JP2012238767A - Resin composition for semiconductor light-emitting device package, semiconductor light-emitting device package and manufacturing method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor light-emitting device package having moderate hardness and excellent reflectance.SOLUTION: A resin composition for a semiconductor light-emitting device includes (A) polyorganosiloxane having an aromatic group bonded to silicon atoms composing a main chain, (B) a white pigment of a mixture of titania and alumina in which a ratio of the both in the mixture is represented as titania/alumina=2/98-50/50 (weight ratio), and (C) cure catalysis.

Description

  The present invention relates to a silicone resin composition used for a package or a substrate for a semiconductor light emitting device, and relates to a composition and a package having good moldability and high reflectance of the obtained semiconductor light emitting device.

  A light-emitting device using a semiconductor light-emitting element is small, has high power efficiency, and has a bright emission color. Further, the semiconductor light emitting device has good durability without worrying about a broken ball. Furthermore, it has excellent initial drive characteristics and is strong against repeated on / off of vibration and lighting. Because of such excellent characteristics, light-emitting devices using light-emitting elements such as light-emitting diodes (LEDs) and laser diodes (LDs) are used as various light sources including various lighting fixtures.

Such a semiconductor light emitting device includes a lead and an electric package in a semiconductor light emitting device package (hereinafter simply referred to as a “package”) having a resin molded body in which a lead and a resin composition are integrally molded. The basic structure is a structure in which light-emitting elements that are connected to each other are mounted and the light-emitting elements are covered with a sealing material.
As a material of the resin molded body constituting this package, a thermoplastic resin composition in which a white pigment is blended as a reflective material for increasing light reflection efficiency in a thermoplastic resin such as polyamide has been widely used. It has been pointed out that the reflow soldering condition in the manufacturing process of the semiconductor light emitting device uses a high melting point lead-free solder for avoiding the use of lead, so that the processing temperature becomes high and the heat resistance is insufficient.

Thus, it has been proposed to use a thermosetting resin such as an epoxy resin or a silicone resin excellent in heat resistance instead of the thermoplastic resin for the package (see Patent Documents 1 and 2).
Patent Document 1 describes a resin molded body excellent in mass productivity and a method for manufacturing a surface mount light emitting device, in which a lead and a resin are integrally molded by a transfer molding method. Patent Document 2 describes a silicone resin composition having excellent solder heat resistance and good durability, a package based thereon, and a light emitting device.

  However, the resin used for the package for the semiconductor light emitting device is required to be further improved in mass productivity, and the liquid injection molding method is attracting attention as a molding method, and a silicone resin composition suitable for this molding method is desired. It has been.

JP 2006-156704 A JP 2009-21394 A JP 2009-164275 A

  In the transfer molding method disclosed in Patent Document 1, since a raw material composition that is solid at room temperature is used, a thermosetting resin composition containing a large amount of polar groups and rigid organic groups without using an aromatic component, and a semi-solid composition are used. A curable epoxy compound can be used. However, since the obtained cured product is a resin mainly composed of an organic skeleton, the heat resistance is not sufficient. Moreover, since the refractive index of these thermosetting resins is also high, it is difficult to obtain a package having a high reflectance in a wide wavelength range because only a composition mainly using titania can be selected as a reflecting material. In addition, transfer molding has a longer molding cycle than injection molding, is not suitable for mass production, and has a problem in the degree of freedom in selecting the shape of a molded product. Furthermore, in order to manufacture a large number of pieces in one shot, there is a problem in terms of capital investment, such as requiring an expensive dicer.

  The liquid injection molding method can solve such problems, but in order to be applied to this molding method, the silicone resin composition needs to be thermosetting and fluid at normal temperature. For this reason, many of the packages obtained are relatively flexible, and it is difficult to detach from the mold during molding, or the resulting package is excessively flexible and the lead and resin may peel off after molding. There was a thing.

  Patent Document 2 and Patent Document 3 use a composition containing silicone resin and titania or alumina, respectively, as a material for a package for a semiconductor light emitting device, thereby providing a semiconductor light emitting device package with good heat resistance. It is supposed to be obtained. Although these methods can provide a corresponding improvement effect, the composition state is almost solid to semi-solid, and can be used for liquid injection molding, although compression molding and transfer molding are possible. It was not obtained.

  The present invention solves the above-mentioned problems of the prior art, and has a high reflectance and a suitable hardness for a semiconductor light emitting device package suitable for liquid injection molding, and a silicone resin composition obtained therefrom. An object is to provide a package and a semiconductor light emitting device using the same.

As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that the following invention can achieve the above object, and have reached the present invention.
The resin composition for a semiconductor light emitting device package of the present invention is characterized by the following points.
(1) (A) a polyorganosiloxane having an aromatic group bonded to a silicon atom constituting the main chain, (B) a mixture of titania and alumina, the mixing ratio of titania / alumina = 2 / 98-50 A resin composition for a semiconductor light emitting device package, comprising a white pigment containing a mixture of / 50 (weight ratio), and (C) a curing catalyst.
(2) (A) 10 to 900 parts by weight of white pigment and (C) 1 to 100 ppm by weight of curing catalyst per 100 parts by weight of polyorganosiloxane. Furthermore, it is also a preferable aspect that (D) 2 to 300 parts by weight of a fluidity modifier is contained.
Furthermore, the following aspects (3) to (5) are more preferable.
(3) The viscosity at a shear rate of 100 s ⁻¹ at 25 ° C. is from 10 Pa · s to 10,000 Pa · s.
(4) The Shore D hardness (according to JIS K6253) of the molded body is 50 or more.
(5) The light reflectance measured on the condition of a wavelength of 460 nm for a molded sample having a thickness of 0.4 mm is 80% or more.
(6) Moreover, the package for semiconductor light-emitting devices which is another aspect of this invention is obtained by liquid injection-molding the resin composition which has the characteristics in any one of said (1)-(5).
(7) Furthermore, in the liquid injection molding method, it is preferable to use a manufacturing method including the following steps.
<First Step> A first gold having a concave portion corresponding to the shape of a semiconductor light emitting device package having a bottom portion and a concave portion and integrally formed with a lead, and a convex portion corresponding to the shape of the concave portion of the molded body A step of sandwiching the lead between the mold and the second mold;
<Second Step> The resin composition for a semiconductor light emitting device package described in any one of (1) to (5) above, in a space portion formed between the recessed portion of the first mold and the lead. Filling a product by liquid injection molding,
<Third Step> A step of heating and curing the filled resin composition for a semiconductor light emitting device package.
(8) A semiconductor light-emitting device in which a semiconductor light-emitting element electrically connected to a lead is placed on the package for a semiconductor light-emitting device and is covered with a sealing material is provided.

  According to the present invention, there is provided a silicone resin composition for a semiconductor light emitting device package having a high reflectivity and suitable hardness suitable for a liquid injection molding method, a package obtained therefrom, and a semiconductor light emitting device using the same Provided.

It is a graph which shows the measurement result of the reflectance of each test piece in the present invention. It is a schematic sectional drawing which shows an example of the semiconductor light-emitting device using the package of this invention. It is a schematic sectional drawing which shows the semiconductor light-emitting device concerning other embodiment of this invention. It is a schematic sectional drawing which shows the semiconductor light-emitting device concerning other embodiment of this invention.

Hereinafter, a composition for a semiconductor light emitting device package, a package for a semiconductor light emitting device, and a semiconductor light emitting device using the same according to the present invention will be described using embodiments and examples thereof.
<1. Composition for Semiconductor Light Emitting Device Package>
Hereinafter, the characteristic and each component of the composition for semiconductor light-emitting device packages of this invention are demonstrated more concretely.
<1.1 Characteristics of Composition for Semiconductor Light Emitting Device Package>
(1) Composition The composition for a semiconductor light emitting device package of the present invention is (A) a polyorganosiloxane having an aromatic group bonded to a silicon atom constituting the main chain (hereinafter abbreviated as “aromatic polyorganosiloxane”). (B) a white pigment containing a mixture of titania and alumina, the mixture ratio of which is titania / alumina = 2/98 to 50/50 (weight ratio) (hereinafter referred to as “mixed white pigment”) And (C) a curing catalyst.

A preferable composition is (A) 10 to 900 parts by weight of a mixed white pigment and (C) a curing catalyst per 100 parts by weight of a polyorganosiloxane having an aromatic group bonded to a silicon atom constituting the main chain. 1 to 100 ppm by weight, and (D) 2 to 300 parts by weight of a fluidity modifier is preferably contained.
The more preferable content of (B) the mixed white pigment in the composition is 30 to 600 parts by weight, more preferably 50 to 300 parts by weight, per 100 parts by weight of (A) aromatic polyorganosiloxane.

By setting the content of the mixed white pigment in the above range, it is possible to achieve viscosity characteristics suitable for molding processing and high reflection efficiency of the molded product.
The total weight ratio of (B) white pigment and (D) fluidity modifier in the resin composition, including the case where (D) fluidity modifier is used in combination, is 50% by weight or more. Is more preferable, 60% by weight or more is more preferable, and 65% by weight or more is particularly preferable. The upper limit of the weight ratio is preferably 85% by weight or less, and more preferably 80% by weight or less. If the total weight ratio is higher than this, the viscosity of the thermosetting silicone resin composition tends to be too high and the fluidity tends to be inferior, the composition cannot be transferred, or it may not be transferred to a part of the mold during molding. Filling (short mold) is likely to occur. On the other hand, if the amount is less than the lower limit, the reflectivity when the thin molded body is formed becomes low, or the viscosity becomes too low and burrs and fog are likely to occur during molding.

As the white pigment (B), a mixture containing at least titania and alumina is used, and the ratio of both in the mixture needs to be titania / alumina = 2/98 to 50/50 (weight ratio).
When the titania content is less than the above range, the refractive index difference between (B) the white pigment and (A) the polyorganosiloxane having an aromatic group bonded to the silicon atom constituting the main chain is small enough. On the other hand, when the titania content is increased beyond the above range when the reflectance is not obtained, the light emitted from the semiconductor light emitting element when using a semiconductor light emitting element having a wavelength of about 470 nm or less due to the photocatalytic property of titania, The light emitted from the phosphor excited by the light significantly deteriorates the resin molded body (package) in the vicinity of the titania particles. In particular, when a semiconductor light-emitting element that emits light in the blue region or near-ultraviolet region is used, the light resistance of the resin molded product is significantly deteriorated. Further, as the titania ratio increases, the durability of the material tends to decrease.

Since titania has a large refractive index and a large refractive index difference from the silicone resin, it has a characteristic that the reflectance when formed is high, but the titania / alumina mixing ratio in the white pigment should be in the above range. As a result, the reflectance is improved more than expected from the ratio of the titania content, and a decrease in light resistance due to titania can be suppressed as much as possible.
A white pigment other than titania and alumina may be used in the mixed white pigment, but the total content of titania and alumina in the mixed white pigment is preferably 70% by weight or more, more preferably 90% by weight or more. . Most preferably, the total amount is composed of only titania and alumina (total ratio is 100% by weight). If the total ratio of titania and alumina in the white pigment is less than 70% by weight, the above effect may be diluted and the effect may not be sufficiently obtained.

  The content of the (C) curing catalyst is preferably 1 to 100 ppm by weight as the catalyst metal concentration per 100 parts by weight of the (A) polyorganosiloxane. By setting the content of the curing catalyst within the above range, curing proceeds sufficiently quickly during molding, and curing is difficult to occur during storage, that is, without heating, thereby extending the pot life of the composition. It is possible.

  If the catalyst content is less than the above range, the reaction does not proceed sufficiently at the time of molding, so there is a risk of curing failure or exudation from the mold, while if there is a large amount of catalyst beyond the above range, Curing progresses in the middle of filling the mold during molding, and the resulting molded product does not sufficiently reproduce the mold shape, which tends to cause molding defects.

(2) Hardness of molded product The hardness (Shore D) of the molded product obtained from the composition for semiconductor light emitting device package of the present invention is preferably 50 or more. The upper limit of Shore D hardness is usually 90.
By setting the hardness of the molded product within the above range, an appropriate stiffness can be imparted to the product semiconductor light emitting device package while maintaining good mold release properties at the time of molding.
The hardness of the molded product can be increased by increasing the aromatic group content ratio of the polyorganosiloxane (A) used in the semiconductor light emitting device package composition or by increasing the crosslinking density. ) It is also increased by increasing the amount of white pigment.

(3) Viscosity The viscosity of the resin composition for a semiconductor light emitting device package of the present invention at a shear rate of 100 s ⁻¹ at 25 ° C. is preferably 10 Pa · s or more and 10,000 Pa · s or less.
More preferable viscosity is 50 Pa · s or more and 5,000 Pa · s or less, and further preferably 150 Pa · s or more and 1,000 Pa · s or less.
If the viscosity at a shear rate of 100 s ⁻¹ is greater than 10,000 Pa · s, the resin will have poor fluidity, so that the mold will be insufficiently filled, and it will take time to supply the raw material composition when performing injection molding. As a result, the molding cycle becomes longer and the molding efficiency tends to decrease.

On the other hand, if the viscosity is less than 10 Pa · s, the raw material composition leaks from the gaps between the molds and burrs are generated, or the injection pressure easily escapes into the gaps between the molds and the molding becomes unstable. Again, the molding efficiency tends to decrease. In particular, when the compact is small, it is difficult to remove burrs. Therefore, suppression of burrs is important in terms of molding efficiency.
It should be noted that if the gap between the molds is excessively reduced in order to suppress the generation of burrs, another problem such as a short mold (unfilled) is likely to occur.

Furthermore, the composition of the present invention is a ratio of viscosity at 25 ° C. shear rate 1 s ⁻¹ to viscosity at 25 ° C. shear rate 100 s ⁻¹ (viscosity (1 s ⁻¹ ) / viscosity (100 s ⁻¹ )). ) Is preferably 15 or more and 500 or less, and more preferably 30 or more and 300 or less.
When the ratio of the viscosity at a shear rate of 1 s ⁻¹ to the viscosity at a shear rate of 100 s ⁻¹ at 25 ° C. is less than 15, that is, when the viscosity at the shear rate of 1 s ⁻¹ is relatively small, It may be difficult to control molding, such as the material can easily enter the gap and burrs are easily generated, liquid is easily dripped at the nozzle, the injection pressure is not easily transmitted to the material, and molding is difficult to stabilize. is there. In liquid injection molding, resin leakage in the sprue parting line tends to be a problem, but adjusting to the above viscosity range is effective in suppressing resin leakage.

The viscosity at a shear rate of 100 s ⁻¹ at 25 ° C. and the viscosity at a shear rate of 1 s ⁻¹ are measured using, for example, an ARES-G2-strain-controlled rheometer (manufactured by TI Instruments Japan Co., Ltd.). be able to.
By using a composition with viscosity behavior as described above, there are few burrs and short molds (unfilled) during molding, material weighing time and molding cycle can be shortened, molding is easy to stabilize, molding efficiency Can be high.

  In general, the viscosity of the resin composition tends to be high when titania alone is used, but in the present invention, it is easy to adjust the particle size distribution of both by using a mixed system of alumina and titania. It becomes easier to control.

<1.2 Components of Composition for Semiconductor Light Emitting Device Package>
(1) (A) Aromatic polyorganosiloxane Polyorganosiloxane is a polymer material in which an organic group is added to a structure in which a silicon atom is bonded to another silicon atom through oxygen. Those having an aromatic group bonded to silicon atoms constituting the main chain of the polyorganosiloxane (hereinafter sometimes referred to as “aromatic polyorganosiloxane”) are used.

The aromatic polyorganosiloxane is preferably a liquid at normal temperature and pressure. This is because the material can be easily handled when the resin molded body is manufactured. The polyorganosiloxane is represented by the following general composition formula (1).
(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)
Here, in the above formula (1), R ¹ to R ⁶ are independently an optionally substituted hydrocarbon group or a hydrogen atom. M, D, T, and Q are 0 or more and less than 1, and M + D + T + Q = 1.

In the aromatic polyorganosiloxane used in the present invention, in formula (1), at least one of R ¹ to R ⁶ is an aromatic group, and examples of the aromatic group include an aryl group, an aralkyl group, and a naphthyl group. In the present invention, an aromatic group having 6 to 20 carbon atoms is preferable, and a phenyl group is particularly preferable.
The content of the aromatic group is preferably 3 to 40% (equivalent ratio) in the total substituents. By setting it as the said range, it is possible to obtain the molded article excellent in the balance of appropriate molded article hardness and yellowing resistance. If the content is less than 3%, the hardness may be insufficient and the “koshi” of the molded product may be insufficient. On the other hand, if the content exceeds 40%, the viscosity of the polyorganosiloxane itself increases. The handleability may be deteriorated due to the increase, and the yellowing resistance of the molded product may be insufficient.

As the substituent (R ^{1 to} R ⁶ ) bonded to silicon of the main chain other than aromatic, for example, an alkyl group having 1 to 20 carbon atoms, an alkenyl group, an alkoxy group and the like are preferable, and in particular, a methyl group, an ethyl group, A vinyl group, an allyl group, and the like are preferable because they have a good balance between durability and curing reactivity.
In general, polyorganosiloxane can be cured by applying heat energy, light energy or the like in the presence of a curing catalyst. Here, the presence or absence of curing can be determined from the presence or absence of flow after standing for 30 minutes with the composition tilted 45 degrees from the horizontal.

  The polyorganosiloxane is classified into an addition polymerization curing type, a condensation polymerization curing type, an ultraviolet curing type, a peroxide crosslinking type, and the like depending on the curing mechanism, but in the present invention, an addition polymerization curing type (addition type polyorganosiloxane), Further, a condensation-curing type (condensation-type polyorganosiloxane) is preferable, and an addition-type polyorganosiloxane that has no by-product during the curing reaction and cures by hydrosilylation, which is an irreversible reaction, is more preferable.

If a by-product is generated during the curing reaction, the pressure in the molding container may be increased, or it may remain as bubbles in the molded material.
The addition-type polyorganosiloxane is produced by reacting, for example, a silicon-containing compound having an alkenyl group such as vinylsilane and a silicon compound having a hydrosilyl group such as hydrosilane using a catalyst such as a platinum catalyst. A C-Si bond is a crosslinking point.

Examples of the condensed polyorganosiloxane include compounds having a Si—O—Si bond obtained by hydrolysis and polycondensation of an alkylalkoxysilane as a crosslinking point.
The viscosity of the aromatic polyorganosiloxane used in the present invention is usually 100,000 mPa · s or less, preferably 20,000 mPa · s or less, more preferably 10,000 mPa · s or less, for ease of handling. The lower limit is not particularly limited, but is preferably 15 mPa · s or more from the viewpoint of volatility (boiling point) and exuding property to the mold gap during liquid injection molding.

Moreover, as a weight average molecular weight (polystyrene conversion) of polyorganosiloxane, it is preferable that it is 500 or more and 100,000 or less, and 700 or more and 50,000 or less are more preferable.
Among these, considering the tackiness of the mold due to the low molecular weight component, mold contamination, or bleeding from the molded product, the lower limit of the weight average molecular weight is preferably 1,000, while considering the handleability of the composition The upper limit is 40,000, particularly preferably 30,000. The weight average molecular weight can be measured according to a conventional method using a gel permeation chromatography method.

  The aromatic polyorganosiloxane used in the present invention is slightly higher in refractive index of about 1.43 to 1.53 than polyorganosiloxane composed of aliphatic substituents (refractive index: about 1.41). However, in the combination using titania as the white pigment of the present invention, the difference in refractive index between the two is sufficiently large. Therefore, the hardness of the molded product can be improved while maintaining an excellent reflectance.

  As described above, the hardness can also be increased by increasing the crosslink density of the silicone resin, but at this time, the molded product tends to become brittle, and there is a risk of damage after molding or deterioration of workability. .

(2) (B) White pigment (B) The white pigment used in the present invention is a mixture (mixed white pigment) containing at least titania and alumina in a ratio of 2/98 to 50/50 (weight ratio). ).
As the alumina used in the present invention, those having an aspect ratio of primary particles of 1.2 to 4.0 and a primary particle diameter of 0.1 to 2.0 μm are preferable because the reflectance can be increased. A more preferable primary particle diameter is 0.2 to 1.0 μm.
Alumina has a low ultraviolet-absorbing ability, and therefore can be suitably used particularly when an ultraviolet to near-ultraviolet light emitting element is used as the light emitting element. As the alumina used in the present invention, α-alumina having characteristics such as chemically stable, high melting point, high mechanical strength and hardness, and high electric insulation resistance is preferable.

In addition, the alumina used in the present invention preferably has a crystallite size of 500 to 2,000, more preferably 700 to 1,500, and particularly preferably 900 to 1,300. . A crystallite is the largest group that can be regarded as a single crystal.
When the crystallite size of the alumina crystal is in the above range, it is preferable in that the wear of piping, screws, molds, etc. during molding is small, and therefore impurities due to wear are difficult to be mixed.

As for the crystallite size, the crystallite diameter (crystallite size) can be calculated according to Scherrer's equation from the half width of the X-ray diffraction measurement.
Specific examples of such alumina include A30 series, AN series, A40 series, MM series, LS series, AHP series manufactured by Nippon Light Metal Co., Ltd., “Admafine Alumina” (trade name) AO-5 type, AO manufactured by Admatechs. -8 type, CR series manufactured by Nippon Bikosky Co., Ltd., Tymicron manufactured by Daimei Chemical Industry Co., Ltd., 10 μm ² diameter alumina powder manufactured by Aldrich, A-42 series, A-43 series, A-50 series manufactured by Showa Denko KK, AS Series, AL-43 series, AL-47 series, AL-160SG series, A-170 series, AL-170 series, Sumitomo Chemical AM series, AL series, AMS series, AES series, AKP series, AA series etc. Can be mentioned.

In general, alumina has higher durability than titania, and when titania is used in combination, the durability of the material tends to decrease as the titania ratio increases, while titania has a large refractive index and a difference in refractive index from the resin. Since it is large, the reflectance becomes high.
In the present invention, it has been found that by adding titania to alumina, the reflectance is improved more than expected from the weight ratio of titania, and the amount of alumina is less than alumina (weight ratio of 50/50 or less). By using this titania together, a composition capable of suppressing the decrease in durability as much as possible while increasing the reflectance of the material has been achieved. If the titania ratio is too small, such as less than 2/98, a sufficient reflectance improvement effect cannot be obtained. By adding titania to alumina in the above range, the reflectance of light having a wavelength of 420 nm or more can be made higher than when alumina alone is used, and the ratio of the white pigment in the material is small, Even when the thickness is small, the reflectance tends to be difficult to decrease, which is preferable.

By using a mixed white pigment combined with titania, the amount of white pigment used to obtain the same reflectance can be reduced, so the degree of freedom in the composition of the resin composition is increased, and the amount of components other than the white pigment can be reduced. You can do more.
Further, the combined use of titania is very advantageous because the reflectance is increased even when the thickness of the molded body is thin, and the degree of freedom of the shape of the resin molded body is increased. In particular, the effect of improving the brightness of the semiconductor light emitting device can be expected by increasing the reflectance of the material even in a thin resin molded body (package) whose thickness cannot be increased.

The titania that can be used in the present invention preferably has a rutile crystal system that is stable even at high temperatures, has a high refractive index, and has a relatively good light resistance, and has a primary particle diameter of 0.2 to 1.0 μm. In order to suppress the photocatalytic property, titania having a particle surface coated with a thin film of silica or alumina is preferable.
Specific examples of titania include TA series and TR series manufactured by Fuji Titanium Industry Co., Ltd., TTO series, MC series, CR-EL series, PT series, ST series, FTL series, and TYPE WHITE manufactured by Ishihara Sangyo Co., Ltd. Can be mentioned.

  Examples of white pigments that can be used in the present invention in addition to alumina and titania include various inorganic powders and resin fine particles. Specifically, examples of inorganic powders include zinc oxide, magnesium oxide, and zirconium oxide. Metal oxides: Metal salts of calcium carbonate, barium carbonate, magnesium carbonate, barium sulfate, etc .; boron nitride, colloidal silica, aluminum silicate, zirconium silicate, aluminum borate, clay, talc, kaolin, mica, synthetic mica, etc. Examples of the resin fine particles include fluorine resin particles, guanamine resin particles, melamine resin particles, acrylic resin particles, and silicone resin particles.

(3) (C) Curing Catalyst The (C) curing catalyst in the present invention is a catalyst for curing the polyorganosiloxane of (A). This catalyst includes an addition polymerization catalyst and a condensation catalyst depending on the curing mechanism of the polyorganosiloxane.
The addition polymerization catalyst is a catalyst for accelerating the addition reaction between a reactive double bond and a hydrosilyl group in polyorganosiloxane, such as platinum black, platinous chloride, chloroplatinic acid, chloroplatinic acid. And platinum group metal catalysts such as platinum-based catalysts such as platinum bisacetoacetate, palladium-based catalysts, rhodium-based catalysts, and the like.

The blending amount of the addition polymerization catalyst in the semiconductor light emitting device package composition is, as described above, (A) 100 parts by weight of the polyorganosiloxane, usually 1 ppm by weight or more, preferably 2 ppm by weight or more, and usually 2 ppm by weight or more. 100 ppm by weight or less, preferably 50 ppm by weight or less, more preferably 30 ppm by weight or less.
In addition, the said content is content as a weight of the metal (for example, platinum) in a catalyst, and a quantitative analysis is possible by ICP analysis of the metal component.

  As the condensation catalyst, acids such as hydrochloric acid, nitric acid, sulfuric acid and organic acids, alkalis such as ammonia and amines, organic boron compounds such as boron alkoxides, metal chelate compounds, etc. can be used. A metal chelate compound containing at least one metal selected from Al, Zn, and Ga can be preferably used. These catalysts are selected in consideration of stability when blended as a resin molding material for a semiconductor light emitting device, coating hardness, non-yellowing, curability and the like.

(4) (D) Fluidity modifier The composition for a semiconductor light emitting device package of the present invention further contains (D) a fluidity modifier for the purpose of controlling fluidity of the composition and suppressing sedimentation of a white pigment. It is preferable.
As the fluidity adjusting agent, for example, inorganic particles such as silica fine particles, quartz beads, and glass beads, inorganic fibers such as glass fibers, boron nitride, aluminum nitride, and the like are used, and solid particles that increase the viscosity of the composition when used are used. Is not particularly limited, but it has no or very small property of absorbing light from the light emitting element and light converted by the phosphor, and does not extremely reduce the reflectance of the molded material. Those having small discoloration and alteration due to heat and high durability are preferred.

Among them, silica fine particles having a large thixotropy-imparting effect, for example, having a specific surface area of 50 to 300 m ² / g by the BET method, can easily control the viscosity and viscosity behavior of the composition and can be suitably used. Quartz beads, glass beads, glass fibers, etc. are preferred because they can be expected not only as an effect of fluidity control, but also as an effect of increasing the strength and toughness of the material after thermosetting and an effect of reducing the linear expansion coefficient of the material. It may be used alone or in combination with the fine particles.

The thixotropy and fluidity can also be changed depending on the amount of (B) white pigment added, but the reflectance is affected by increasing or decreasing the amount of (B) component added. The adjustment is preferably performed by using a component other than (B) the white pigment.
Moreover, in order to adjust the viscosity of a thermosetting silicone resin composition, you may use the non-curable polyorganosiloxane which does not correspond to (A) component of this invention as a liquid thickener. As the polyorganosiloxane used in such a liquid thickener, the viscosity at 25 ° C. is usually 0.001 Pa · s to 3 Pa · s, preferably 0.001 Pa · s to 1 Pa · s, The hydroxyl number is usually 1.0 × 10 ^{−2 to} 7.7 × 10 ⁻⁵ mol / g, preferably 1.0 × 10 ^{−2 to} 9.5 × 10 ⁻⁵ mol / g, A linear organopolysiloxane containing a hydroxyl group (silanol group) bonded to at least one silicon atom is preferred.

  The amount of polyorganosiloxane used as the liquid thickener may be adjusted according to the target viscosity. (A) Polyorganosiloxane having an aromatic group bonded to the silicon atom constituting the main chain The amount is 10 parts by weight or less, 5 parts by weight or less, more preferably 3 parts by weight or less per 100 parts by weight. If the amount of the liquid thickener used is too large, the molded product may become excessively flexible or bleed from the molded product.

  Moreover, when (D) a flow regulator is added to the composition for semiconductor light-emitting device packages of this invention, it is preferable to consider the usage-amount comprehensively as a total amount with (B) white pigment. This is because it is necessary to consider the balance between reflectance and fluidity as described above.

(4) Other components In addition to the various components described above, the composition for a semiconductor light-emitting device package according to the present invention may include one or more other components as necessary without departing from the object and effect of the present invention. These components can be contained in any ratio and combination.

For example, it is preferable that the composition for a semiconductor light emitting device package further contains a curing rate control agent. Here, the curing rate control agent is for controlling the curing rate in order to improve the molding efficiency when molding the resin molding material, and includes a curing retarder or a curing accelerator.
The curing retarder is an important component particularly in the liquid injection molding of an addition polymerization type polyorganosiloxane composition having a high curing rate.

  Examples of the curing retarder used in the addition polymerization reaction include 3-hydroxy-3-methyl-1-butyne, 3-hydroxy-3-phenyl-1-butyne, and 3- (trimethylsilyloxy) -3-methyl-1-butyne. , Propargyl alcohols such as 1-ethynyl-1-cyclohexanol, maleic esters such as dimethyl malate, compounds containing aliphatic unsaturated bonds, organic phosphorus compounds, organic sulfur compounds, nitrogen-containing compounds, tin-based compounds Examples thereof include compounds and organic peroxides.

By selecting the type and blending amount of the curing rate control agent according to the molding conditions, the filling rate of the mold for molding the semiconductor light emitting device package composition into the mold is increased, or the mold from the mold at the time of injection molding is increased. An effect of suppressing leakage and making it difficult for burrs to occur can be obtained.
Other components that can be added to the semiconductor light emitting device package composition of the present invention include ion migration (electrochemical migration) inhibitors, anti-aging agents, radical inhibitors, ultraviolet absorbers, adhesion improvers, A flame retardant, a surfactant, a light stabilizer, a coupling agent, an antioxidant, a heat stabilizer, a conductivity imparting agent, an antistatic agent, a metal deactivator, and the like can be contained as necessary.

<2. Semiconductor light emitting device>
1. Production of Semiconductor Light-Emitting Device Package The semiconductor light-emitting device package of the present invention can be produced as follows using a composition mainly comprising the specific silicone resin of the present invention, for example, using a liquid injection molding method.
(1) Using a first mold having a recess corresponding to the outer shape of a package having a bottom and a recess, and a protrusion corresponding to the shape of the recess, and a second mold, these two molds are used. In the mold, the two leads are arranged at predetermined positions, the mold is closed, and the lead is sandwiched between the first mold and the second mold.
(2) Next, the semiconductor light emitting device package composition of the present invention is injected and filled into the space formed in the gap between the recessed portion of the first mold and the lead using a liquid injection molding machine.
The injection molding pressure in this step is usually 10 to 1200 kg / cm ² , and the cylinder temperature of the liquid injection molding machine is 0 ° C. to 100 ° C.
(3) Next, the mold is heated to a predetermined temperature, and the filled composition of the present invention is heated and cured to obtain a package in which the lead and the resin molded body are integrally molded.
The curing temperature and time in this step are preferably 120 ° C. to 230 ° C. and 3 seconds to 10 minutes, respectively.

  The package molded based on the resin composition for a semiconductor light emitting device package of the present invention is an alumina / titania-based mixed white pigment, which reduces the amount of titania and suppresses deterioration of the material due to photocatalysis, and The use of aromatic polyorganosiloxane as the silicone resin increases the hardness of the molded product, resulting in a molded product having an excellent reflectivity and a moderate hardness. Is good.

2. Overview of Semiconductor Light Emitting Device As described above, a semiconductor light emitting device package is manufactured from the resin composition for a semiconductor light emitting device package of the present invention, and a semiconductor light emitting device is manufactured using this package.
The semiconductor light-emitting device is usually disposed in the recess and electrically connected to the lead (metal member), a package formed with a recess having a bottom surface and a side surface from which a portion can be exposed. And a sealing material filled in the recess. As a package of this semiconductor light emitting device, when a package having an appropriate hardness and excellent light reflectance manufactured from the resin composition of the present invention is used, a semiconductor light emitting device that is easy to handle and has high luminance can be manufactured. it can.

A specific example of the semiconductor light emitting device is shown in FIG.
The semiconductor light emitting device 5 generally includes a semiconductor light emitting element 2, a resin molded body 1 constituting an outer shell of the entire apparatus, a bonding wire for electrically connecting the semiconductor light emitting element 2 and the lead 4, and a seal for sealing the semiconductor light emitting element. It is comprised from the stop material 3, the lead | read | reed 4 etc. which supply electricity to a semiconductor light-emitting device. A package is composed of conductive metal wiring such as leads and an insulating resin molded body.

The material of the lead is not particularly limited, and examples include one containing two or more kinds of silver-white metals such as silver (Ag), aluminum (Al), platinum group element, nickel (Ni), etc. Silver or a silver alloy having a high reflectance is preferably used.
Further, the lead may be composed of a single metal material, or as a laminated structure, the surface layer is formed of a metal having good light reflectivity exemplified above, and the lower layer is made of another metal such as Cu, Ti, Ni, Fe, Co, Cr, W, Ti—W alloy and the like can also be used.

For example, when the lead 4 having a thickness of a test piece having a thickness of 0.4 mm and having a light reflectance of 460 nm is 85% or more, preferably 90% or more, the luminous 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. In addition to improving the light output of the light emitting device, it also has a function of insulating the positive and negative leads.

In addition, if a silicone-based encapsulant is used as the encapsulant for the light-emitting device, the characteristics of the material approximate, or the adhesion between the package and the encapsulant will be good, such as peeling during molding or use Since fear becomes small, it is more preferable.
The resin composition for a semiconductor light-emitting device package according to the present invention has a light-emitting element mounted directly on a substrate and sealed as a form of the semiconductor light-emitting device in addition to the above-described typical package structure. You may use in order to form a one part reflection material layer of the wiring board for chip-on-board mounting sealed with the stop material layer.

The semiconductor light emitting device can be manufactured, for example, according to the procedures (1) and (2) below.
(1) Assembly of light-emitting device Using a package for a semiconductor light-emitting device manufactured from the composition of the present invention, a semiconductor light-emitting element having a desired light emission wavelength (eg, 460 nm) is exposed in the recess of the package. After the conductive die-bonding material is placed on the lead, the die-bonding material is heat-cured, the semiconductor light-emitting element is mounted on the package, and the other lead of the package and the semiconductor using a bonding wire such as a gold wire Connect the light emitting element.

(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.

3. Application Examples to Other Semiconductor Light Emitting Devices An application example of the semiconductor light emitting device package obtained from the resin composition for a semiconductor light emitting device package of the present invention to other semiconductor light emitting devices will be briefly described.
(1) Embodiment of FIG. 3 The semiconductor light emitting device of FIG. 3 will be described.
The semiconductor light emitting device 5A, whose schematic cross-sectional view is shown in FIG. 3, is an example in which the exposure of the lead 4 is reduced compared to the semiconductor light emitting device of FIG. This is an example of a remote phosphor mode in which a phosphor layer 7 containing a luminescent substance is placed away from the light emitting element 2 in order to prevent deterioration.
The light emitting element 2 is placed on the resin molded body 1. However, when heat radiation is important, such as when a large light emitting element of 1 W or more is mounted, the portion of the lead 4 that directly contacts the light emitting element 2 is exposed to emit light. The element 2 may be directly bonded to the lead 4 through an insulating die bond material. In the case of a vertically conductive light emitting element, the light emitting element 2 may be mounted directly on the lead 4 and bonded with solder or a conductive die bond material.

The phosphor layer 7 can be provided as necessary when the encapsulant 3 does not contain a phosphor, and can be formed by directly applying the encapsulant 3 on the transparent encapsulant 3 by potting, printing, or batch molding. Alternatively, it may be formed by applying a phosphor to a transparent base material having low gas permeability such as polycarbonate, PET, or glass.
By separating the phosphor from the light emitting element 2, it is possible to suppress a decrease in luminance due to light degradation of the phosphor, and by making the thickness of the phosphor layer 7 constant, the in-plane distribution of light emission of the light emitting device is uniform. Thus, a high-luminance light emitting device with little color unevenness can be obtained.

(2) Embodiment of FIG. 4 A semiconductor light emitting device according to the embodiment of FIG. 4 will be described.
The semiconductor light emitting device 5B, whose schematic cross-sectional view is shown in FIG. 4, has a package structure composed of two leads 4 and a resin molded body 1 suitable for the liquid injection molding (LIM) method, and has good heat dissipation. It has become a structure.
The package resin composition for a semiconductor light-emitting device of the present invention uses an aromatic polyorganosiloxane as a silicone resin as a main component, and thus has higher hardness and stronger stiffness than conventional silicone resins. The possibility of deterioration of mold release due to the tackiness of the resin, which is a problem with liquid injection molding using silicone resin, and molding defects due to molded product fragments remaining in the mold at the time of mold release can be greatly reduced. .

  In addition, when a semiconductor light emitting device package is molded or released, when a package piece is transferred by a parts feeder or robot arm, or when a light emitting element is mounted, the lead may be peeled off from the package due to torsional stress on the package. As for the problem of falling off, by utilizing the strength of the molded body by the composition of the present invention, the lead as shown in this figure has a structure that penetrates into the resin molded body of the package. It is possible to make the structure strong against local stress.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples without departing from the gist thereof.
1. Synthesis of polyorganosiloxane (1) Synthesis of aromatic polyorganosiloxane (A1)
Vinyl group-containing polymethylphenylsiloxane (vinyl group: 0.5 mmol / g (2.4 mol%), methyl group: 13.7 mmol / g (67 mol%), phenyl group: 6.3 mmol / g (31 mol%), platinum Concentration: 68 ppm) and hydrosilyl group-containing polymethylphenylsiloxane (vinyl group: 1.5 mmol / g (8.6 mol%), hydrosilyl group: 1.9 mmol / g (11 mol%), methyl group: 8.8 mmol / g ( 50 mol%) and phenyl group: 4.6 mmol / g (26 mol%)) were mixed at 1:10 to prepare a liquid thermosetting aromatic polyorganosiloxane (A1) having a viscosity of 8000 mPa · s and a platinum concentration of 6.2 ppm. Obtained.
In addition, the refractive index of this aromatic polyorganosiloxane (A1) was 1.53.

(2) Synthesis of polyorganosiloxane (A2) (non-aromatic)
Vinyl group-containing polydimethylsiloxane (vinyl group: 0.3 mmol / g (1.1 mol%), viscosity: 4200 mPa · s, platinum concentration: 14 ppm) and hydrosilyl group-containing polydimethylsiloxane (vinyl group: 0.04 mmol / g) (0.12 mol%), hydrosilyl group: 4.8 mmol / g (15 mol%), viscosity 700 mPa · s) and (E) a polydimethylsiloxane (vinyl group: 0) containing a curing rate control agent (curing retarder). 0.2 mmol / g (36 mol%), hydrosilyl group: 0.1 mmol / g (24 mol%), alkynyl group of curing retarder: 0.2 mmol / g (40 mol%), viscosity 500 mPa · s), 100: 10 : 5 to obtain a liquid thermosetting polyorganosiloxane (A2) having a platinum concentration of 12 ppm.
In addition, the refractive index of this liquid thermosetting polyorganosiloxane (A2) was 1.41.

2. Preparation of composition for semiconductor light emitting device package and preparation of test piece <Example 1>
(A) Liquid thermosetting polyorganosiloxane (A1) obtained above, (B) White pigment (primary particle size 0.3 μm, crushed α-alumina having a purity of 99.1%, primary particle size 0. 28 μm, purity 90%, mixed white pigment of titania / alumina = 17/83 (weight ratio) of rutile titania coated with silica and alumina thin film on the surface), (D) silica as fluidity modifier Fine particles “AEROSIL RX200” (manufactured by Nippon Aerosil Co., Ltd .: specific surface area: 140 m ² / g) were blended and stirred at a weight ratio shown in Table 1 to disperse the white pigment and the silica fine particles in the (A1). A composition for a semiconductor light emitting device package was obtained.

  This composition was heated and cured with a hot press so as to have a thickness of about 400 μm to obtain a circular test piece having a diameter of 13 mm.

<Examples 2-4, Comparative Examples 1-3>
(A) (A1) or (A2) as liquid thermosetting polyorganosiloxane, (B) white pigment, (D) compounding amount of silica fine particles “AEROSIL RX200” as fluidity adjusting agent is blended by weight shown in Table 1. A test piece was obtained under the same conditions as in Example 1 except that.

3. Evaluation (1) Reflectance For each of the test pieces (thickness 350 to 430 μm) in Examples 1 to 4 and Comparative Examples 1 to 3, SPECTROTOPOMETER CM-2600d manufactured by Konica Minolta Co., Ltd. was used and the wavelength was 360 nm at a measurement diameter of 6 mm. The reflectance of light at 740 nm was measured. The thickness and reflectance of each test piece are shown in Table 1 and FIG.

(2) Shore D hardness Each test piece (thickness 3 mm) obtained in the above examples and comparative examples was post-cured for 10 minutes in a thermostat at 200 ° C., and then the two test pieces were stacked. The Shore D hardness near the center of the test piece was measured according to JIS K6753 using a plastic hardness meter KORI Durometer KR-25D. (In Table 1, expressed as “D hardness”)

(3) Heat resistance evaluation Each test piece (thickness 1 mm) of Examples 1 to 4 and Comparative Examples 1 to 3 was stored in a thermostat at 200 ° C for 960 hours, and the weight change before and after storage was measured. The results are shown in Table 1.

<Evaluation of results>
According to Table 1, in Examples 1 to 4 using a composition containing a mixed white pigment of polymethylphenylsiloxane (aromatic polyorganosiloxane) and titania / alumina, the Shore D hardness is 50 or more and 460 nm light Was found to have a very high reflectance.
Comparative Example 1 containing only polydimethylsiloxane, which is a polyorganosiloxane having no aromatic group, and alumina has a high reflectance of 460 nm light but a low hardness, whereas aromatic polyorganosiloxane (polymethylphenylsiloxane) In Comparative Example 2 containing only alumina as a white pigment, the reflectance was low.

  Further, in Comparative Example 3 containing only polymethylphenylsiloxane and titania as a white pigment, the hardness is high and the reflectance of 460 nm light is very high, but the weight change after 820 hours at 200 ° C. is relatively large, and alumina is included. The viscosity before curing is higher than in Example 1, and molding defects such as unfilling are likely to occur when used for injection molding.

DESCRIPTION OF SYMBOLS 1 Resin molding 2 Semiconductor light-emitting device 3 Sealing material 4 Lead electrode 5, 5A, 5B Semiconductor light-emitting device 6 Bonding wire 7 Phosphor layer

Claims (9)

  (A) a polyorganosiloxane, (B) a white pigment, and (C) a curing catalyst, wherein the (A) polyorganosiloxane has an aromatic group bonded to a silicon atom constituting the main chain. And (B) the white pigment is a mixture of titania and alumina, and the mixture ratio is titania / alumina = 2/98 to 50/50 (weight ratio). Resin composition for device package.   2. The semiconductor according to claim 1, comprising (B) 10 to 900 parts by weight of a white pigment and (C) 1 to 100 ppm by weight of a curing catalyst per 100 parts by weight of the (A) polyorganosiloxane. Resin composition for light emitting device package.   The resin composition for a semiconductor light-emitting device package according to claim 1, further comprising 2 to 300 parts by weight of (D) a fluidity modifier per 100 parts by weight of the (A) polyorganosiloxane. . The resin composition for a semiconductor light-emitting device package according to any one of claims 1 to 3, wherein a viscosity at a shear rate of 100 s ^-1 at 25 ° C is 10 Pa · s or more and 10,000 Pa · s or less. object.   The resin composition for a semiconductor light-emitting device package according to any one of claims 1 to 4, wherein the molded product has a Shore D hardness (according to JIS K6253) of 50 or more.   The resin for semiconductor light emitting device packaging according to any one of claims 1 to 5, wherein a light reflectance measured on a molded sample having a thickness of 0.4 mm under a condition of a wavelength of 460 nm is 80% or more. Composition.   The semiconductor light-emitting device package formed by liquid injection molding the resin composition for semiconductor light-emitting device packages as described in any one of Claims 1-6. A method of manufacturing a semiconductor light emitting device package having a bottom portion and a recess, wherein a lead is integrally formed,
A first step of sandwiching the lead between a first mold having a concave portion corresponding to the shape of the resin molded body, a convex portion corresponding to the shape of the concave portion of the molded body, and a second mold;
The resin composition for a semiconductor light-emitting device package according to any one of claims 1 to 6 is applied by a liquid injection molding method to a space portion formed between the recessed portion of the first mold and the lead. A second step of filling,
A third step of heating and curing the filled resin composition for a semiconductor light emitting device package;
The method of manufacturing a semiconductor light emitting device package according to claim 7, comprising: It has at least the semiconductor light emitting device package according to any one of claims 1 to 6, a semiconductor light emitting element, and a sealing material that covers the semiconductor light emitting element,
The semiconductor light emitting device, wherein the semiconductor light emitting element is electrically connected to a lead of the semiconductor light emitting device package.

Images