JP2010144016A - Epoxy resin composition for sealing optical semiconductor element, and optical semiconductor device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an epoxy resin composition for sealing an optical semiconductor element, which has both of excellent solder resistance and good mold releasability. <P>SOLUTION: The epoxy resin composition for sealing the optical semiconductor element contains (A) an epoxy resin, (B) a phenolic resin, (C) a curing accelerator and (D) a mold releasing agent consisting of the compound shown by general formula (1), wherein, A<SB>1</SB>is a hydrogen atom or R<SB>1</SB>COOH (R<SB>1</SB>: divalent organic group), COR<SB>2</SB>(R<SB>2</SB>: monovalent aliphatic group of 30 or less carbons); x is a positive number of 1-200; y is 0 or a positive number of 0.1-200; z is a positive number of 0.1-200; provided that above x, y and z each denotes an averaged value. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an epoxy resin composition for sealing an optical semiconductor element used for sealing various optical semiconductor elements (hereinafter also simply referred to as an “epoxy resin composition”) and an optical semiconductor element using the epoxy resin composition. The present invention relates to an optical semiconductor device.

  Conventionally, as a sealing material used for sealing various optical semiconductor elements such as a light receiving sensor, a light emitting diode (LED), and a charge coupled device (CCD), the cured product has transparency, moisture resistance and heat resistance. In general, epoxy resin compositions obtained by using an acid anhydride-based curing agent together with an epoxy resin are widely used.

  In recent years, however, the package of optical semiconductor elements has been reduced in size, and at the same time, the surface mounting form on the substrate has become mainstream, so that mounting by infrared (IR) reflow has been widely adopted. Therefore, since the temperature at the time of mounting to which the optical semiconductor device is exposed rises and becomes higher than the conventional one, a transparent sealing material having high heat resistance and the like is required. In some cases, a lead-free solder material may be used as the solder material. In this case, the melting point of the solder material further increases, so that the reflow temperature becomes higher.

For this reason, a premix that melts and mixes a biphenyl type epoxy resin and a phenol aralkyl resin and a curing accelerator are essential for the purpose of reducing the stress caused by the sealing resin generated during heating. It is proposed to use an epoxy resin composition (see Patent Document 1).
JP 2000-281868 A

  However, in order to improve solder resistance, including the epoxy resin composition as described above, a resin composition obtained by using an epoxy resin composition for encapsulating an optical semiconductor as a curing agent is used. This causes a problem that the cured product firmly adheres to the molding die. That is, in molding an optical semiconductor sealing epoxy resin composition using a molding die, the cured product of the obtained resin composition is firmly attached to the molding die. It becomes extremely difficult to remove from the mold.

  The present invention has been made in view of such circumstances, and has an epoxy resin composition for sealing an optical semiconductor element, which has excellent releasability while having excellent solder resistance, and the same. An object of the present invention is to provide an optical semiconductor device having high reliability.

In order to achieve the above object, the present invention provides a first epoxy resin composition for encapsulating an optical semiconductor element comprising the following (D) component together with the following (A) to (C) components: The gist.
(A) Epoxy resin.
(B) Phenolic resin.
(C) A curing accelerator.
(D) A mold release agent comprising a compound represented by the following general formula (1).

  Moreover, this invention makes the 2nd summary the optical semiconductor device formed by resin-sealing an optical semiconductor element using the said epoxy resin composition for optical semiconductor element sealing.

  In the above formula (1), the bonding mode of each structural unit x, y, z may be present in a block manner, continuously in the molecule, or randomly. That is, it may exist. Furthermore, the coupling order of the structural units of the repeating units x, y, z may be any coupling order, such as x, y, z, x, z, y, y, z, x. The order may be any of the following: y, x, z, z, x, y, z, y, x.

  That is, the present inventors have intensively studied to obtain a sealing material for an optical semiconductor element to which good releasability is imparted in addition to excellent transparency as well as good transparency. As a result, when a release agent [(D) component] composed of the compound represented by the general formula (1) is used as the release agent component, the action of the specific release agent [(D) component] As a result, it was found that excellent releasability as well as excellent solder resistance was imparted, and the present invention was achieved.

  Thus, the present invention comprises a release agent [(D) component] comprising a compound represented by the general formula (1) together with an epoxy resin [(A) component] and a phenol resin [(B) component]. It is the epoxy resin composition to contain. For this reason, it has the good releasability at the time of shaping | molding with the outstanding solder resistance. Therefore, a highly reliable optical semiconductor device can be obtained by sealing the optical semiconductor element with the epoxy resin composition.

  And as said phenol resin [(B) component], when the phenol resin represented by the said General formula (2) and the phenol resin represented by General formula (3) are used, sclerosis | hardenability essential as an epoxy resin composition Is obtained, and the solder resistance is further improved.

  The epoxy resin composition of the present invention is obtained using an epoxy resin (component A), a phenol resin (component B), a curing accelerator (component C), and a specific release agent (component D). Usually, it is used in the sealing material in the form of a liquid or powder, or a tablet obtained by tableting the powder.

  Examples of the epoxy resin (component A) include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, 4,4'-biphenylphenol type epoxy resin, tetramethylbisphenol A type epoxy resin, and dimethyl. Bisphenol A type epoxy resin, tetramethyl bisphenol F type epoxy resin, dimethyl bisphenol F type epoxy resin, tetramethyl bisphenol S type epoxy resin, dimethyl bisphenol S type epoxy resin, alicyclic epoxy resin, triglycidyl isocyanurates, hydantoin type Nitrogen-containing ring epoxy resins such as epoxy resins, hydrogenated bisphenol A type epoxy resins, aliphatic epoxy resins, glycidyl ether type epoxy resins, and low water absorption rate cured type Biphenyl type epoxy resin, dicyclo type epoxy resins, naphthalene type epoxy resins. These may be used alone or in combination of two or more. Among the various epoxy resins, bisphenol A type epoxy resin, alicyclic epoxy resin, triglycidyl isocyanurates are preferable from the viewpoint that the cured product of the epoxy resin composition is less likely to discolor after sealing the optical semiconductor element. Is used.

  Furthermore, the epoxy resin composition of the present invention can be used in combination with other epoxy resins within a range that does not hinder physical properties. Specific examples of other epoxy resins include polyfunctional epoxy resins that are glycidyl ethers of polyphenol compounds, polyfunctional epoxy resins that are glycidyl ethers of various novolak resins, heterocyclic epoxy resins, and glycidyl ester epoxy resins. Glycidylamine epoxy resins, epoxy resins obtained by glycidylation of halogenated phenols, and the like. These may be used alone or in combination of two or more.

  Examples of the polyfunctional epoxy resin that is a glycidyl etherified product of the above polyphenol compound include other bisphenol A, bisphenol F, bisphenol S, 4,4'-biphenylphenol, tetramethylbisphenol A, dimethylbisphenol A, and tetramethylbisphenol F. , Dimethyl bisphenol F, tetramethyl bisphenol S, dimethyl bisphenol S, tetramethyl-4,4'-biphenol, dimethyl-4,4'-biphenylphenol, 1- (4-hydroxyphenyl) -2- [4- [1,1-bis- (4-hydroxyphenyl) ethyl] phenyl] propane, 2,2'-methylene-bis (4-methyl-6-tert-butylphenol), 4,4'-butylidene-bis (3- Methyl-6-te t-butylphenol), trishydroxyphenylmethane, resorcinol, hydroquinone, pyrogallol, phenols having a diisopropylidene skeleton, phenols having a fluorene skeleton such as 1,1-di-4-hydroxyphenylfluorene, phenolized polybutadiene, etc. Examples thereof include polyfunctional epoxy resins which are glycidyl etherified products of polyphenol compounds. These may be used alone or in combination of two or more.

  Examples of the polyfunctional epoxy resin that is a glycidyl etherified product of the above various novolak resins include various phenols such as phenol, cresol, ethylphenols, butylphenols, octylphenols, bisphenol A, bisphenol F, bisphenol S, and naphthols. Examples thereof include glycidyl etherified products of various novolak resins such as novolak resin, xylylene skeleton-containing phenol novolak resin, dicyclopentadiene skeleton-containing phenol novolak resin, biphenyl skeleton-containing phenol novolak resin, and fluorene skeleton-containing phenol novolak resin. These may be used alone or in combination of two or more.

  Examples of the alicyclic epoxy resin include alicyclic epoxy resins having an aliphatic skeleton such as cyclohexane such as 3,4-epoxycyclohexylmethyl-3 ′, 4′-cyclohexylcarboxylate. Examples of the aliphatic epoxy resins include 1,4-butanediol, 1,6-hexanediol, polyethylene glycol, polypropylene glycol, pentaerythritol, xylylene glycol derivatives and other glycidyl ethers of polyhydric alcohols. It is done. And as said heterocyclic epoxy resin, the heterocyclic epoxy resin etc. which have heterocyclic rings, such as an isocyanuric ring and a hydantoin ring, are mention | raise | lifted, for example. Examples of the glycidyl ester-based epoxy resin include epoxy resins composed of carboxylic acids such as hexahydrophthalic acid diglycidyl ester and tetrahydrophthalic acid diglycidyl ester. Examples of the glycidylamine epoxy resin include epoxy resins obtained by glycidylation of amines such as aniline, toluidine, p-phenylenediamine, m-phenylenediamine, diaminodiphenylmethane derivative, diaminomethylbenzene derivative and the like. Examples of the epoxy resin obtained by glycidylation of the halogenated phenols include, for example, brominated bisphenol A, brominated bisphenol F, brominated bisphenol S, brominated phenol novolak, brominated cresol novolak, chlorinated bisphenol S, and chlorinated bisphenol A. And epoxy resins obtained by glycidylation of halogenated phenols such as the above. These may be used alone or in combination of two or more.

  As the epoxy resin as described above, generally, an epoxy resin having a solid or viscous epoxy equivalent of 50 to 5000 and a softening point of 120 ° C. or lower is used.

  As a phenol resin (B component) used with the said A component, the phenol resin represented by the following general formula (2) and the phenol represented by the following general formula (3) from the point of improvement of solder resistance It is preferable to use at least one of the resins. These specific phenol resins may be used alone or in combination.

  In the above formula (2), the repeating number n is preferably 0 to 1. Moreover, in said formula (3), the repetition number m becomes like this. Preferably it is 0-3. And in these phenol resins, it is preferable to use the thing of the range of the hydroxyl equivalents 145-567.

  And in this invention, it is also possible to use another phenol resin together with the said specific phenol resin as a phenol resin component.

  Examples of the other phenol resins include bisphenol A, bisphenol F, bisphenol S, 4,4′-biphenylphenol, tetramethylbisphenol A, dimethylbisphenol A, tetramethylbisphenol F, dimethylbisphenol F, tetramethylbisphenol S, Dimethylbisphenol S, tetramethyl-4,4'-biphenol, dimethyl-4,4'-biphenylphenol, 1- (4-hydroxyphenyl) -2- [4- [1,1-bis- (4- Hydroxyphenyl) ethyl] phenyl] propane, 2,2'-methylene-bis (4-methyl-6-tert-butylphenol), 4,4'-butylidene-bis (3-methyl-6-tert-butylphenol), tris Hydroxyphenyl meta , Resorcinol, hydroquinone, pyrogallol, diisopropylidene, phenols having a terpene skeleton, phenols having a fluorene skeleton such as 1,1-di-4-hydroxyphenylfluorene, phenolized polybutadiene, phenol, cresols, ethylphenols , Novolak resins made from various phenols such as butylphenols, octylphenols, bisphenol A, bisphenol F, bisphenol S, naphthols, terpene diphenols, xylylene skeleton-containing phenol novolac resins, dicyclopentadiene skeleton-containing phenol novolac resins, Biphenyl skeleton-containing phenol novolak resin, fluorene skeleton-containing phenol novolak resin, furan skeleton-containing phenol novolak resin, etc. Various novolak resins. These may be used alone or in combination of two or more.

  And in this invention, you may use acid anhydrides together as a hardening | curing agent component with the phenol resin which is (B) component. As the acid anhydrides, for example, those having a molecular weight of about 140 to 200 are preferably used. Specifically, phthalic anhydride, maleic anhydride, trimellitic anhydride, pyromellitic anhydride, benzophenone tetracarboxylic anhydride , Aromatic glycolic anhydrides such as ethylene glycol trimellitic anhydride and biphenyltetracarboxylic anhydride, aliphatic carboxylic anhydrides such as azelaic acid, sebacic acid and dodecanedioic acid, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, Examples thereof include colorless or light yellow acid anhydrides such as methyl nadic anhydride, anhydrous nadic acid, glutaric anhydride, het anhydride, hymic anhydride, methyl hexahydrophthalic anhydride, methyl tetrahydrophthalic anhydride and the like. These may be used alone or in combination of two or more. Of the acid anhydrides, phthalic anhydride, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, and methylhexahydrophthalic anhydride are preferably used.

  In addition to the above acid anhydrides and phenol resins, conventionally known amine curing agents, those obtained by esterifying the above acid anhydrides with glycols, hexahydrophthalic acid, tetrahydrophthalic acid, methylhexahydrophthalic acid, etc. Curing agents such as carboxylic acids can be used. These may be used alone or in combination of two or more.

  The blending ratio of the epoxy resin (component A) and the phenol resin (component B) is such that the hydroxyl group equivalent in the phenol resin is acid anhydride as another curing agent component with respect to 1 equivalent of the epoxy group in the epoxy resin. When using things etc., it is preferable to add an acid anhydride equivalent to this and to set it so that it may become 0.5-1.5 equivalent. Most preferably, it is 0.8-1.2 equivalent. That is, in the above blending ratio, if the hydroxyl equivalent is small, the hue after curing of the resulting epoxy resin composition is deteriorated. Conversely, if the hydroxyl equivalent is large, the moisture resistance tends to decrease.

  Examples of the curing accelerator (C component) used together with the A component and the B component include 1,8-diazabicyclo [5.4.0] undecene-7, triethylenediamine, tri-2,4,6-dimethylamino. Tertiary amines such as methylphenol, imidazoles such as 2-ethyl-4-methylimidazole and 2-methylimidazole, triphenylphosphine, tetraphenylphosphonium / tetraphenylborate, tetra-n-butylphosphonium-o, o- Examples thereof include phosphorus compounds such as diethyl phosphorodithioate, quaternary ammonium salts, organometallic salts, and derivatives thereof. These may be used alone or in combination of two or more. Of these curing accelerators, tertiary amines, imidazoles, and phosphorus compounds are preferably used.

  And it is preferable to set content of the said hardening accelerator (C component) to 0.05-7.0 weight part with respect to 100 weight part of said epoxy resins (A component), More preferably, it is 0.2. -3.0 parts by weight. That is, if the content of the curing accelerator (component C) is too small, it is difficult to obtain a sufficient curing accelerating effect, and if it is too large, the resulting cured product may be discolored.

  As the specific release agent (D component) used together with the components A to C, a compound represented by the following general formula (1) is used.

In the above formula (1), the repetition number x is a positive number of 0.1 to 200, and the repetition number y is 0 or a positive number of 0.1 to 200. Moreover, the repetition number z is a positive number of 0.1-200. Further, A ₁ is a hydrogen atom, or R ₁ COOH, COR ₂ , R ₃ (R ₁ : a divalent organic group, R ₂ : a monovalent aliphatic group having 30 or less carbon atoms, R ₃ : a carbon number of 30 or less. Monovalent aliphatic group). Further, as described above, each structural unit of x, y, z, which is a repeating unit in formula (1), may exist in a block form in the molecule, or continuously. It may exist or may exist randomly. Furthermore, the coupling order of the structural units of the repeating units x, y, z may be any coupling order, such as x, y, z, x, z, y, y, z, x. The order may be any of the following: y, x, z, z, x, y, z, y, x. Note that the repetition numbers x, y, and z each represent an average value.

In the above formula (1), preferably, A ₁ is a hydrogen atom, the repetition number x is a positive number of 13 to 28, and the weight represented by the following formula in the y unit and the z unit in the formula (1). The ratio (%) is 35 to 85% by weight.

  In the present invention, in addition to the above specific release agent (component D), for example, a normal release agent such as montanic acid, stearic acid and its metal salt, and polyethylene carnauba wax may be used in combination. The amount used in this case is preferably set in a range that does not impair the light transmittance of the cured resin.

  The content of the specific release agent (component D) is preferably set to 0.01 to 15% by weight, particularly preferably 0.1 to 5% by weight, based on the entire epoxy resin composition. That is, if the content of the component D is too low, sufficient release properties tend to be difficult to obtain, and conversely if too high, compatibility tends to decrease and white turbidity tends to appear.

  Furthermore, in the epoxy resin composition of the present invention, in addition to the components A to D, as long as the physical properties such as light transmittance of the cured epoxy resin composition are not impaired, if necessary, for example, Various additives such as a dye, a flexibility imparting agent, a denaturing agent, a discoloration preventing agent, an antioxidant, a light stabilizer, and an adhesion imparting agent can be appropriately blended.

  The dye is not particularly limited and includes conventionally known ones.

  Examples of the flexibility-imparting agent include silicone-based flexibility imparting agents.

  Examples of the modifying agent include silicone-based modifying agents, glycols, and other polyhydric alcohols.

  Examples of the discoloration preventing agent include phosphorus organic compounds.

  Examples of the antioxidant include phenol compounds, amine compounds, phosphorus organic compounds, organic sulfur compounds, and the like.

  Examples of the light stabilizer include ultraviolet absorbers such as benzophenone compounds and light stabilizers such as HALS.

  Examples of the adhesion imparting agent include alkoxysilane coupling agents.

  In addition, when a light dispersibility is required, you may mix | blend a filler other than the said component. Examples of the filler include inorganic fillers such as quartz glass powder, talc, silica powder, alumina powder, and calcium carbonate.

  And the epoxy resin composition of this invention can be obtained as a tablet which formed the liquid, powder form, or tableted the powder by manufacturing as follows, for example. That is, in order to obtain a liquid epoxy resin composition, for example, various known additives such as the above-described components A to D and, if necessary, a deterioration inhibitor, a modifier, a release agent, a dye, a pigment, and a filler. May be appropriately blended at a predetermined ratio. In addition, in order to obtain a powder form or a tablet form in which the powder is tableted, for example, the above-described components are appropriately blended and premixed, and then this is dry blended or melt blended according to a conventional method. Can be appropriately mixed, kneaded, then cooled to room temperature, then subjected to a ripening step, pulverized by known means, and tableted as necessary. Next, the epoxy resin composition can be produced by cooling and pulverizing, and further compressing the powder as necessary.

  The epoxy resin composition of the present invention thus obtained is used as a sealing material for optical semiconductor elements such as a light receiving sensor, a light emitting diode (LED), and a charge coupled device (CCD). That is, using the epoxy resin composition of the present invention to seal an optical semiconductor element is not particularly limited, and can be performed by a known molding method such as ordinary transfer molding or casting. In addition, when the epoxy resin composition of the present invention is in a liquid state, at least the epoxy resin component and the curing agent component are stored separately and mixed immediately before use so-called two-component type. . In addition, when the epoxy resin composition of the present invention is in a powder form or a tablet form through a predetermined aging step, when the above-described components are melt-mixed, it is set as a B stage (semi-cured state). What is necessary is just to heat-melt at the time of use.

  And in the epoxy resin composition of the present invention, the cured product is suitably used in which the light transmittance at a wavelength of 650 nm is 70% or more at room temperature and a thickness of 1 mm as measured by a spectrophotometer, Particularly preferably, it is 80% or more. However, this does not apply to the light transmittance when the above-mentioned fillers and pigments are used. In the present invention, the room temperature means 25 ° C. ± 5 ° C.

  Next, examples will be described together with comparative examples. However, the present invention is not limited to these examples.

  First, each component shown below was prepared prior to the preparation of the epoxy resin composition.

〔Epoxy resin〕
Bisphenol A type epoxy resin (epoxy equivalent 186)

[Phenolic resin a]
Phenol resin represented by the general formula (2) [m = 0.6 in the formula (2), phenol biphenylene resin, hydroxyl group equivalent 203]

[Phenolic resin b]
Phenol resin represented by the general formula (3) [n = 0 in the formula (3), phenol-p-xylylene glycol dimethyl ether polycondensate, hydroxyl group equivalent 172]

[Curing accelerator]
2-ethyl-4-methylimidazole

〔Release agent〕
Compound represented by the general formula (1) [in the formula (1), x = 24.0 (average value), y = 0.0 (average value), z = 6.4 (average value), A ₁ = Hydrogen atom: Each structural unit x, y, z in formula (1) is block polymerization. ]

[Examples 1-9, Comparative Examples 1-3]
The components shown in Tables 1 and 2 below were blended in the proportions shown in the same table, melt kneaded (50 to 150 ° C.) with a mixing roll machine, aged, and then allowed to cool at room temperature (25 ° C.). The target powdery epoxy resin composition was produced by pulverizing later.

  Using the epoxy resin compositions of Examples and Comparative Examples thus obtained, various properties were evaluated according to the following methods. The results are also shown in Tables 1 and 2 below.

[Solder resistance]
Using each of the above epoxy resin compositions, an optical semiconductor element (SiN photodiode: 1.8 mm × 2.3 mm × thickness 0) is formed by transfer molding (molding at 150 ° C. for 4 minutes, post-curing at 150 ° C. for 3 hours) using a dedicated mold. .25 mm) was molded to produce a surface mount type optical semiconductor device. This surface-mount type optical semiconductor device has an 8-pin small outline package [SOP-8: 4.9 mm × 3.9 mm × thickness 1.5 mm, lead frame: 42 plated alloy layer (thickness) on the entire surface of the alloy alloy body. 0.5 μm)].

  Next, using the SOP-8 package, after performing moisture absorption treatment under a moisture absorption condition of 30 ° C./60 RH% × 192 hours, the package is subjected to infrared (IR) reflow, and the package itself is not peeled or cracked. The rate of occurrence was measured and evaluated individually. The case where the probability of occurrence of package peeling / crack is less than 0 to 34% is indicated as “◯”, the case where the probability of occurrence of package peeling / crack is less than 34 to 67% is indicated as Δ, and the probability of occurrence of package peeling / crack is 67% to 100%. The case of was displayed as x.

(Releasability)
Evaluation was performed by molding a package of SOP-8 by transfer molding (molding at 150 ° C. for 4 minutes) using the above-described dedicated mold. That is, after the mold surface was washed with a nonionic strong alkaline solution, two dummy shots with a mold habituation material were performed, and then each of the epoxy molds was used to make SOP-8 with the dedicated mold. The package was transfer molded (molded at 150 ° C. for 4 minutes). And mold release property was evaluated by operation required when taking out a molding (SOP-8 package) from a metallic mold. The evaluation is ○ when the release property is good, that is, release by air blow (air spray) only, △ when release is not complete by air spray alone but easy release by hand, and release is The case where it was extremely difficult was indicated as x.

  From the above results, each Example product containing a specific release agent was able to obtain better solder resistance and superior release properties than the Comparative Example product.

  On the other hand, the comparative product produced without blending a specific mold release agent showed good solder resistance but resulted in remarkably inferior mold release properties.

  Furthermore, by using each epoxy resin composition of the above example and transfer molding under the same molding conditions as above, a sample for light transmittance measurement (cured product having a thickness of 1 mm) was produced. This sample was immersed in liquid paraffin in a quartz cell, and the light transmittance at a wavelength of 650 nm was measured at room temperature (25 ° C.) with light scattering on the sample surface suppressed. Spectrophotometer (Shimadzu Corporation, UV3101) It measured using. As a result, the light transmittance of all the samples was 85% or more, and the high light transmittance was satisfied.

Claims (3)

The epoxy resin composition for optical semiconductor element sealing containing the following (D) component with the following (A)-(C) component.
(A) Epoxy resin.
(B) Phenolic resin.
(C) A curing accelerator.
(D) A mold release agent comprising a compound represented by the following general formula (1).

The optical semiconductor according to claim 1, wherein the phenol resin as the component (B) is at least one of a phenol resin represented by the following general formula (2) and a phenol resin represented by the following general formula (3). An epoxy resin composition for device encapsulation.

  An optical semiconductor device obtained by resin-sealing an optical semiconductor element using the epoxy resin composition for optical semiconductor element sealing according to claim 1.