JP5516026B2 - Glass ceramic composition, light emitting diode element substrate, and light emitting device - Google Patents

Description

  The present invention relates to a glass ceramic composition, a substrate for a light emitting diode element, and a light emitting device, and more particularly, a glass ceramic composition used for manufacturing a substrate on which a light emitting diode element is mounted, and a light emitting diode element comprising the glass ceramic composition. The present invention relates to a substrate and a light emitting device.

  In recent years, with the increase in luminance and efficiency of light emitting diode (hereinafter referred to as LED) elements, light emitting devices using LED elements for backlights such as mobile phones and large liquid crystal TVs, general lighting, and the like have been developed. It has come to be used. Along with this, higher performance is required for members around the LED element. Conventionally, a substrate made of a resin material is used as an LED device substrate for mounting the LED device, but it is easily deteriorated by heat and light accompanying the increase in brightness of the LED device, and is made of an inorganic material, for example, ceramics. The use of these is being considered.

  Examples of the ceramic substrate include an alumina substrate and an aluminum nitride substrate used for a wiring substrate. Ceramic substrates have higher durability against heat and light than resin substrates, and are promising as LED element substrates. However, the ceramic substrate has a lower reflectance than the resin substrate, and the light from the LED element leaks to the rear of the substrate, so that there is a problem that the front luminous intensity is lowered. In addition, since the ceramic substrate is generally difficult to sinter, high temperature firing exceeding 1500 ° C. is required, and there is a problem that the process cost becomes high.

  In order to solve such a problem, use of a low-temperature co-fired ceramic (hereinafter sometimes referred to as LTCC) substrate has been studied. The LTCC substrate is generally composed of a composite of glass and a ceramic filler such as alumina, and can be fired at about 850 to 950 ° C., which is lower than that of conventional ceramics, in order to sinter by the low temperature fluidity of the glass. Thereby, it can bake simultaneously with the Ag conductor used as a wiring conductor, and can reduce cost compared with the conventional ceramic substrate. Moreover, since light is diffusely reflected at the interface between the glass and the ceramic filler, a higher reflectance than that of the conventional ceramic substrate can be obtained. Furthermore, since it consists of an inorganic substance, sufficient durability with respect to heat and light can be obtained.

  In many cases, a wiring conductor is provided on the surface of such an LTCC substrate, and plating is performed to protect the wiring conductor or to facilitate connection to a bonding wire. However, in general, the plating solution has strong acidity. If the acid resistance of the LTCC substrate is low, the plating solution dissolves in the plating solution and easily contaminates the plating solution. As a result, it is necessary to replace the plating solution and the production efficiency of the LTCC substrate is reduced. For this reason, the LTCC substrate is required to have excellent acid resistance.

  In addition, the LTCC substrate is processed into a predetermined size by cutting or cutting or cutting to make an LED element substrate. However, if the bending strength is low, the LTCC substrate is cracked at the time of cutting or the like. Or chipping easily occurs. For this reason, the LTCC substrate is also required to have a high bending strength.

Excellent acid resistance, and as is also high LTCC substrate flexural strength, for example, a SiO _{2 57-65%} by mole fraction _display, B 2 _{O 3} and 13 to 18%, the _Al 2 _{O 3 3~8%,} K A glass ceramic composition containing a glass powder containing 0.05 to 6% of at least one of ₂ O and Na ₂ O in total and a ceramic filler is known (for example, Patent Document 1). reference). Here, as the ceramic filler, alumina powder is typically used, and zirconia powder is also used together with the alumina powder. Moreover, what consists of a glass-ceramics composition containing 10 weight% or less titania powder is also known as an LTCC board | substrate which improved the optical characteristic (for example, refer patent document 2).

  However, when mass-producing light emitting devices, it is necessary to efficiently plate a large number of LTCC substrates, and the LTCC substrates are required to have higher acid resistance than ever. In addition to the acid resistance, the LTCC substrate is also required to have a practically sufficient reflectance and a sufficient gas barrier property that can suppress the sulfidation of the wiring conductor, that is, a denseness. Further, the LTCC substrate is preferably suppressed in crystallization of the glass phase so as to reduce warping during firing, and is also required to be simultaneously fired with an Ag conductor serving as a wiring conductor as in the prior art. .

WO 2009/128354 A1 JP2007-129191A

  The present invention has been made in order to solve the above-described problems, and provides a glass ceramic composition that is particularly excellent in acid resistance and that provides a substrate for an LED element having sufficient reflectance and density. It is an object. Moreover, this invention aims at providing the board | substrate for LED elements which is excellent in acid resistance, and has sufficient reflectance and denseness. Furthermore, an object of the present invention is to provide a light emitting device using an LED element substrate having excellent acid resistance and sufficient reflectivity and density.

As a result of intensive studies to solve the above problems, the present inventor used a borosilicate glass powder having a low content of Li ₂ O, Na ₂ O, and K ₂ O, which are particularly alkaline components, By finding a glass ceramic composition containing 10 to 20% by mass of zirconia powder as a high refractive filler, it is found that a substrate for an LED element having excellent acid resistance and sufficient reflectance and density can be obtained. The present invention has been completed.

That is, the glass ceramic composition of the present invention includes 30 to 50% by mass of borosilicate glass powder, 35 to 60% by mass of alumina powder, and 10 to 20% by mass of zirconia powder, and mounts a light emitting diode element. The borosilicate glass powder is used in the production of a substrate for the purpose, and the borosilicate glass powder is 45 to 65% by mass of SiO ₂ , 5 to 20% by mass of B ₂ O ₃ in terms of oxide, Al 5 to 25% by mass of ₂ O ₃ and 15 to 35% by mass of CaO and no Li ₂ O, Na ₂ O and K ₂ O, or Li ₂ O, Na ₂ O and K ₂ O The total content of is less than 0.5% by mass.

  The substrate for a light-emitting diode element of the present invention is a substrate for mounting a light-emitting diode element, and is characterized by being formed and fired from the glass ceramic composition of the present invention described above. The light-emitting device of the present invention is a light-emitting device comprising a light-emitting diode element substrate and a light-emitting diode element mounted on the light-emitting diode element substrate, wherein the light-emitting diode element substrate is as described above. It is characterized by being a light emitting diode element substrate.

  ADVANTAGE OF THE INVENTION According to this invention, the glass-ceramic composition from which it is excellent in acid resistance and the board | substrate for LED elements which has sufficient reflectance and denseness is obtained can be provided. Moreover, according to this invention, the board | substrate for LED elements which is excellent in acid resistance, and has sufficient reflectance and denseness can be provided. Furthermore, according to this invention, the light-emitting device which is excellent in an optical characteristic and productivity can be provided by using such a substrate for LED elements.

Sectional drawing which shows an example of the LED package of this invention.

Hereinafter, embodiments of the present invention will be described.
The glass-ceramic composition according to the embodiment of the present invention is used for manufacturing an LED element substrate for mounting an LED element, and is 30 to 50% by mass of borosilicate glass powder, 35 to 60% by mass. % Alumina powder and 10-20% by weight zirconia powder.

Further, the borosilicate glass powder, in terms of oxide, the SiO ₂ 45 to 65 _wt%, the B 2 _{O 3} 5 to 20 wt%, the _Al 2 _{O 3} 5 to 25% by weight, and CaO 15 ˜35% by mass, Li ₂ O, Na ₂ O, and K ₂ O are not contained, or the total content of Li ₂ O, Na ₂ O, and K ₂ O is less than 0.5% by mass .

According to such a glass ceramic composition, since the content of Li ₂ O, Na ₂ O, and K ₂ O, which are alkali components in the borosilicate glass powder, is small, a sintered body (LED having excellent acid resistance) An element substrate, the same applies hereinafter) can be obtained. Further, since zirconia powder is mainly contained as a high refractive filler for improving the reflectance, a sintered body having a high reflectance as a whole can be obtained, and in the vicinity of 400 nm as in the case of mainly containing titania powder. It is possible to obtain a sintered body with little reduction in reflectance due to light absorption.

Here, zirconia powder is a component that lowers sinterability. Further, Li ₂ O, Na ₂ O, and K ₂ O in the borosilicate glass powder are components that improve the sinterability. Therefore, when using a borosilicate glass powder having a low content of Li ₂ O, Na ₂ O, and K ₂ O while using zirconia powder, the acid resistance is improved, but the sinterability tends to be lowered. . However, according to the glass ceramic composition of this embodiment, since the content of the zirconia powder is below a certain value, a decrease in sinterability is suppressed, and a sufficiently dense sintered body can be obtained. Moreover, since content of a zirconia powder is more than a fixed value, the sintered compact which has practically sufficient reflectance can be obtained.

Furthermore, according to such a glass ceramic composition, since crystallization of the glass phase at the time of firing is suppressed, a sintered body with less warpage can be obtained. In addition, there is a possibility that a sintered body excellent in acid resistance can be obtained by making the glass powder in the glass ceramic composition mainly composed of Bi ₂ O ₃ , but the raw material cost is excessively high for such a thing. There is a risk. According to the glass ceramic composition having the above composition, a sintered body having excellent acid resistance can be obtained relatively inexpensively.

Hereinafter, the glass ceramic composition will be specifically described.
The content of the borosilicate glass powder in the glass ceramic composition is 30 to 50% by mass. When the content of the borosilicate glass powder is less than 30% by mass, a dense sintered body cannot be obtained. From the viewpoint of obtaining a denser sintered body, the content of the borosilicate glass powder is preferably 33% by mass or more, and more preferably 35% by mass or more.

  On the other hand, when the content of the borosilicate glass powder exceeds 50% by mass, a sintered body having a high bending strength cannot be obtained. From the viewpoint of obtaining a sintered body having higher bending strength, the content of the borosilicate glass powder is preferably 45% by mass or less, and more preferably 40% by mass or less.

The 50% particle size (D ₅₀ ) of the borosilicate glass powder is preferably 0.5 to ₅ μm. If D ₅₀ is equal to or greater than 0.5 [mu] m, industrially easy to manufacture, also it becomes easy to handle in order to become difficult aggregation also easily dispersed in the glass ceramic composition. D ₅₀ is preferably 0.8 μm or more, and more preferably 1.5 μm or more. On the other hand, if D ₅₀ is 5μm or less, easily obtain a dense sintered body by firing. D ₅₀ is preferably 4 μm or less, and more preferably 3 μm or less. Incidentally, D ₅₀ in the present specification is a value measured by a laser diffraction scattering method.

  The alumina powder is added to improve the bending strength of the sintered body, and is added in an amount of 35 to 60% by mass in the glass ceramic composition. When the content of the alumina powder is less than 35% by mass, a sintered body having a high bending strength cannot be obtained. From the viewpoint of obtaining a sintered body having higher bending strength, the content of the alumina powder is preferably 40% by mass or more, and more preferably 42% by mass or more.

  On the other hand, when the content of the alumina powder exceeds 60% by mass, a dense sintered body cannot be obtained, and a sintered body with reduced surface smoothness is easily obtained. From the viewpoint of obtaining a denser and smoother sintered body, the content of the alumina powder is preferably 55% by mass or less, and more preferably 50% by mass or less.

_{D 50} of the alumina powder is 0.3~5μm is preferred. If D ₅₀ is equal to or greater than 0.3 [mu] m, easily obtain a high flexural strength sintered body. From the viewpoint of obtaining a sintered body with higher bending strength, D ₅₀ is preferably 0.6 μm or more, and more preferably 1.5 μm or more. On the other hand, if D ₅₀ is 5μm or less, easily obtain a smooth sintered body dense and surfaces. From the viewpoint of obtaining a denser and smoother sintered body, D ₅₀ is preferably 4 μm or less, and more preferably 3 μm or less.

  A zirconia powder is added in order to improve the reflectance of a sintered compact, and 10-20 mass% is added in a glass ceramic composition. When the content of the zirconia powder is less than 10% by mass, a sintered body having a practically sufficient reflectance, specifically, a reflectance of 85% or more cannot be obtained. The reflectance in the present invention is at a wavelength of 460 nm. From the viewpoint of obtaining a sintered body with higher reflectivity, the content of the zirconia powder is preferably 11% by mass or more.

On the other hand, when the content of the zirconia powder exceeds 20% by mass, a dense sintered body cannot be obtained. That is, in this glass ceramic composition, in order to improve the acid resistance of the sintered body, inclusion of Li ₂ O, Na ₂ O, and K ₂ O, which are components for improving the sinterability in the borosilicate glass powder The amount is reduced. And since a zirconia powder is a component which reduces sinterability, when it uses with the above-mentioned borosilicate type | system | group glass powder, when the content exceeds 20 mass%, a precise | minute sintered compact cannot be obtained. From the viewpoint of obtaining a denser sintered body, the content of the zirconia powder is preferably 19% by mass or less.

The zirconia powder may be unstabilized zirconia, but is preferably partially stabilized zirconia or stabilized zirconia that is at least partially stabilized by the addition of Y ₂ O ₃ , CaO, or MgO. . By using partially stabilized zirconia or stabilized zirconia, for example, a phase transition at a high temperature is suppressed, and a sintered body having various characteristics can be obtained. The kind of the partially stabilized zirconia is not necessarily limited, but Y ₂ O ₃ -added zirconia that can be easily obtained industrially at low cost is preferable. In particular, the amount of Y ₂ O ₃ added is preferably 0.1 to 10 mol%.

_{D 50} of the zirconia powder is preferably 0.05 to 5 [mu] m. When D ₅₀ is 0.05 μm or more, the size of the zirconia powder does not become excessively small with respect to the wavelength of light (460 nm in the present invention), so that a high reflectance can be obtained. From the viewpoint of obtaining a higher reflectance, D ₅₀ is preferably 0.1 μm or more, and more preferably 0.15 μm or more. On the other hand, if D ₅₀ is 5μm or less, to the size of the zirconia powder is not excessively large relative to the wavelength of light, it is possible to obtain a high reflectivity. From the viewpoint of obtaining a higher reflectance, D ₅₀ is preferably 3 μm or less, and more preferably 1.5 μm or less.

In industrially available zirconia powder, relatively small secondary particles (typically 0.05 μm) are formed by aggregation of very small primary particles (typically 0.05 μm or less). There are some that form (about 5 μm). Since the secondary particle diameter is more important than the primary particle diameter in order to obtain a high reflectivity, when the zirconia powder is composed of secondary particles, that D ₅₀ of the secondary particles is 0.05~5μm Is preferred. From the viewpoint of obtaining a higher reflectance, the D ₅₀ of the secondary particles is preferably 0.1 μm or more, and more preferably 0.15 μm or more. On the other hand, from the viewpoint of obtaining a high reflectance, the D ₅₀ of the secondary particles is preferably 3 μm or less, and more preferably 1.5 μm or less.

  It is preferable that the glass ceramic composition basically does not contain a high refractive filler other than zirconia powder, but may contain 3% by mass or less of high refractive fillers other than zirconia powder in total. Examples of highly refractive fillers other than zirconia powder include those having a refractive index exceeding 1.95. For example, titania, titanium compounds such as barium titanate, strontium titanate, and potassium titanate, and titanium or zirconium as a main component. And other composite materials.

As for the high refractive filler other than the zirconia powder, the D ₅₀ is preferably 0.05 to 5 μm like the zirconia powder. D ₅₀ of the high refractive filler other than zirconia powder is preferably 0.1 μm or more, and more preferably 0.15 μm or more. Further, D ₅₀ of the high refractive filler other than zirconia powder is preferably 3 μm or less, and more preferably 1.5 μm or less.

  Next, each component of the borosilicate glass powder will be described.

SiO ₂ is a component and an essential component that suppresses crystallization of glass to improve stability and improve acid resistance. The content of SiO ₂ in the borosilicate glass powder is 45% by mass or more. If it is less than 45% by mass, crystals may precipitate during firing, the sintered body tends to warp, and acid resistance may not be sufficient. From the viewpoint of more excellent stability and acid resistance, the content of SiO ₂ is preferably 47% by mass or more.

On the other hand, the content of SiO ₂ in the borosilicate glass powder is 65% by mass or less. When it exceeds 65% by mass, it is difficult to produce a homogeneous glass at low cost because the solubility is lowered, and there is a possibility that a dense sintered body cannot be obtained because the sinterability of the glass is also lowered. From the viewpoint of more excellent productivity and sintering properties, the content of SiO ₂ is preferably 60% by mass or less.

B ₂ O ₃ is a component that improves the sinterability of glass and is an essential component. The content of B ₂ O ₃ in the borosilicate glass powder is 5% by mass or more. When the amount is less than 5% by mass, the sintered property of the glass is lowered, so that there is a possibility that a dense sintered body cannot be obtained. From the viewpoint of further improving the sinterability, the content of B ₂ O ₃ is preferably 6% by mass or more, and more preferably 7% by mass or more.

On the other hand, the content of B ₂ O ₃ in the borosilicate glass powder is 20% by mass or less. If it exceeds 20% by mass, the glass tends to undergo phase separation, so that there is a possibility that the sintered body cannot be stably mass-produced, and the acid resistance may not be sufficient. From the viewpoint of more stable mass production and excellent acid resistance, the content of B ₂ O ₃ is preferably 15% by mass or less, and more preferably 11% by mass or less.

Al ₂ O ₃ is a component that suppresses the phase separation of glass and improves stability, and is an essential component. The content of Al ₂ O ₃ in the borosilicate glass powder is 5% by mass or more. When the content of Al ₂ O ₃ is less than 5% by mass, the glass tends to be phase-separated, so that there is a possibility that the sintered body cannot be mass-produced stably. From the viewpoint of making phase separation more difficult, the content of Al ₂ O ₃ is preferably 6% by mass or more, and more preferably 7% by mass or more.

On the other hand, the content of Al ₂ O ₃ in the borosilicate glass powder is 25% by mass or less. When the content of Al ₂ O ₃ exceeds 25% by mass, crystals represented by anorthite (SiO ₂ —Al ₂ O ₃ —CaO) are precipitated during firing, and the sintered body tends to warp, and acid resistance May not be sufficient. The content of Al ₂ O ₃ is preferably 22% by mass or less, and more preferably 19% by mass or less from the viewpoint of further reducing crystal precipitation and excellent acid resistance.

  CaO is a component that lowers the melting temperature of the glass and improves the sinterability and is an essential component. The content of CaO in the borosilicate glass powder is 15% by mass or more. When the content of CaO is less than 15% by mass, the sinterability of the glass is lowered, so that there is a possibility that a dense sintered body cannot be obtained. From the viewpoint of obtaining a denser sintered body, the CaO content is preferably 18% by mass or more, and more preferably 20% by mass or more.

  On the other hand, the content of CaO is 35% by mass or less. When the content of CaO exceeds 35% by mass, crystals typified by anorthite are precipitated during firing, so that the sintered body tends to warp and acid resistance may not be sufficient. From the viewpoint of reducing crystal precipitation and excellent acid resistance, the CaO content is preferably 30% by mass or less, and more preferably 25% by mass or less.

  The borosilicate glass powder can contain CaO and at least one selected from SrO and BaO. SrO and BaO are components that lower the melting temperature and improve the sinterability as in CaO. However, SrO and BaO tend to deteriorate the acid resistance more than CaO. For this reason, content of SrO and BaO is 6 mass% or less in a borosilicate type glass powder, respectively, and 3 mass% or less is respectively preferable. More preferably, it is 1 mass% or less. The total content of CaO, SrO, and BaO is 15% by mass or more and 35% by mass or less in the borosilicate glass powder.

  The borosilicate glass powder can contain MgO and ZnO together with CaO, SrO and BaO. MgO and ZnO are components that improve the sinterability like CaO and the like. However, MgO and ZnO tend to promote crystallization more than CaO or the like. The contents of MgO and ZnO are each 3% by mass or less, preferably 1% by mass or less, in the borosilicate glass powder. The total content of CaO, SrO, BaO, MgO, and ZnO is 15% by mass or more and 35% by mass or less in the borosilicate glass powder.

Li ₂ O, Na ₂ O, and K ₂ O are components that improve the sinterability, but are also components that reduce the acid resistance of the glass. Therefore, the total content of Li ₂ O, Na ₂ O, and K ₂ O in the borosilicate glass powder is less than 0.5% by mass. From the viewpoint of making the glass more excellent in acid resistance, the total content of Li ₂ O, Na ₂ O, and K ₂ O is preferably less than 0.3% by mass, more preferably less than 0.1% by mass, particularly It is preferable not to contain all of Li ₂ O, Na ₂ O, and K ₂ O. Incidentally, Li 2 _O, Na 2 _O, and K ₂ is _O sinterability and contains less tends to be reduced, the content of the zirconia powder to lower the sinterability, as described above, the glass ceramic composition By suppressing to 20% by mass or less in the product, it is possible to have sufficient sinterability while having a practically sufficient reflectance.

The borosilicate glass powder may contain, for example, Fe ₂ O ₃ . However, since Fe ₂ O ₃ absorbs light of 460 nm, the reflectance at this wavelength decreases when the content is excessively increased. For this reason, the content of Fe ₂ O ₃ is 0.05% by mass or less, preferably 0.03% by mass or less, more preferably 0.01% by mass or less, and substantially no Fe ₂ O ₃ is contained. preferable.

Further, in order to improve the chemical durability of the glass, it can also contain _{ZrO 2, La 2 O 3,} Gd 2 O 3 or the like borosilicate glass powder. The total content of these components is 5% by mass or less, preferably 4% by mass or less, and more preferably 3% by mass or less in the borosilicate glass powder. In consideration of environmental burden, the borosilicate glass powder does not contain PbO.

  The borosilicate glass powder can be usually produced by producing a glass having the above composition by a melting method and then pulverizing the glass. The pulverization method is not particularly limited, and may be dry pulverization or wet pulverization. In the case of wet pulverization, it is preferable to use water as a solvent. For pulverization, a pulverizer such as a roll mill, a ball mill, or a jet mill can be appropriately used. After pulverization, the glass may be dried and classified as necessary.

  The glass ceramic composition can be prepared by blending and mixing borosilicate glass powder, alumina powder, zirconia powder, and other components as required in a predetermined mass ratio. The glass ceramic composition is usually used as a green sheet. That is, a glass ceramic composition, a resin such as polyvinyl butyral or an acrylic resin, and a plasticizer such as dibutyl phthalate, dioctyl phthalate, or butyl benzyl phthalate as necessary are blended and mixed. Next, a solvent such as toluene, xylene, or butanol is added to the mixture to form a slurry, and the slurry is formed into a sheet on a film of polyethylene terephthalate or the like by a doctor blade method or the like. Furthermore, it is set as a green sheet by drying what was shape | molded in the sheet form, and removing a solvent.

  If necessary, the green sheet is formed with a wiring pattern, a via that is a through conductor, or the like by screen printing using Ag paste or the like. Moreover, you may form the overcoat glass for protecting the wiring conductor etc. which are formed by baking of a wiring pattern by screen printing etc.

  The green sheet can be made into a substrate for an LED element by processing into a desired shape after firing. Here, the LED element substrate may be obtained by firing one green sheet, or may be obtained by stacking and firing a plurality of green sheets. Baking is normally performed by holding at 850 to 950 ° C. for 20 to 60 minutes. A more preferable firing temperature is 860 to 940 ° C. Since the melting point of Ag is about 960 ° C., baking at 950 ° C. or lower suppresses the softening of Ag during baking and facilitates maintaining the shape of the wiring pattern, vias, and the like.

The LED element substrate is preferably plated for protection of the wiring conductor as required. The LED element substrate preferably has an acid resistance (elution amount) of 600 μg / cm ² or less, and 300 μg / cm ² , which is obtained by a measurement method described later, from the viewpoint of suppressing a decrease in productivity due to contamination of the plating solution. The following is more preferable. In addition, the LED element substrate preferably has a water absorption rate of 3% or less, which is required by a measurement method described later, from the viewpoint of having sufficient gas barrier properties capable of suppressing the sulfidation of the wiring conductor. % Or less is more preferable.

  Further, the LED element substrate preferably has a reflectance of 85% or more, more preferably 86% or more, more preferably 87%, from the viewpoint of practically sufficient optical characteristics. More preferably, it is the above. In addition, the LED element substrate preferably has a glass phase crystallization ratio of 60% or less, more preferably 35% or less, from the viewpoint of suppressing warping during firing (during manufacturing). More preferably, it is 15% or less. Here, the crystallization rate refers to the existence ratio (volume ratio) of the crystalline region in the glass phase. The crystallization rate is measured, for example, by measuring the X-ray diffraction of the produced LED element substrate and evaluating the ratio between the diffraction peak intensity due to alumina particles (or zirconia particles) and the diffraction peak intensity due to crystals precipitated from the glass phase. Can be obtained. Alternatively, the degree of crystallinity can also be obtained by observing a cross section of the produced LED element substrate with an electron microscope and evaluating the area ratio between the precipitated crystal and the amorphous region.

  Such a substrate for an LED element can be suitably used for manufacturing an LED package (light emitting device). The LED package includes at least the above-described LED element substrate and the LED element mounted on the LED element substrate. Such an LED package can be suitably used for a backlight of, for example, a mobile phone or a large liquid crystal TV.

  FIG. 1 is a cross-sectional view showing an example of an LED package having the above-described LED element substrate. The LED package 1 has, for example, a substantially flat LED element substrate 2, and the LED element 4 is mounted on a mounting portion 21 provided at a substantially central portion thereof with an adhesive 3. The LED element substrate 2 has a pair of connection terminals 22 around the mounting portion 21, and a pair of electrodes (not shown) of the LED elements 4 are electrically connected to the connection terminals 22 via bonding wires 5. ing.

  Inside the LED element substrate 2, an energization via 23 is provided in the thickness direction so as to be electrically connected to the pair of connection terminals 22, and is electrically connected to the energization via 23. A pair of external electrode terminals 24 is provided to do this. Further, a thermal via 25 is provided directly below the mounting portion 21. Furthermore, the LED package 1 is configured by providing the molding material 6 so as to cover the LED elements 4 and the connection terminals 22.

  For example, the connection terminals 22 in the LED element substrate 2 are plated to protect the connection terminals 22 or to facilitate the connection to the bonding wires 5. According to this LED element substrate 2, since it consists of the glass ceramic composition described above, it has excellent acid resistance, and it is possible to suppress a decrease in productivity due to contamination of the plating solution. Further, the LED element substrate 2 can be suitably used for the LED package 1 because it has a practically sufficient reflectance. Furthermore, the LED element substrate 2 has sufficient density (gas barrier properties), and can effectively suppress sulfidation of the wiring conductor.

(Examples 1-5, Comparative Examples 1-4)
The raw materials are blended and mixed so that the mass ratio shown in the column of the glass powder in Table 1 is obtained. The mixture is put in a platinum crucible and melted at 1500 to 1600 ° C. for 60 minutes, and then the molten glass is cooled to obtain a glass block. It was. The glass block was pulverized with an alumina ball mill for 20 to 60 hours using water as a solvent to obtain a borosilicate glass powder. When the D ₅₀ of the borosilicate glass powder was measured using a laser diffraction particle size distribution analyzer (SALD2100) manufactured by Shimadzu Corporation, all were 2.0 μm.

Next, a borosilicate glass powder, an alumina powder, and a zirconia powder were blended and mixed so that the mass ratio shown in the column of the glass ceramic composition in Table 1 was obtained to obtain a mixture. Incidentally, the alumina powder was used Showa Denko Co. _{AL47-H (D 50 = 2.1μm} ). Further, the zirconia powder was used portion is a stabilized zirconia powder manufactured by Daiichi Kigenso Kagaku Kogyo Co., _{HSY-3F-J (D 50} = 0.56μm).

  50 g of this mixture, 15 g of an organic solvent (toluene, xylene, 2-propanol, 2-butanol mixed at a mass ratio of 4: 2: 2: 1), and 2.5 g of a plasticizer (di-2-ethylhexyl phthalate) Then, 5 g of a resin (polyvinyl butyral PVK # 3000K manufactured by Denka) and a dispersant (DISPERBYK180 manufactured by BYK Chemie) were mixed to obtain a slurry. This slurry was applied onto a PET film by a doctor blade method and dried to obtain a green sheet having a thickness of 0.2 mm.

  Next, the sintered body made of such a green sheet was evaluated for reflectivity, water absorption, and acid resistance by the following methods. The results are also shown in Table 1.

(Reflectance)
The reflectance was measured by the following method. In other words, a square green sheet having a side of about 30 mm, a stack of two sheets, a stack of three sheets, and a stack of three sheets are each fired by holding at 925 ° C. for 30 minutes, and the thicknesses are 140 μm, 280 μm, and 420 μm. Three types of sintered bodies were obtained. The reflectance of these sintered bodies was measured using a spectroscope USB2000 and a small integrating sphere ISP-RF manufactured by Ocean Optics, and linearly complemented with respect to the thickness, whereby the reflectance of the sintered body having a thickness of 300 μm (unit: %) Was calculated. The reflectance was at a wavelength of 460 nm, and barium sulfate was used as a reference.

(Water absorption rate)
The water absorption was measured by the following method. In other words, a sintered body was obtained by firing the laminate of six square green sheets each having a side of about 40 mm at 925 ° C. for 30 minutes. The sintered body was immersed in water for 1 hour under a reduced pressure of 0.1 atm or less, and the amount of water absorption was determined as a ratio to the mass of the sintered body (before immersion). The water absorption rate is an index for easily evaluating the sinterability, that is, the denseness (gas barrier property) of the sintered body. Usually, if the water absorption is 3% or less, more preferably 1% or less, it has sufficient density, and for example, sulfidation of the wiring conductor formed on the surface can be sufficiently suppressed.

(Acid resistance)
A stack of six square green sheets having a side of about 40 mm was fired at 925 ° C. for 30 minutes to obtain a sintered body having a thickness of about 0.85 mm. The mass of this sintered body was measured. Next, the sintered body was immersed in an oxalic acid solution having a temperature of 85 ° C. and a pH of 1.68 for 1 hour, then taken out, subjected to ultrasonic cleaning, and further dried at 120 ° C. for 1 hour to measure the mass. A value obtained by subtracting the mass after the immersion from the mass before the immersion in the oxalic acid solution and dividing by the surface area of the sintered body was used as an acid resistance index. The smaller the acid resistance value, the less elution into the oxalic acid solution, indicating better acid resistance. From effectively suppressing contamination of the plating solution when the plating mass production of LED device substrate that has been subjected to, the value of acid resistance is preferably 600 [mu] g / cm ² or less, 300 [mu] g / cm ² or less being more preferred.

  As is apparent from Table 1, the sintered bodies of Examples 1 to 5 made of glass ceramic compositions containing a specific composition of borosilicate glass powder, alumina powder, and zirconia powder within a predetermined range are 85. It can be seen that a reflectance of% or more can be obtained. In addition, it can be seen that the sintered bodies of Examples 1 to 5 have sufficient denseness and acid resistance.

  On the other hand, for the sintered body of Comparative Example 1 using the same borosilicate glass powder as in Example 1 and comprising a glass ceramic composition containing no zirconia powder, the compactness and acid resistance are sufficient, but 85% It can be seen that the above reflectance cannot be obtained. Moreover, about the sintered compact of the comparative example 2 which consists of the glass-ceramics composition which contains the excessive zirconia powder using the borosilicate type | system | group glass powder similar to Example 1, the reflectance of 85% or more is obtained, and acid resistance It can be seen that the density is reduced, though the properties are sufficient.

Furthermore, although the borosilicate glass powder similar to that of Example 2 was used and the sintered body of Comparative Example 3 made of a glass ceramic composition containing no zirconia powder had sufficient density and acid resistance, 85% It can be seen that the above reflectance cannot be obtained. Further, using a borosilicate glass powder containing Na 2 _O and K _{2 O,} for the sintered body of Comparative Example 4 made of a glass ceramic composition containing excessive zirconia powder, a reflectivity of 85% or more Although it is obtained and the density is sufficient, it can be seen that the acid resistance is greatly reduced.

1 ... LED package (light emitting device)
2 ... LED element substrate 4 ... LED element

Claims (4)

Glass ceramic composition used for manufacturing a substrate for mounting a light-emitting diode element, comprising 30-50 mass% borosilicate glass powder, 35-60 mass% alumina powder, and 10-20 mass% zirconia powder A thing,
The borosilicate glass powder, in terms of oxide, the SiO ₂ 45 to 65 _wt%, the B 2 _{O 3} 5 to 20 wt%, _Al 2 _{O 3} 5 to 25 wt%, and the CaO 15 to 35 containing _mass%, Li 2 O, _Na 2 O, and _K do not contain ₂ O, or _Li 2 O, _Na 2 O, and the total content of _{K 2} O is to be less than 0.5 wt% A glass ceramic composition characterized.   The glass ceramic composition according to claim 1, wherein the zirconia powder is made of stabilized zirconia or partially stabilized zirconia. A substrate for mounting a light emitting diode element,
A substrate for a light emitting diode element, which is obtained by molding and firing the glass ceramic composition according to claim 1. A light emitting device comprising: a light emitting diode element substrate; and a light emitting diode element mounted on the light emitting diode element substrate,
4. The light emitting device according to claim 3, wherein the light emitting diode element substrate is the light emitting diode element substrate according to claim 3.

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