JP2007092002A - Epoxy resin composition, hollow package for semiconductor device and semiconductor part device by using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an epoxy resin composition excellent in molding property such as flowing property, curing property, etc., and reliability such as moisture resistance, etc., also a hollow package for a semiconductor device molded from the same and a semiconductor part device obtained by sealing the semiconductor element in the package. <P>SOLUTION: This epoxy resin composition contains an epoxy resin derived from cyanulic acid or isocyanulic acid as component (A), a phenol-based curing agent as component (B) and an inorganic filler as component (C). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an epoxy resin composition excellent in moldability such as fluidity and curability and reliability such as moisture resistance, a hollow package for a semiconductor device molded using the same, and a semiconductor element in the package. The present invention relates to a hermetically sealed semiconductor component device.

  Semiconductor elements such as transistors, ICs, and LSIs may be damaged by moisture or fine dust in the atmosphere, so they are conventionally used after being hermetically sealed with ceramic or resin sealed. However, in recent years, sealing using a resin has become the mainstream in terms of productivity and cost, and in particular, a sealing resin composition based on an epoxy resin has been widely used. . Epoxy resins have an excellent balance in various properties such as electrical properties, moisture resistance, heat resistance, mechanical properties, and adhesion to inserts among various resins.

  Solid-state image sensors such as CCDs and MOSs that require strict light transmission levels are also seeing a trend toward resin sealing. From conventional hermetic sealing with ceramics, hollow plastic packages are molded with epoxy resin, etc. A method of hermetically sealing the container after it has been accommodated has been spreading.

  Among the characteristics required for solid-state image sensor mounted packages such as CCD and MOS, preventing moisture from entering into the hollow package and preventing condensation inside the package, that is, the moisture resistance of the package is normal for the package. This is one of the most important characteristics for ensuring proper operation.

As a technique for improving package moisture resistance such as CCD and MOS, a technique of adding a specific amount of an inorganic moisture absorbent such as silica gel or zeolite to a resin composition (for example, Patent Document 1), a zeolite having a specific property is used as a resin composition (For example, Patent Document 2), a method for adding silica having specific properties to an epoxy resin composition (for example, Patent Document 3, Patent Document 4), an epoxy resin having a specific structure and a specific structure There are reports such as a technique (for example, Patent Document 5) of adding an inorganic moisture absorbent to a resin composition comprising a phenolic curing agent.
Japanese Patent No. 2750254 Japanese Patent No. 3410173 Japanese Patent No. 2846551 Japanese Patent No. 3119104 Japanese Patent No. 3022135

  However, inorganic hygroscopic agents with high hygroscopic performance often have a relatively large specific surface area, and if these are added in a large amount to obtain sufficient moisture resistance, moldability such as fluidity and curability is deteriorated. easy. On the other hand, if the addition of the inorganic moisture absorbent is made small in order to avoid deterioration of fluidity and curability, it becomes difficult to secure moisture resistance this time. The above method does not necessarily solve this dilemma.

  The present invention has been made in view of such circumstances, an epoxy resin composition excellent in moldability such as fluidity and curability, and reliability such as moisture resistance, and a hollow package for a semiconductor device molded thereby, and It is an object of the present invention to provide a semiconductor component device in which a semiconductor element is hermetically sealed in the package.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that the intended purpose can be achieved by adding an epoxy resin having a specific structure to the molding resin composition. The headline and the present invention were completed.

The present invention relates to the following.
1. An epoxy resin composition containing an epoxy resin derived from cyanuric acid or isocyanuric acid as the component (A), a phenolic curing agent as the component (B), and an inorganic filler as the component (C).
2. Item 2. The epoxy resin composition according to Item 1, wherein a part of the component (C) is an inorganic moisture absorbent.
3. Item 3. A hollow package for a semiconductor device formed by the epoxy resin composition according to Item 1 or 2.
4). Item 4. A semiconductor component device in which a semiconductor element is sealed in the hollow package for a semiconductor device according to Item 3.

  The epoxy resin composition according to the present invention is excellent in moldability such as fluidity and curability and reliability such as moisture resistance. Therefore, by producing a hollow package using such a resin composition, it is possible to give high reliability to an electronic component device equipped with a solid-state imaging device such as a CCD or MOS, and its industrial value is high.

Details of the present invention will be described below.
The epoxy resin composition according to the present invention includes (A) an epoxy resin having a specific structure, (B) a phenolic curing agent, and (C) an inorganic filler. The epoxy resin composition by this invention may contain various additives, such as a hardening accelerator, a mold release agent, a coupling agent, a flame retardant, as needed other than the said (A)-(C) component. Hereinafter, various components constituting the epoxy resin composition according to the present invention will be described in detail.

(A) Epoxy resin In the present invention, it is necessary to use an epoxy resin derived from cyanuric acid or isocyanuric acid in order to give the resin composition high moisture resistance (water absorption performance). Here, “epoxy resin derived from cyanuric acid or isocyanuric acid” means “epoxy group and functional group having reactivity with active hydrogen in cyanuric acid or isocyanuric acid in one molecule”. It refers to a compound or a mixture obtained by addition reaction between the contained compound and cyanuric acid or isocyanuric acid. Such an epoxy resin has relatively high hydrophilicity and exhibits excellent moisture absorption performance.

  “A compound containing both an epoxy group and a functional group reactive with active hydrogen in cyanuric acid or isocyanuric acid in one molecule” includes one molecule from the viewpoint of imparting high hydrophilicity to the epoxy resin. Among them, a compound having 15 or less carbon atoms is preferably used, a compound having 10 or less is more preferable, and a compound having 7 or less is particularly preferable. As examples of such compounds, mention may be made of epihalohydrins such as epichlorohydrin.

  As an example of an epoxy resin derived from cyanuric acid or isocyanuric acid, for example, tris (2,3-epoxypropyl) isocyanurate obtained by adding three molecules of epichlorohydrin to isocyanuric acid can be cited, and TEPIC-S (Nissan Chemical) Kogyo Co., Ltd. trade name) is available on the market.

In this invention, the epoxy resin induced | guided | derived from the said cyanuric acid or isocyanuric acid may be used independently, and you may use together and use the epoxy resin generally used for the epoxy resin composition for sealing. Examples of epoxy resins that can be used in combination include phenol novolac-type epoxy resins, orthocresol novolac-type epoxy resins, phenols, cresols, xylenol, resorcin, catechol, bisphenol A, bisphenol F and other phenols and / or α-naphthol Epoxylated novolak resin obtained by condensation or cocondensation of naphthols such as β-naphthol and dihydroxynaphthalene with compounds having an aldehyde group such as formaldehyde, acetaldehyde, propionaldehyde, benzaldehyde, salicylaldehyde in the presence of an acidic catalyst , Diglycidyl ethers such as bisphenol A, bisphenol F, bisphenol S, bisphenol A / D, diglycidyl of alkyl-substituted or unsubstituted biphenol Epoxy compounds such as phenol aralkyl resins, naphthol aralkyl resins, biphenyl aralkyl resins, etc. synthesized from diphenyl ether biphenyl type epoxy resins, phenols and / or naphthols and dimethoxyparaxylene or bis (methoxymethyl) biphenyl , Stilbene type epoxy resin, hydroquinone type epoxy resin, glycidyl ester type epoxy resin obtained by reaction of polybasic acid such as phthalic acid and dimer acid and epichlorohydrin, diaminodiphenylmethane, co-condensation resin of cyclopentadiene and phenols Dicyclopentadiene type epoxy resin, epoxy resin having naphthalene ring, triphenylmethane type epoxy resin, trimethylolpropane type epoxy resin, terpene-modified epoxy resin Xyresins, epoxy resins containing sulfur atoms, linear aliphatic epoxy resins obtained by oxidizing olefinic bonds with peracids such as peracetic acid, alicyclic epoxy resins, and these epoxy resins with silicone, acrylonitrile, butadiene, Examples thereof include an epoxy resin modified with isoprene-based rubber, polyamide-based resin, and the like.
In order to sufficiently obtain the effects of the present invention, the epoxy resin derived from cyanuric acid or isocyanuric acid is preferably 50% by weight or more of the entire epoxy resin composition, more preferably 60% by weight or more, It is particularly preferable that the content be 70% by weight or more.

(B) Phenol-based curing agent The phenol-based curing agent may be a phenol-based curing agent generally used in epoxy resin compositions for sealing, and may be used in combination of one or more of them. it can. Although not particularly limited, examples of the (B) phenolic curing agent that can be used in the present invention include phenols such as phenol, cresol, resorcin, catechol, bisphenol A, bisphenol F, phenylphenol, and aminophenol. Novolac type phenol resin and phenol obtained by condensation or cocondensation of naphthols such as α-naphthol, β-naphthol, dihydroxynaphthalene and the like and compounds having an aldehyde group such as formaldehyde, benzaldehyde, salicylaldehyde in the presence of an acidic catalyst Phenol / aralkyl resins, naphthol / aralkyl resins, biphenyl / aralkyl resins, etc. synthesized from naphthols and / or naphthols and dimethoxyparaxylene or bis (methoxymethyl) biphenyl Examples thereof include a rukyle type phenol resin, a dicyclopentadiene type phenol resin, a terpene-modified phenol resin, and a triphenylmethane type phenol resin. These resins may be used alone or in combination of two or more.

  Among the phenol resins exemplified above, from the viewpoint of water absorption performance, it is preferable to use a phenol / aralkyl resin, a naphthol novolak resin, a naphthol / aralkyl resin, a biphenyl / aralkyl resin, etc. alone or in combination. It is preferable that at least one of these be 50% by weight or more of the entire phenolic curing agent.

  The equivalent ratio of the (A) component epoxy resin to the (B) component phenolic curing agent (that is, the ratio of the number of epoxy groups in the epoxy resin / the number of phenolic hydroxyl groups in the curing agent) is not particularly limited. Absent. However, the equivalent ratio is preferably in the range of 0.5 to 2, more preferably in the range of 0.6 to 0.6 so that each component reacts without excess and deficiency and does not remain unreacted in the composition. A range of 1.5 is preferable.

(C) Inorganic filler In this invention, it is necessary to mix | blend (C) inorganic filler for linear expansion coefficient reduction, strength improvement, etc. Examples of inorganic fillers include fused silica, crystalline silica, synthetic silica, alumina, zircon, calcium silicate, calcium carbonate, potassium titanate, silicon carbide, silicon nitride, aluminum nitride, boron nitride, beryllia, zirconia, zircon, phosphor Examples include stellite, steatite, spinel, mullite, titania and other powders, or spherical beads, glass fibers, etc., which contain flame retardant effects such as aluminum hydroxide and magnesium hydroxide. May be. From the viewpoint of securing moldability such as fluidity and curability, it is preferable that at least a part of the component (C) is fused silica, crystalline silica, synthetic silica, or the like.

  The epoxy resin composition of the present invention can sufficiently exert its effect by containing the components (A) to (C), but a part of the component (C) is an inorganic moisture absorbent. In particular, it is possible to further improve the moisture resistance. Examples of the inorganic moisture absorbent include silica gel, zeolite, amorphous aluminosilicate, and the like.

In general, the amount of the inorganic hygroscopic agent added is preferably 50% by weight or less of the total component (C) from the viewpoint of securing moldability such as fluidity and curability, but the moisture absorption performance is further improved. Therefore, when blending more than 50% by weight of the total component (C), it is preferable to blend two or more inorganic moisture absorbents having different average particle sizes and specific surface areas, and the average particle size is 5 to 5%. It is more preferable to blend at least one inorganic moisture absorbent having a specific surface area of 20 μm and 3 to 30 m ² / g.

  In the present invention, “moisture resistance” required for a package using an epoxy resin composition is “a chip (main seal) in a high humidity environment (eg, 60 ° C./90%) for a long time (eg, 1000 h). “It is possible to guarantee the normal operation of the airtight seal with a stopper and glass or the like”. For that purpose, it is necessary that the sealing material itself has the ability to continue to absorb “a certain amount” of moisture over a long period of time (ability to prevent moisture from entering the package). Therefore, it is advantageous that the water absorption rate at a certain time and the “possible water absorption capacity (difference from the water absorption rate)” at that time are large.

  In the epoxy resin composition for sealing according to the present invention, in addition to the above components (A) to (C), known curing generally used for the epoxy resin composition for sealing for the purpose of improving productivity. An accelerator may be added. Although it does not specifically limit as a hardening accelerator, For example, organophosphorus compound type hardening accelerators, such as a triphenylphosphine and a tetraphenyl phosphonium tetraphenyl borate, 1,8- diazabicyclo [5.4.0] undecene. Examples include amine compound-based curing accelerators such as -7 and imidazole compound-based curing accelerators, and these may be used alone or in combination of two or more.

  In the present invention, for the purpose of enhancing the adhesion between the resin component and the inorganic filler, a known coupling agent generally used in an epoxy resin composition for sealing may be added. The coupling agent is not particularly limited. For example, various silane compounds such as epoxy silane, mercapto silane, amino silane, alkyl silane, ureido silane, and vinyl silane, titanium compounds, aluminum chelates, and aluminum / zirconium compounds. Compounds may be mentioned, and these may be used alone or in combination of two or more.

  In this invention, you may add the well-known mold release agent generally used for the epoxy resin composition for sealing for the purpose of smooth mold release from a shaping | molding die. The release agent is not particularly limited, and examples thereof include higher fatty acid waxes such as stearic acid and montanic acid, higher fatty acid ester waxes, higher fatty acid amide waxes, and polyethylene. You may use, or may use it in combination of 2 or more types.

In the present invention, in addition to the above components, carbon black, organic dyes, organic pigments, various colorants such as titanium oxide, various adhesion imparting agents such as imidazole, triazole, tetrazole, and triazine, NBR rubber, silicone rubber, and the like Add various additives such as low stress agent, brominated epoxy resin, antimony trioxide, organophosphorus flame retardant, nitrogen flame retardant etc. to epoxy resin composition for sealing as required Is possible. In addition, the additive which can be added is not limited to the above-mentioned illustration, Various additives well-known in this technical field may be used.

  The epoxy resin composition for sealing according to the present invention can be prepared by any method as long as various raw materials can be uniformly dispersed and mixed. As a general method, there can be mentioned a method in which raw materials having a predetermined blending amount are sufficiently mixed with a mixer or the like, then melt kneaded with a mixing roll, a kneader, an extruder or the like, then cooled and pulverized. In order to facilitate handling, the composition may be tableted with a size and weight suitable for the molding conditions.

  As a method for sealing a semiconductor element using the epoxy resin composition for sealing according to the present invention, a low-pressure transfer molding method is the most common, but other molding methods such as an injection molding method and a compression molding method are used. May be. When the sealing epoxy resin composition becomes liquid or paste at normal temperature, it is possible to apply a dispensing method, a casting method, a printing method, or the like.

EXAMPLES Hereinafter, although an Example demonstrates this invention more concretely, the scope of the present invention is not limited by a following example.
(Examples 1-9, Comparative Examples 1-8)
Hereinafter, various raw materials used in each example and each comparative example are shown.
(A) Epoxy resin Epoxy resin 1: Tris (2,3-epoxypropyl) isocyanurate (trade name “TEPIC-S” manufactured by Nissan Chemical Industries, Ltd.) having an epoxy equivalent of 100 and a melting point of 115 ° C.
Comparative epoxy resin 1: Biphenyl type epoxy resin having an epoxy equivalent of 192 and a melting point of 105 ° C. (trade name “Epicoat YX4000H” manufactured by Japan Epoxy Resin Co., Ltd.).
Comparative epoxy resin 2: Orthocresol novolak type epoxy resin having an epoxy equivalent of 200 and a melting point of 70 ° C. (trade name “EPICLON N500P” manufactured by Dainippon Ink and Chemicals, Inc.).
Comparative epoxy resin 3: a dicyclopentadiene type epoxy resin having an epoxy equivalent of 265 and a softening point of 60 ° C. (trade name “EPICLON HP-7200” manufactured by Dainippon Ink and Chemicals, Inc.).

(B) Curing agent Curing agent 1: Phenol novolac resin having a softening point of 85 ° C. and a hydroxyl group equivalent of 105 (product name “H-100” manufactured by Meiwa Kasei Co., Ltd.).
Curing agent 2: Phenol aralkyl resin having a softening point of 70 ° C. and a hydroxyl group equivalent of 175 (trade name “Mirex XL-225” manufactured by Mitsui Chemicals, Inc.).
Curing agent 3: Biphenyl aralkyl resin having a softening point of 67 ° C. and a hydroxyl group equivalent of 203 (trade name “MEH-7851” manufactured by Meiwa Kasei Co., Ltd.).
Curing agent 4: Triphenylmethane type phenol resin having a softening point of 83 ° C. and a hydroxyl equivalent weight of 103 (Maywa Kasei Co., Ltd., trade name “MEH-7500”).
Curing agent 5: a naphthol novolak resin having a softening point of 85 ° C. and a hydroxyl group equivalent of 180 (trade name “SN-170L” manufactured by Tohto Kasei Co., Ltd.).

(C) Inorganic filler C1 component: fused crushed silica having an average particle size of 15 μm and a specific surface area of 2.0 m ² / g (trade name “RD-8S” manufactured by Tatsumori Co., Ltd.).
C2 component: fused crushed silica having an average particle size of 5 μm and a specific surface area of 5.0 m ² / g (trade name “F-205” manufactured by Fukushima Ceramics Co., Ltd.).
C3 component: fused spherical silica having an average particle size of 12 μm and a specific surface area of 5.0 m ² / g (trade name “FB-105” manufactured by Denki Kagaku Kogyo Co., Ltd.).
C4 component: synthetic spherical silica having an average particle size of 0.5 μm and a specific surface area of 6.5 m ² / g (manufactured by Admatechs Co., Ltd., trade name “SO-25R”).
C5 component: silica gel having an average particle size of 3.5 μm and a specific surface area of 600 m ² / g (manufactured by Mizusawa Chemical Co., Ltd., trade name “S-200”).
C6 component: amorphous aluminosilicate having an average particle size of 10 μm and a specific surface area of 5 m ² / g (manufactured by Mizusawa Chemical Co., Ltd., trade name “AMT-100R”).

(Other additives)
Curing accelerator: triphenylphosphine.
Release agent: Oxidized polyethylene wax.
Coupling agent: γ-glycidoxypropyltrimethoxysilane (epoxysilane).
Colorant: Carbon black (trade name MA-100 manufactured by Mitsubishi Chemical Corporation).
Flame retardant: Brominated epoxy resin, antimony trioxide.

  The above-mentioned various raw materials are blended in parts by weight shown in the following Tables 1 and 2, respectively, and roll kneading is performed under conditions of a kneading temperature of 80 ° C. and a kneading time of 10 minutes, and Examples 1 to 9 and Comparative Examples 1 to 8 are used. The corresponding sealing epoxy resin composition was prepared.

Next, the prepared epoxy resin molding materials for sealing in Examples and Comparative Examples were evaluated by the following tests. The evaluation results are shown in Tables 3 and 4 below. The sealing epoxy resin composition was molded using a transfer molding machine under conditions of a mold temperature of 180 ° C., a molding pressure of 6.9 MPa, and a curing time of 90 seconds. Further, post-curing was performed at 175 ° C. for 6 hours.
(1) Spiral flow (indicator of fluidity / fillability)
The sealing epoxy resin composition was molded under the above conditions using a spiral flow measurement mold in accordance with EMMI-1-66, and the flow distance (cm) was determined.
(2) Hardness when heated Using a varis mold made by Mitomi Metal Co., Ltd. having a cull part with a diameter of 30 mm and a depth of 4 mm in the center, the epoxy resin molding material for sealing is 30 mm in diameter and thickness under the above conditions. Shore D of molded product (Cull part at the center of the mold) immediately after molding (immediately after removing the mold 5 seconds after the lower mold of the transfer press starts to open) Hardness was measured.
(3) Moisture resistance A test piece of φ50 × 3.0mmt is prepared, after post-curing, left in an 85 ° C / 85% RH environment, and after 500h after standing, the change in weight of the test piece after 1000h is measured. The water absorption was determined.
(Water absorption rate (%)) = (W ₁ −W ₀ ) × 100 / W ₀
(Wherein, _{W 0:} initial weight of the test piece, _{W 1:} Weight after standing of the test piece)
A resin composition having a large water absorption after standing for 500 hours and a large difference in water absorption after standing for 500 hours and after standing for 1000 hours was judged as a resin composition having excellent moisture resistance.

As is apparent from Tables 3 and 4, when the component (A) according to the present invention is not included (Comparative Examples 1 to 8), satisfactory results are obtained in either moisture resistance or moldability (curability). There wasn't. On the other hand, when (A) component by this invention, ie, the epoxy resin induced | guided | derived from cyanuric acid or isocyanuric acid is included (Examples 1-9), about any of moldability and moisture resistance, such as fluidity | liquidity and sclerosis | hardenability. It was found that when part of the component (C) was an inorganic moisture absorbent (Examples 8 and 9), the moisture resistance was particularly excellent.

Claims (4)

  An epoxy resin composition containing an epoxy resin derived from cyanuric acid or isocyanuric acid as the component (A), a phenolic curing agent as the component (B), and an inorganic filler as the component (C).   The epoxy resin composition according to claim 1, wherein a part of the component (C) is an inorganic moisture absorbent.   The hollow package for semiconductor devices shape | molded with the epoxy resin composition of Claim 1 or 2. A semiconductor component device, wherein a semiconductor element is sealed in the hollow package for a semiconductor device according to claim 3.