JP2781279B2 - Epoxy resin composition for encapsulating optical semiconductor elements - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

TECHNICAL FIELD The present invention relates to an epoxy resin composition for encapsulating an optical semiconductor element, which can be used as an encapsulating material having excellent releasability and transparency. BACKGROUND ART Conventionally, an epoxy resin composition has been used as a sealing material for an optical semiconductor element such as a light receiving element and a light emitting element from the viewpoint that transparency, moisture resistance and heat resistance must be excellent. However, the epoxy resin composition conventionally used is excellent in transparency, but when the optical semiconductor element and the epoxy resin composition are transferred and molded into an optical semiconductor device in a molding die, a molding die is formed. There is a problem that the mold releasability when taking out the optical semiconductor device from inside is significantly deteriorated. For this reason, the optical semiconductor device is deformed due to the stress at the time of release, cracks are generated in the package,
Various problems such as peeling of the optical semiconductor element and the sealing resin and peeling of the gold wire occur. The occurrence of such a problem becomes remarkable when various life tests of the optical semiconductor device are performed. However, in general, it is determined that the optical semiconductor device is malfunctioning before being subjected to the life test, and is separated as a defective product. . For this reason, it has been studied to add a known release agent to an epoxy resin composition as a sealing material in advance. Depending on the type of the release agent, the epoxy resin composition to which the release agent is added can produce a resin composition excellent in transparency, which is an important property of the resin composition for optical semiconductor element encapsulation. However, there has not been developed any material having both excellent transparency and releasability. Conversely, if a sealing resin composition having excellent releasability is produced by adding a release agent, there is a problem that transparency is deteriorated. As described above, an epoxy resin composition for encapsulation which is excellent in both transparency and releasability has not yet been obtained. The present invention has been made in view of such circumstances,
Excellent releasability from the mold during transfer molding,
Moreover, it is an object of the present invention to provide an epoxy resin composition for encapsulating an optical semiconductor element having excellent transparency. DISCLOSURE OF THE INVENTION In order to achieve the above object, the epoxy resin composition for encapsulating an optical semiconductor device of the present invention has a configuration containing the following components (A) to (C). (A) Epoxy resin. (B) a curing agent. (C) At least one of a compound represented by the following general formula (1) and a compound represented by the following general formula (2).

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That is, the present inventors have conducted a series of studies in order to obtain an epoxy resin composition for encapsulating an optical semiconductor element which is excellent in both transparency and releasability. Then, as a result of repeated studies using various compounds for the purpose of obtaining good releasability without impairing the transparency of the sealing resin, as a result of the general formula (1)
When at least one of the specific compound represented by the formula (1) and the specific compound represented by the general formula (2) [component (C)] is used, the optical semiconductor element sealing excellent in both the transparency and the releasability. The present inventors have found that the epoxy resin composition of the present invention can be obtained, and have reached the present invention. In particular, by setting the content of the component (C) in the range of 0.01 to 15% by weight (hereinafter abbreviated as “%”) of the entire epoxy resin composition for encapsulating an optical semiconductor element, the glass transition temperature or the moisture resistance can be improved. A sufficient releasability can be obtained by preventing a decrease in reliability. The epoxy resin composition for encapsulating an optical semiconductor element of the present invention comprises: an epoxy resin (A component); a curing agent (B component);
It is obtained using a specific compound (component (C)) and optionally a curing accelerator, and is usually in the form of a powder or a tablet obtained by compressing the powder. The epoxy resin (A component) is not particularly limited as long as there is no problem in transparency, and conventionally known epoxy resins, for example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenol novolak type epoxy resin, cresol Novolak type epoxy resin, alicyclic epoxy resin, triglycidyl isocyanurate, nitrogen-containing ring epoxy resin such as hydantoin epoxy resin, water-added bisphenol A type epoxy resin, aliphatic epoxy resin, glycidyl ether type epoxy resin,
Bisphenol S type epoxy resin and the like can be mentioned. These may be used alone or in combination of two or more. Among the above various epoxy resins, bisphenol A type epoxy resin, bisphenol F type epoxy resin, alicyclic epoxy resin, triglycidyl are preferable since the sealing resin (cured product) is hardly discolored after the optical semiconductor element is sealed. It is preferred to use isocyanurates. The curing agent (component B) used together with the epoxy resin (component A) is not particularly limited as long as there is no problem in transparency, but various acid anhydrides are used because the degree of discoloration of the sealing resin is small. It is preferable to use
Specifically, phthalic anhydride, maleic anhydride, trimellitic anhydride, pyromellitic anhydride, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, methylnadic anhydride, nadic anhydride, glutaric anhydride, methylhexahydroanhydride Examples include phthalic acid and methyltetrahydrophthalic anhydride. These may be used alone or in combination of two or more. Further, among the above curing agents, it is preferable to use phthalic anhydride, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, and methylhexahydrophthalic anhydride. Further, in addition to the acid anhydride-based curing agent, a conventionally known curing agent such as amines, phenols, or carboxylic acids such as hexahydrophthalic acid, tetrahydrophthalic acid, and methylhexahydrophthalic acid is used alone. Or may be used in combination. The mixing ratio of the epoxy resin (A component) and the curing agent (B component) is, for example, when an acid anhydride is used as the curing agent, the acid anhydride in the acid anhydride is equivalent to 1 equivalent of the epoxy group in the epoxy resin. It is preferable to set the equivalent to be 0.5 to 1.5. Particularly preferably, it is 0.7 to 1.2. That is, in the above mixing ratio, the acid anhydride equivalent is
If the amount is less than 0.5 equivalent, the hue after curing of the obtained epoxy resin composition is deteriorated, while if it exceeds 1.5 equivalents, the moisture resistance tends to decrease. As the curing agent (component B), in addition to the acid anhydride, the amines described above,
Even when a curing agent such as a phenol or a carboxylic acid is used alone or in combination, the compounding ratio is based on the compounding ratio (equivalent ratio) using the above-mentioned acid anhydride. The specific compound (component C) used together with the component A and the component B is at least one of a compound represented by the following general formula (1) and a compound represented by the following general formula (2). By using the compound, the optical semiconductor device can be easily released from the mold at the time of transfer molding without impairing the transparency of the sealing resin. The use of these compounds is a feature of the present invention.

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Embedded image Y ₁ in the above formula (1) is a hydrogen atom, —RCOOH (R is 2
Valent organic group), -COR 'or -R' (R 'is an alkyl group having 30 or less carbon atoms). Preferably, Y ₁ is a hydrogen atom, -RCOOH in which R is an alkylene group having 30 or less carbon atoms, -C in which R 'is an alkyl group having 1 to 30 carbon atoms.
OR 'or -R' is mentioned. Further, as the metal atom which is Y ₂ in the above formula (2),
For example, zinc, calcium, barium, aluminum,
Examples include magnesium, lead, potassium, and sodium. Particularly, considering transparency, calcium, sodium and zinc are preferable as Y ₂ . In each of the above formulas (1) and (2), the number of repetitions x is 8 to 200, and in the repetition portion n, the weight ratio of the portion n is expressed by the formula (1), It is necessary to set each of the compounds represented by the formula (2) in the range of 25 to 95%. More preferably, both the formulas (1) and (2) have a repeating number x of 13 to 28.
And the weight ratio of the repeating portion n is 35 to 85
%. Particularly preferably, in formulas (1) and (2), the repetition number x is a positive number of 17 to 23, and the weight ratio of the repetition portion n is 45 to 70%. In addition, when there are several types of the compounds represented by the formulas (1) and (2), the number of repetitions x is the number of repetitions x for each compound.
The average value of The weight ratio (%) of the repeating portion n is a value calculated by the following equation. For these reasons, the compounds represented by the formulas (1) and (2) each have an average molecular weight of 300 to 300,000. Preferably an average molecular weight of 600 to 12000
It is. More preferably, the average molecular weight is 900-5000. The compound represented by the above formula (1) is, for example,
It can be obtained by adding ethylene oxide to a higher alcohol. The compounding amount of at least one of the compounds represented by the formulas (1) and (2) (component (C)) is preferably set in the range of 0.01 to 15%, more preferably 0.1 to 15% of the entire epoxy resin composition. ~ 5%. And especially preferably, it is 0.5-3%. That is, if the amount of the component C is too small, sufficient releasability of the optical semiconductor device from the molding die in transfer molding cannot be obtained. Conversely, if the amount is too large, the glass transition temperature or moisture resistance reliability decreases. This is because there is a fear. In addition, the epoxy resin composition for encapsulating an optical semiconductor element used in the present invention may further include, in addition to the above-mentioned components A to C, a conventionally used curing agent as long as the transparency is not impaired. Accelerators, dyes, pigments, modifiers, antioxidants, coupling agents, release agents, and the like can be appropriately compounded. The curing accelerator is not particularly limited and is a conventionally known one such as tertiary amines, imidazoles, quaternary ammonium salts and organic metal salts, phosphorus compounds, 1,8-diaza-bicyclo (5 , 4,0) Undecene
7 and their derivatives. These may be used alone or in combination of two or more. And, among the above-mentioned curing accelerators, it is preferable to use tertiary amines and imidazoles. The compounding amount of the curing accelerator is
It is preferably set in the range of 0.01 to 8 parts, more preferably 0.1 to 3 parts, based on 100 parts by weight (hereinafter abbreviated as "part") of the epoxy resin (A component) component. That is, if the compounding amount of the curing accelerator is less than 0.01 part, a sufficient curing promoting effect cannot be obtained, and if it exceeds 8 parts, the sealing resin (cured product) may be discolored. Examples of the modifier include conventionally known glycols and silicones. Examples of the antioxidant include phenol compounds, amine compounds, organic sulfur compounds, and phosphine compounds. Examples of the coupling agent include silane compounds, titanate compounds, and the like. Examples of the release agent include long-chain carboxylic acids such as stearic acid, behenic acid and montanic acid and metal salts thereof, higher alcohols such as stearyl alcohol, amides such as stearyl bisamide, esters such as carnauba and phosphate esters. And conventionally known paraffin waxes. The amount of the release agent used is generally 3% or less of the whole resin composition, but is not limited thereto as long as the transparency is not impaired as described above. If light dispersibility is required, a filler may be further added in addition to the above components. Examples of the filler include silica glass powder, talc, silica powder, alumina powder, and inorganic fillers such as calcium carbonate. With respect to the epoxy resin composition for encapsulating an optical semiconductor element constituted by using such components, a preferable combination of the components is an epoxy resin (component A) from the viewpoint of its excellent transparency and releasability. Bisphenol A type epoxy resin, triglycidyl isocyanurate, novolak type epoxy resin, alicyclic epoxy resin, as curing agent (component B), tetrahydrophthalic anhydride, phthalic anhydride, and other additives. Tertiary amines and imidazoles are used as curing accelerators, and combinations of these compounds with the compounds represented by the formulas (1) and (2) (component (C)) can be given. At this time, as described above, the number of repetitions x in the above equations (1) and (2) is a positive number in the range of 13 to 28, and the repetition part n
In the above, the weight ratio of the part n is 35 to
A range of 85% is preferred. Among the above preferred combinations, a particularly preferred combination is a bisphenol A type epoxy resin and triglycidyl isocyanurate as the epoxy resin (A component) in that the discoloration of the sealing resin cured product is less likely to occur. Tetrahydrophthalic anhydride is used as a curing agent (component B), and imidazoles are used as a curing accelerator as another additive, and the number of repetitions x in the above formulas (1) and (2) together with these components is Positive numbers in the range of 17 to 23, and in the repeating portion n, a combination using the compound (component C) in which the weight ratio of the portion n is set in the range of 45 to 70% of the whole compound. The epoxy resin composition for encapsulating an optical semiconductor element of the present invention can be produced, for example, as follows. That is, the above components A to C and, if necessary, a curing accelerator, a dye, a pigment, a modifier, an antioxidant, a coupling agent, a release agent, a filler, and the like are mixed in a predetermined ratio. Then, this is mixed and kneaded by appropriately employing a dry blending method or a melt-blurring method according to a conventional method. Subsequently, the epoxy resin composition can be manufactured by cooling, pulverizing, and, if necessary, tableting. The sealing of the optical semiconductor device using such an epoxy resin composition is not particularly limited, and can be performed by a known molding method such as transfer molding. The optical semiconductor device obtained in this manner has excellent transparency due to its sealing resin, and also has excellent mold releasability during transfer molding. There is no adverse effect on the semiconductor device. In the present invention, the cured product as the sealing resin is preferably a cured product having a thickness of 1 mm and having a light transmittance of 70% or more at a wavelength of 600 nm as measured by a spectrophotometer, particularly preferably 80%. That is all. BEST MODE FOR CARRYING OUT THE INVENTION Next, examples will be described together with comparative examples. First, prior to Examples, compounds a shown in Table 1 below were prepared.
~ L was prepared. Compounds a to i are compounds represented by the above general formula (1), in which terminal Y ₁ is a hydrogen atom.

Table 1 In addition to the above-mentioned compounds al, compounds mo shown in Table 2 below were prepared. The compounds mo are compounds represented by the general formula (1).

Further, in addition to the above compounds a to o, compounds pr shown in Table 3 below were prepared. The compounds p to r are compounds represented by the general formula (2).

Table 3 Epoxy resins A to D and curing agents E to
G, curing accelerators H and I, and antioxidants J to L were prepared. [Epoxy resin A] Bisphenol A type epoxy resin (Epoxy equivalent 65
0, melting point 83 ° C) [Epoxy resin B] Tris (2,3-epoxypropyl) isocyanurate (epoxy equivalent 100, melting point 110 ° C) [Epoxy resin C] Cresol novolac type epoxy resin (epoxy equivalent
215, softening point 92 ° C) [Epoxy resin D] Alicyclic epoxy resin represented by the following general formula (3) (epoxy equivalent 187, softening point 73 ° C)

[Curing agent E] Tetrahydrophthalic anhydride [Curing agent F] Diaminodiphenylmethane [Curing agent G] Phenol novolak resin (hydroxyl equivalent 105, softening point 7
[Curing accelerator H] 2-Ethyl-4-methylimidazole [Curing accelerator I] Dimethylbenzylamine [Curing inhibitor J] 2,6-di- represented by the following structural formula (4) tert-
Butyl-hydrotoluene.

Embedded image [Antioxidant K] Triphenyl phosphite represented by the following structural formula (5).

Embedded image [Antioxidant L] 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide

Examples 1 to 27 and Comparative Examples 1 to 6 The components shown in Tables 4 to 8 below are blended in the proportions shown in the table, and are melt-kneaded (80 to 130 ° C.) by a mixing roll machine.
After aging, the mixture was cooled at room temperature and pulverized to obtain a desired powdery epoxy resin composition.

[Table 4]

[Table 5]

[Table 6]

[Table 7]

[Table 8] As described above, the optical semiconductor device was subjected to transfer molding (molding condition: 150 ° C × 4 minutes) using the powdery epoxy resin compositions obtained in Examples and Comparative Examples, and further to 150 ° C. The optical semiconductor device was manufactured by performing after-curing under the condition of × 3 hours. In the optical semiconductor device thus obtained, the releasability from the transfer mold was evaluated. The above-mentioned releasability was evaluated using a melamine resin (Nikaret ECR Gray, manufactured by Nippon Carbide Co., Ltd.).
AA), after cleaning molding, continuous molding by transfer molding, and for the optical semiconductor device obtained in the fourth shot, the optical semiconductor device (package size: 19) from the mold (cavity) by operating only the ejector pin. .
8 mm x 13.9 mm x 2.8 mm thick) was extracted from the mold by the operation of the ejector pin and the air blown, and the ejector pin was activated by the ejection of the optical semiconductor device from the mold. In addition, the optical semiconductor device could not be taken out by blowing air or the like, and the optical semiconductor device was taken out by applying a mechanical force.
To Table 13. Furthermore, using each of the above epoxy resin compositions, a thickness of 1 mm
[Curing conditions: 150 ° C x 4 minutes + 150 ° C
× 3 hours (after cure)]. About this, wavelength 60
The light transmittance at 0 nm is measured using a spectrophotometer (Shimadzu Corporation, U
V-3101PC). The results are shown in Table 9 below.
To Table 13 together.

[Table 9]

[Table 10]

[Table 11]

[Table 12]

[Table 13] From the results in Tables 9 to 13, all the products of Examples were high in light transmittance and excellent in releasability. From this, it can be seen that the products of Examples are excellent in both transparency and mold release properties. On the other hand, the products of Comparative Examples 1 to 3 and the product of Comparative Example 5 had good releasability, but very poor light transmittance. Further, Comparative Example 4
And 6 products had high light transmittance, but very poor releasability. As described above, in the comparative example, either one of the results of the light transmittance and the releasability was good, and the other result was bad, and both were not satisfactory. INDUSTRIAL APPLICABILITY As described above, the epoxy resin composition for encapsulating an optical semiconductor element of the present invention has a specific compound represented by the general formula (1) and a specific compound represented by the general formula (2). At least one of the compounds (C component). For this reason, the sealing resin made of the epoxy resin composition becomes a sealing material having excellent releasability from a molding die such as transfer molding while maintaining high transparency. In particular, by setting the content of the component (C) in the range of 0.01 to 15% of the entire epoxy resin composition for encapsulating an optical semiconductor element, it is possible to prevent a decrease in the glass transition temperature or the moisture resistance reliability and sufficiently High releasability. Therefore, when an optical semiconductor element is sealed using this epoxy resin composition, an optical semiconductor device having excellent reliability can be obtained without being treated as a defective product due to a defect caused by poor releasability. .

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI H01L 23/31 (72) Inventor Takahiko Maruhashi 1-2-1, Shimohozumi, Ibaraki-shi, Osaka Nitto Denko Corporation (72) Inventor Katsumi Shimada 1-1-2 Shimohozumi, Ibaraki-shi, Osaka Nippon Tenko Corporation (72) Inventor Satoshi Tanigawa 1-2-1, Shimohozumi, Ibaraki-shi, Osaka Nippon Tenko Corporation (56) References JP-A-6-228281 (JP, A) JP-A-4-142070 (JP, A) JP-A-3-94454 (JP, A) JP-A-1-247414 (JP, A) JP-A Sho 62 -283616 (JP, A) JP-A-58-84820 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C08L 63/00-63/10 C08L 23/26 C08L 71/02 H01L 23/29

Claims (10)

(57) [Claims] An epoxy resin composition for encapsulating an optical semiconductor device, comprising the following components (A) to (C): (A) Epoxy resin. (B) a curing agent. (C) At least one of a compound represented by the following general formula (1) and a compound represented by the following general formula (2). 2. In the formulas (1) and (2), the number of repetitions x is a positive number of 13 to 28, and the weight ratio of the repeating portion n is 35 to 85% by weight of the whole compound. 2. The epoxy resin composition for sealing an optical semiconductor element according to 1. 3. In the formulas (1) and (2), the number of repetitions x is a positive number of 17 to 23, and the weight ratio of the repetition portion n is 45 to 70% by weight of the whole compound. 2. The epoxy resin composition for sealing an optical semiconductor element according to 1. 4. The composition according to claim 1, wherein the content of the component (C) is set in the range of 0.01 to 15% by weight of the whole epoxy resin composition for encapsulating an optical semiconductor element. An epoxy resin composition for encapsulating an optical semiconductor element. 5. The content according to claim 1, wherein the content of the component (C) is set in the range of 0.1 to 5% by weight of the entire epoxy resin composition for encapsulating an optical semiconductor element. An epoxy resin composition for encapsulating an optical semiconductor element. 6. The method according to claim 1, wherein the content of the component (C) is set in a range of 0.5 to 3% by weight of the whole epoxy resin composition for encapsulating an optical semiconductor element. An epoxy resin composition for encapsulating an optical semiconductor element. 7. The component (A) is at least one epoxy resin selected from the group consisting of bisphenol A type epoxy resin, triglycidyl isocyanurate, novolak type epoxy resin and alicyclic epoxy resin,
The component (B) is at least one of tetrahydrophthalic anhydride and phthalic anhydride, the component (C) is at least one of the compounds represented by the formulas (1) and (2), and In 1) and formula (2), the number of repetitions x is a positive number of 13 to 28, the weight ratio of the repeating portion n is 35 to 85% by weight of the whole compound, and the above (A) to (C) The epoxy resin composition for encapsulating an optical semiconductor element according to any one of claims 1 to 6, further comprising a curing accelerator comprising at least one of a tertiary amine and an imidazole together with the component. 8. The component (A) is at least one of a bisphenol A type epoxy resin and triglycidyl isocyanurate, the component (B) is tetrahydrophthalic anhydride, and the component (C) is a compound represented by the formula (1) or (2). In addition to at least one of the compounds represented by the formula (2), in the above formulas (1) and (2), the number of repetitions x is 17 to 23.
Wherein the weight ratio of the repeating portion n is 45 to 70% by weight of the whole compound, and further the above (A) to (C)
The epoxy resin composition for encapsulating an optical semiconductor element according to any one of claims 1 to 6, further comprising an imidazole as a curing accelerator together with the component. 9. An optical semiconductor device comprising an optical semiconductor element encapsulated with an epoxy resin composition containing the following components (A) to (C). (A) Epoxy resin. (B) a curing agent. (C) At least one of a compound represented by the following general formula (1) and a compound represented by the following general formula (2). 10. The optical semiconductor device according to claim 9, wherein the content of the component (C) is set in a range of 0.01 to 15% by weight of the whole epoxy resin composition.