JP2006073587A - Optical semiconductor device and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical semiconductor device sealed by a transparent resin hardened material having excellent resistance against ultraviolet rays and having little coloring at the time of hardening, and also to provide its manufacturing method. <P>SOLUTION: An epoxy resin composite contains as an essential component a liquid epoxy resin having a light transmittance of 80% or above for light having a wavelength of 400 nm at an optical path length of 1 mm, and starts heating at a temperature between 60 and 100°C when measured by a differential scanning calorimeter (DSC). A semiconductor element is sealed by such an epoxy resin composite hardened at a temperature between 60 and 100 °C to manufacture the optical semiconductor device. The manufacturing method of the optical semiconductor device is also provided. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an optical semiconductor device sealed with a cured resin that is transparent and excellent in ultraviolet resistance, and a method for manufacturing the same.

  Conventionally, semiconductor light emitting devices such as light emitting diodes (LEDs) used for backlights, display boards, displays, various indicators, etc. are generally sealed with a transparent resin. As a sealing resin, bisphenol is used. An A-type epoxy resin as a main component and an acid anhydride blended with it as a curing agent is frequently used because of its excellent heat resistance, mechanical strength, electrical properties, etc. and excellent transparency.

  However, in recent years, in the field of LEDs, those that emit light of short wavelengths such as blue and white with good luminous efficiency have been developed, and the following problems have arisen accordingly.

  That is, in the element that emits light having a short wavelength such as blue or white as described above, secondary ultraviolet light is emitted. On the other hand, the bisphenol A type epoxy resin used for the conventional sealing resin contains a benzene ring. Since this benzene ring easily absorbs ultraviolet rays, it absorbs near-ultraviolet rays that are emitted by the above-described light emitting element. As a result, the resin gradually deteriorates, resulting in a decrease in transparency due to coloring.

  In addition, acid anhydrides blended as curing agents in conventional sealing materials also have unsaturated bonds that easily absorb ultraviolet rays, which is a cause of resin transparency deterioration.

  Therefore, in order to solve such a problem, for example, a technique that eliminates the use of acid anhydrides and reduces the proportion of unsaturated bonds in the resin by thermal cationic polymerization of an epoxy resin using a latent catalyst. Has been proposed (see, for example, Patent Document 1). However, although the sealing material using this latent catalyst has better UV resistance than a sealing material using acid anhydride as a curing agent, it is colored (yellowing) and transparent during heat curing. There was a problem that the performance was greatly reduced.

The above coloration is considered to be caused by oxidation due to heat generation during heat curing, and therefore the coloration can be suppressed by curing the resin in an inert atmosphere. However, creating an inert atmosphere in the actual manufacturing process is neither easy nor costly.
JP 2003-73452 A

  As described above, with the development of LEDs that emit near-ultraviolet light, a sealing resin material for optical semiconductors that has high ultraviolet transmittance and excellent ultraviolet resistance that does not impair transparency due to ultraviolet light has been proposed. Yes. However, this encapsulating resin material has a problem that it is colored when cured, and the transparency is greatly reduced.

  The present invention has been made in response to such a conventional situation, and provides an optical semiconductor device sealed with a cured resin that is transparent, excellent in ultraviolet resistance, and less colored during curing, and a method for manufacturing the same. The purpose is to provide.

  As a result of intensive studies to achieve the above object, the present inventors, as a result of sealing resin materials that are transparent and excellent in UV resistance, have specific thermal characteristics under specific curing conditions. It has been found that by curing, an optical semiconductor device sealed with a resin cured product having a high initial transparency and excellent ultraviolet resistance can be obtained. The invention has been completed.

  That is, the optical semiconductor device according to the first aspect of the present invention has a liquid epoxy resin having an optical transmittance of 80% or more at an optical path length of 1 mm and a wavelength of 400 nm as an essential component, and generates heat by a differential scanning calorimeter (DSC). A semiconductor element is sealed with a cured product obtained by curing an epoxy resin composition having a starting temperature in a range of 60 to 100 ° C. at a temperature of 60 to 100 ° C.

According to a second aspect of the present invention, in the optical semiconductor device according to the first aspect, the cured product is 100 light with a wavelength of 365 nm or less filtered using a high-pressure mercury lamp with an illuminance of 30 mW / cm ² at a wavelength of 365 nm. The light transmittance at a wavelength of 400 nm at an optical path length of 1 mm after time irradiation is 80% or more.

  The invention according to claim 3 is the optical semiconductor device according to claim 1 or 2, wherein the epoxy resin composition has (A) an alicyclic epoxy resin, (B) an organoaluminum compound, and (C) an organic compound having a hydroxyl group. It is a composition containing a silicon compound.

（式中、Ｒ^１は水素原子およびアルキル基から選択される原子または基であり、ｎは１〜３０の整数である。）

According to a fourth aspect of the present invention, in the optical semiconductor device according to the third aspect, the (A) alicyclic epoxy resin is represented by the epoxy resin represented by the following general formula (1) and / or the following formula (2): It is characterized by being an epoxy resin.

(In the formula, R ¹ is an atom or group selected from a hydrogen atom and an alkyl group, and n is an integer of 1 to 30.)

  According to a fifth aspect of the present invention, in the optical semiconductor device according to the third or fourth aspect, the organoaluminum compound is an aluminum chelate compound and / or an alkoxyaluminum.

  The invention according to claim 6 is the optical semiconductor device according to any one of claims 3 to 5, wherein (C) the organosilicon compound having a hydroxyl group is alkoxysilane and / or alkylsilanol. To do.

  The invention described in claim 7 is the optical semiconductor device according to any one of claims 1 to 6, wherein the semiconductor element is an ultraviolet light emitting element.

  The method for manufacturing an optical semiconductor device according to claim 8 of the present application is based on an epoxy resin having an optical transmittance of 80% or more at a wavelength of 400 nm at an optical path length of 1 mm, and generates heat by a differential scanning calorimeter (DSC). A semiconductor element is sealed by curing an epoxy resin composition having a starting temperature in the range of 60 to 100 ° C. at a temperature of 60 to 100 ° C.

  ADVANTAGE OF THE INVENTION According to this invention, the optical semiconductor device sealed with the resin hardened | cured material which is transparent and excellent in ultraviolet-ray resistance, and is little colored by the thermal deterioration at the time of hardening can be obtained.

Hereinafter, the present invention will be described in detail.
The epoxy resin composition used in the present invention has a liquid epoxy resin having an optical transmittance of 80% or more at a wavelength of 400 nm at an optical path length of 1 mm as an essential component, and an exothermic starting temperature by a differential scanning calorimeter (DSC) is 60 to 100 ° C. It is an epoxy resin composition in the range of.

  In the epoxy resin composition used in the present invention, when the light transmittance at a wavelength of 400 nm in an optical path length of 1 mm of the liquid epoxy resin contained is less than 80%, sufficient transparency cannot be obtained. Moreover, if the exothermic start temperature by the differential scanning calorimeter (DSC) of the composition is less than 60 ° C, the pot life is short and difficult to be practically used. If the exothermic start temperature exceeds 100 ° C, It cannot be cured sufficiently. In the present invention, the light transmittance of the epoxy resin was measured using a spectrophotometer V-530 manufactured by JASCO Corporation. The DSC curve measured by heating the sample up to 300 ° C. at a heating rate of 5 ° C./min using a DSC measuring device manufactured by Seiko Co., Ltd. I asked for it.

  In the present invention, among such epoxy resin compositions, in particular, (A) an alicyclic epoxy resin having a light transmittance at a wavelength of 400 nm at an optical path length of 1 mm of 80% or more, (B) an organoaluminum compound and (C ) Use of an epoxy resin composition containing an organosilicon compound having a hydroxyl group is preferred.

また、その他のエポキシ樹脂としては、例えば、ビスフェノールＡ型エポキシ樹脂、ビスフェノールＦ型エポキシ樹脂、ビスフェノールＳ型エポキシ樹脂、ビフェニル型エポキシ樹脂、フェノールノボラック型エポキシ樹脂、クレゾールノボラック型エポキシ樹脂、トリグリシジルイソシアヌレートなどの複素環型エポキシ樹脂や、これらを水素化したエポキシ樹脂等が挙げられる。これらのエポキシ樹脂は、１種を単独で使用してもよく、２種以上を混合して使用してもよい。 Examples of the alicyclic epoxy resin having a light transmittance at a wavelength of 400 nm at an optical path length of 1 mm in (A) of 80% or more include those represented by the above formulas (1) and (2). ) Is preferred.
In the present invention, an alicyclic epoxy resin other than the above alicyclic epoxy resin can be used in combination as long as the effects of the present invention are not impaired. Examples of the alicyclic epoxy resin used in combination include those represented by the following formulas (3) and (4).

Other epoxy resins include, for example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, biphenyl type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, triglycidyl isocyanurate. And the like, and epoxy resins obtained by hydrogenating them. These epoxy resins may be used individually by 1 type, and 2 or more types may be mixed and used for them.

  (B) The organoaluminum compound and (C) the organosilicon compound having a hydroxyl group are components that act as a curing agent or a curing accelerator for the epoxy resin component as described above. , Trimethoxyaluminum, triethoxyaluminum, triisopropoxyaluminum, isopropoxydiethoxyaluminum, alkoxy compounds such as tributoxyaluminum, acyloxy compounds such as triacetoxyaluminum, tristearate aluminum, tributyratealuminum, aluminum isopropylate, aluminum sec-butylate, aluminum tert-butylate, aluminum tris (ethylacetoacetate), trishexafluoroacetylacetonate alumini , Trisethylacetoacetate aluminum, tris (n-propylacetoacetate) aluminum, tris (iso-propylacetoacetate) aluminum, tris (n-butylacetoacetate) aluminum, trissalicylaldehydealuminum, tris (2-ethoxycarbonylpheno) And chelates such as lato) aluminum and tris (acetylacetonato) aluminum. These organoaluminum compounds may be used individually by 1 type, and 2 or more types may be mixed and used for them. Among these, an alkoxy compound and a chelate compound are preferable, and a chelate compound is more preferable.

（式中、Ｒ^２はアルキル基、フェニル基、アラルキル基、ビニル基およびアリル基から選択される基を示し、Ｒ^３は同一または異なって、アルキル基、フェニル基、アラルキル基、ビニル基、アリル基および水酸基から選択される基を示し、少なくとも１つは水酸基である。）

（式中、Ｒは同一または異なって、アルキル基、フェニル基、アラルキル基、ビニル基、アリル基および水酸基から選択される基を示し、少なくとも１つは水酸基である。また、ｍは０または１以上の整数を示す。） Further, the organosilicon compound having a hydroxyl group (C) may be any compound having at least one hydroxyl group directly bonded to a silicon atom. For example, an organosilane represented by the following general formula (5) or the following general formula: The polyorganosiloxane shown by (6) is mentioned.

(In the formula, R ² represents a group selected from an alkyl group, a phenyl group, an aralkyl group, a vinyl group and an allyl group, and R ³ is the same or different, and represents an alkyl group, a phenyl group, an aralkyl group, a vinyl group, an allyl group) A group selected from a group and a hydroxyl group, at least one of which is a hydroxyl group.)

(In the formula, R is the same or different and represents a group selected from an alkyl group, a phenyl group, an aralkyl group, a vinyl group, an allyl group and a hydroxyl group, at least one is a hydroxyl group, and m is 0 or 1) Indicates the integer above.)

  Specific examples of the organosilicon compound (C) include alkoxy compounds such as diphenyldimethoxysilane, diphenyldiethoxysilane, diphenyldiisopropoxysilane, diphenyldiacetoxysilane, triphenylmethoxysilane, triphenylethoxysilane, and diphenylvinylethoxysilane. Examples thereof include alkylsilanols such as silane, diphenyldisianol, diphenylmethylsilanol, trimethylsilanol, and triphenylsilanol. These organosilicon compounds may be used alone or in combination of two or more.

  The (B) organoaluminum compound and (C) the organosilicon compound having a hydroxyl group are 0.005 to 10 parts by weight (hereinafter, simply referred to as parts) of (B) the organoaluminum compound per 100 parts by weight of the epoxy resin. C) It is preferable to mix 0.1-20 parts of organosilicon compounds. If the blending amount of any one of (B) the organoaluminum compound and (C) the organosilicon compound is less than the above range, the epoxy resin may be insufficiently cured and the adhesiveness may not be sufficiently exhibited. Conversely, if any one of (B) the organoaluminum compound and (C) the organosilicon compound is blended in excess of the above range, the reaction is accelerated and there is a risk of extreme heat generation or ignition. A more preferable range of the blending amount is a range of 0.01 to 5 parts of (B) organoaluminum compound and 0.01 to 10 parts of (C) organosilicon compound.

  In the present invention, a curing accelerator other than the (B) organoaluminum compound and (C) organosilicon compound can be used in combination as long as the effects of the present invention are not impaired. Curing accelerators used in combination include trimethylphosphine, triethylphosphine, tributylphosphine, triphenylphosphine, tri (p-methylphenyl) phosphine, tri (nonylphenyl) phosphine, methyldiphenylphosphine, dibutylphenylphosphine, tricyclohexylphosphine, bis (Diphenylphosphino) methane, 1,2-bis (diphenylphosphino) ethane, tetraphenylphosphonium tetraphenylborate, triphenylphosphine tetraphenylborate, triphenylphosphine triphenylborane and other organic phosphine compounds, 1,8-diazabicyclo [5,4,0] undecene-7 (DBU), triethylamine, triethylenediamine, benzyldimethylamine, α-methylbenzyldimethyl Tertiary amine compounds such as ruamine, triethanolamine, dimethylaminoethanol, tris (dimethylaminomethyl) phenol, 2-heptadecylimidazole, 2-methylimidazole, 2-ethylimidazole, 2-phenylimidazole, 2-phenyl-4 -Methylimidazole, 4-methylimidazole, 4-ethylimidazole, 2-phenyl-4-hydroxymethylimidazole, 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-methylimidazole, 2-phenyl-4-methyl- Examples thereof include imidazole compounds such as 5-hydroxymethylimidazole, 2-phenyl-4, and 5-dihydroxymethylimidazole. These can be used alone or in admixture of two or more.

  In addition to the above components, inorganic fillers, reaction diluents, antifoaming agents, coupling agents, etc., which are generally blended in this type of composition, are necessary as long as the effects of the present invention are not impaired. It can be blended according to.

  Examples of the inorganic filler include fused silica, crystalline silica, titanium oxide, and alumina. The shape of the inorganic filler may be spherical or crushed, but a fine spherical shape is preferable from the viewpoint of transparency.

  As coupling agents, silane coupling agents such as γ-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, and tetraisopropylbis (dioctyl phosphite) Examples thereof include titanate coupling agents such as titanate, tetraoctyl bis (dioctyl phosphite) titanate, isopropyl tris (dioctyl pyrophosphate) titanate, isopropyl tristearoyl titanate, and isopropyl tridodecylbenzenesulfonyl titanate.

  In preparing the above epoxy resin composition as a molding material, (A) an alicyclic epoxy resin, (B) an organoaluminum compound, (C) an organosilicon compound having a hydroxyl group, and What is necessary is just to stir-mix the various components mix | blended according to a mixer etc. fully. At that time, the organoaluminum compound and the organosilicon compound having a hydroxyl group may be individually mixed in advance with the epoxy resin.

The optical semiconductor device of the present invention can be manufactured by sealing a semiconductor element with the epoxy resin composition thus prepared. The sealing method is not particularly limited and can be performed by low pressure transfer method, injection molding, compression molding, casting, etc. In the present invention, in order to prevent coloring at the time of curing, epoxy is used. The resin composition is usually cured at a temperature of 60 to 100 ° C. for 30 minutes or longer. When the curing temperature is less than 60 ° C., it takes too much time for curing, and when the curing temperature exceeds 100 ° C., coloring occurs and the transparency of the cured product decreases. The cured product has a light transmittance of 80 nm at a wavelength of 400 nm at an optical path length of 1 mm after irradiating light with a wavelength of 350 nm or less filtered at a wavelength of 365 nm with an illuminance of 30 mW / cm ² for 100 hours using a high-pressure mercury lamp. % Or more, and has high transparency and UV resistance. The light transmittance of this cured product was measured using a spectrophotometer V-530 manufactured by JASCO Corporation.

  In the present invention, photodiodes, phototransistors, photothyristors, photoconductors, etc. are exemplified as the optical semiconductor elements to be sealed. However, when an ultraviolet light emitting element that requires high ultraviolet resistance is sealed. In particular, a remarkable effect can be obtained.

  EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited to these Examples at all.

Examples 1 and 2 and Comparative Examples 1 to 4
Alicyclic epoxy resin represented by the above general formula (2) (trade name Celoxide 2021P, epoxy equivalent 200 manufactured by Daicel Chemical Industries), and ethyl acetoacetate aluminum diisopropylate as an organoaluminum compound (trade name ALCH, manufactured by Kawaken Fine Chemical Co., Ltd.) In addition, alkoxysilicone (trade name KR213 manufactured by Toray Dow Corning Co., Ltd.) as an organosilicon compound is introduced into a mixer at a blending ratio shown in Table 1 and mixed thoroughly, and then vacuum degassed to obtain a liquid epoxy resin composition. Prepared.

  Subsequently, while inject | pouring the said epoxy resin composition in the resin mold for LED, LED was fixed, the epoxy resin composition was hardened on the hardening conditions shown in Table 1, and the LED lamp was produced.

  In order to evaluate the properties of the cured product of the epoxy resin composition in the obtained LED lamp, the sealing resin composition was cured under the same curing conditions as described above separately from the production of the LED lamp, and 30 mm × A molded product of 20 mm × 1 mm was produced, and the light transmittance immediately after molding and after light irradiation was measured by the following method.

That is, the light transmittance of a molded product immediately after molding having a wavelength of 400 nm and a thickness of 1 mm was measured using a spectrophotometer V-530 (manufactured by JASCO Corporation). Moreover, after irradiating the molded article with light having a wavelength of 350 nm or less filtered using a high-pressure mercury lamp HANDYUV-800 (manufactured by Oak Manufacturing Co., Ltd.) at an illuminance of 30 mW / cm ² at a wavelength of 365 nm, a spectrophotometer Using V-530, the light transmittance at a wavelength of 400 nm and a thickness of 1 mm was measured.

These results are also shown in Table 1.

  As is clear from Table 1, the cured products of the examples have high light transmittance immediately after molding and after light irradiation, and are excellent in initial transparency and ultraviolet resistance.

Claims (8)

  An epoxy resin composition having a liquid epoxy resin having a light transmittance of 80% or more at a wavelength of 400 nm at an optical path length of 1 mm as an essential component and an exothermic starting temperature in a range of 60 to 100 ° C. by a differential scanning calorimeter (DSC), An optical semiconductor device, wherein a semiconductor element is sealed with a cured product cured at a temperature of 60 to 100 ° C. The cured product has a light transmittance of 80% at a wavelength of 400 nm at an optical path length of 1 mm after irradiating light having a wavelength of 350 nm or less filtered with a high-pressure mercury lamp with an illuminance of 30 mW / cm ² at a wavelength of 365 nm for 100 hours. The optical semiconductor device according to claim 1, which is as described above.   The epoxy resin composition is a composition comprising (A) an alicyclic epoxy resin, (B) an organoaluminum compound, and (C) an organosilicon compound having a hydroxyl group. Optical semiconductor device. 4. The optical semiconductor device according to claim 3, wherein the (A) alicyclic epoxy resin is an epoxy resin represented by the following general formula (1) and / or an epoxy resin represented by the following formula (2).

(In the formula, R ¹ is an atom or group selected from a hydrogen atom and an alkyl group, and n is an integer of 1 to 30.)

  5. The optical semiconductor device according to claim 3, wherein the organoaluminum compound is an aluminum chelate compound and / or an alkoxyaluminum.   6. The optical semiconductor device according to claim 3, wherein the organosilicon compound having a hydroxyl group is alkoxysilane and / or alkylsilanol.   7. The optical semiconductor device according to claim 1, wherein the semiconductor element is an ultraviolet light emitting element.   An epoxy resin composition having an epoxy resin having an optical path length of 1 mm and a light transmittance at a wavelength of 400 nm of 80% or more as an essential component, and an exothermic start temperature by a differential scanning calorimeter (DSC) in the range of 60 to 100 ° C. A method for producing an optical semiconductor device, wherein a semiconductor element is sealed by curing at a temperature of -100 ° C.