JP2005146157A - Epoxy resin composition and hollow package for housing semiconductor element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an epoxy resin composition which has a sufficient moisture resistance and does not injure its resin flowability or its resin strength after curing; and a hollow package prepared by using the composition and used for housing a semiconductor element. <P>SOLUTION: The epoxy resin composition gives a cured resin having the following features: in an environment with a relative humidity of 100% at 121°C, the cured resin with a size of 50 mm × 50 mm × 1.5 mm has a saturated water absorption coefficient of 1 mass% or higher and the time from its dry state to its saturated water absorption state is 64 hours or longer. The composition contains at least one kind of epoxy resin selected from epoxy resins having a naphthalene ring structure and epoxy resins having a dicyclopentadiene structure, a curing agent composed of at least one kind of phenol resin selected from aralkylphenol resins, dicyclopentadiene type phenol resins, and naphthalene type phenol resins, a water-absorbing agent, and if necessary an inorganic filler. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an epoxy resin composition having low moisture permeability of a cured product and excellent mold moldability when producing parts, and particularly suitable for use as a hollow package for housing a semiconductor element, and the epoxy resin composition The present invention relates to a hollow package for housing a semiconductor element, manufactured in the above.

  It is known that a semiconductor element is greatly affected by changes in ambient temperature and humidity, or fine dust and dust, and its characteristics are deteriorated, and it is easily damaged due to mechanical vibration and impact. In order to protect the semiconductor element from these external factors, it is well known that the semiconductor element is sealed with a ceramic box or resin and used as a package.

  Among them, solid-state imaging devices such as CCD and CMOS, laser devices such as LD and PD, photodiode devices, etc. need a light path from the outside of the package. Like general LSI devices, The surroundings cannot be sealed with resin or ceramics. These semiconductor elements are generally packaged by being mounted in a hollow type package in which one side is opened, and then the open part is sealed with a transparent material such as glass.

  In manufacturing this hollow type package, the hermetic sealing method using metal or ceramics is essentially non-moisture permeable, but has disadvantages such as high manufacturing cost and poor dimensional accuracy. On the other hand, in the case of resin sealing, the manufacturing cost is relatively low and the dimensional accuracy is high, but the resin basically has a property of diffusing moisture, and gradually passes moisture over time, There has been a drawback that reliability of the semiconductor element is deteriorated or moisture permeated into the inside of the package maintaining airtightness causes the glass surface to dew and lose reliability (for example, Non-Patent Document 1, Non-Patent Document). 2 etc.).

  Until now, various devices have been made to use a resin in a hollow package. Among them, a technique for preventing water from entering the hollow interior by adding a hygroscopic material to the resin composition and adsorbing moisture penetrating through the resin has been proposed (for example, Patent Document 1, (See Patent Document 2 and Patent Document 3).

TECHNICICAL REPORT OF IEICE. ICD95-194 (1995-12) The Institute of Electronics, Information and Communication Engineers Nitto Technique Vol. 28, no. 2, Oct. 1990 p. 84-95 Japanese Patent No. 2750254 JP-A-6-49333 Japanese Patent Laid-Open No. 2001-220696

  Since all of these techniques add a hygroscopic material, the resin fluidity and the resin strength after curing may be adversely affected. For this reason, attempts have been made to minimize and improve impurities (for example, alkali metals) contained in the hygroscopic material and to optimize and improve the shape and particle size of the hygroscopic material, but have not yet reached a fundamental solution.

  For example, Japanese Patent Application Laid-Open No. 2001-220296 is characterized in that the porous silica is contained in an amount of 55% by mass or more of the entire epoxy resin composition in order to give a predetermined moisture resistance. When mixed with the porous silica, the release agent component (wax) in the resin composition is adsorbed to deteriorate the resin fluidity, or the coupling agent (silane coupling agent etc.) is adsorbed to the resin. There is a problem that the adhesive strength of the inorganic filler is weakened, and as a result, the resin strength after curing is lowered.

  Furthermore, if the package is relatively large, the amount of moisture-absorbing material to be added can be reduced due to the effect of the thickness of the package, and a decrease in resin fluidity and resin strength after curing can be prevented. With the demand for higher functionality and size reduction of electronic devices, the demand for miniaturization and thinning of hollow packages has become stricter, and moisture resistance performance has been demanded more than ever. For this reason, a larger amount of moisture-absorbing material must be contained, and satisfactory resin fluidity and resin strength after curing cannot be obtained.

  Accordingly, an object of the present invention is to provide an epoxy resin composition that has sufficient moisture resistance and does not impair resin flowability and resin strength after curing, and a hollow package for housing semiconductor elements using the same. .

  As a result of intensive studies, the present inventors have a specific saturated water absorption rate in a wet heat environment and a time required to reach a saturated water absorption state from a dry state (hereinafter, sometimes referred to as “saturated water absorption time”). The present invention has been completed by finding that the above problems can be solved by using an epoxy resin composition having a specific time or longer.

  That is, the epoxy resin composition of the present invention has a saturated water absorption of 1% by mass or more and a saturated water absorption time of a cured resin having a size of 50 mm × 50 mm × 1.5 mm in an environment of 121 ° C. and 100% relative humidity. Is 64 hours or more.

  Moreover, the epoxy resin composition which made the specific epoxy resin and the hardening | curing agent contain the water absorbing agent has the said characteristic, and if it was used, the said subject could be solved and it came to this invention.

That is, the epoxy resin composition of the present invention is characterized by containing an epoxy resin comprising the following (a), a curing agent comprising the following (b), a water-absorbing agent and, if necessary, an inorganic filler.
(A) at least one epoxy resin selected from either an epoxy resin having a naphthalene ring structure, an epoxy resin having a dicyclopentadiene structure, or both;
(B) Any one of aralkylphenol resin, dicyclopentadiene type phenol resin, naphthalene type phenol resin, or at least one phenol resin selected from two or more.

An epoxy resin composition containing a silica of the following (c) and containing the silica in an amount of 1% by mass or more and 50% by mass or less of the total amount of the epoxy resin composition is a preferred embodiment of the present invention.
(C) The density measured using 1-butanol as the medium is less than 2.1 g / cm ³ , the moisture absorption after 24 hours in an environment of 60 ° C. and 90% relative humidity is 3% by mass or more, and the average particle size Silica having a diameter of 0.1 μm or more and less than 3 μm.

An epoxy resin composition containing the porous carbon of the following (d) and containing the porous carbon in an amount of 2% by mass or more and 50% by mass or less of the total amount of the epoxy resin composition is preferable in the present invention. It is an aspect.
(D) Porous carbon having a specific surface area of 0.5 m ² / g or more and 30 m ² / g or less and an average particle diameter of 3 μm or more and 50 μm or less

  According to the present invention, there is provided a hollow package for housing a semiconductor element formed by using the epoxy resin composition.

  ADVANTAGE OF THE INVENTION According to this invention, the epoxy resin composition excellent in moisture resistance used for preparation of the hollow package for semiconductor element accommodation can be provided. Since the epoxy resin composition can realize the optimum water absorption amount and water absorption speed, it is not necessary to add a large amount of water absorbing agent as in the conventional case, and does not affect the resin fluidity and mechanical strength. By using the epoxy resin composition of the present invention, it is possible to produce a hollow package that is thinner than the conventional one, for example, a surface mount type (SON type, QFN type) hollow package.

  The epoxy resin composition excellent in moisture resistance and the hollow package obtained in the present invention are specifically described below.

  2. The epoxy resin composition of the present invention has a saturated water absorption of 1% by mass or more, preferably 1.0% by mass or more and 3.5% by mass or less, more preferably 1.3% by mass or more. 5% by weight or less, more preferably 1.5% by weight or more, and 3.5% by weight or less, and the time to reach saturation from the dry state is 64 hours or more, preferably 72 hours or more, more preferably It is characterized by being 80 hours or more.

  In the present invention, the cured resin refers to an epoxy resin composition that has been molded and cured, and the epoxy resin composition refers to an epoxy resin blended with an additive such as a curing agent using a hot roll or the like. In the kneaded product, the curing reaction is in an unreacted state or a partial reaction.

In the present invention, the saturated water absorption rate and the time to reach the saturated water absorption state from the dry state are measured as follows. The epoxy resin composition is molded into a 50 mm × 50 mm × 1.5 mm test piece under the conditions of a molding temperature of 160 ° C., a molding pressure of 1.5 MPa, an injection time of 30 seconds, and a curing time of 90 seconds. This is dried at 180 ° C. for 12 hours (this state is referred to as a dry state), and then the weight (W ₀ ) is measured. Next, it is placed in a commercially available pressure cooker tester and left in an environment of 121 ° C. and relative humidity of 100%. The weight is measured every 8 hours, and the time when the weight change becomes 0.02% or less is defined as the saturated water absorption state, the saturated water absorption time is obtained, and the saturated water absorption (%) is calculated from the weight W at that time as follows. Expressed by the formula.
{(W−W ₀ ) / W ₀ } × 100

  The cured resin that has once absorbed moisture can be dried by drying at 180 ° C. for 12 hours. This is apparent from the fact that there is no weight change when dried at 180 ° C. Further, a large-shaped cured resin can be measured and evaluated in the same manner by cutting it into a size of 50 mm × 50 mm × 1.5 mm.

  If the epoxy resin composition has a saturated water absorption rate and a saturated water absorption time in the above range, it takes a long time for water to penetrate into the package even if the hollow package formed using the epoxy resin composition is thin. Therefore, the moisture resistance performance is satisfactory.

The epoxy resin composition of the present invention preferably contains an epoxy resin comprising the following (a), a curing agent comprising the following (b), a water absorbing agent and, if necessary, an inorganic filler.
(A) at least one epoxy resin selected from either an epoxy resin having a naphthalene ring structure, an epoxy resin having a dicyclopentadiene structure, or both;
(B) Any one of aralkylphenol resin, dicyclopentadiene type phenol resin, naphthalene type phenol resin, or at least one phenol resin selected from two or more.

Specific examples of the epoxy resin (a) include NC-7000L (naphthalene type epoxy resin) manufactured by Nippon Kayaku Co., Ltd., ESN-165M (naphthol aralkyl type epoxy resin) manufactured by Tohto Kasei Co., Ltd., Dainippon Ink Co., Ltd. ) EPICLON HP-7200 (dicyclopentadiene type epoxy resin) and the like.
Specific examples of the phenol resin (b) include MILEX (aralkyl phenol resin) manufactured by Mitsui Chemicals, DPP-6095L (dicyclopentadiene type phenol resin) manufactured by Nippon Petrochemical Co., Ltd., SN manufactured by Tohto Kasei Co., Ltd. -180 (naphthalene type phenol resin).

  In addition, as a preferable mixing | blending ratio of the hardening | curing agent with respect to an epoxy resin, when an epoxy equivalent is set to E and a phenol equivalent is set to P, Preferably P is 0.5E or more, 1.5E or less, More preferably, P is 0.6E or more. 1.4E or less, and further P is preferably 0.7E or more and 1.2E or less.

  By selecting the epoxy resin (a) as the epoxy resin and selecting the phenol resin (b) as the curing agent, a low hygroscopic epoxy resin composition can be obtained, and a system in which a water absorbing agent is added to the composition In this case, the water absorption speed is not greatly increased. In addition, by including an epoxy resin composed of (a), a curing agent composed of (b), a water-absorbing agent and, if necessary, an inorganic filler, it has excellent moldability, fluidity and mechanical properties, and has a glass transition point. Since an epoxy resin composition having a high value can be obtained, it is suitable as a resin material for hollow packages. Further, if the epoxy resin has a naphthalene ring structure or a dicyclopentadiene ring structure, it has both desired low hygroscopicity and heat resistance. For example, a naphthol aralkyl type epoxy resin is preferably used.

  As long as the epoxy resin and the curing agent in the epoxy resin composition of the present invention contain the resins (a) and (b), the scope of the present invention is not impaired and other physical properties are not affected. Inside, other resin can also be contained. Examples of the other resin in this case include an epoxy resin such as an ortho cresol novolak type epoxy resin, a bisphenol type epoxy resin, a biphenol type epoxy resin, an aralkylphenol type epoxy resin, and a halogenated epoxy resin. Examples of the phenol resin include a cresol novolac type phenol resin, a bisphenol type phenol resin, a biphenol type phenol resin, and a halogenated phenol resin. Neither is limited to these examples.

In the epoxy resin composition of this invention, it is preferable that the water absorbing agent contains the following silica (c).
(C) The density measured using 1-butanol as the medium is less than 2.1 g / cm ³ , the moisture absorption after 24 hours in an environment of 60 ° C. and 90% relative humidity is 3% by mass or more, and the average particle size Silica having a diameter of 0.1 μm or more and less than 3 μm.
The addition amount of the silica (c) is 1% by mass or more and 50% by mass or less, more preferably 1% by mass or more and 40% by mass or less, and further 2% by mass or more and 30% by mass of the total amount of the epoxy resin composition. The following is preferable. Here, the measuring method of density, moisture absorption and average particle diameter measured using 1-butanol as a medium was the same as the method described in JP-A-6-49333.

Moreover, in the epoxy resin composition of this invention, it is preferable that the water absorbing agent contains the following porous wet carbon (d).
(D) Porous carbon having a specific surface area of 0.5 m ² / g or more and 30 m ² / g or less and an average particle diameter of 3 μm or more and 50 μm or less.
The addition amount of the porous carbon (d) is 2% by mass or more and 50% by mass or less, more preferably 2% by mass or more and 30% by mass or less, and further 2% by mass or more, 20% by mass of the total amount of the epoxy resin composition. It is preferable that it is below mass%. Here, the non-surface area was measured using a three-sample fully automatic gas adsorption amount measuring device Autosorb 3B type manufactured by Cantachrome, and using nitrogen as the adsorption gas. The average particle size was measured using a laser diffraction scattering method particle size distribution analyzer X-100 manufactured by Leeds & Notrup.

  (C) and (d) have hygroscopic performance and are suitable water-absorbing agents for achieving the object of the present invention. These have good wettability with an epoxy resin and a phenol resin, and hardly cause poor dispersion in the kneading process. Moreover, if a density, a moisture absorption rate, an average particle diameter, a specific surface area, and an addition amount are in said range, there will be no bad influence on fluidity | liquidity, mechanical strength, etc. as an epoxy resin composition. In addition, although the one where there are few impurities, such as alkali metals contained in these and alkaline earth metals, is so good, it is usually preferable that it is about 2 ppm or less.

  Further, the amount of silica (c) and / or porous carbon (d) added to the epoxy resin composition may be adjusted so that the saturated water absorption rate and the saturated water absorption time of the cured resin are within the above ranges. preferable. By increasing the addition amount of silica (c) and / or porous carbon (d), the moisture resistance of the epoxy resin composition can be increased. However, since the amount of water absorption increases at the same time, for example, during overheating after water absorption, In a mounting process using solder, a mounting process using solder flow or reflow, etc., the amount of water vapor generated due to high temperatures increases, resulting in inconveniences such as package breakage (reflow cracks). Moreover, the fluidity of the epoxy resin composition and the mechanical strength after curing are also adversely affected.

  In addition, other hygroscopic materials, for example, zeolite-based or titania-based hygroscopic materials, hygroscopic materials such as silica gel, metal oxides such as calcium oxide, and the like, within the range not affecting the properties of the present invention, Further addition to the epoxy resin composition is also possible.

  The epoxy resin composition of the present invention preferably has a molding shrinkage of 0.03% or more and 0.35% or less, more preferably 0.05% or more, 0.30% or less, and further 0.08% or more. It is preferable that it is 0.20% or less. By setting the molding shrinkage rate within the above range, a molded article having excellent mold releasability and excellent dimensional accuracy can be obtained. The molding shrinkage mentioned here refers to a value at a molding pressure and a molding temperature when a desired hollow package is manufactured. That is, the package shown in FIG. 1 and FIG. 2 is manufactured, and the curing shrinkage rate for the cavity is determined from the outer dimensions and the mold cavity size at that time, and this is the molding shrinkage rate. In order to make the molding shrinkage within the above range, an inorganic filler is usually blended and the blending amount is adjusted. In addition, it is possible to adjust the molding shrinkage rate by changing the kind and blending amount of the epoxy resin and phenol resin.

  In addition to the inorganic filler, the epoxy resin composition of the present invention may further contain a curing catalyst, a colorant, a release material, a coupling material, a stress reducing material, a flame retardant, and the like as long as the object of the present invention is not impaired. Can do. The inorganic filler affects the fluidity, moldability, shrinkage rate, water absorption rate, resin kneading property, and the like of the epoxy resin composition, and is added while adjusting the type, particle size, and addition amount according to the purpose. That is, according to the type and viscosity of the selected resin, the type, particle size, addition amount, and the like of the inorganic filler are adjusted so that the epoxy resin composition satisfies the molding shrinkage rate.

  As the inorganic filler, for example, inorganic substances such as silica other than silica (c) and alumina are preferable, and silica is particularly preferable. The average particle size of the inorganic filler is preferably 5 μm or more and 30 μm or less, more preferably 10 μm or more and 30 μm or less, and further preferably 15 μm or more and 30 μm or less. The addition amount of the inorganic filler is preferably 30% by mass or more and 80% by mass or less, more preferably 40% by mass or more and 78% by mass or less, and further 45% by mass or more and 75% by mass or less of the total amount of the epoxy resin composition. Is preferred. However, when using the said silica (c), it is preferable that the total amount of an inorganic filler and a silica (c) shall be 92 mass% or less of the epoxy resin composition whole quantity. These inorganic fillers preferably have a low uranium content in order to prevent malfunction of the semiconductor element.

  1 and 2 are cross-sectional views showing an example of a hollow package for housing a semiconductor element formed using the epoxy resin composition of the present invention. The hollow package for housing a semiconductor element was manufactured by transfer molding a tablet obtained by compressing the epoxy resin composition prepared as described above into a mold having a lead frame. Specifically, transfer molding is performed under the conditions of an injection pressure of 1.5 MPa, an injection time of 1 minute, a curing time of 1 minute, and a mold temperature of 160 ° C., and then the obtained molded body is post-cured in a 180 ° C. environment for 3 hours. A hollow package for semiconductor storage was obtained.

  In the illustrated hollow package, a moisture permeation prevention plate (for example, the one described in Japanese Patent No. 2539111) is shown. However, in order to prevent moisture permeation from the bottom surface of the package as much as possible, a metal plate is provided on the bottom surface portion. The moisture resistance can be further improved by inserting a moisture permeation preventive plate made of and having an island structure.

(Example 1)
An epoxy resin, a curing agent, an inorganic filler, a curing catalyst, and other additives were blended in the amounts shown in Table 1 (the unit of numerical values is parts by mass). This was heat-kneaded with a hot roll at 95 ° C., and then cooled and pulverized to obtain an epoxy resin composition (EX-1). Using the resulting epoxy resin composition, the hollow package shown in FIG. 1 (SOP (Small Outline Package) type) and the surface mount type hollow shown in FIG. A package (SON (Small Outline Non-Lead Package) type) was produced. The thinnest part of the package is a part (die attach part) on which a semiconductor element is mounted. This thickness was 0.8 mm for the SOP type and 0.3 mm for the SON type. As a metal frame to be used, CA194 alloy (copper alloy) was used.

  The molding conditions were 160 ° C. and 1.5 MPa, the injection time was 1 minute, and the curing time was 1 minute. The molding shrinkage of the outer shape of the package molded under these conditions is the same as that obtained by measuring the dimension of the mold cavity (this is Lm) using a three-dimensional measuring instrument XYZAX-GC1000D manufactured by Tokyo Seimitsu Co., Ltd. The dimension of the package to be measured (this is assumed to be Lt) was determined by the formula of (Lm−Lt) / Lm.

  After this package was dried at 180 ° C. for 6 hours, a sealant (World Lock No. 8723K8L, manufactured by Kyoritsu Chemical Industry Co., Ltd.) was applied to the lid adhering portion, and a 0.8 mm thick glass was pasted and sealed. Then, it was cured using UV light from a metal halide lamp (irradiation conditions were 100 mW for 30 seconds). This package was placed in a commercial pressure cooker tester and exposed for 2 hours in an environment of 121 ° C. and 100% relative humidity. After being removed from the tester and allowed to stand at room temperature for 15 minutes, the temperature was stabilized, and then the glass surface was pressed against a 100 ° C. hot plate for 10 seconds and then against a 23 ° C. Peltier cooling plate for 7 seconds. The glass surface was immediately confirmed, and it was visually examined whether or not moisture in the hollow portion was condensed (hereinafter, this test method is referred to as “fogging test”). This operation was repeated and the maximum time during which no condensation was observed was shown in the lower column of Table 1 as the fogging test result.

  Separately, the saturated water absorption rate and saturated water absorption time of the epoxy resin composition were measured, and the results are also shown in the lower column of Table 1.

In addition, the following were used for each raw material described in Table 1.
Naphthalene type epoxy resin: Nippon Kayaku Co., Ltd. NC-7000L,
Naphthol aralkyl epoxy resin: ESN-165M manufactured by Tohto Kasei Co., Ltd.
Dicyclopentadiene-type epoxy resin: EPICLON HP-7200 manufactured by Dainippon Ink Co., Ltd.
Orthocresol novolac type epoxy resin: EOCN-102S manufactured by Nippon Kayaku Co., Ltd.
Aralkylphenol resin: MILEX XLC-LL, manufactured by Mitsui Chemicals, Inc.
Dicyclopentadiene type phenolic resin: DPP-6095L manufactured by Nippon Petrochemical Co., Ltd.
Naphthalene type phenolic resin: SN-180 manufactured by Tohto Kasei Co., Ltd.
Phenol novolac resin: HF-3M manufactured by Meiwa Kasei Co., Ltd.
Brominated epoxy resin: Nippon Kayaku Co., Ltd. BREN-S,
Flame retardant: antimony trioxide (Nippon Seiko Co., Ltd. PATOX-M),
Low density spherical silica (silica (c)): density 1.83 g / cm ³ , moisture absorption 10.7% average particle size 1 μm,
Porous carbon (porous carbon (d)): specific surface area 4.5 m ² / g, average particle size 13.6 μm,
Fused silica: FB-820X (High purity spherical fused silica, average particle size 24 μm) manufactured by Denki Kagaku Kogyo Co., Ltd.
Curing catalyst: Shikoku Kasei Co., Ltd. Curazole (registered trademark) 2MZ (2-methylimidazole),
Colorant: Carbon black # 45 manufactured by Mitsubishi Chemical Corporation
Coupling agent: Shin-Etsu Chemical Co., Ltd. KBM-403,
Mold release agent: Carnauba wax.

(Example 2)
An epoxy resin composition (EX-2) was prepared in the same manner as in Example 1 except that a naphthol aralkyl type epoxy resin and a dicyclopentadiene type epoxy resin were used for the epoxy resin and a dicyclopentadiene type phenol resin was used for the phenol resin. did. A package was molded in the same manner as in Example 1, and a haze test was conducted. The results are shown in the lower column of Table 1. In addition, the results of measuring the saturated water absorption rate and the saturated water absorption time of the epoxy resin composition are shown in the lower column of Table 1.

(Example 3)
An epoxy resin composition (EX-3) was produced in the same manner as in Example 1 except that a naphthalene type phenol resin was used as the phenol resin. A package was molded in the same manner as in Example 1 and a haze test was performed. The results are shown in the lower column of Table 1. In addition, the results of measuring the saturated water absorption rate and the saturated water absorption time of the epoxy resin composition are shown in the lower column of Table 1.

Example 4
An epoxy resin composition (EX-4) was produced in the same manner as in Example 1 except that porous carbon was used as the hygroscopic material. A package was molded in the same manner as in Example 1 and a haze test was performed. The results are shown in the lower column of Table 1. In addition, the results of measuring the saturated water absorption rate and the saturated water absorption time of the epoxy resin composition are shown in the lower column of Table 1.

(Example 5)
An epoxy resin composition (EX-5) was produced in the same manner as in Example 1 except that the amount of low-density spherical silica added was 14.5% by mass. A package was molded in the same manner as in Example 1 and a haze test was performed. The results are shown in the lower column of Table 1. In addition, the results of measuring the saturated water absorption rate and the saturated water absorption time of the epoxy resin composition are shown in the lower column of Table 1.

(Comparative Example 1)
Ortho-cresol novolac epoxy was selected as the epoxy resin, phenol novolac was selected as the phenol resin, and an epoxy resin composition (EX-6) was prepared in the same manner as in Example 1. A package was molded in the same manner as in Example 1 and a haze test was performed. The results are shown in the lower column of Table 1. In addition, the results of measuring the saturated water absorption rate and the saturated water absorption time of the epoxy resin composition are shown in the lower column of Table 1.

(Comparative Example 2)
An epoxy resin composition (EX-7) was produced in the same manner as in Example 1 except that the amount of low-density spherical silica added was 0.7% by mass. A package was molded in the same manner as in Example 1, and a haze test was conducted. The results are shown in the lower column of Table 1. In addition, the results of measuring the saturated water absorption rate and the saturated water absorption time of the epoxy resin composition are shown in the lower column of Table 1.

(Comparative Example 3)
An epoxy resin composition (EX-8) was produced in the same manner as in Example 1 except that the amount of low-density spherical silica added was 5.5% by mass and the amount of fused silica added was 1000 parts by weight. A package was molded in the same manner as in Example 1 and a haze test was performed. The results are shown in the lower column of Table 1. In addition, the results of measuring the saturated water absorption rate and the saturated water absorption time of the epoxy resin composition are shown in the lower column of Table 1.

  To summarize the above results, the epoxy resin compositions of Examples 1 to 5 are all within the range of the saturated water absorption amount and the saturated water absorption time. As a result, the haze test results of 16 hours or more with the SOP type package of FIG. 1 and 8 hours or more with the thin SON type package of FIG. 2 were found, and it was found that the semiconductor package has good moisture resistance. The thinnest part of the package resin is the die attach part 3, and naturally, water enters the package most rapidly from this part. In particular, in the thin package of FIG. 2, since the resin portion was as thin as 0.3 mm, it was easy to permeate moisture, and it was revealed that the resin composition of the present invention showed good performance.

On the other hand, in Comparative Example 1, the saturated water absorption is sufficient at 1.9% by mass, but the saturated water absorption time is faster than in the Examples. Therefore, a package with a thick package resin as shown in FIG. 1 exhibits relatively high moisture resistance, but the thin package of FIG. 2 lacks moisture resistance.
Moreover, since the comparative example 2 has a low saturated water absorption rate, the moisture resistance was insufficient in the fog test.
In Comparative Example 3, the saturated water absorption time is fast. Therefore, it was found that the thin package as shown in FIG. 2 does not have sufficient moisture resistance.

  The epoxy resin composition of the present invention can be suitably used for, for example, a package for a laser element that requires the performance of preventing moisture from penetrating inside. In addition, since the package molded with the epoxy resin composition of the present invention has high molding flexibility, for example, a package using a lens barrel, a package with a focusing component, a substrate integrated package, etc. Production is also possible.

FIG. 3 is a schematic cross-sectional view of an SOP type package (a package size excluding a lead frame is 10.0 mm × 10.0 mm × 2.0 mm). It is a schematic sectional drawing of a SON type package (The package size except a lead frame is 10.0 mm x 10.0 mm x 1.0 mm).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Epoxy resin composition 2 Lead frame 3 Die attach part (the thinnest part in a package, 0.8 mm in FIG. 1, 0.3 mm in FIG. 2)
4 Moisture permeable prevention plate (island part)

Claims (5)

  Under an environment of 121 ° C. and a relative humidity of 100%, a cured resin having a size of 50 mm × 50 mm × 1.5 mm has a saturated water absorption of 1% by mass or more, and it takes 64 hours to reach a saturated water absorption state from a dry state. An epoxy resin composition characterized by the above. An epoxy resin composition comprising an epoxy resin comprising the following (a), a curing agent comprising the following (b), a water absorbing agent and, if necessary, an inorganic filler.
(A) at least one epoxy resin selected from an epoxy resin having a naphthalene ring structure and an epoxy resin having a dicyclopentadiene structure;
(B) At least one phenol resin selected from aralkyl phenol resins, dicyclopentadiene type phenol resins, and naphthalene type phenol resins. The epoxy resin composition according to claim 2, wherein the water-absorbing agent contains silica of the following (c), and the silica is contained in an amount of 1% by mass to 50% by mass of the total amount of the epoxy resin composition.
(C) The density measured using 1-butanol as the medium is less than 2.1 g / cm ³ , the moisture absorption after 24 hours in an environment of 60 ° C. and 90% relative humidity is 3% by mass or more, and the average particle size Silica having a diameter of 0.1 μm or more and less than 3 μm. The epoxy resin composition according to claim 2 or 3, wherein the water-absorbing agent contains porous carbon of the following (d), and the porous carbon is contained in an amount of 2% by mass to 50% by mass of the total amount of the epoxy resin composition. .
(D) Porous carbon having a specific surface area of 0.5 m ² / g or more and 30 m ² / g or less and an average particle diameter of 3 μm or more and 50 μm or less.   A hollow package for housing a semiconductor element formed by using the epoxy resin composition according to claim 1.

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