JP6150159B2 - Glass ceramic for light emitting diode package, ceramic substrate using the same, and light emitting diode package - Google Patents

Description

  The present invention relates to a glass ceramic having a high visible light reflectance and suitable for a light emitting diode package, and a ceramic substrate and a light emitting diode package using the glass ceramic.

  From the viewpoint of energy saving and product life, in recent years, a light emitting diode element (LED: Light Emitting Diode) is used as a backlight light source for liquid crystal displays of mobile phones and liquid crystal TVs, or as an illumination light source for automobiles, indoors, or decorations. ) Using light emitting diode packages (also referred to as light emitting devices) has come to be used.

  As an example, FIG. 9 shows a surface-mounted light-emitting device. In the light emitting device 500, a light emitting diode element 503 is mounted on an insulating substrate 501 with a wiring pattern 502 formed of an electrode material such as Ag or Cu. The light emitting diode element 503 is connected to the wiring pattern 502 by wire bonding using a metal wire 504 such as Au and sealed with a transparent resin 505.

  The insulating substrate 501 is not limited to a flat plate shape, and there is a configuration as shown in FIG. In this light-emitting device 601, an insulating substrate 604 in which two layers of a flat substrate 602 and a substrate 603 with a tapered central portion are stacked is used. The light-emitting diode element 605 is disposed in a depression at the center of the substrate surrounded by the tapered portion 609 and sealed with a resin 608. Each of the insulating substrates 501 and 604 is made of epoxy resin added with glass fiber, alumina ceramic, or aluminum nitride.

The insulating substrate is required to efficiently reflect light generated from the light emitting diode element and to quickly release the generated heat to the outside. Resin materials such as epoxy resin have been used as the material of the insulating substrate, but as the light emitting diode element becomes brighter, the light intensity and heat generation increase, and the performance deterioration such as discoloration of the insulating substrate is a problem. It has become.
Ceramic substrates do not change color tone due to heat or discoloration due to heat, but alumina ceramics have a problem of low thermal conductivity and inferior heat dissipation, and their use is limited to some fields, replacing resin materials. It is not. In addition, aluminum nitride has low reflectivity and needs to be fired at a temperature exceeding 1600 ° C., which consumes a large amount of energy, and the heating elements and furnace bodies used in the firing furnace are limited, resulting in high manufacturing costs. easy. Another problem is that the conductor that can be fired simultaneously is also limited to W (tungsten).

In response to the problem of conventional ceramic substrates for light emitting devices, ceramics (LTCC: Low Temperature Co-fired Ceramic) that can be fired at a low temperature even below 900 ° C. have been used. In Patent Document 1, a composition comprising a SiO ₂ —Al ₂ O ₃ —B ₂ O ₃ —CaO glass and a high-refractive index ceramic filler such as TiO ₂ or ZrO ₂ is in a tape form (also referred to as a sheet form). It is disclosed that a ceramic substrate for a light emitting device having excellent reflectivity can be obtained using the ceramic substrate. The composition is a composite composed of glass and a ceramic filler, and is sintered using the low-temperature fluidity of glass. Therefore, the composition can be sintered at a lower temperature than a conventional ceramic substrate. Further, the ceramic filler increases the diffuse reflection at the interface between the glass and the ceramic filler to increase the reflectance. Further, in order to overcome the low thermal conductivity, a thermal via is provided to transfer heat from the light emitting diode element to the heat sink to reduce the thermal resistance.

JP 2007-129191 A

In the ceramic disclosed in Patent Document 1, borosilicate glass can be added to enable firing at a low temperature of 800 ° C. to 950 ° C., and a high refractive index filler such as TiO ₂ or ZrO ₂ should be added. This enables high light reflectance. However, the B (boron) compound contained in the borosilicate glass damages the firing furnace material and is not preferable from the viewpoint of maintenance of the furnace material, and dissolves in water and alcohol in the ceramic sheet manufacturing process and segregates during drying. In some cases, this may cause problems in the manufacturing process.

In addition, in a ceramic substrate for a light-emitting device used as a light source for high-luminance illumination such as a headlight, the average reflectance (hereinafter referred to as average reflectance) of light at a visible light wavelength of 380 nm to 740 nm is high. It has been demanded. In Patent Document 1, it is described that TiO ₂ is used as a ceramic filler having a high refractive index so as to have a high reflectance. As will be described in detail later, the reflectance of TiO ₂ alone is not more than a wavelength of 430 nm or more. Although it has a reflectivity of 90%, it significantly decreases below 430 nm, and decreases to about 10% at 370 nm. For this reason, when TiO ₂ is used as the ceramic filler, there is a problem that a high reflectance cannot be obtained at a visible light wavelength of 380 nm to 740 nm.

Moreover, since ZrO ₂ used as a ceramic filler has a high sintering temperature, it functions as a sintering inhibitor for ceramics containing it, and raises the sintering temperature. In order to suppress an increase in the sintering temperature, the amount of B (boron), which promotes the crystallinity of the glass, or its compound is increased, but the problem has already been described.

  In view of the above, the present invention is a light-emitting diode that does not contain B or Ti, can be fired at 1200 ° C. or less, which is 400 ° C. or more lower than aluminum nitride, and has a high reflectance at wavelengths of 380 nm to 740 nm. It is an object to provide a glass ceramic for a package, a ceramic substrate using the glass ceramic, and a light emitting diode package.

The first invention is obtained by sintering a glass ceramic composition containing Al, Si, Sr, and Na, does not contain B and Ti, contains at least Al ₂ O ₃ as a high refractive index ceramic filler, and has a wavelength of 450 nm. A glass ceramic for a light emitting diode package, characterized in that the reflectance of light is 85% or more and the average reflectance of light having a wavelength of 380 nm to 740 nm is 87% or more.

In the present invention, as a high refractive index ceramic filler, a Zr oxide having a refractive index higher than that of Al ₂ O ₃ is further included so that the reflectance of light having a wavelength of 450 nm is 87% or more and the wavelength of 380 nm to 740 nm. A glass ceramic for a light emitting diode package having an average light reflectance of 88% or more can be obtained.

  In the present invention, it is preferable to further contain Sr feldspar.

In the present invention, the glass-ceramic composition is composed of 25 mass% ≦ a ≦ 55 mass% in terms of Al ₂ O ₃ and 0.5 mass% ≦ b ≦ 3.0 mass in terms of Na ₂ Na. %, K in terms of K ₂ O 0% by weight ≦ c ≦ 2.0% by weight K, Si in terms of SiO ₂ 25% by weight ≦ d ≦ 45% by weight, Sr in terms of SrO 10% by weight ≦ e ≦ 35% by mass, and preferably a + b + c + d + e = 100% by mass.

In the present invention, the glass ceramic composition preferably contains 84 parts by weight or less of Zr in terms of ZrO ₂ and 10 parts by weight or less of Bi in terms of Bi ₂ O ₃ with respect to 100 parts by weight.

  A second invention is a glass ceramic substrate characterized in that the glass ceramic for a light emitting diode package according to the first invention is used, and an electrode of Ag, Cu, Au, or Ni is provided as a metal conductor. is there.

  According to a third aspect of the present invention, there is provided a light emitting diode package comprising the ceramic substrate and the light emitting diode element according to the second aspect of the present invention.

According to the present invention, a glass ceramic for a light-emitting diode package that can be fired at 1200 ° C. or less without containing a B compound that easily causes problems in the manufacturing process and has a high reflectance at a wavelength of 380 nm to 740 nm, and A ceramic substrate and a light emitting diode package can be obtained.
Since it can be fired at a low temperature of 1200 ° C. or lower, the manufacturing cost can be reduced, and simultaneous firing with a low melting Ag, Cu, Au, Ni conductor as a heat conductor or an electric conductor can be performed. Moreover, since the reflectance in visible light wavelength 380nm -470nm is high, it is suitable for the high-intensity use used for an indoor illumination, a car headlight, etc.

It is a perspective view of the ceramic substrate which concerns on one embodiment of this invention. It is a disassembled perspective view of the ceramic substrate which concerns on one embodiment of this invention. It is a perspective view of the ceramic substrate which concerns on the other embodiment of this invention. It is sectional drawing of the light emitting diode package which concerns on one embodiment of this invention. It is a perspective view of a light emitting diode package according to another embodiment of the present invention. FIG. 6 is a partially enlarged perspective view of a light emitting diode package according to another embodiment of the present invention. It is a figure which shows the relationship of the reflectance with respect to the wavelength of the oxide used as a high refractive index ceramic filler. It is a figure which shows the relationship of the reflectance with respect to the wavelength of the complex oxide containing the metal element of the oxide used as a high refractive index ceramic filler. It is sectional drawing of the conventional light emitting diode package. It is sectional drawing of the other conventional light emitting diode package.

  The glass ceramic for a light emitting diode package according to the present invention (hereinafter referred to as glass ceramic) is obtained by sintering a glass ceramic composition containing Al, Si, Sr, Na and the like, and does not contain B and Ti.

Al exists in the structure as Al ₂ O ₃ crystal grains that function as a high-reflectance filler, and constitutes a compound together with other metal elements to increase the reflectance of light with a wavelength of 380 nm to 740 nm of the glass ceramic. In the glass-ceramic composition, preferably 25 wt% to 55 wt% of Al in terms _{of Al} 2 _{O 3.}

Si is an essential component for constituting the glass, and is preferably 25% by mass ≦ d ≦ 45% by mass in terms of SiO ₂ .

  Sr lowers the melting temperature of the glass and constitutes a compound (Sr feldspar) with Al and Si to increase the average reflectance of the glass ceramic having a wavelength of 380 nm to 740 nm. It is preferable that 10% by mass ≦ e ≦ 35% by mass in terms of SrO.

  Na and K have a function of reducing the softening point of the glass obtained in the calcining step described later, and are glass ceramics that can be fired at a low temperature.

Na is preferably 0.5 to 3.0% by mass in terms of Na ₂ O. When Na is less than 0.5% by mass, the effect of lowering the firing temperature is insufficient. On the other hand, if Na exceeds 3.0% by mass, diffusion of the metal conductor used as an electrode when forming a light emitting diode package is likely to occur, and a partial discoloration may be caused accordingly. The color tone of the glass ceramic is white. For this reason, it is not preferable in terms of appearance, and when the discoloration is remarkable, the reflectance is lowered, which is not preferable.

K is preferably 0 to 2.0% by mass in terms of K ₂ O, and if K exceeds 2.0% by mass, diffusion of the metal conductor is likely to occur similarly to Na, which is not preferable. Even if K alone is used at the above composition amount, the effect of lowering the softening point of the glass is small. However, when combined with Na, the softening point is even lower even when Na is used alone. Since it can reduce, it is preferable.

  Examples of inevitable impurities mixed in the process include Fe, Ca, Ga, and Cr. The content of these inevitable impurities must be within a range that does not deteriorate the performance of the glass ceramic composition.

Furthermore, ZrO ₂ , which is a higher refractive index ceramic filler than Al ₂ O ₃ , a composite oxide of ZrO ₂ and Y ₂ O ₃ , or MgO (yttria-stabilized zirconia [(Y ₂ O ₃ ) _x (ZrO ₂ ) _1-x ], magnesia partially stabilized zirconia [(MgO) _x (ZrO ₂ ) _1-x ]) and the like can further increase the reflectance at a visible light wavelength of 380 nm to 470 nm.
In addition, since Zr oxide degrades sinterability, it is preferable to use together Bi oxide used as a low temperature sintering aid. Since Bi may ooze out as Bi ₂ O _{3 on} the surface of the glass ceramic after sintering and cause a decrease in insulation resistance, in the present invention, the glass ceramic composition is added to 100 parts by weight of ZrO _2. Zr of 84 parts by weight or less in terms of conversion and Bi of 10 parts by weight or less in terms of Bi ₂ O ₃ are preferred.

The glass ceramic according to the present invention has a calcination step during the production process. Here, calcination means that a component of glass ceramic, such as Al, Si, Sr, Na, and other oxides (including oxides of K if necessary), carbonates, etc., are weighed into a predetermined amount as raw materials. Then, after mixing, firing is performed at a temperature lower than the temperature of the main firing of the ceramic substrate. The calcining temperature is preferably 700 to 850 ° C.
The composition after calcination contains Al ₂ O ₃ crystal grains together with vitrified Si, Sr, Na, etc., and in the subsequent firing step, the glass produced in the calcination step is a sintering accelerator. And densification is achieved even at a temperature of 1200 ° C. or lower. If the glass ceramic is not sufficiently densified and is porous, the bending strength is low and practical bending strength cannot be obtained. However, by using Bi oxide as a low-temperature sintering aid, the sinterability can be reduced. It can be improved.

  The main baking is performed at a temperature higher than the calcining temperature and 1200 ° C. or lower. Note that the optimum calcination and main firing temperatures and times may vary depending on the composition of the glass ceramic composition, the amount of the hardly sinterable ceramic filler, and the amount of the sintering aid. In general, the calcination temperature is preferably 750 ° C. to 850 ° C., the main calcination temperature is relatively higher than the calcination temperature, 820 ° C. to 1200 ° C. or less, and the temperature holding time is preferably 30 minutes to 4 hours.

In the main firing, feldspar group crystals may be generated from the glass. Here, the feldspar group crystal is mainly Sr feldspar (SrAl ₂ Si ₂ O ₈ ), and depending on the glass component, (Na, K) feldspar [(Na, K) SiAl ₃ O ₈ ] or Na feldspar (NaAlSi ₃ O ₈ ) and K feldspar (KAlSi ₃ O ₈ ). Therefore, the glass ceramic of the present invention may further contain Sr feldspar in addition to the case mainly composed of a high refractive index ceramic filler and glass. Since Sr feldspar (SrAl ₂ Si ₂ O ₈ ) undergoes a phase change from hexagonal to monoclinic as the firing temperature increases, the crystal structure of Sr feldspar in the glass ceramic also varies depending on the firing temperature. Become.

The reflectance of glass ceramic is greatly influenced by the crystal phase contained therein. The present inventors evaluated the reflectance at a wavelength of 350 nm to 750 nm with respect to Al ₂ O ₃ , ZrO ₂ , TiO _2, and some other complex oxides including Sr feldspar, which are high-reflectance ceramic fillers. The results are shown in FIG. 7 and FIG. The reflectance here is measured with a standard white plate defined by the National Standards Organization NPL using a spectrocolorimeter CM-3700d manufactured by Konica Minolta, making a measurement sample with an outer diameter of 29 mm and a thickness of 0.4 mm. It is a thing. Hereinafter, when a value is shown as the reflectance, the reflectance is obtained at a wavelength of 450 nm with the measuring instrument and the measurement sample, and when shown as an average reflectance, each wavelength when the wavelength is 380 nm to 740 nm (10 nm pitch) Represents the average of 47 points).

The reflectivity of TiO _{2 used} as a high reflectivity ceramic filler changes greatly with a wavelength of about 430 nm as a boundary, and the reflectivity decreases to about 10% at a wavelength of 380 nm. This tendency is the same for the SrTiO ₂ compound containing Ti. It can be seen that the use of Ti oxide as the high refractive index ceramic filler reduces the reflectance at a wavelength of 380 nm to 740 nm of glass ceramics containing it.

Sr feldspar (SrAl ₂ Si ₂ O ₈ ) has a different refractive index between the hexagonal crystal and the monoclinic crystal, and the reflectance also differs between the hexagonal crystal and the monoclinic crystal. Hexagonal Sr feldspar (H-SrAl ₂ Si ₂ O ₈ ) exhibits high reflectivity comparable to Al ₂ O ₃ and ZrO, which are high refractive index ceramic fillers, at a wavelength of 380 nm to 740 nm. Although M-SrAl ₂ Si ₂ O ₈ ) has a reflectivity of about 15% lower than that of the hexagonal crystal, an average reflectivity exceeding 75% was obtained.

Hexagonal Sr feldspar is thermally unstable and has a narrow temperature range. Therefore, in Sr feldspar in glass ceramics, as the firing temperature in the main firing increases, hexagonal Sr feldspar first precipitates from the glass, and part of the phase changes to monoclinic Sr feldspar, resulting in hexagonal Sr feldspar. Coexisting state, and further phase change proceeds, and monoclinic Sr feldspar exists.
The hexagonal Sr feldspar first precipitated as Sr feldspar has the property that the reflectance is as high as that of the high refractive index ceramic filler. Accordingly, the presence of the hexagonal Sr feldspar in the structure together with a ceramic filler such as Al ₂ O ₃ allows the reflectance to be obtained even when the main baking contains a large amount of unreacted glass at a relatively low temperature. Can be improved. Further, since the glass is relatively reduced, the mechanical strength can be improved. In the case where monoclinic Sr feldspar exists, the crystallization of the glass component proceeds, so that the overall scattering increases and the reflectance can be further improved.

  Since the glass ceramic of the present invention can be densified even by firing at 1200 ° C. or less, a low-melting-point metal (Ag, Cu, Au, Ni or It is easy to co-fire with an electrode material made of an alloy based on these. Using the low melting point metal, a die for mounting a light emitting diode element or a thermal via for radiating heat generated from the light emitting diode element can be configured. In addition, a practical bending strength exceeding 200 MPa is obtained for a light emitting diode package, and the light emitting diode package has excellent mechanical strength as well as a light emitting function.

Example 1
The glass ceramic composition uses Al ₂ O ₃ powder, SiO ₂ powder, SrCO ₃ powder, Na ₂ CO ₃ powder, and K ₂ CO ₃ powder as starting materials. An example of the composition ratio is shown in Table 1. In Table 1, SrCO _3, Na ₂ CO _{3 and} K ₂ CO ₃ are converted into SrO, Na ₂ O and K ₂ O, respectively. Each starting material used had a purity of 99.9% or more and an average particle size of 0.5 μm.

  The starting materials are weighed so that the composition ratio shown in Table 1 is obtained, the raw material powder is put into a polyethylene ball mill, and further, zirconium oxide balls and pure water are added and wet mixed for 40 hours. The mixed slurry was dried by heating to evaporate the moisture, and then crushed in a mortar, and calcined by holding at 800 ° C. for 2 hours.

  The obtained calcined powder is put into a ball mill, wet pulverized for 20 hours, and dried to obtain a pulverized powder. A 10% aqueous solution of polyvinyl alcohol is added to the pulverized powder, and the mixture is kneaded in a mortar and then sized by passing through a 32 mesh sieve to obtain a granulated powder. This powder was put into a mold and subjected to pressure molding at a pressure of 196 MPa to obtain a molded body. The molded body was heated up to a predetermined firing temperature at a rate of 200 ° C./hr, held at 900 ° C. for 2 hours, then cooled at a rate of 200 ° C./hr for firing, and glass in several sample shapes. A ceramic was obtained. From the sample obtained. Identification of the crystal phase, evaluation of the reflectance and average reflectance, evaluation of the bending strength, and evaluation of the sintered density were performed by the following methods.

(Identification of crystal phase)
Part of the obtained sample is pulverized, the crystal state is confirmed by powder X-ray diffraction using Cu-Kα ray, and Al ₂ O ₃ crystal or ZrO ₂ crystal is selected depending on whether it matches or approximates the JCPDS card chart. And feldspar such as SrAl ₂ Si ₂ O ₈ crystal was identified. As the X-ray diffraction measurement apparatus, RINT2000 made by RIGaku was used. Regarding the crystal structure of the SrAl ₂ Si ₂ O ₈ crystal, the peak of the (101) plane of hexagonal SrAl ₂ Si ₂ O ₈ and the peak of the (002) plane of monoclinic SrAl ₂ Si ₂ O ₈ in X-ray diffraction Identified. Hereinafter, the hexagonal Sr feldspar will be referred to as H-SrAl ₂ Si ₂ O ₈ , and the monoclinic Sr feldspar will be referred to as M-SrAl ₂ Si ₂ O ₈ .

(Reflectance and average reflectance)
With respect to a measurement sample having an outer diameter of 29 mm and a thickness of 0.4 mm, the reflectance at a wavelength of 350 nm to 750 nm was evaluated using a spectrocolorimeter CM-3700d manufactured by Konica Minolta. Here, the reflectance is data with a wavelength of 450 nm, and the average reflectance represents the average of the reflectances at each wavelength (47 points at a pitch of 10 nm) when the wavelength is 380 nm to 740 nm.

(Folding strength)
The maximum when the test piece breaks when a three-point bending test (JIS C2141) is performed with a measurement sample of 38 mm × 12 mm × 1 mm as a test piece, a distance between fulcrums of 30 mm, a load speed of 0.5 mm / min. The bending strength (bending strength) was evaluated from the load. When the bending strength is 200 MPa or more, the bending strength is good, and when it is less than 200 MPa, the bending strength is poor.

(Sintering density)
Using the measurement sample for bending strength evaluation, the sintered density ds was evaluated by the volume weight method.

The evaluation results obtained are summarized in Table 2. As for the structure, SrAl ₂ Si ₂ O ₈ crystal is not precipitated, Al ₂ O ₃ crystal and glass phase are mainly, other SrSiO ₃ crystal, Zr oxide crystal derived from the ball used in the grinding process Although confirmed, the amount is so small that it is not listed in the table.
According to the present invention, a glass ceramic that can be fired at 900 ° C. and has excellent bending strength, reflectance, and average reflectance was obtained.

(Examples 2-14, Reference Examples 1-3, Comparative Examples 1-3)
Based on the glass ceramic composition having the composition shown in Table 1, a glass ceramic was further prepared by adding ZrO ₂ or TiO ₂ as a high reflectance ceramic filler and Bi ₂ O ₃ as a sintering accelerator. The measured composition ratio is shown in Table 3. In the table, ZrO _2, TiO _{2, and} Bi ₂ O ₃ are shown as parts by weight with respect to 100 parts by weight of the glass ceramic composition.

First, each starting material (Al ₂ O ₃ , SiO ₂ , SrCO ₃ , Na ₂ CO ₃ , K ₂ CO ₃ ) of the glass ceramic composition is weighed so as to have the same composition as in Example 1. Next, with respect to 100 parts by weight of the starting material, ZrO ₂ powder, TiO ₂ powder, Bi ₂ O ₃ powder having a purity of 99.9% or more and an average particle size of 0.5 μm, according to the parts by weight shown in Table 3. Was weighed.
Each raw material powder is put into a polyethylene ball mill, and then a zirconium oxide ball and pure water are added and wet mixed for 40 hours. The mixed slurry is heated and dried to evaporate water, and then crushed in a mortar. And calcining by holding at 800 ° C. for 2 hours. Since the subsequent steps are the same as those of the first embodiment, the description thereof is omitted.

In the same manner as in Example 1, the obtained glass ceramic was subjected to identification of crystal phase, measurement of reflectance and average reflectance, evaluation of bending strength, and measurement of sintered density. The results are shown in Table 3. In the table, a sample at a firing temperature at which the density does not saturate when the firing temperature is changed is marked as insufficiently sintered. As in Example 1, SrSiO ₃ crystals and balls-derived Zr oxide crystals used in the pulverization process were confirmed in the structure, and Bi oxide was also confirmed. However, the amount was small. Not shown in the table.

In glass plus ZrO ₂ ceramic (Example 2-14), the reflectance and the average reflectance in accordance with the ZrO ₂ amount was increased. Moreover, the reflectance and the average reflectance were further improved by increasing the calcination temperature and promoting crystallization to precipitate feldspar such as SrAl ₂ Si ₂ O ₈ crystal. In the firing at 1200 ° C., both the reflectance and the average reflectance were 98% (Example 14). On the other hand, it became difficult to sinter with an increase in the amount of ZrO ₂ , and a sufficient sintered density might not be obtained depending on the firing temperature (Reference Examples 1 to 3). The samples of Reference Examples 1 to 3 with insufficient sintering tend to have high reflectance and average reflectance, which is presumed to be due to the tendency of scattering on the surface of the sample.

Glass ceramics (Comparative Examples 1 to 3) containing TiO ₂ which is a high refractive index ceramic filler can be sintered at 900 ° C. and have a reflectance of about 83%, but the average reflectance is less than 80%. It was inferior.

(B) Ceramic Substrate Hereinafter, a ceramic substrate configured using the glass ceramic of the present invention (Example 12) will be described. 1 is a perspective view of a ceramic substrate having a laminated structure, and FIG. 2 is an exploded perspective view showing a layer structure of the ceramic substrate.
On the upper surface of the ceramic substrate 1, a mounting electrode (die) 20 on which a light emitting diode element is mounted and a terminal electrode 10 electrically connected to the light emitting diode element by a bonding wire or the like are provided. On the lower surface, there are provided a terminal 9 connected to the mounting electrode 20 via a via hole (indicated by a black circle in the figure) filled with a metal conductor, and similarly a terminal 8 connected to the terminal electrode 10 via the via hole. . The terminals 8 and 9 are used as mounting terminals on the substrate, and a plurality of via holes provided between the terminals 9 and the mounting electrodes 20 function as thermal vias for heat dissipation that guide the heat generation of the light emitting diode elements to the substrate. .

  A method for manufacturing a ceramic substrate will be described. First, calcined powder is prepared by the procedure for obtaining the glass ceramic of Example 12, and this calcined powder is dispersed in a mixed organic solvent of ethanol and butanol and pulverized to an average particle size of 1.0 μm with a ball mill. After pulverization, the slurry is in a slurry state. Polyvinyl butyral as a binder and butylphthalyl butyl glycolate as a plasticizer are dispersed in the slurry to obtain a sheet forming slurry. After defoaming and partial evaporation of the solvent under reduced pressure, the viscosity of the slurry was adjusted to about 10,000 MPa · s, and then a sheet was formed by a doctor blade to obtain a long ceramic green sheet having a dry thickness of about 150 μm. It was. This ceramic green sheet was cut into a predetermined size for subsequent processing.

  A plurality of ceramic green sheets were drilled with a laser and filled with a metal conductor (Ag paste) by screen printing. The formed via holes connect the electrode patterns between the layers and are used for electric wiring and heat conduction. Furthermore, the electrode pattern used as a mounting electrode etc. was printed on the surface with Ag paste.

  Each ceramic green sheet on which the electrode pattern was printed was aligned, laminated with high accuracy, and then crimped. The pressure bonding conditions were a pressure of 12 MPa, a temperature of 850 ° C., and a holding time of 10 minutes. The obtained laminate was cut into chip sizes, placed on a firing setter, and subjected to binder removal and main firing in a continuous furnace, to obtain a ceramic substrate 1 of 2.5 mm × 2.8 mm × 0.25 mm. The main calcination was performed by holding at 950 ° C. for 2 hours in an air atmosphere.

  FIG. 3 shows a ceramic substrate according to another embodiment. The basic structure of the ceramic substrate 1 is the same as that shown in FIG. 1, but is different in that a cavity 30 is provided so as to surround the mounting electrode 20 on which the light emitting diode element is mounted. . The cavity 30 is configured using a ceramic green sheet. The laminate is formed by laminating a part of the ceramic green sheet so as to overlap with a part of the terminal electrode 10, and the subsequent process is the same as that of the ceramic substrate shown in FIG. Since a multilayer structure is possible, a ceramic substrate having a cavity can be easily obtained.

(C) Light-Emitting Diode Package A light-emitting diode package was manufactured using the ceramic substrate 1 having a cavity having the structure shown in FIG. FIG. 4 is a sectional view thereof. The ceramic substrate 1 is composed of a layer 5 constituting a cavity 30 and ceramic layers 6 a and 6 b (6) in which electrodes 8, 9, 10, 20 and via holes 14 are formed. After mounting the light emitting diode element 50 by soldering or mounting the mounting electrode 20 that can be seen from the cavity 30 with solder or a conductive adhesive, the light emitting diode element 50 and the terminal electrode 10 are connected by a bonding wire 60. Thereafter, the cavity 30 was filled with a silicone resin (not shown in the figure) in which a phosphor was dispersed as required, and solidified to obtain the light emitting diode package 3. A lens may be further fixed on the upper surface of the cavity side. The light emitting diode package 3 is excellent in luminance by using a glass ceramic excellent in reflectance and the like. The thermal via 14 also has excellent heat dissipation.

  FIG. 5 is a perspective view of an array type light emitting diode package as another embodiment of the light emitting diode package. FIG. 6 is a partially enlarged view thereof. The light emitting diode package 3 shown in FIG. 3 uses one light emitting diode element, but the array type light emitting diode package 3 has a light emitting diode element group 25 in which a plurality of light emitting diode elements 50 are connected in series by bonding wires 60. Is used. The light emitting diode element group 25 protected by the epoxy resin is connected in parallel by the bus electrode 12 connected to the common terminal electrode 15. The basic configuration of the light emitting diode package 3 is the same as that shown in FIG. 1 and the like, and the manufacturing process is the same procedure, and an array type light emitting diode of 20 mm × 20 mm × 0.55 mm is obtained. By using glass shellac having excellent reflectivity and the like and using a plurality of light emitting diode elements 50, the obtained array type light emitting diode package 3 is further excellent in luminance.

DESCRIPTION OF SYMBOLS 1 Ceramic substrate 3 Light emitting diode package, light-emitting device 8, 9 Terminal 10 Terminal electrode 12 Bus electrode 15 Common terminal electrode 20 Mounting electrode 25 Light emitting diode element group 30 Cavity 50 Light emitting diode element 60 Bonding wire

Claims (6)

Sintered glass ceramic composition containing Al, Si, Sr, Na,
Does not contain B and Ti,
Including at least Al ₂ O ₃ as a high refractive index ceramic filler,
In the glass ceramic composition, Al is 25% by mass ≦ a ≦ 55% by mass in terms of Al ₂ O ₃ , Na is 0.5% by mass ≦ b ≦ 3.0% by mass in terms of Na ₂ O, and K is K ₂ 0 mass% ≦ c ≦ 2.0 mass% in terms of O, Si is composed of 25 mass% ≦ d ≦ 45 mass% in terms of SiO ₂ , and Sr is 10 mass% ≦ e ≦ 35 mass% in terms of SrO, a + b + c + d + e = 100% by mass,
A glass ceramic for a light emitting diode package, characterized in that the reflectance of light having a wavelength of 450 nm is 85% or more and the average reflectance of light having a wavelength of 380 nm to 740 nm is 87% or more. The glass ceramic for a light emitting diode package according to claim 1,
Further containing Zr oxide as a high refractive index ceramic filler,
A glass ceramic for a light emitting diode package, characterized by having a reflectance of light having a wavelength of 450 nm of 87% or more and an average reflectance of light having a wavelength of 380 nm to 740 nm being 88% or more.   The glass ceramic for a light emitting diode package according to claim 1, further comprising Sr feldspar. The glass ceramic for a light emitting diode package according to claim 1 ,
For the light emitting diode package, comprising 100 parts by weight of the glass ceramic composition, 84 parts by weight or less of Zr in terms of ZrO ₂ and 10 parts by weight or less of Bi in terms of Bi ₂ O ₃ Glass ceramic. Glass ceramic substrate, characterized by using a light emitting diode package glass ceramic according to any one of claims 1 to 4, as the metal conductor Ag, Cu, Au, one of the electrodes of the Ni provided. A light emitting diode package comprising the ceramic substrate according to claim 5 and a light emitting diode element.

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