WO2011122551A1 - Glass composition for reflective material, material for firing, and light-emitting element package - Google Patents

Abstract

A glass composition for reflective materials which comes to exhibit excellent light-reflecting properties upon firing is provided to thereby provide a material for firing in which an inorganic filler is used in a limited amount to avoid problems concerning sinterability and which forms a reflective material having excellent light-reflecting properties. The material for firing improves the luminescent efficiency of light-emitting element packages. The glass composition for reflective materials, which is intended to configure at least the reflective surface of a reflective material that reflects light, comprises SiO₂, Al₂O₃, etc. in respective given proportions in terms of oxide amount.

Description

Glass composition for reflector, firing material, and light emitting device package

The present invention relates to a glass composition for a reflecting material used to constitute at least a reflecting surface of a reflecting material for reflecting light, a firing material containing glass powder made of such a glass composition, and such a material. The present invention relates to a light emitting device package in which a light emitting device is mounted on a substrate formed of a firing material.

In recent years, with the increase in brightness and whiteness of light-emitting elements such as light-emitting diodes (hereinafter also referred to as “LEDs”), light-emitting devices using LEDs for backlights such as mobile phones and large liquid crystal TVs have come to be used. Yes.
When the light-emitting element such as an LED is used in a light-emitting device, it is used in the form of a light-emitting element package in which the light-emitting element is mounted on a substrate (see Patent Document 1 below).

Conventionally, glass substrates and ceramic substrates have been formed using a firing material such as a glass paste containing glass powder or a green sheet further containing an inorganic filler, and the firing material is formed into a predetermined shape. It is produced by a method of firing the molded product.
For example, for a substrate for mounting a light emitting element as described above, a low-temperature co-fired ceramic is obtained by holding a firing material containing a glass powder that can be fired at a low temperature together with an alumina filler in the shape of the substrate and firing it. A method of forming a substrate (hereinafter also referred to as “LTCC substrate” or simply “LTCC”) is employed (see Patent Document 2 below).

By the way, the substrate of the light emitting device package is also expected to play a role as a reflective material for improving the light emission intensity by reflecting the light of the light emitting device to the surface thereof, and efficiently reflects the light emitted from the light emitting device. It is demanded.
Therefore, a firing material capable of obtaining a fired body with high whiteness during firing has been demanded, and various studies have been conducted on glass compositions for constituting glass powder of the firing material (described below). (See Patent Document 3).

However, in general, a substrate used as a reflector in a light emitting device package such as an LED package is required to have a reflectance of 85% or more with a plate thickness of about 300 to 400 μm, but a ceramic substrate such as an alumina substrate. The reflectance is about 50% to 70%, and is generally about 70% to 85% even for LTCC substrates.
Therefore, in order to improve the whiteness and improve the reflectance, the following Patent Documents 2 and 3 and the like have examined addition of inorganic fillers such as titanium oxide particles, zirconium oxide particles, and zirconium silicate particles. As a result, it is difficult to obtain a dense fired body, which causes a problem of reducing the sinterability of the firing material.
That is, in the conventional glass composition for reflectors and firing materials, it is difficult to satisfactorily satisfy the required reflection characteristics while suppressing a decrease in sinterability. However, it is difficult to improve luminous efficiency.

It should be noted that such a problem is a problem common to all reflective materials that reflect light, and is not limited to a substrate for an LED package.

Japanese Unexamined Patent Publication No. 2006-41230 Japanese Unexamined Patent Publication No. 2007-129191 International Publication Gazette WO 2009/128354

The present invention suppresses the use of excessive inorganic fillers in the firing material by providing a glass composition for a reflector that exhibits excellent light reflectivity when fired, and causes problems in sinterability. It is an object of the present invention to provide a firing material capable of satisfying both prevention and formation of a reflective material having excellent light reflectivity, and consequently improving light emission efficiency of a light emitting element package.

The present invention relating to the glass composition for a reflector for solving the above-mentioned problems is, in terms of oxide, SiO ₂ : 40 to 60% by mass, Al ₂ O ₃ : 1 to 12% by mass, Li ₂ O, Na ₂ One or more of O and K ₂ O have a composition ratio of a total of 8 to 20% by mass and TiO _{2 of} 8 to 23% by mass.

In the present invention, it is preferable that the reflecting glass composition further contains B ₂ O _{3 in an} amount of 2 to 15% by mass in terms of the oxide.
Further, it is preferable that the glass composition for a reflective material further contains CaO in an amount of 0.1 to 10% by mass in terms of the oxide, and instead of a part or all of this CaO, MgO Any one or more of SrO and BaO is preferably contained in a total amount of 5.0% by mass or less.

Further, the present invention relating to a firing material for solving the above-mentioned problems is a firing material used to constitute at least a reflective surface of a reflective material containing glass powder and fired to reflect light, As glass powder, the glass powder which has the above composition ratios is contained.

In the firing material of the present invention, an inorganic filler is contained together with the glass powder, and the glass powder and the inorganic filler are in a mass ratio of (glass powder / inorganic filler) = 40/60 to 75/25. It is preferably contained.
As this inorganic filler, aluminum oxide particles are preferable.

The firing material contains at least one of titanium oxide particles, zirconium silicate particles, and zirconium oxide particles as the inorganic filler. The titanium oxide particles, the zirconium silicate particles, and the zirconium oxide The particles are preferably contained so that the total amount thereof is 1 to 10% by mass with respect to the total amount of the glass powder and the inorganic filler.

Furthermore, the firing material includes at least one selected from the group consisting of α-quartz particles, cordierite particles, magnesia spinel particles, β-eucryptite particles, spodumene particles, mullite particles, and forsterite particles as the inorganic filler. It is preferable that the seed is further contained.

The light emitting device package of the present invention is a light emitting device package in which a light emitting device is mounted on a substrate, and light emitted from the light emitting device is reflected on the surface of the substrate. Is obtained by firing the firing material as described above.

The glass composition of the present invention contains SiO ₂ and Al ₂ O ₃ at a predetermined ratio, and TiO ₂ is contained at a ratio as high as 8 to 23% by mass together with these, and thus a glass having such a composition ratio. When a fired body is formed using powder or the like, a crystal phase is easily formed in the glass by this TiO ₂ , and more TiO ₂ crystals that greatly contribute to light reflection are precipitated in the glass. The deposited TiO ₂ can exhibit excellent light reflectivity.
Therefore, a reflective material excellent in light reflectivity can be produced by forming a glass powder once as a glass composition for a reflective material of the present invention and forming a reflective material with a firing material containing the glass powder. .
Moreover, a reflective material excellent in light reflectivity can be formed without containing an inorganic filler until it becomes difficult to obtain a dense fired body.
Furthermore, by using the firing material, a substrate having excellent light reflectivity can be formed, so that the light emission efficiency of the light emitting element package can be improved.

Hereinafter, the glass composition for a reflector of the present invention (hereinafter also simply referred to as “glass composition”) and the firing material will be described.
Examples of the firing material of the embodiment include a material composed only of glass powder obtained by pulverizing a glass base material having a predetermined composition ratio, or a material containing an inorganic filler together with the glass powder.
It is an important requirement for the glass powder as a raw material of the firing material that the TiO ₂ crystal can be precipitated in the fired body by firing the fired material, and the light reflection excellent in the fired body. In terms of imparting the rate, it is important to have the following component composition.

That is, the glass powder contains at least one of SiO ₂ : 40 to 60% by mass, Al ₂ O ₃ : 1 to 12% by mass, Li ₂ O, Na ₂ O, and K ₂ O in terms of oxides. It is important to have a composition ratio of total: 8 to 20% by mass and TiO ₂ : 8 to 23% by mass.
Below, each component of a glass composition is demonstrated.

The SiO ₂ is an essential component in the glass composition of the present invention and is a glass network former.
If the SiO ₂ content is less than 40% by mass, the chemical durability of the glass decreases. If it exceeds 60% by mass, it becomes difficult to melt the glass. It is preferable to be set to ˜55% by mass, and more preferably 45 to 55% by mass.

The Al ₂ O ₃ is an essential component in the glass composition of the present invention, has a function of improving the stability of the glass against devitrification and crystallization during melting of the glass by including an appropriate amount.
If the content of Al ₂ O ₃ is less than 1% by mass, the glass tends to be devitrified at the time of melting the glass, and if it exceeds 12% by mass, the glass material tends to be crystallized, making it difficult to obtain a glass powder that can be easily fired. For example, in terms of increasing the apparent porosity of the sintered body, it is usually 1 to 12% by mass, and preferably 3 to 10% by mass.

Any one or more of Li ₂ O, Na ₂ O, and K ₂ O is an essential component in the glass composition of the present invention. Among them, Na ₂ O and K ₂ O are used for producing a glass body. In addition to lowering the melting temperature of the glass, it is an effective component for facilitating introduction of a TiO ₂ component, which will be described later, into the glass base while maintaining the glass state when the glass base is produced.
In addition, these are effective components for suppressing rapid firing shrinkage behavior when firing a light emitting device package substrate or the like using a firing material containing glass powder and an inorganic filler.
When the content of Na ₂ O and K ₂ O is less than 8% by mass, the melting temperature at the time of producing the glass base becomes high, and moreover, it becomes difficult to introduce the TiO ₂ component while it exceeds 20% by mass. Since the chemical durability of glass, for example, water resistance is lowered, it is usually 8 to 20% by mass, preferably 10 to 16% by mass.
A part of the Na ₂ O and _{K 2} O, or, there is also possible to adopt a Li ₂ O in place of the whole, but it is preferable to employ a Na ₂ O and _{K 2} O.
Further, when an aluminum oxide filler is added, these alkali metal oxide (R ₂ O) components are adjusted to the amount of the B ₂ O ₃ component in the glass composition, so that the reaction with the filler causes feldspar based Crystals can be precipitated. That is, the R ₂ O component is a constituent component of feldspar-based crystals, and is a component that can impart excellent strength to a sintered body such as a light-emitting element package substrate by precipitation of the feldspar-based crystals.

The TiO ₂ is an essential component in the glass composition of the present invention, exists in a state where crystallization is hardly observed in the glass raw material, and is effective in improving reflectance when the glass powder is baked (TiO 2). ₂ ) A component that precipitates as crystals.
Further, it is a component that also serves as a nucleating agent for the crystallization reaction of glass that occurs during firing of the firing material.
If the content of TiO ₂ is less than 8% by mass, the degree of crystallinity in the fired product after firing becomes low, and sufficient improvement in reflectance cannot be obtained, and if it exceeds 23% by mass, it is difficult to produce the glass raw material itself. Therefore, it is usually 8 to 23% by mass, preferably 8 to 20% by mass, more preferably 10 to 16% by mass.

In addition to the essential components, one or more optional components selected from the group consisting of B ₂ O ₃ , CaO, BaO, MgO, SrO, and ZrO ₂ (hereinafter also referred to as “first optional component”) are included. be able to.
Among the first optional components, B ₂ O ₃ has a risk of reducing the chemical durability of the glass if the content exceeds 15% by mass, and therefore the content is usually 0 to 15% by mass. .
On the other hand, B ₂ O ₃ can be expected to have an effect as a flux and has an action of promoting crystallization of TiO ₂ .
Therefore, if the purpose is to exert these effects, the content of B ₂ O ₃ is preferably 2 to 15% by mass, more preferably 2 to 13%, and more preferably 3 to 9%. % Is particularly preferable.

Of the first optional component, CaO can be contained in the glass composition usually in a content of 0 to 10% by mass.
CaO has the effect of lowering the melting temperature at the time of producing the glass body and contains CaO to react with the filler when not only the TiO ₂ crystals but also the aluminum oxide filler is added when the glass powder is fired. By this, anorthite crystals can also be precipitated.
That is, CaO is a constituent component of anorthite crystal, and is a component that can impart excellent strength to a fired body such as a substrate for a light emitting device package by precipitation of the anorthite crystal.
In this respect, the CaO content is preferably 0.1 to 10% by mass, more preferably 1 to 9%, and particularly preferably 2 to 9%.
Of the first optional components, BaO, MgO, and SrO can be substituted for some or all of the CaO.
However, the total content of BaO, MgO, and SrO is preferably 5% by mass or less.

Among the first optional components, ZrO ₂ is a component that plays the same role as TiO ₂ and can be contained in place of part of TiO ₂ .
In general, the optional components (B ₂ O ₃ , CaO, BaO, MgO, SrO, ZrO ₂ ) shown above may significantly impair the effects of the present invention if the total amount is 20% by mass or less. And can be contained in the glass composition of the present invention.

Furthermore, ZnO, P ₂ O ₅ , CeO ₂ , Fe ₂ O ₃ , MnO ₂ , CuO, CoO, SnO ₂ , Sb ₂ O ₃ , V ₂ O ₅ , NiO, Cr ₂ O ₃ , and Bi ₂ O ₃ One or more optional components selected from the group consisting of (hereinafter also referred to as “second optional component”) may be contained within a range that does not significantly impair the effects of the present invention.
Normally, the second optional component group (ZnO, P ₂ O ₅ , CeO ₂ , Fe ₂ O ₃ , MnO ₂ , CuO, CoO, SnO ₂ , Sb ₂ O ₃ , V ₂ O ₅ , NiO, Cr _{2 is used.} O ₃ , Bi ₂ O ₃ ) can be contained in the glass composition of the present invention without significantly impairing the effects of the present invention as long as the total amount is 5% by mass or less. More preferably.
Moreover, it is preferable that the total sum of said 1st arbitrary component and this 2nd arbitrary component shall be 25 mass% or less.
Incidentally, PbO, SeO, _TeO 2, F in terms of environmental impact, it is preferable to not substantially contained. In particular, F is preferably not included because it may volatilize during firing.
In addition, if these are 1000 ppm or less in conversion of an oxide, it can be considered as what is not contained substantially.

In order to form a glass powder having such a composition ratio, a metal oxide as a raw material is prepared and melted at a temperature of, for example, 1300 to 1500 ° C. and then cooled to obtain a glass raw material (crystallized). No) may be dry pulverized or wet pulverized and classified as necessary.

In the present embodiment, the particle size of the glass powder varies depending on the shape of the firing material such as glass paste or green sheet, and is not particularly limited. 5 to 5 μm.

Next, the inorganic filler constituting the firing material together with such glass powder will be described.
When the inorganic filler is composed of the glass powder as a main component without containing the inorganic filler, the volume ratio of TiO ₂ crystals in the fired fired body can be increased. Although a fired body having a higher reflectivity can be produced, when the fired material is fired, its fluidity becomes high, so that shape retention becomes difficult.
For example, when an LED package substrate is formed of a firing material such as a green sheet, if an inorganic filler that is inferior in light reflectivity to that of TiO ₂ crystal is included, the light reflectivity of the resulting substrate is reduced accordingly. Although it has a fear, it has an advantage that the substrate is easily fired into a target shape.
On the other hand, when an inorganic filler is not contained, a substrate having excellent light reflectivity can be formed, but it may be difficult to impart a desired thickness to the substrate.

In addition, when the ratio of the inorganic filler to the total amount of the inorganic filler and the glass powder is less than 25% by mass, sufficient mechanical strength may not be obtained in the fired body. It becomes difficult to obtain a fired body, which may cause a problem in the sinterability of the firing material.
From such a viewpoint, the proportion of the inorganic filler in the total amount of the inorganic filler and the glass powder is preferably 25 to 60% by mass (glass powder / inorganic filler = 40/60 to 75/25).

A typical example of the inorganic filler is aluminum oxide particles.
Since aluminum oxide can be a constituent component of crystals that precipitate when the firing material is fired, the use of aluminum oxide particles as the inorganic filler can be expected to promote the crystallization of glass, and the fired body has high strength. Can be expected.
The total amount (25 to 60% by mass) of the inorganic filler can be aluminum oxide particles, and the more preferable content of the aluminum oxide particles is 30 to 50% by mass.

Examples of inorganic fillers other than the aluminum oxide particles include titanium oxide particles, zirconium oxide particles, zinc oxide particles, and zirconium silicate particles, and these can be expected to function as white pigments, and can be fired by containing them. Can improve the reflectance.
The content is preferably 1 to 10% by mass, and more preferably 1 to 5% by mass considering the ease of firing of the glass powder material (sinterability).

Furthermore, α-quartz particles, magnesia spinel particles, forsterite particles, and magnesium oxide particles are components that increase the thermal expansion coefficient of the obtained fired body, and cordierite particles, mullite particles, zirconium silicate particles, β-eucrypts. Tight particles and spodumene particles are effective components for reducing the thermal expansion coefficient of the obtained fired body.
Therefore, the thermal expansion coefficient of the fired body obtained by containing these can be adjusted, and for example, it becomes easy to give the fired body the thermal expansion coefficient required for the substrate for an LED package.
The inorganic filler having an effect of adjusting the thermal expansion coefficient can be contained in the firing material so that the total amount thereof exceeds 0% by mass and is 20% by mass or less.

In the present embodiment, the particle size and the like of the inorganic filler are not particularly limited, but those having an average particle size of 0.3 to 3 μm can be usually used.

Conventionally known technical matters can also be adopted in the present invention for components such as an organic binder used for forming a firing material such as a glass paste or a green sheet, and a mixing method of the inorganic filler and the glass powder. .
A conventionally known method can also be adopted for a method of firing this firing material to produce a substrate for a light emitting element package.

And since the baking material which concerns on this invention is comprised with the above components, it can obtain the precise | minute sintered body which has the outstanding light reflectivity.
Thus, for example, a paste-like firing material is prepared, printed on the surface of an alumina substrate or another LTCC substrate, and baked, so that these substrates having low light reflectivity are made into substrates having high light reflectivity. Can be changed.
It should be noted that even when a member used as a reflective material such as a substrate for a light emitting element package is formed by a single material for firing according to the present invention, a material having a high light reflectance can be obtained. It is self-explanatory, and a light emitting device package can be obtained by firing a firing material alone containing the glass powder and the inorganic filler in a predetermined ratio (glass powder / inorganic filler = 40/60 to 75/25). Substrate.

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited thereto.

The raw materials were prepared and mixed so as to have the composition ratios of Examples 1 to 14 and Comparative Examples 1 to 7 shown in Tables 1 and 2, and the prepared raw materials were melted at 1300 to 1500 ° C. for 2 hours, and then rapidly cooled to obtain a glass raw material. Was made.
A glass powder having an average particle diameter of 2 μm was produced by dry pulverization of the obtained glass raw material using a ball mill and wet pulverization using an aqueous or organic solvent.
The average particle diameter of the obtained glass powder was taken as the D50 value of the volume distribution mode measured using a laser scattering particle size distribution analyzer.
Tables 1 to 3 show the glass powder, aluminum oxide particles having an average particle diameter of 1.5 μm, cordierite having an average particle diameter of 1.5 μm, titanium oxide having an average particle diameter of 0.3 μm, and zirconium oxide having an average particle diameter of 2 μm. The mixture was mixed to obtain a mixed powder.
The mixed powder, the polymer resin polyvinyl butyral, the organic solvent toluene, the organic solvent xylene, and the plasticizer diethyl phthalate were mixed to form a slurry, and a green sheet was obtained by a doctor blade method.
The obtained green sheets were stacked and fired to produce a fired body sample having a thickness of about 300 to 400 μm.
The reflectance of this sample with respect to light of wavelengths 630 nm, 525 nm, and 470 nm was measured with a Hitachi U-3010 spectrophotometer, and the reflectance of an aluminum oxide sub-white plate (a standard white plate made of aluminum oxide) as a reference reflective material was 100%. The ratio was calculated. This ratio (unit:%) is shown in Tables 1 and 2 as the reflectance of each sample.
Furthermore, the apparent porosity of the sample was measured by the Archimedes method, and a case where it was 0.1% or less was judged as “◯”, and a case where it exceeded 0.1% was judged as “x”.
In addition, the crystal phase in the sample was measured by powder X-ray diffraction method, and for the sample in which precipitation of TiO ₂ crystals was confirmed, the symbol “T” was added in the table, and precipitation of feldspar crystals was observed. The confirmed sample was given the symbol “N” in the table, and the sample in which the precipitation of anorthite crystal was confirmed was given the symbol “A” in the table.

　

As is clear from the table, it is possible to improve the reflectivity by adding a certain amount of zirconium oxide particles or titanium oxide particles, which can be expected to function as white pigments as in Comparative Examples 5 and 7, as inorganic fillers. However, it can be seen that this causes a problem in the sinterability and the apparent porosity exceeds 0.1%.
Further, in Comparative Example 4 in which Al ₂ O ₃ that easily causes crystallization of glass is contained in an amount higher than the specified amount of the present invention, the crystallinity of the glass itself can be improved by firing, and a fired body (reflecting material). Although excellent light reflectivity can be imparted to the glass, the glass becomes unstable, resulting in a problem in sinterability.
Further, in Comparative Examples 1 and 2, devitrification occurred during the production of the glass base material, and it did not lead to firing.
Furthermore, although the comparative examples 3 and 6 do not have a problem in sinterability, the reflectance is a low value of 85% or less.

On the other hand, in the present invention, excellent reflectance was obtained in Example 14 in which no inorganic filler was used, and the glass powder itself can form a fired body having excellent whiteness (light reflectance). It turns out that it is a thing.
That is, according to the present invention, it is not necessary to contain an inorganic filler excessively until the sinterability is adversely affected, and the inorganic filler may be contained to such an extent that shape retention during firing can be ensured. It can be seen that both the prevention of problems and the formation of a reflective material having excellent light reflectivity can be achieved.
Further, Examples 1 to 14 within the scope of the present invention have high reflectance and a dense fired body is formed. Therefore, the firing material of the present invention is excellent in sinterability, and the light emitting device package substrate It turns out that it is suitable for a forming material.

Claims (14)

1. A glass composition for a reflector used to constitute at least a reflecting surface of a reflector that reflects light,
   In terms of oxides, SiO ₂ : 40 to 60% by mass, Al ₂ O ₃ : 1 to 12% by mass, any one or more of Li ₂ O, Na ₂ O, and K ₂ O total: 8 to 20% %, TiO ₂ : a glass composition for a reflector having a composition ratio of 8 to 23% by mass.
2. The glass composition for a reflector according to claim 1, further comprising B ₂ O _{3 in an} amount of 2 to 15% by mass in terms of the oxide.
3. It further contains at least one of CaO, MgO, SrO and BaO, the total content of CaO, MgO, SrO and BaO in terms of oxide is 0.1 to 10% by mass, and The glass composition for a reflector according to claim 1, wherein the total content of MgO, SrO and BaO in terms of oxide is 0 to 5% by mass.
4. It further contains at least one of CaO, MgO, SrO and BaO, the total content of CaO, MgO, SrO and BaO in terms of oxide is 0.1 to 10% by mass, and The glass composition for a reflector according to claim 2, wherein the total content of MgO, SrO and BaO in terms of oxide is 0 to 5% by mass.
5. A firing material used for constituting at least a reflective surface of a reflective material that includes glass powder and is fired to reflect light,
   The glass powder is a total of one or more of SiO ₂ : 40 to 60% by mass, Al ₂ O ₃ : 1 to 12% by mass, Li ₂ O, Na ₂ O, and K ₂ O in terms of oxides. : A firing material characterized by having a composition ratio of 8 to 20% by mass and TiO ₂ : 8 to 23% by mass.
6. The firing material according to claim 5, wherein the glass powder further contains B ₂ O ₃ at a ratio of 2 to 15 mass% in terms of oxide.
7. The glass powder further contains at least one of CaO, MgO, SrO, and BaO, and the total content of CaO, MgO, SrO, and BaO in terms of oxide is 0.1. 6. The firing material according to claim 5, wherein the total content of MgO, SrO and BaO in terms of oxide is 0 to 5% by mass and 0 to 5% by mass.
8. The glass powder further contains at least one of CaO, MgO, SrO, and BaO, and the total content of CaO, MgO, SrO, and BaO in terms of oxide is 0.1. The firing material according to claim 6, wherein the total content of MgO, SrO and BaO in terms of oxide is 0 to 5% by mass in a range of 0 to 10% by mass.
9. 6. The inorganic filler is contained together with the glass powder, and the glass powder and the inorganic filler are contained at a mass ratio of (glass powder / inorganic filler) = 40/60 to 75/25. Baking material.
10. The firing material according to claim 9, wherein aluminum oxide particles are contained as the inorganic filler.
11. Any one or more of titanium oxide particles, zirconium oxide particles, zinc oxide particles, and zirconium silicate particles are contained as the inorganic filler, and the total amount accounts for the total amount of the glass powder and the inorganic filler. The firing material according to claim 9, which is contained so as to have a ratio of 1 to 10% by mass.
12. The inorganic filler further contains at least one selected from the group consisting of α-quartz particles, magnesia spinel particles, forsterite particles, magnesium oxide particles, cordierite particles, mullite particles, β-eucryptite particles, and spodumene particles. The firing material according to claim 9, wherein the total amount is contained so that the ratio of the total amount of the glass powder and the inorganic filler to the total amount exceeds 0% by mass and is equal to or less than 20% by mass.
13. A light emitting device package, wherein a light emitting device is mounted on a substrate, and light emitted from the light emitting device is reflected by the surface of the substrate;
    The substrate is obtained by firing a firing material including glass powder, and the glass powder is converted to an oxide in terms of SiO ₂ : 40 to 60% by mass, Al ₂ O ₃ : 1 to 12% by mass, Li One or more of ₂ O, Na ₂ O, and K ₂ O have a composition ratio of a total of 8 to 20% by mass and TiO _{2 of} 8 to 23% by mass. A featured light emitting device package.
14. The firing material contains an inorganic filler together with the glass powder, and the glass powder and the inorganic filler are contained at a mass ratio of (glass powder / inorganic filler) = 40/60 to 75/25. The light emitting device package according to claim 13.