JP2012238636A - Silicone-based sealing material composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor light emitting device using a silicone resin-based sealing material, which prevents color changes with time of a lead electrode to maintain brightness of the light emitting device.SOLUTION: A silicone-based sealing material composition containing (A) a bifunctional thermosetting silicone resin, (B) a polyfunctional thermosetting silicone resin and (C) a hardening catalyst has the following features. (1) The rate (weight ratio) of (B) present in the total amount of (A) and (B) is 0.5/100 or greater and less than 100/100. (2) The functional number of the component (B) is 2.5 or greater and 4.0 or less. (3) The weight average molecular weight of the component (B) is 1000 to 10000. (4) At a temperature of 80°C, (A) and (B) are immiscible with each other and the density of (B) is higher by 0.01 g/cmor more than that of (A).

Description

  The present invention relates to a silicone-based encapsulant composition that can be suitably used for a semiconductor light emitting device and the like, and a semiconductor light emitting device encapsulated thereby.

In a semiconductor light emitting device using a light emitting diode (hereinafter abbreviated as “LED” where appropriate), a semiconductor laser (hereinafter abbreviated as “LED etc.”) or the like, the semiconductor light emitting element is protected. Therefore, sealing with a transparent resin or the like is generally performed.
Epoxy resin is widely used as a sealing material for such semiconductor light-emitting devices, but due to higher output of LEDs, etc., and shorter emission wavelength, discoloration due to deterioration of epoxy resin and accompanying semiconductor light emission The decrease in device brightness has become a problem.

Therefore, a silicone resin having good heat resistance and light resistance has been used as a sealing material for LEDs and the like.
However, since the silicone resin has a high moisture and gas permeability, the surface of a metal member such as a lead electrode included in the semiconductor light emitting device is discolored due to oxidation or sulfuration, and the light reflectance decreases with time. There is a problem that the output of.

  On the other hand, as disclosed in Patent Document 1, a metal part in a device is coated with a light-transmitting inorganic material layer such as glass, or a package bottom surface of a light-emitting device is transmitted through water vapor as in Patent Document 2. A method of forming a silicone resin-based sealing material layer after coating with a modified silicone resin having low properties has been proposed.

JP 2007-324256 A JP 2009-170824 A

  The present invention relates to a semiconductor light emitting device using a silicone resin-based sealing material, without using a material previously coated as a lead electrode as in the prior art, without the moisture content of the silicone resin constituting the sealing material composition. To provide a silicone-based encapsulant composition that can prevent a decrease in luminance of a light-emitting device and maintain high luminance over a long period of time by reducing gas permeability, and a semiconductor light-emitting device using the same Let it be an issue.

  The present inventors have intensively studied to solve the above problems, and by using a combination of a silicone resin having specific properties as a silicone resin constituting a sealing material for a semiconductor light emitting device, moisture and a sulfur-containing compound can be used. The present inventors have found that sulfur containing sulfur can be prevented from reaching the electrode surface from the encapsulant layer to prevent discoloration of the electrode surface and maintain the reflectance of the lead electrode over a long period of time.

That is, the gist of the present invention is as follows.
(1) A silicone-based encapsulant composition comprising (A) a bifunctional thermosetting silicone resin, (B) a polyfunctional thermosetting silicone resin, and (C) a curing catalyst, wherein: A composition having a characteristic of the following 1) to 4).
1) The ratio of (B) in the total amount of (A) and (B), the value of (B) / ((A) + (B)) (weight ratio) is 0.5 / 100 or more, Less than 100/100 2) Functionality of component (B) is 2.5 or more and 4.0 or less 3) Weight average molecular weight of component (B) is 1000 to 10,000
4) At 80 ° C., (A) and (B) are not compatible, and the density of (B) at the temperature is 0.01 g / cm ³ or more higher than the density of (A).
(2) The present invention also provides:
The silicone-based encapsulant composition according to the above (1), which is a two-part composition composed of a liquid composition containing (A) and (B) and a liquid composition containing (C), is preferred. It is an aspect.
(3) The present invention also provides:
The melting point of any one of (A) and (B) is 25 degrees C or less, and the composition as described in said (1) or (2) whose other melting point is 30-100 degreeC is also a preferable aspect.
(4) Furthermore, the present invention provides:
The ratio of (B) in the total amount of (A) and (B), the value of (B) / ((A) + (B)) is 1/100 to 50/100 (weight ratio). The composition according to any one of (1) to (3) is a more preferred embodiment.
(5) The present invention also provides:
(C) Content of a curing catalyst is 0.01-0.5 weight% with respect to the total amount of (A) and (B), Any one of said (1)-(4) A composition is a preferred embodiment.
(6) The present invention also provides:
(C) Tin (Sn), zinc (Zn), iron (Fe), titanium (Ti), zirconium (Zr), bismuth (Bi), hafnium (Hf), yttrium (Y), aluminum as a metal component as a curing catalyst The composition according to any one of (1) to (5) above, which is an organic complex or organic acid salt of at least one metal selected from the group consisting of (Al), boron (B) and gallium (Ga). It is an aspect.
(7) The present invention also provides:
In addition to the components (A) to (C) described above, (D) a polyfunctional polyorganosiloxane having a weight average molecular weight of 300 to 800 is added to the total amount of (A) and (B) by 0.00. The composition according to any one of the above (1) to (6), which contains 0.5 to 1% by weight, is a preferred embodiment.
(8) Moreover, another aspect of the present invention is a semiconductor light-emitting device that is sealed with the silicone-based sealing material composition according to any one of (1) to (7).

  By using the silicone-based sealing material composition of the present invention, it is possible to provide an excellent semiconductor light emitting device capable of maintaining the reflectance of the lead electrode over a long period of time.

It is a conceptual diagram showing the one aspect | mode of the semiconductor light-emitting device of this invention.

The present invention relates to a specific silicone-based encapsulant composition and a semiconductor light emitting device encapsulated with the encapsulant composition.
Hereinafter, although specific embodiments of the silicone-based sealing material composition and the semiconductor light-emitting device are described in detail, the present invention is not limited to these descriptions.
<1. Components of composition>
The silicone-based encapsulant composition for semiconductor light-emitting devices of the present invention preferably comprises (A) a bifunctional thermosetting silicone resin, (B) a polyfunctional thermosetting silicone resin, and (C) a curing catalyst as essential components. Is a silicone-based encapsulant composition further comprising (D) a reactive polyorganosiloxane having a weight average molecular weight of 300 to 800, each having a specific composition ratio and characteristics.

Hereinafter, each component used in the present invention will be described.
1.1 (A) Bifunctional thermosetting silicone resin (A) The bifunctional thermosetting silicone resin used in the present invention is an organic polymer having a siloxane bond as the main chain, and has the following general composition The average functional number of the compound represented by formula (1) is about 2.

(R ¹ R ² R ³ SiO _1/2 ) _M (R ⁴ R ⁵ SiO _2/2 ) _D (R ⁶ SiO _3/2 ) _T (SiO _4/2 ) _Q (1)
However, R ¹ to R ⁶ are each independently a hydrocarbon group such as an alkyl group or a phenyl group. In addition, these R ¹ to R ⁶ sites may be substituted with a halogen atom or an alkali metal atom. In such a case, these atoms do not correspond to R ¹ to R ⁶ , and the above formula (1 ) Is counted as an oxygen atom.

M, D, T, and Q are 0 or more and less than 1, and M + D + T + Q = 1. The unit constituting the polyorganosiloxane represented by the above formula (1) is monofunctional [R ₃ SiO _0.5 ] (triorganosyl hemioxane), bifunctional [R ₂ SiO] (diorganosiloxane). ), Trifunctional [RSiO _1.5 ] (organosilsesquioxane), tetrafunctional [SiO ₂ ] (silicate) (in this description, R ¹ to R ⁶ are combined with R for simplification. The functional number of the polyorganosiloxane is determined by the composition ratio of these four types of units.

That is, the functional number of the polyorganosiloxane of the above formula (1) can be calculated by the following formula (2).
Functional number = (2 × D + 3 × T + 4 × Q) / (D + T + Q) (2)
Note that typical bifunctional thermosetting silicone resins are all structural units of the formula (1) (R ⁴ R ⁵ SiO _2/2 ), that is, a diorganosiloxane structure (—O—Si (R ^4). ) (R ⁵ ) —O—) only, and the functional number in this case is 2.0.

In the present invention, not only such a typical bifunctional thermosetting silicone resin as described above but also a thermosetting silicone resin having an average functional number of about 2 can be used without particular limitation.
Specific examples of such bifunctional thermosetting silicone resin include U111, U113D, U211, U213D, S111, S113D, S211, S213D, N111, N113D, N211, N213D (manufactured by Mitsubishi Chemical Corporation), YF3800. XF3905, YF3057, YF3807, YF3802, YF3897, XC96-723, YF3804 (manufactured by Momentive Performance Materials Japan GK), X-21-5841, KF9701 (manufactured by Shin-Etsu Chemical Co., Ltd.), etc. Can be mentioned.

1.2 (B) Multifunctional thermosetting silicone resin (B) The polyfunctional thermosetting silicone resin used in the present invention is a thermosetting silicone resin having a functional number of about 3 or more in the above formula (1). is there. The functional number is preferably 2.5 or more and less than 4.0, more preferably 2.8 or more and 3.5 or less.
When the functional number is in the above range, a tight cross-linked structure is formed in the silicone resin at the time of heat curing, and a cured resin having low gas and moisture permeability and excellent gas barrier properties can be formed.
When the functional number is less than 2.5, the gas barrier property is not sufficiently high, and when 4.0, the controllability of the effect reaction is deteriorated, and it is difficult to form a uniform crosslinked structure, resulting in insufficient gas barrier property. May be.

Moreover, as (B) component, what has a weight average molecular weight of the range of 1000-10000 is used. When the weight average molecular weight is less than 1000, the chain length of the component (B) is shortened, so that the uniformity of cross-linking tends to be insufficient, and the gas barrier property improving effect cannot be sufficiently obtained. On the other hand, when it exceeds 10,000, the curing reactivity is lowered, the melting property is lowered, the curing reaction is insufficient, or the molecular chain is lengthened, so that the distance between the crosslinking points is increased and the gas barrier property is lowered. Specific examples of such a polyfunctional thermosetting silicone resin include KR220L, KR242A, KR-271, KR-282, KR-300, and KR311 (manufactured by Shin-Etsu Chemical Co., Ltd.). .

1.3 (C) Curing Catalyst In the present invention, (C) curing catalyst is a dehydration / dealcoholization condensation reaction of a mixture of the above (A) bifunctional thermosetting silicone resin and (B) polyfunctional thermosetting silicone resin. It is used to promote crosslinking by

  As a preferable catalyst, tin (Sn), zinc (Zn), iron (Fe), titanium (Ti), zirconium (Zr), bismuth (Bi), hafnium (Hf), yttrium (Y), aluminum (as a metal component) Examples thereof include organic metal compound catalysts such as organic complexes or organic acid salts of at least one metal selected from the group consisting of Al), boron (B), and gallium (Ga).

Among these, Sn, Ti, Zn, Zr, Hf, and Ga are preferable because of their high reaction activity. When used in light-emitting devices, they have moderate catalytic activity with little electrode corrosion and light absorption, and no polysiloxane chain is required. Zr, Hf, and Ga, which are difficult to cause severe cutting deterioration, are particularly preferable.
Examples of the organometallic compound catalyst containing tin (Sn) include tetraalkyltin, dialkyltin oxide, dialkyltin dicarbonate, etc. (however, the alkyl group or the carboxylic acid preferably has 1 to 10 carbon atoms).

Examples of the organometallic compound catalyst containing titanium (Ti) include tetraalkoxy titanium or an oligomer thereof (the alkyl group preferably has 3 to 8 carbon atoms), titanium acetylacetonate, and the like.
Examples of the organometallic compound catalyst containing zinc (Zn) include zinc triacetylacetonate, zinc stearate, bis (acetylacetonato) zinc (II) (monohydrate), and the like.

  Examples of the organometallic compound catalyst containing zirconium (Zr) include zirconium tetraacetylacetonate, zirconium dibutoxydiacetylacetonate, zirconium tetraalkoxide (the number of carbon atoms in the alkyl group is preferably 3 to 8), zirconyl (2 -Ethyl hexanoate), zirconium (2-ethylhexanoate) and the like.

Examples of the organometallic compound catalyst containing hafnium (Hf) include compounds having the same form as zirconium.
Examples of organometallic compound catalysts containing gallium (Ga) include gallium triacetylacetonate, gallium trialkoxide (the alkyl group preferably has 2 to 8 carbon atoms), gallium octoate, gallium laurate, gallium acetate, and the like. Can be mentioned.

In the present invention, one type of curing catalyst may be used alone, or two or more types may be used in any combination and ratio. Moreover, you may use together with a reaction accelerator and reaction inhibitor.
The content of the curing catalyst is preferably 0.01 to 0.5% by weight (in terms of metal atoms), more preferably 0.03 to 0, based on the total amount of (A) and (B). .2% by weight.
When the content of the curing catalyst is small, such as less than 0.01% by weight, the curing reaction is slowed down and the curing may not be completed within the desired time, while the amount exceeding 0.5% by weight is large. When used in, the foaming due to water or alcohol generated by the curing reaction that is a condensation reaction becomes remarkable, and good sealing cannot be performed, or the light transmittance of the sealing material layer decreases due to light absorption of the catalyst, In some cases, the heat shrinkage of the resin after curing becomes significant, and the encapsulant layer may peel off from the package.
The content of the curing catalyst can be measured by ICP analysis of the metal component.

1.4 (D) Polyfunctional polyorganosiloxane having a weight average molecular weight of 300 to 800 In addition to the essential components (A) to (C) described above, the silicone-based encapsulant composition of the present invention includes (D) It is preferable to contain a polyfunctional polyorganosiloxane having a weight average molecular weight of 300 to 800. Such a polyfunctional polyorganosiloxane has a weight average molecular weight lower than that of the polyfunctional thermosetting silicone resin (B) and is liquid at room temperature, so that the handleability of the composition is improved and the heat curing reaction is performed. In some cases, (B) is involved in the crosslinking reaction to form a denser crosslinked structure, which is effective for improving the gas barrier properties of the resulting sealing material layer.

The content of (D) is preferably 0.05 to 1% by weight with respect to the total amount of (A) and (B), and more preferably 0.1 to 0. 8% by weight.
If the content is less than 0.05%, the effect of improving gas barrier properties due to the inclusion of (D) becomes insufficient. On the other hand, if it is added in excess of 1% by weight, low molecular components (water, alcohol) during the curing reaction And the like), the foaming due to the generation of the sealing material layer may become remarkable, and the transparency of the sealing material layer may be lowered, and the light transmittance may be lowered.

  Specific examples of the polyfunctional polyorganosiloxane that can be used as the component (D) include KC-89S, KF-351A, KF353, KF6011, X-22-2516, KF410, FL-5, X manufactured by Shin-Etsu Chemical Co., Ltd. -222-21, X-22-822, FL-100-100cs, KF-4003, KF-4917, KF-96, KF-50 and the like.

1.5 Other components In the silicone-based encapsulant composition of the present invention, in addition to the above components, for example, viscosity, curing rate, hardness of the cured product, solubility of the catalyst, as long as the purpose and effect thereof are not impaired. Inorganic particles, curing rate modifiers, and liquids for the purpose of adjusting properties such as improvement and handling, and improving the optical properties, mechanical properties, and physicochemical properties of the sealing material obtained after curing You may contain additives, such as a medium.

As the inorganic particles, for the purpose of adjusting the viscosity of the encapsulant composition or improving the light scattering property, refractive index, dimensional stability, mechanical strength of the obtained encapsulant layer, for example, silica, Inorganic particles such as titania, alumina, silicon nitride, boron nitride, silicon carbide, and aluminum nitride can be used.
The average particle size of the inorganic particles is appropriately selected according to the purpose of addition, but is generally selected from a range of 1 nm to 100 μm in many cases.

Although the usage-amount of an inorganic particle should just be adjusted according to the addition objective, Usually, about 0.01 to 10 weight% is used with respect to the total weight of (A) and (B).
The curing speed adjusting agent is used to adjust (delay) the speed in order to control excessive foaming during the curing reaction. For example, 3-hydroxy-3-methyl-1-butyne, 3-hydroxy-3 -A compound containing an aliphatic unsaturated bond such as phenyl-1-butyne, an organic phosphorus compound, an organic sulfur compound, a nitrogen-containing compound, an organic peroxide and the like may be mentioned, and these may be used in combination.

The curing rate modifier may be added in a necessary amount depending on the degree of adjustment intended, but for example, about 0.1 to 100 mol is added to 1 mol of the (C) curing catalyst to be used. Is preferable, and more preferably about 1 to 50 mol.
A curing rate modifier may be used independently and may use 2 or more types together.
The silicone-based sealing material composition of the present invention is used for improving the solubility of the silicone resin or catalyst (A) or (B) used, adjusting the viscosity of the composition, the curing rate, or the hardness of the cured product. You may add liquid media other than said each component.

As such a liquid medium, an organic solvent such as an aliphatic hydrocarbon having no hydroxyl group or hydrosilyl group, silicone oil, or the like can be used.
The amount of the liquid medium used may be appropriately selected according to the usage form of the silicone-based sealing material composition. However, when a volatile organic solvent is used, attention should be paid to the amount used. This will be described in another section (3.).

  Further, as will be described later, when a phosphor is added to the composition to form a semiconductor light emitting device, a sealing material layer having a function of converting excitation light emitted from the semiconductor light emitting element into fluorescence can be obtained. it can. The phosphor used for such purpose is appropriately selected according to the wavelength of the excitation light of the semiconductor light emitting device.

  For example, in the case of a light emitting device that emits white light, a yellow phosphor is included in the encapsulant composition using a semiconductor light emitting element that emits blue excitation light, or green and red phosphors are encapsulated in the encapsulant composition. Or blue and yellow phosphors are included in the encapsulant composition using a semiconductor light emitting device that emits purple excitation light, or blue, green, and red phosphors are encapsulated. White light can be generated by inclusion in the material composition.

<2. Composition and characteristics of constituents>
2.1 Ratio of (B) in the total amount of (A) and (B) In the silicone-based encapsulant composition for a semiconductor light-emitting device of the present invention, the (A) bifunctional thermosetting silicone resin And (B) the ratio of (B) in the total amount of the polyfunctional thermosetting silicone resin, that is, the value of “(B) / ((A) + (B))” is 0. 5/100 or more and less than 100/100.

  When the content of (B) is less than 0.5 / 100, the gas barrier property is insufficient, and the gloss retention of the lead electrode tends to be lowered. On the other hand, when the component (B) is 100%, the curing rate is remarkably increased, the controllability of the curing reaction is lowered, the hardness after curing is increased, and the sealing material is easily cracked or peeled off. There is a risk that foaming at the time of curing increases and the light transmittance of the encapsulant layer decreases, or shrinkage at the time of molding becomes significant.

Compared to (B), (A) the bifunctional thermosetting silicone resin has less shrinkage and is easy to relieve stress. By using this together with (B) polyfunctional thermosetting silicone resin, the stress due to curing shrinkage is relieved. It is thought that the effect which prevents peeling is expressed.
Considering the balance between the releasability of the sealing material and foaming at the time of molding, a more preferable weight ratio is 1/100 or more and 50/100 or less, more preferably 3/100 or more and 15/100 or less, and particularly preferably 5 / 100 or more and 10/100 or less.

2.2 Properties of (A) and (B) The silicone resins (A) and (B) used in the present invention have the above-mentioned properties, respectively, and at 80 ° C., which is the temperature at which curing proceeds. , (A) and (B) are incompatible with each other, and the density of (B) at the temperature (80 ° C.) is required to be 0.01 g / cm ³ or more higher than the density of (A). .

In the sealing material composition of the present invention, the above-mentioned two types of silicone resins are used, and the crosslinking reactive polyfunctional silicone resin (B) is incompatible with (A) in the curing process. Both will phase separate in the system. Moreover, since the density of (B) is higher than that of (A) by 0.01 g / cm ³ or more under the condition of 80 ° C. close to the curing temperature, it mainly settles in the encapsulant composition in which component (B) is liquefied. As a result, the surface of the lead electrode is covered with a layer having a high gas barrier property by gathering in the vicinity of the lead electrode at the bottom and causing a high degree of crosslinking reaction there, so that sulfur such as moisture and sulfur-containing compounds approach the lead electrode. Can be prevented.

As a result, it is considered that the gloss maintaining effect of the present invention can be obtained.
Here, (A) and (B) are incompatible with each other. For example, when equal amounts of (A) and (B) are mixed and the temperature is adjusted to 80 ° C., the mixture is stirred. Sometimes it can be determined that they are not compatible by forming a homogeneous phase, for example, in a cloudy state or by phase separation.

As the ratio of (A) and (B) in the evaluation of the compatibility, it is preferable to use a specific ratio that is going to be used as a sealing material composition.
For example, the density is measured in a glass (pyrex (registered trademark)) measuring cylinder having a volume of 100 ml, which has been previously weighed. Then, after leaving it in an incubator at 80 ° C. for 1-2 hours, it is taken out and its volume is immediately confirmed, and the density at 80 ° C. can be determined from this volume and the weight of the sample measured previously. If the sample is solid at room temperature, for example, about 10 g of the sample is weighed in a graduated cylinder and weighed, and then left in an incubator at 80 ° C. for 1 to 2 hours together with the graduated cylinder. After dissolving, the volume at 80 ° C. is measured, and the density at 80 ° C. can be calculated.

2.3 Melting point of (A) and (B) In (A) and (B) used in the present invention, either one has a melting point of 25 ° C. or lower and the other melting point is 30 to 100 ° C. preferable.
Since (A) and (B) have such a melting point, the behavior based on the density difference at the time of heat curing as described above appears more remarkably, and the lead electrode is covered with a more uniform coating in the settled portion. It becomes possible to do.
A more preferable melting point relationship is that one melting point is 20 ° C. or lower and the other melting point is 60 ° C. to 80 ° C.

A component having a melting point of 25 ° C. or lower is a liquid at room temperature, and when another component having a melting point of 30 to 100 ° C. is mixed in a finely pulverized state having a diameter of 1 mm or less, for example, both components are Due to the similarity in chemical composition, it can be dispersed almost uniformly, and thixotropy due to the component having a fine particle diameter can be expressed to keep the dispersed state stable.
In addition, the film obtained in the above curing process can be a uniform film with no unevenness in thickness.

<3. Silicone Sealant Composition>
The silicone type sealing material composition of this invention can be manufactured by mix | blending and containing said each component in each suitable composition range.
Even if such a sealing material composition is a one-component composition containing all of the above components (A) to (C), the component (A) and the component (B) are used as one liquid composition. (C) A two-component composition in which the condensation catalyst is the other liquid composition may be used. At this time, even when at least one of the two liquid compositions is mixed with each component at a predetermined mixing ratio, when it does not become liquid at room temperature, or when the capacity used is extremely different when using two liquids, etc. In order to obtain a stable liquid composition or balance the amount used, it is preferable to use the above-mentioned organic solvent in combination as appropriate.

The type and amount of the organic solvent may be determined according to the purpose. For example, the organic solvent is selected so that the boiling point of the liquid composition is 40 to 200 ° C, preferably 50 to 150 ° C. The content ratio is usually preferably as small as possible, but is preferably about 20% by weight in the composition at the maximum.
When the boiling point of the liquid composition is lower than the above range, there may be a safety problem due to the flammability of the solvent. On the other hand, at a temperature higher than the above range, the organic solvent remains in the encapsulant layer even after curing. A decrease in transmittance may occur.

Further, when the content ratio of the organic solvent exceeds the above range, curing shrinkage may occur due to volatilization of the solvent when the sealing material is heat-cured, and it should be originally separated by its dissolving power (A), ( B) Both components may become a uniform solution, and the effects of the present invention may not be obtained.
Furthermore, since the solvent is vaporized during the curing, the light transmittance of the cured sealing material may be deteriorated by the bubbles.

The upper limit of the content of the preferred organic solvent is 10% by weight, more preferably 7% by weight.
The silicone-based sealing material composition of the present invention is preferably used as a two-pack type because the stability during storage becomes good.
When the one-pack type is used, the convenience at the time of use becomes high, but it is necessary to consider such as storing in a freezer at the time of storage or limiting the usable period to be short.

<4. Semiconductor light emitting device>
The silicone-based sealing material composition of the present invention can be preferably used as a sealing material for semiconductor light-emitting devices.
The semiconductor light-emitting device of the present invention includes a package comprising a metal member corresponding to a lead electrode and a resin molded body having a recess having a bottom surface and a side surface from which a part of the metal member can be exposed, And a light emitting element electrically connected to the metal member and a sealing material filled in the recess.
In this semiconductor light emitting device, by using the silicone-based encapsulant composition according to the present invention as an encapsulant, the permeability of sulfur such as moisture and sulfur-containing compounds can be reduced, and lead electrodes and the like can be reduced. The reflectance of the metal member can be effectively maintained over a long period.

A specific example of a semiconductor light emitting device is shown in FIG.
The semiconductor light-emitting device 5 generally seals the semiconductor light-emitting element 2, the resin molded body 1 constituting the outer shell of the entire device, the bonding wire that electrically connects the semiconductor light-emitting element 2 and the lead electrode 4, and the semiconductor light-emitting element. It is comprised from the sealing material 3, the lead electrode 4 etc. which supply electricity to a semiconductor light-emitting device. In addition, the structure which consists of conductive metal wirings, such as a lead electrode, and an insulating resin molding is called a package.
The material of the lead electrode is not particularly limited, and examples thereof include one containing two or more kinds of silver-white metals such as silver (Ag), aluminum (Al), platinum group elements, nickel (Ni), etc. Silver or a silver alloy having a high light reflectance is preferably used.

For example, the light reflectance of the lead electrode 4 is preferably 70% or more, more preferably 80% or more, and still more preferably 85% or more for light having a wavelength of 460 nm. By using a lead electrode having a high light reflectance, the light emission efficiency of the entire light emitting device is increased.
The resin molded body 1 constituting the package maintains the outer structure of the semiconductor light emitting device and reflects light from the semiconductor light emitting element emitted in all directions in the light emitting direction of the semiconductor light emitting device. It also has the functions of improving the light output of the light emitting device and insulating the positive and negative lead electrodes.

  The reflective material that can be used in the semiconductor light emitting device of the present invention is not particularly limited as long as it has an insulating property and can reflect light. In the light concentration range, the reflective material and the lead electrode are likely to be deteriorated by light energy, leading to a decrease in luminance of the semiconductor light emitting device over time. Therefore, the reflective material used in the present invention is preferably a highly durable material. .

Specifically, non-resin-type reflectors such as ceramics and resin-type reflectors such as silicone resins and polyamide resins are preferably used. Among these, resin-type reflectors are used from the viewpoint of moldability and cost. preferable.
As a material of such a resin-type reflective material, the silicone-based encapsulant composition of the present invention is similar to the resin composition, and the one using a silicone resin has good adhesion between the two, at the time of molding or This is preferable because there is less risk of peeling during use. In general, the silicone resin-based reflective material contains a light-reflective filler such as titania or alumina in addition to the thermosetting polyorganosiloxane as the main component.

Further, the shape of the reflecting material is not particularly limited, but a cup shape having a tapered side surface as shown in FIG. 1 is preferable because it can provide directivity to light.
In addition to the semiconductor light emitting device having the package type structure described above, as a form of the semiconductor light emitting device, a wiring substrate for chip-on-board mounting in which a light emitting element is directly mounted on a substrate and sealed with a sealing material layer may be used. .

Furthermore, as described above, the phosphor can be contained in the silicone-based encapsulant composition of the present invention so that the light emitting element is sealed, and at the same time, light having a desired wavelength such as white light can be extracted from the light emitting device. It is.
The light emitting device of the present invention can be manufactured, for example, according to the following procedures (1) and (2).

(1) Assembly of light emitting device Using a commercially available package for a semiconductor light emitting device, a semiconductor light emitting element having a desired light emission wavelength (eg, 460 nm) is conductively bonded to the lead electrode exposed in the recess of the package. After installing using a material, the die bond material is cured by heating, the semiconductor light emitting device is mounted on the package, and the other lead electrode of the package is connected to the semiconductor light emitting device using a bonding wire such as a gold wire. To do.

(2) Sealing of semiconductor light emitting device Subsequently, a sealing material composition is dropped and charged into the recess of the package so as to be the same height as the upper edge of the opening, and the sealing material is subsequently kept under a predetermined temperature condition. The composition is heat-cured to seal the semiconductor light-emitting element, thereby manufacturing a semiconductor light-emitting device.
Since the semiconductor light-emitting device of the present invention uses the above specific silicone-based encapsulant composition, the semiconductor light-emitting device is excellent in sulfur resistance and can be an excellent semiconductor light-emitting device capable of maintaining the reflectance of the lead electrode over a long period of time.

Hereinafter, specific embodiments of the present invention will be described in more detail using examples, but the present invention is not limited to these examples.
1. Preparation of Silicone Sealant Composition (1) Silicone Resin The silicone resin used in the composition of this example is as follows.
(A) Component As the bifunctional thermosetting silicone resin of the component (A), “S111” (main component: dimethylpolyorganosiloxane, weight average molecular weight: 13000, functionality: 2.08, manufactured by Mitsubishi Chemical Corporation) Liquid at normal temperature, density: 0.98 g / ml) was used.
(B) component (B) polyfunctional thermosetting silicone resin used for the Example was prepared as follows.
In a 1 L separable flask, 100 parts by weight of methyltrichlorosilane and 200 parts by weight of toluene were placed, and while cooling with a circulation cooler, 10 parts by weight of water, 50 parts by weight of methanol,
And 10 parts by weight of isopropanol was added dropwise over 10 hours with the internal temperature maintained at 0 ° C. After completion of the dropwise addition, the mixed alcohol of the solvent was refluxed by heating to 80 ° C. for 20 minutes. Thereafter, the mixture was cooled to room temperature, and 10 parts by weight of water was added dropwise over 30 minutes while cooling so that the internal temperature did not exceed 30 ° C. Further, 25 parts by weight of water was added dropwise over 10 minutes, followed by stirring at 50 ° C. for 1 hour.

200 parts by weight of water was added and allowed to stand, and the separated organic layer was collected and washed repeatedly with water until neutral. Water was dehydrated by heating from the separated organic layer. After filtration, water was further distilled off under reduced pressure to obtain a colorless and transparent thermosetting silanol group compound having a melting point of 75 to 80 ° C.
The obtained compound is a polyfunctional thermosetting silicone resin having a weight average molecular weight of 4000, a functionality of 3.15, a melting point of 75 to 80 ° C., and a density of 1.14 g / cm ³ , mainly composed of methyltrimethoxysilane oligomer. there were.

  As a component corresponding to the component (B) used in the comparative example, “KC89S” (manufactured by Shin-Etsu Chemical Co., Ltd.), which is a polyfunctional thermosetting silicone compound that is liquid at room temperature (that is, a melting point of 30 ° C. or less), is used. did.

(2) Two-pack type sealing material composition 1) First liquid The following components (A) and (B) were mixed at the ratio shown in Table 1 to obtain a first liquid of the sealing material composition. In addition, since the component (B) prepared above is solid at room temperature, when preparing the first liquid of the sealing material, it is pulverized to a particle size of about 100 μm and then mixed with the component (A). And used as a dispersion form.
However, in Comparative Example 1, the component (B) was used alone, and in Comparative Example 2, only the component (A) was used. In Comparative Example 3, “KC89S”, which is a polyfunctional thermosetting silicone compound that is liquid at room temperature, was used in place of the polyfunctional thermosetting silicone resin prepared above.

2) Second liquid (C) As the curing catalyst, an aliphatic hydrocarbon solvent solution containing 2% by weight of zirconium tetra (2-ethylhexanoate) was used as the second liquid.

The usage-amount of the 2nd liquid was adjusted so that it might become 0.1 weight% as a metal zirconium with respect to the total amount of (A) and (B).
2. Curing of encapsulant and exposure test to sulfur atmosphere Mix the above two-component encapsulant composition into a package having a silver lead electrode (“High Power LED Package 90 × 90” manufactured by Kanamori Tohei Corp.) The sealing material composition was cured by heating in a constant temperature oven at 150 ° C. for 3 hours.

The sealed package is affixed to a large slide glass with a width of 5 cm and a length of 8 cm using double-sided tape, and the package is affixed to a petri dish (diameter 6 cm, depth 1.5 cm) in which 1 g of sulfur powder has been spread evenly. It was mounted so that the attached side faced the sulfur powder.
This petri dish was further stored in a large petri dish (diameter 15 cm, depth 4.5 cm), and the petri dish was covered with an upper lid, and the side of the large petri dish was sealed with a fluororesin seal tape (manufactured by Three Bond Co., Ltd.). And sealed.
This was held in a constant temperature oven at 80 ° C. for 6 hours, and then taken out and evaluated for the discoloration state of the package by the following method.

3. Measurement / Evaluation (1) Light reflectance The reflectance of the package at 350 nm to 750 nm was measured using a reflectance measuring device (CM-2600d, manufactured by Konica Minolta Co., Ltd.).
The package before sealing and the package sealed with each sealing material composition were set on the probe of the measuring instrument, and the reflectance before and after the sulfur atmosphere exposure test was measured.
As a result of the measurement, the order of the reflectivity between the samples did not change in the entire range of the above wavelength range. Therefore, the light reflectivity was evaluated using 550 nm as a representative wavelength, and the light reflectivity at this wavelength was used. The rate maintenance rate was used.

(2) Coloring degree The coloring conditions of the unsealed package and the sealed package before and after exposure to the sulfur atmosphere were visually observed and evaluated according to the following criteria.

A: No coloration is observed. B: A slight coloration may be observed partially, but almost no coloration is observed. Δ: Clear coloration is clearly observed. X: Significant coloration is observed.

(3) Foaming About the sealed package, the foaming state of the sealing material layer was observed before exposure to the sulfur atmosphere, and evaluated according to the following criteria.
○: No foaming is observed Δ: Small amount of foaming is observed ×: Foaming is remarkable

4). Evaluation of results (1) Examples 1 to 5 in which (A) component and (B) component have characteristic values specified in the present application and have a composition ratio specified in the present application, ) As compared with Comparative Example 2 in which the component is used alone, the reflectance is maintained and the degree of coloring is good. Similarly, even in comparison with Comparative Example 1 in which the component (B) is used alone, the foamability is suppressed and an excellent reflectance is maintained.
(2) In Comparative Example 3 using a component (B) that deviates from the molecular weight regulation, the reflectance retention rate is lower than the corresponding Example 3, and the sulfur resistance is insufficient. It is seen that there is.

DESCRIPTION OF SYMBOLS 1 Resin molding 2 Semiconductor light-emitting device 3 Sealing material 4 Lead electrode 5 Semiconductor light-emitting device

Claims (8)

A silicone-based sealing material composition comprising (A) a bifunctional thermosetting silicone resin, (B) a polyfunctional thermosetting silicone resin, and (C) a curing catalyst, the silicone having the following characteristics System sealing material composition.
1) The ratio of (B) in the total amount of (A) and (B), the value of (B) / ((A) + (B)) (weight ratio) is 0.5 / 100 or more, Less than 100/100 2) Functionality of component (B) is 2.5 or more and 4.0 or less 3) Weight average molecular weight of component (B) is 1000 to 10,000
4) At 80 ° C., (A) and (B) are not compatible, and the density of (B) at the temperature is 0.01 g / cm ³ or more higher than the density of (A).   2. The silicone-based sealing material according to claim 1, which is a two-component composition comprising a liquid composition containing (A) and (B) and a liquid composition containing (C). Composition.   The melting point of any one of (A) and (B) is 25 ° C. or lower, and the other melting point is 30 to 100 ° C. 3. The silicone-based sealing material composition according to claim 1 or 2, .   The ratio of (B) in the total amount of (A) and (B), (B) / ((A) + (B)) (weight ratio) is 1/100 or more and 50/100 or less. The silicone type sealing material composition according to any one of claims 1 to 3.   (C) Content of a curing catalyst is 0.01 to 0.5 weight% with respect to the total amount of (A) and (B), The any one of Claims 1-4 characterized by the above-mentioned. The silicone-based sealing material composition according to Item.   (C) Tin (Sn), zinc (Zn), iron (Fe), titanium (Ti), zirconium (Zr), bismuth (Bi), hafnium (Hf), yttrium (Y), aluminum as a metal component as a curing catalyst The organic complex or organic acid salt of at least one metal selected from the group consisting of (Al), boron (B), and gallium (Ga), according to any one of claims 1 to 5, Silicone-based sealing material composition.   Furthermore, (D) 0.05 to 1 weight% of polyfunctional polyorganosiloxanes having a weight average molecular weight of 300 to 800 are contained with respect to the total amount of (A) and (B). The silicone type sealing material composition of any one of -6. A semiconductor light-emitting device which is sealed with the silicone-based sealing material composition according to claim 1.

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