JPH07216196A - Epoxy resin composition - Google Patents

Abstract

PURPOSE:To obtain an epoxy resin compsn. capable of forming a high-quality cure product excellent in low moisture permeability, by adding an inorg. water absorbent to a compsn. comprising an epoxy resin, a curing agent and an inorg. filler as the main components, and having a specific water diffusion coefficient of a cure product thereof. CONSTITUTION:This epoxy resin compsn. is prepd. by adding at least 1-wt.% inorg. water absorbent to an epoxy resin compsn. which comprises an epoxy resin, a curing agent and an inorg. filler as the main components, and a cure product of which, when 3mm in thickness, has a water diffusion coefficient of at most 1X10<-4>cm<2>/hr as measured under moistening conditions involving a temp. of 85 deg.C and an RH of 85%. The epoxy resin to be used is suitably a naphthalene skeleton-contg. epoxy resin. When an epoxy resin having a stiff naphthalene skeleton is used as the epoxy resin, there can be obtd. a cure product having a low expansion coefficient, a high glass transition temp., a low water absorption and a low water diffusion coefficient. When a naphthalene skeleton-contg. phenol resin is used as the curing agent, there can also be obtd. a cure product having a stiff main chain and hence a high heat resistance, a low water absroption and a low water diffusion cofficlent.

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 which has a low moisture permeability of a cured product and is suitable as a material for premolded hollow packages.

[0002]

2. Description of the Related Art Currently,
Plastics are used in various fields because they have various performances such as mass productivity, low cost, processability, and electrical insulation properties, and new plastics are born one after another with the development of synthetic chemistry. Regarding strength, which has been regarded as a drawback of plastics, its toughness has also been improved by the production of reinforced plastics by combining different kinds of plastics. In the future, plastics are expected to grow significantly not only as building materials and transportation packaging materials but also as structural materials.

Among various plastics, the epoxy resin has a well-balanced cured physical property, and is particularly excellent in moisture resistance and adhesiveness.
It can be used for a wide range of applications such as laminated plates, composite materials, adhesives, paints, and semiconductor encapsulants.

Among the above-mentioned uses, as the required characteristics of the semiconductor encapsulating material, it is the best means to suppress the water absorption of the package itself in order to improve the crack resistance against solder thermal shock after moisture absorption in the reliability test. Therefore, low water absorption is emphasized. Therefore, the epoxy resin composition generally used as a semiconductor encapsulant is better to be blended with a naphthalene skeleton-containing epoxy resin or a biphenyl skeleton-containing epoxy resin having a lower water absorption than the conventional orthocresol novolac type epoxy resin. It can be performance, and also
Similarly, as a curing agent, use an aralkyl skeleton-containing phenol resin, a dicyclopentadiene skeleton-containing phenol resin, or a terpene skeleton-containing phenol resin, which has a lower water absorption than the phenol novolac resin used in the conventional semiconductor encapsulant. Is valid.

Further, while metals and ceramics are essentially impermeable to moisture, plastics have various inherent moisture diffusion coefficients, and when exposed to humidifying conditions, they absorb water according to this diffusion coefficient. , Breathing moisture. Therefore, when using plastics for precision machines such as wristwatches and calculators, electronic parts such as semiconductor packages, especially for waterproof and airtight applications such as hollow packages for solid-state imaging device (CCD) encapsulation, The moisture vapor permeability of plastics is often a problem.
For example, when exposed to a hot and humid environment for a long time without being in direct contact with water, a plastic CCD hollow package gradually absorbs water, permeates moisture, and is saturated with water vapor in a space that maintains airtightness. If there is water in excess of the saturated water vapor amount obtained from the pressure, condensation occurs due to the aggregation of water,
The device becomes unusable.

Therefore, in the epoxy resin composition,
Improving moisture permeability is an issue.

The present invention has been made in view of the above circumstances,
An object of the present invention is to provide an epoxy resin composition that gives a high-quality cured product having excellent low moisture permeability.

[0008]

Means and Actions for Solving the Problems As a result of intensive studies for achieving the above-mentioned object, the present inventor has found that the epoxy resin, the curing agent and the inorganic filler are the main components, and the moisture diffusion coefficient of the cured product is By adding at least 1% by weight or more of an inorganic water-absorbing agent to an epoxy resin composition which is 1 × 10 ⁻⁴ cm ² / hr or less when a cured product has a thickness of 3 mm under humidified conditions of 85 ° C. and 85% RH, The inventors have found that an epoxy resin composition suitable for a pre-mold type hollow package material can be obtained by giving a cured product of low moisture permeability and high quality, and completed the present invention.

In this case, first of all, how to lower the moisture permeability of the cured product of the epoxy resin composition becomes a problem, but it is generally said that there is the following relationship between the water absorption rate and the moisture permeability. ing.

Moisture diffusion coefficient D (cm ² / hr) = q ² k ²
/2.266 ² Q ² t (established when q / Q <0.55) Moisture permeability K (mg · cm / cm ² · hr) = DQ _V = 10d
DQ Q: Saturated water absorption (wt%) q: Water absorption at time t (hr) (wt%) k: Sample thickness (cm) Q _V : Saturated water absorption (mg / cm ³ ) d: Sample density (g / Cm ³ )

From the above relationship, it is possible to lower the moisture permeability of the above-mentioned cured product by lowering at least one of the saturated water absorption rate and the diffusion coefficient. First, for example, as described above, the low water absorption rate is obtained. It can be said that it is effective to use an epoxy resin, for example, a naphthalene skeleton-containing epoxy resin, a biphenyl skeleton-containing epoxy resin and a low water-absorption curing agent, for example, a naphthalene skeleton-containing phenol resin, an aralkyl skeleton-containing phenol resin.

Next, as the constituent component of the epoxy resin composition, an inorganic filler is indispensable in addition to the epoxy resin and the curing agent. The inorganic filler lowers the expansion coefficient of the cured product to reduce stress. Although the main role is to achieve the water absorption, it is basically considered that the water absorption is almost zero. Therefore, as the amount of addition increases, the organic component decreases relatively, and the water absorption rate can also decrease. Therefore, it can be said that the addition amount of the inorganic filler needs to be adjusted.

From this point of view, in the present invention, in the curable epoxy resin composition containing the epoxy resin, the curing agent and the inorganic filler as the main components, the moisture diffusion coefficient of the cured product is 8
It was limited to 1 × 10 ⁻⁴ cm ² / hr or less when the thickness of the cured product was 3 mm under humidified conditions of 5 ° C. and 85% RH.

Further, merely using the above-mentioned curable epoxy resin composition having a small diffusion coefficient is not sufficient as a material for a hollow package, and further lowers the moisture permeability, so at least 1 part by weight of an inorganic water-absorbing agent is used. %, The moisture that permeates the cured product is adsorbed to suppress the moisture permeation speed. In addition to the inorganic water-absorbing agent, an organic water-absorbing resin can be considered as a water-absorbing agent, but the organic water-absorbing resin is unsuitable because it causes volume expansion simultaneously with water absorption.

As described above, according to the present invention, with respect to the epoxy resin composition which is essentially water permeable, the moisture permeability of the epoxy resin composition can be minimized by selecting and combining the components that can reduce the water diffusion coefficient of the cured product. In addition to suppressing to, by adding an inorganic water-absorbing agent, to trap the moisture permeation of the cured product, it is possible to dramatically improve the life of the hollow package formed of such an epoxy resin composition, It is possible to obtain a highly reliable premolded hollow package.

Therefore, according to the present invention, the epoxy resin, the curing agent and the inorganic filler are the main components, and the cured product has a moisture diffusion coefficient of 85 ° C. and a humidity of 85% RH.
In this case, at least 1% by weight or more of an inorganic water-absorbing agent is added to the epoxy resin composition of 1 × 10 ⁻⁴ cm ² / hr or less, to provide an epoxy resin composition.

The present invention will be described in more detail below. A naphthalene skeleton-containing epoxy resin is preferably used as the epoxy resin which is the first component of the epoxy resin composition of the present invention. When an epoxy resin having a rigid naphthalene skeleton is used as the epoxy resin, a cured product having a small expansion coefficient, a high glass transition temperature, low water absorption, and a small water diffusion coefficient can be obtained.

As the naphthalene skeleton-containing epoxy resin, those represented by the following formula are particularly preferable.

[0019]

[Chemical 5]

The epoxidized product of α-naphthol or α, β-naphthol in the naphthalene skeleton-containing epoxy resin is preferably 10% by weight or less, and more preferably 7% by weight or less from the viewpoint of heat resistance and moisture resistance. Is. In addition to this, the content of the binuclear body consisting of phenol alone and phenylglycidyl ether is preferably 0.5% by weight or less, more preferably 0.2% by weight or less.

The softening point of the naphthalene skeleton-containing epoxy resin is influenced by the content of the epoxidized products of α-naphthol and α, β-naphthol in the naphthalene skeleton-containing epoxy resin, but these epoxy resins have a softening point of 50 to 50. 12
Epoxy equivalent is 100-4 at 0 ° C, especially 70-110 ° C.
Those having 00 are desirable. When an epoxy resin having a softening point of less than 50 ° C. is used, not only the glass transition temperature of the cured product is lowered, but also burrs and voids are likely to occur during molding, and when the softening point exceeds 120 ° C., the viscosity is increased. It may become too high to be molded.

When these resins are used for semiconductor encapsulation, the content of hydrolyzable chlorine is 1000 ppm or less, especially 500.
It is preferable that the content of ppm or less and the content of sodium or potassium be 10 ppm or less. 1000ppm of hydrolyzable chlorine
When the semiconductor device is sealed with a resin whose sodium content exceeds 10 ppm or whose sodium and potassium content exceeds 10 ppm and the semiconductor device is left under high temperature and high humidity for a long time, the moisture resistance may deteriorate. An epoxy resin composition having excellent reliability can be obtained by selecting such an epoxy resin.

Specific examples of the naphthalene skeleton-containing epoxy resin include the following compounds.

[0024]

[Chemical 6]

In order to obtain a resin composition having extremely low water absorption and good adhesiveness, the content of naphthalene ring in the total of these epoxy resins is in the range of 5 to 80% by weight, particularly 10 to 60% by weight. It is desirable to adjust the content of the naphthalene skeleton-containing epoxy resin so that the content of the naphthalene ring is within this range.

Further, a biphenyl skeleton-containing epoxy resin is also preferably used as the epoxy resin, and by using the biphenyl skeleton-containing epoxy resin having a relatively low melt viscosity, excellent adhesiveness, good fluidity and low water absorption are obtained. It is possible to obtain a cured product having good properties and a small water diffusion coefficient.

As the biphenyl skeleton-containing epoxy resin, those represented by the following formula (II) are particularly preferable.

[0028]

[Chemical 7]

In this case, the substituent R ² in the above formula (II) is
Are hydrogen atom, halogen atom (for example, chlorine atom,
Bromine atom, fluorine atom, etc.) or a monovalent hydrocarbon group having 1 to 5 carbon atoms (eg, methyl group, ethyl group, propyl group, butyl group, pentyl group, etc.), and n is an integer of 0-5.

Specific examples of the biphenyl skeleton-containing epoxy resin of the above formula (II) include compounds having the following structures.

[0031]

[Chemical 8] (In the above formula, n ₁ = 0 to 5, n ₂ = 0 to 5, n ₁ + n ₂ = 0
~ 5. )

In the present invention, either one of the above naphthalene skeleton-containing epoxy resin and biphenyl skeleton-containing epoxy resin may be used alone, or both resins may be used together in an appropriate ratio.

Further, as the epoxy resin, another epoxy resin can be blended within a range not impairing the effects of the present invention. As the other epoxy resin, for example, an epoxy resin having at least two epoxy groups in one molecule is suitable, and specifically, bisphenol A type epoxy resin, phenol novolac type epoxy resin, triphenol alkane type epoxy resin. And its polymers, dicyclopentadiene-phenol novolac type epoxy resin, phenol aralkyl type epoxy resin, glycidyl ester type epoxy resin, alicyclic epoxy resin, heterocyclic type epoxy resin, brominated epoxy resin, bishydroxybiphenyl type epoxy resin Etc. are illustrated.

Next, as the second component curing agent, a naphthalene skeleton-containing phenol resin is suitable. By using the naphthalene skeleton-containing phenol resin, a rigid main chain has high heat resistance and low water absorption. A cured product having a small water diffusion coefficient can be obtained.

As the naphthalene skeleton-containing phenol resin, those represented by the following formula (III) are preferably used.

[0036]

[Chemical 9] (Wherein R ³ is an alkyl group having 1 to 10 carbon atoms, B is a hydroxyl group or a hydrogen atom, k is an integer of 0 to 5, q is an integer of 0 to 3, m is an integer of 0 to 2, and p is Indicates 1 or 2.
OH may be added to any ring of the naphthalene ring, or may be added to both rings at the same time. )

Specific examples of the naphthalene skeleton-containing phenol resin include the following compounds.

[0038]

[Chemical 10]

The above-mentioned phenol resin has a softening point of 6
Those having 0 to 150 ° C. are preferable, and those having 70 to 130 ° C. are more preferable. Hydroxyl equivalent is 90 to 2
50 is preferable. When using this phenol resin for semiconductor encapsulation, sodium and potassium are 10ppm
The following is preferable, and sodium and potassium are 1
When the semiconductor device is sealed with a resin exceeding 0 ppm and the semiconductor device is left under high temperature and high humidity for a long time, deterioration of moisture resistance may be accelerated.

Further, the aralkyl skeleton-containing phenol resin represented by the following formula (IV) can be preferably used as the curing agent, and the use of the aralkyl skeleton-containing phenol resin provides good fluidity, low water absorption and a water diffusion coefficient. It is possible to obtain a cured product having a small size.

[0041]

[Chemical 11] (However, in the formula, R ⁴ is an alkyl group having 1 to 10 carbon atoms or a hydrogen atom, m is an integer of 0 to 2, and r is an integer of 1 to 5.)

Specific examples of the aralkyl skeleton-containing phenol resin of the above formula (IV) include the following compounds.

[0043]

[Chemical 12]

In the present invention, one of the above naphthalene skeleton-containing phenol resin and the aralkyl skeleton-containing phenol resin may be used alone, or both resins may be used in an appropriate ratio.

Further, as a curing agent, another phenol resin or the like can be added within a range that does not impair the effects of the present invention. Examples of other phenolic resins include novolak type resins.

The compounding amount of the curing agent can be 20 to 90 parts, preferably 50 to 80 parts, relative to 100 parts (parts by weight, hereinafter the same) of the epoxy resin.

The inorganic filler is capable of reducing the expansion coefficient of the encapsulant and reducing the stress applied to the semiconductor element. Specifically, the fused silica having a crushed or spherical shape, Crystalline silica is mainly used, and in addition to this, alumina, silicon nitride, alumina nitride, and the like can also be used. In the present invention, in order to achieve both low expansion of the cured product and moldability, it is preferable to use a blend of spherical and crushed products or only spherical products as the inorganic filler.

The inorganic filler is preferably surface-treated with a silane coupling agent before use.

Further, as the inorganic filler, those having an average particle diameter of 5 to 30 μm are preferably used.

The blending amount of the inorganic filler is 200 to 120 with respect to 100 parts of the total amount of the epoxy resin and the total curing agent.
0 part is preferable, and if it is less than 200 parts, the expansion coefficient increases and the stress applied to the semiconductor element increases, which may lead to deterioration of the element characteristics. If it exceeds 1200 parts, the viscosity at the time of molding increases and molding There is a case where the sex becomes worse.

The epoxy resin composition of the present invention comprises the above-mentioned epoxy resin, a curing agent and an inorganic filler as main components, and the cured product has a moisture diffusion coefficient of 85 ° C. and a humidity of 85% RH. At that time, it is 1 × 10 ⁻⁴ cm ² / hr or less, preferably 1 × 10 ^{−5 to} 7 × 10 ⁻⁵ cm ² / hr, and it is possible to select each component so as to obtain this moisture diffusion coefficient. is necessary. The water diffusion coefficient is 1 × 10
^If it is larger than ^-4 cm ² / hr, it is out of the scope of the present invention to suppress the moisture permeability of the cured product to the minimum,
Even if the inorganic hygroscopic agent is added, the hollow package formed of the epoxy resin composition has a short life and is not suitable as a premolded hollow package which requires high reliability.

Further, the composition of the present invention contains an inorganic water absorbing agent as an essential component in addition to the above-mentioned main components. Examples of the inorganic water absorbing agent include molecular sieve, silica gel, porous silica, activated alumina and the like.

Here, the molecular sieve is usually used for a desiccant of an organic solvent, and is characterized in that the pore size distribution existing on the surface is sharp. The one having a pore size of 3Å is the one having a zeolite size of 3A, 4Å. Zeolite 4A, 5
Zeolite 5A for Å, Zeolite 1 for 9Å
The ones with 0X and 10Å are called zeolite 13X. An inorganic water-absorbing agent of the present invention has a suitable particle size distribution with respect to a powder which is a raw material of a usual pellet type molecular sieve.

Silica gel is generally used as a desiccant for packaging, but since the general type shows acidity due to the influence of the silanol hydroxyl group on the surface, it adversely affects the curability and storage stability of the epoxy resin composition. Therefore, silica gel having substantially neutral surface acidity and controlled particle size distribution and water absorption is suitable as the inorganic water absorbing agent of the present invention.

The porous silica has a specific surface area of 400.
It is preferably about 600 m ² / g, which is much larger than ordinary silica, and it is desirable to use a spherical powder in consideration of the fluidity of the epoxy resin composition. Activated alumina is
Amorphous alumina can be used as the inorganic water absorbing agent of the present invention.

The particle size distribution of the inorganic water-absorbing agent is preferably one having an average particle size of 1 to 20 μm, considering the range that does not impair the characteristics of the epoxy resin composition. In addition, when blending, it is necessary to regenerate at a regeneration temperature suitable for each hygroscopic agent before use. For example, molecular sieves are 200 to 300 ° C. for 2 to 8 hours, and silica gels are 1 to 1.
It is preferable to perform the treatment at 00 to 200 ° C. for about 1 to 4 hours.

Further, as the inorganic water-absorbing agent, one whose surface is treated with a hydrophilic surface treating agent may be used. Usually, the surface of the inorganic filler is treated with a hydrophobic surface treatment agent to improve the properties of the composition.
In the case of an inorganic water-absorbing agent, on the contrary, the effect that the surface repels permeated water is not preferable, and therefore a hydrophilic surface treatment agent is suitable.

As the hydrophilic surface treatment agent, for example, a hydrolyzate of tetraethoxysilane or the following compound is preferable. _{(CH 3 O) 3 Si (} CH 2) 3 OH H 2 N (CH 2) 2 NH (CH 2) 3 Si (OC 2 H 5) 3 H 2 N (CH 2) 3 Si (OC H 3) 3

The amount of the inorganic water absorbing agent used is at least 1% by weight or more, preferably 5% by weight, based on the entire composition.
The amount is 50% by weight or less. If the amount used is less than 1% by weight, the moisture permeability of the cured product cannot be sufficiently lowered, and if it exceeds 50% by weight, the fluidity of the epoxy resin composition may be reduced.

In addition to the above-mentioned essential components, it is preferable to add various conventionally known curing accelerators to the epoxy resin composition of the present invention. Examples of the curing accelerator include imidazole or its derivative, phosphine derivative, tertiary amine or its derivative, and the like. The addition amount of the curing accelerator can be a usual amount as long as the curing of the present invention is not hindered.

The epoxy resin composition of the present invention preferably contains a silicone-based flexibility-imparting agent in order to reduce stress. Examples of the flexibility-imparting agent include silicone rubber powder, silicone gel, block polymers of organic resin and silicone polymer, and the like. In addition,
Instead of adding such a flexibility-imparting agent, the surface of the inorganic filler may be treated with a two-pack type silicone rubber or silicone gel.

The amount of the flexibility-imparting agent used is preferably 0.5 to 10% by weight, more preferably 1 to 5% by weight, based on the whole composition. If the amount is less than 0.5% by weight. It may not give sufficient impact resistance, and if it exceeds 10% by weight, mechanical strength may become insufficient.

If desired, the epoxy resin composition of the present invention may further contain other optional components within a range that does not impair the effects of the present invention.

Examples of such optional components include various conventionally known thermoplastic resins, mold release agents such as carnauba wax, higher fatty acids and synthetic waxes, silane coupling agents, and brominated epoxy resins as flame retardants. Examples thereof include antimony oxide and phosphorus compounds.

As for the release agent, it is preferable to add a release agent having a good compatibility with the curable epoxy resin composition in the minimum amount as long as the moldability is not hindered. In a pre-mold type semiconductor device such as a CCD, for example, a step of mounting an element in the hollow portion and then adhering a glass lid after the epoxy resin composition is structurally formed is involved. If a large amount of a release agent that is incompatible with is added, the bleeding of the release agent on the package bonding surface makes it extremely difficult to bond the glass lid.For this reason, the package bonding surface can be burned with a hydrogen flame burner or ripped. This is because there is no choice but to add steps such as roughening. Therefore, as a mold release agent, higher fatty acids such as stearic acid amide, rather than incompatible carnauba wax,
Synthetic waxes such as polyethylene wax and montan wax are suitable.

When adding the releasing agent, the releasing agent is added to the organic component (various resins, etc.) of the epoxy resin composition,
It is preferable to pre-mix with a kneader or the like and sufficiently disperse it, and then add and mix the inorganic filler and the inorganic water-absorbing agent. By adding in this way, the releasing effect and the water-repellent effect can be improved.

In the production of the epoxy resin composition of the present invention, predetermined amounts of the above-mentioned components are uniformly stirred and mixed,
It can be obtained by a method such as kneading with a kneader, roll, extruder or the like which has been heated to 70 to 95 ° C. in advance, cooling and pulverizing. There is no particular limitation on the order of mixing the components.

As described above, the epoxy resin of the present invention can be suitably used as a premolded hollow package material.

Here, when pre-molding is performed, a molding method conventionally used, for example, transfer molding,
It can be performed by employing injection molding, casting method, or the like. In this case, the molding temperature of the epoxy resin composition is 150 to 180 ° C., and the post cure is 150 to 180 ° C.
It is preferable to carry out 2 to 16 hours.

[0070]

The epoxy resin composition of the present invention gives a cured product of high quality excellent in low moisture permeability and is suitable as a material for premolded hollow packages. Further, when the composition of the present invention is used as a premolded hollow package, the moisture permeability can be lowered, so that the range of use conditions can be expanded.

[0071]

EXAMPLES The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to the following examples. All parts are parts by weight.

Examples and Comparative Examples To the components shown in Tables 1 and 2, 1.5 parts of stearic acid amide as a mold release agent was added to 100 parts of the organic components, and after sufficiently kneading with a kneader, γ- Glycidoxypropyltrimethoxysilane 1.
5 parts, antimony trioxide 8.0 parts, carbon black 2.0 parts, and triphenylphosphine 0.8 parts were added, and the resulting blend was uniformly melt-kneaded with a hot double roll to obtain 13
Types of epoxy resin compositions (Examples 1-7, Comparative Examples 1-)
6) was produced.

The following various properties (a) to (f) of these epoxy resin compositions were measured. The results are shown in Tables 1 and 2.
Shown in. (A) Spiral flow Using a mold conforming to the EMMI standard, 175 ° C, 70
It was measured under the condition of kg / cm ² . (B) Mechanical strength (bending strength) 175 ° C., 70 kg / cm according to JIS K6911
^{2. A} bending bar of 10 × 100 × 4 mm was molded under the condition of molding time of 2 minutes, and post-cured at 180 ° C. for 4 hours for measurement. (C) Glass transition temperature, expansion coefficient 175 ° C., 70 kg / cm ² , molding time 2 minutes 4
It was measured by molding a test piece of × 4 × 15 mm, post-curing at 180 ° C. for 4 hours, and raising the temperature at 5 ° C./min with a dilatometer. (D) Saturated water absorption rate, moisture diffusion coefficient of 175 ° C., 70 kg / cm ² , and a molding time of 2 minutes to prepare a disk-shaped cured product having a diameter of 50 mm and a thickness of 3 mm, and
Post-cure for 4 hours at 0 ° C. This cured product is 85
Saturated water absorption was defined as the water absorption measured after being left to stand in an atmosphere of 85 ° C. and 85% RH for 500 hours to absorb water.

Further, the water absorption time at which the half saturated water absorption was obtained was measured, and the water diffusion coefficient was calculated by the following equation.

D = q ² k ² /2.266 ² Q ² t (q / Q
<Established at 0.55) When q = Q / 2 and k = 0.3 D = 4.382 × 10
^-3 / t [Q: saturated water absorption (% by weight), q: water absorption (% by weight) at time t (hour), k: sample thickness (cm)] (e) Moisture transmission start time 175 ° C, 70 kg / Cm ² , for a molding time of 2 minutes, a disk-shaped cured product having a diameter of 70 mm and a thickness of 0.5 mm is prepared,
Post cure was performed at 180 ° C. for 4 hours. This cured product was subjected to JIS Z0208 cup method at 40 ° C, 90
The moisture permeability was measured in an atmosphere of% RH. Immediately after the start of the measurement, only water absorption of the cured product occurred and moisture permeation did not occur, but after a certain period of time, it was observed that moisture permeation gradually started.
The time required for shifting from the water absorption to the moisture permeability was measured as the moisture permeability start time. (F) CCD moisture permeation reliability As shown in FIG. 1, the epoxy resin composition 1 was used as a hollow box type pre-molded package with a lead frame 2 interposed therebetween under the conditions of 175 ° C., 70 kg / cm ² , and a molding time of 2 minutes. After molding, post-curing was performed at 180 ° C. for 4 hours.
Next, after mounting the silicone chip 3 in the hollow portion, the bonding wire 4 was wired, and the transparent glass lid 5 was further adhered to the package with the epoxy resin adhesive 6 to obtain a measurement test body.

This hermetically sealed package was heated to 85 ° C.
It was left to stand in an atmosphere of 85% RH for 250 hours, and it was measured at room temperature whether or not dew condensation was observed on the inside of the glass lid. Those without dew condensation were expressed as OK, and those with dew condensation were expressed as NG. The following was used as each component.

[0077]

[Chemical 13]

[0078]

[Chemical 14]Molecular sieve: Zeolite 3A powder with an average particle size of 9.4 μm Silica gel: Powder of crushed silica gel with an average particle size of 6.0 μm Porous silica: Average particle size of 2.2 μm, specific surface area of about 500 m²/ G of Siri
Mosquito powder Surface-treated porous silica: Silane coupling agent (CH ₃
O) Si (CH₂)₃OH to the above-mentioned porous silica,
Surface-treated porous sili treated with addition of 1.0% by weight
Mosquito

[0079]

[Table 1]

[0080]

[Table 2]

The water diffusion coefficient of the curable epoxy resin used in the examples in the system containing no inorganic water absorbing agent was measured. The method for preparing the cured product test piece and the method for measuring the water diffusion coefficient are the same as those in (d) Saturated water absorption rate and water diffusion coefficient. Reference example

[0082]

[Table 3]

From the results of Tables 1 and 2, 85 ° C., 85% RH
The moisture diffusion coefficient of the cured product with a thickness of 3 mm is 1 in a humidified atmosphere.
The curable epoxy resin composition having a density of x10 ^-4 cm ² / hr or less and an inorganic water-absorbing agent added (Examples 1 to 3) is excellent in low moisture permeability and is an inorganic filler. It was found that when the content of the fused spherical silica was increased (Example 4) or the amount of the inorganic water absorbing agent added was increased (Example 5), the low moisture permeability was further improved. Further, the combined use of two kinds of inorganic water-absorbing agents (Example 6) is also effective depending on the humidified atmosphere conditions or the package shape, and the case where no silicone-based low stress agent is added (Example 7) has better low moisture permeability. It was also found that the addition of the inorganic water absorbing agent whose surface was treated with the hydrophilic silane coupling agent (Example 8) was more effective.

On the other hand, no addition of the inorganic water absorbing agent (Comparative Examples 1 to 4) does not result in low moisture permeability, and even if the inorganic water absorbing agent is added, the water diffusion coefficient of the cured product is 1 ×. 10
It was found that when it exceeds ⁻⁴ cm ² / hr (Comparative Examples 5 and 6), a desired low moisture permeability cannot be obtained.

The compositions of the present invention (Examples 1 to 8) were
The release agent, stearic acid amide, is pre-mixed with the curable epoxy resin so that the dispersed state is good, the release property at the time of molding of the cured product is good, it is also highly water repellent, and it has low moisture permeability. It was a thing.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a test body for measuring the moisture permeability reliability of a CCD.

[Explanation of symbols]

 1 Epoxy resin 2 Lead frame 3 Chip 4 Bonding wire 5 Glass lid 6 Epoxy adhesive

Front page continuation (72) Inventor Toshio Shiobara 1 Hitomi, Oita, Matsuida-cho, Usui-gun, Gunma 10 Shin-Etsu Chemical Co., Ltd. Silicone Electronic Materials Research Laboratory

Claims (2)

[Claims] 1. A cured product comprising an epoxy resin, a curing agent and an inorganic filler as main components and having a water diffusion coefficient of 85 ° C. and 85% R.
1 × 10 ^-4 c when the thickness of the cured product is 3 mm under H humidification condition
An epoxy resin composition, wherein an inorganic water-absorbing agent is added at least 1% by weight to an epoxy resin composition having m ² / hr or less. 2. An epoxy resin is represented by the following formula (I): A naphthalene skeleton-containing epoxy resin represented by and / or the following formula (II) (However, in the formula, R ² represents a hydrogen atom, a halogen atom or a monovalent hydrocarbon group having 1 to 5 carbon atoms, and n is an integer of 0 to 5.), which is a vinyl skeleton-containing epoxy resin.
The phenolic resin has the following formula (III): (Wherein R ³ is an alkyl group having 1 to 10 carbon atoms, B is a hydroxyl group or a hydrogen atom, k is an integer of 0 to 5, q is an integer of 0 to 3, m is an integer of 0 to 2, and p is Indicates 1 or 2.
OH may be added to any ring of the naphthalene ring, or may be added to both rings at the same time. ) A phenol resin containing a naphthalene ring skeleton and / or the following formula (IV): (However, in the formula, R ⁴ is an alkyl group having 1 to 10 carbon atoms or a hydrogen atom, m is an integer of 0 to 2, and r is an integer of 1 to 5.) The epoxy resin composition according to claim 1.