirconia, zircon, and the like, or spherical beads may be used, and one type or a mixture of plural types may be used. The blending amount of the filler is required to be 60 to 85% by volume in order to reduce the hygroscopicity and improve the strength, and preferably 68% by volume to 85% by volume. If the compounding amount of the filler exceeds 85% by volume, the fluidity is lost, which is not preferable as a molding material.

Other additives include liquid or solid silicone compounds, flexible agents such as telechelic rubber and thermoplastic elastomers, release agents such as higher fatty acids, metal salts of higher fatty acids and ester waxes, carbon black, etc. Colorant, epoxy silane, amino silane, ureido silane, vinyl silane, alkyl silane, organic titanate,
Coupling agents such as aluminum alcoholate and flame retardants can be used.

As a general method for producing the epoxy resin molding material for electronic component encapsulation of the present invention using the above-described raw materials, a predetermined amount of the raw materials is sufficiently mixed with a mixer or the like, and then mixed. A method of kneading using a mixing roll or an extruder, cooling, and pulverizing to obtain a molding material may be used.

As a method for sealing an electronic component using the epoxy resin molding material of the present invention, a low pressure transfer molding method is the most common, but an injection molding method or a compression molding method is also possible.

In the case of a usual reaction between a polyhydric phenol compound and an epoxy resin, a hydrophilic hydroxyl group is by-produced as the epoxy group is opened. However, when an active ester group compound reacts with the epoxy resin, It is thought that the acyl group of the active ester group compound reacts with the hydroxyl group together with the ring opening of the epoxy group to form an ester having low hydrophilicity. That is, the reason that the water absorption property of the epoxy resin cured product is improved by using the active ester group compound as the curing agent is different from the ordinary curing reaction between the epoxy resin and the polyhydric phenol,
It is presumed that since no hydroxyl group is generated, the hydrophilicity of the cured resin can be kept low.

Hereinafter, the present invention will be specifically described with reference to specific examples, but the present invention is not limited to these.

[0033]

【Example】

<Synthesis Example 1> 370 g of HP-850N (phenol novolak resin, trade name of Hitachi Chemical Co., Ltd.) was charged into a 5-liter four-necked flask equipped with a thermometer, a cooling pipe, a nitrogen introduction pipe, and a stirring rod. Methyl isobutyl ketone (MI
BK) 2 liters were added and dissolved by stirring under a nitrogen stream. Next, 429 g of acetic anhydride was added and the mixture was stirred until it became uniform, and then 5.7 g of sodium acetate anhydride was added to completely dissolve it. Thereafter, the temperature was raised in an oil bath, and the reaction was carried out at a reflux temperature for 4 hours.

After cooling, a 5% aqueous sodium hydrogen carbonate solution 1
Liters were added, and further neutralized by adding sodium hydrogen carbonate until the aqueous layer became neutral. After separating the aqueous layer, the product was sufficiently washed with distilled water and concentrated under reduced pressure to obtain a product.

1H-NMR spectrum of the obtained product (model: AC300P manufactured by Bruker, solvent: CDC13,
(Concentration: 10% by weight) is shown in FIG. According to FIG.
A signal of a methyl proton of an acetyl group was observed at 2.1 ppm. Further, the integral value and the aromatic ring proton (6.
9-7.2 ppm) and methylene protons (3.7-7.2 ppm).
(3.9 ppm) to the sum of the integrated values was 3: 5.
From the above, it was confirmed that the product was a phenol novolak resin in which phenolic hydroxyl groups were acetylated. The amount of the obtained acetylated phenol novolak resin (hereinafter referred to as APN) was 270 g.

<Synthesis Example 2> In Synthesis Example 1, HP-8
A synthesis reaction was carried out in the same manner as in Synthesis Example 1 except that 420 g of a cresol novolak resin (number average molecular weight = 1010) was used instead of 50N to obtain 515 g of an acetylated cresol novolak resin (hereinafter, referred to as ACN).

<Synthesis Example 3> A synthesis reaction was carried out in the same manner as in Synthesis Example 1 except that 550 g of propionic anhydride was used instead of acetic anhydride, and 505 g of propionylated phenol novolak resin (hereinafter referred to as PPN) was obtained. Obtained.

<Synthesis Example 4> In Synthesis Example 1, HP-8
Except that 475 g of PP-700-300 (phenol-added polybutadiene resin, trade name of Nippon Petrochemical Co., Ltd.) was used instead of 50N, and the blending amounts of acetic anhydride and sodium acetate were 185 g and 2.5 g, respectively. A synthesis reaction was carried out in the same manner as in Synthesis Example 1, and an acetylated phenol-added polybutadiene resin (hereinafter referred to as APP)
455 g were obtained.

<Synthesis Example 5> HP-85 in Synthesis Example 1
DPP-600 (dicyclopentadiene-modified phenol resin, trade name of Nippon Petrochemical Co., Ltd.) instead of 0N
A synthesis reaction was carried out in the same manner as in Synthesis Example 1 except that 425 g was used, and the blending amounts of acetic anhydride and sodium acetate were 305 g and 4.1 g, respectively, to obtain an acetylated dicyclopentadiene-modified phenol resin (ADP) 45.
0 g was obtained.

<Example 1> 80 parts (parts by weight, hereinafter the same) of ESCN195 (cresol novolak type epoxy resin, epoxy equivalent = 200, trade name of Sumitomo Chemical Co., Ltd.) as two or more epoxy resins in one molecule. ) And E
In 20 parts of SB-400 (brominated bisphenol A type epoxy resin, epoxy equivalent = 395, trade name, manufactured by Sumitomo Chemical Co., Ltd.), 65 parts of APN which is a compound having an active ester group of the present invention and N as a curing accelerator 1.3 parts of methylimidazole, 60% by volume of silica glass powder as an inorganic filler, and carnauba wax 2
Parts, 1 part of carbon black, and 2 parts of γ-glycidoxypropyltrimethoxysilane, and has a diameter of 254 mm.
(10 inches) using a heating roll at a temperature of 80 to 90
The mixture was kneaded at a temperature of 7 ° C. for 7 to 10 minutes to prepare an epoxy resin molding material.

Example 2 ESC was used as an epoxy resin.
N195 80 parts and ESB-400 20 parts, ACN 75 parts which is a compound having an active ester group of the present invention,
1.2 parts of dimethylaminopyridine as a curing accelerator,
An epoxy resin molding material was prepared under the same conditions as in Example 1 except that 60% by volume of quartz glass powder was added.

Example 3 ESC was used as an epoxy resin.
80 parts of N195 and 20 parts of BREN-S (brominated phenol novolak type epoxy resin, epoxy equivalent = 285, trade name of Nippon Kayaku Co., Ltd.), 85 parts of PPN which is a compound having an active ester group of the present invention, curing acceleration As an agent, 1.5 parts of 1,8-diazabicyclo [5,4,0] undecene-7, 60% by volume of quartz glass powder were added, and the other components were blended in the same manner as in Example 1 and the epoxy resin molding material was used under the same conditions. Was prepared.

<Example 4> As an epoxy resin, YX-
4000H (biphenyl type epoxy resin, epoxy equivalent = 195, trade name of Yuka Shell Epoxy Co., Ltd.) 80
Parts, 20 parts of BREN-S, 170 parts of APP which is a compound having an active ester group of the present invention, 1.2 parts of dimethylaminopyridine as a curing accelerator, quartz glass powder 6
8% by volume was added, and the other conditions were the same as in Example 1 to produce an epoxy resin molding material under the same conditions.

<Example 5> As an epoxy resin, YX-
80 parts of 4000H and 20 parts of ESB-400, ADP 95 which is a compound having an active ester group of the present invention.
Parts, 1.5 parts of 2-methylimidazole as a curing accelerator
Part, 68 volume% of quartz glass powder was added, and
And an epoxy resin molding material was prepared under the same conditions.

Example 6 An epoxy compound was prepared in the same manner as in Example 1 except that 44 parts of APN, a compound having an active ester group of the present invention, and 16 parts of phenol novolak resin HP-850N were used together as a curing agent. A resin molding material was produced.

<Comparative Example> In Example 1, HP-850N, a conventional phenol novolak resin, was used instead of APN, a compound having an active ester group of the present invention, for 48 hours.
Part, 1,8-diazabicyclo [5,4,0] undecene-7 instead of N-methylimidazole as a curing accelerator
Was used in the same manner as in Example 1 except that 1.5 parts was used.

The properties of the obtained epoxy resin molding material were evaluated by the following methods.

Spiral flow: Using a mold conforming to EMMI 1-66, 180 ° C., 90 seconds, 6.9 MP
The measurement was performed under the condition of a.

Glass transition temperature (Tg): A linear expansion curve was obtained using a thermomechanical analyzer (TMA) manufactured by Rigaku Denki Co., Ltd., and determined from the bending point.

High-temperature strength: Measured at 215 ° C. by a three-point bending test method in accordance with JIS K6911.

Water absorption: According to JIS K6911,
A disk having a diameter of 50 mm and a thickness of 3 mm is prepared,
Humidification was performed under the condition of 5% RH, and the change in weight was determined.

Table 1 shows the measurement results. From Table 1, the molding material according to the present invention (Example) shows fluidity (spiral flow) and heat resistance (glass transition temperature, high-temperature strength) equivalent to those of the conventional molding material (Comparative Example). It turns out that it is much lower than the molding material of the comparative example.

[0053]

Table 1----------------------------------------------------------------------------------------- 0.15 0.20 Example 2 45 150 12 0.12 0.14 0.19 Example 3 40 145 12 0.12 0.16 0.21 Example 4 39 140 11 0.10 0.12 0.15 Example 5 43 142 11 0.10 0.12 0.16 Example 6 40 150 12 0.15 0.19 0.25 Comparative example 39 150 12 0.18 0.23 0.33 ――――――――――――――――――――――――――――――― Note) A: Spiral flow (in), B: Glass transition temperature (° C) C: High temperature strength (MPa) ac: Water absorption (%) (a: 48 hours, b: 72 hours, c: 168 hours)

Further, an IC package is molded under the conditions of 180 ° C., 90 seconds, and 6.9 MPa.
After curing for a time, crack resistance during solder reflow and moisture resistance after solder reflow were evaluated by the following methods.

Crack resistance; A flat package (outer dimension: 19 × 14 × 2.0 mm) of 42 pins and an alloy lead having 8 × 10 × 0.4 mm elements mounted thereon was used as an evaluation IC. 85 ° C, 85% R
After humidification with H for a predetermined time, the mixture was heated for 90 seconds in a vapor phase reflow furnace at 215 ° C., and the presence or absence of occurrence of a package crack was determined by microscopic observation.

Moisture resistance after solder reflow: A 5 × 10 × 0.4 mm test element provided with an aluminum wiring having a width of 10 μm was mounted, and wire-bonded with a 25 μm gold wire.
A 50 mil, 28-pin outline package was used as an evaluation IC, and this package was used at 85 ° C. and 85% R.
H, humidified for 72 hours, and heated in a vapor phase reflow furnace at 215 ° C. for 90 seconds.
Humidification was performed for a predetermined time under the condition of 0% RH, and the occurrence of disconnection failure due to aluminum wiring corrosion was examined.

Table 2 shows the results of these tests. From Table 2, it can be seen that the molding material according to the present invention (Example) has significantly improved crack resistance during solder reflow and moisture resistance after solder reflow as compared with the conventional molding material (Comparative Example). I understand.

[0058]

Table 2: Crack resistance during reflow Moisture resistance after reflow------------------------------------ −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− 18h 24h 36h 48h 200h 400h 600h 800h 1000h −−−−−−− −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− Example 1 0/5 0/5 0/5 1/5 0/14 0/14 0/14 0/14 0/14 Example 2 0/5 0/5 0/5 1/5 0/14 0/14 0/14 0/14 0/14 Example 3 0/5 0/5 0 / 5 1/5 0/14 0/14 0/14 0/14 0/14 Example 4 0/5 0/5 0/5 0/5 0/14 0/14 0/14 0/14 0/14 Example 5 0/5 0/5 0/5 0/5 0/14 0/14 0/14 0/14 0/14 Example 6 0/5 0/5 0/5 1/5 0/14 0/14 0/14 0/14 0/14 Comparative example 0/5 1/5 3/5 5/5 0/14 0/14 3/14 6/14 7/14 ------------ -------------------------------------------------- --------- Note) Crack resistance during reflow: Humidification at 85 ° C and 85% RH, hold for the time shown in the table Displays the number of defects / number of tests. Moisture resistance after reflow: PCT (0.2 MPa, 121 ° C., 100% RH) and (number of defects / number of tests) after holding for the time shown in the table.

[0059]

As described above, the epoxy resin molding material for encapsulating electronic parts of the present invention has a lower water absorption than conventional molding materials, and has crack resistance during solder reflow and moisture resistance after solder reflow. It is good and is suitable as a molding material for encapsulating a plastic package IC for surface mounting.

[Brief description of the drawings]

FIG. 1 is a 1H-NMR spectrum of an active esterified phenol novolak resin (APN) showing one embodiment of the compound having an active ester group of the present invention.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Fumio Furusawa 48 Wadai, Tsukuba, Ibaraki Prefecture Within Tsukuba Development Laboratory, Hitachi Chemical Co., Ltd.

Claims (10)

[Claims] 1. The main component is (A) 2 in one molecule.
Epoxy resin having at least one epoxy group, (B) a compound having at least one active ester group in one molecule, (C)
An epoxy resin molding material for electronic component sealing, comprising: a curing accelerator; and (D) 60 to 85% by volume of an inorganic filler. 2. The main component (A) is 2 per molecule.
Epoxy resin having at least one epoxy group, (B) a compound having at least one active ester group in one molecule, (C)
A curing accelerator, (D) 60 to 85% by volume of an inorganic filler,
(E) An epoxy resin molding material for encapsulating electronic parts, which comprises a compound having two or more phenolic hydroxyl groups in one molecule. 3. The epoxy resin molding material for sealing electronic parts according to claim 1, wherein the compound (B) is a polyhydric phenol compound obtained by esterifying a phenolic hydroxyl group with a fatty acid. . 4. The epoxy resin molding material for sealing electronic parts according to claim 1, wherein the compound (B) is a polyhydric phenol compound in which a phenolic hydroxyl group is acetylated. 5. The epoxy resin molding material for electronic parts according to claim 3, wherein the polyhydric phenol compound is a phenol novolak resin. 6. The epoxy resin molding material for sealing electronic parts according to claim 3, wherein the polyhydric phenol compound is a cresol novolak resin. 7. The polyhydric phenol compound is a phenol-added polybutadiene resin.
Or the epoxy resin molding material for electronic component sealing according to claim 4. 8. The epoxy resin molding material for sealing electronic parts according to claim 3, wherein the polyhydric phenol compound is a dicyclopentadiene-modified phenol resin. 9. The epoxy resin having two or more epoxy groups in one molecule of (A) is a cresol novolak type epoxy resin, a biphenyl type epoxy resin, a naphthol-modified novolak type epoxy resin, a brominated bisphenol A type epoxy resin and The epoxy resin molding material for sealing electronic parts according to any one of claims 1 to 8, which is a single or a mixture of two or more brominated phenol novolak type epoxy resins. 10. The curing accelerator of (C) alone or selected from 1,8-diazabicyclo [5,4,0] undecene-7, 1-methylimidazole, 2-methylimidazole and N-dimethylaminopyridine. The epoxy resin molding material for sealing electronic parts according to claim 1, wherein the epoxy resin molding material is a mixture of at least one kind.