JP2014017375A - Substrate for light emitting element and light emitting device - Google Patents

Abstract

Provided is a light-emitting element substrate in which a sealing layer having a desired shape can be formed by potting a resin material, and a decrease in light extraction efficiency is prevented by preventing corrosion of a silver layer.
The light-emitting element substrate is made of an inorganic insulating material, has a base having a light-emitting element mounting surface, an element connection terminal formed on the mounting surface and a reflective layer made of silver or a silver alloy, and A coating layer made of a first glass ceramic sintered body formed so as to cover the surface and edge of the reflective layer in a region excluding the element connection terminal on the mounting surface, and the coating layer, A damming layer made of a second glass ceramic sintered body formed so as to surround the element connection terminal.
[Selection] Figure 1

Description

  The present invention relates to a light emitting element substrate and a light emitting device, and more particularly to a light emitting element substrate for obtaining a light emitting device with high light extraction efficiency and a light emitting device using the light emitting element substrate.

  In recent years, in a light emitting device using a light emitting diode (LED) element, a sealing layer made of silicone resin or epoxy resin is provided to protect the light emitting element and wiring conductor mounted on the substrate. In addition, a light-emitting device in which a fluorescent material is dispersed to obtain white light emission in combination with light emission of a light-emitting element has been put into practical use.

  In order to improve the color tone unevenness, the light collection rate, and the like in such a light emitting device, it is considered to form the sealing layer into a lens shape having a spherical outer surface. That is, by mounting a light emitting element on a flat substrate and potting a fluid resin material so as to cover the light emitting element, a hemispherical lens-shaped translucent sealing layer is formed. A light emitting device has been developed in which the length of the path through which the emitted light passes through the sealing layer is equal in all directions.

  However, when a resin material having fluidity is potted, the resin material tends to wet and spread on the substrate, so that a recess is likely to be formed on the outer surface of the interface between the resin material and the substrate. The sealing layer having such a shape has a problem that the light extraction efficiency (radiation efficiency) is likely to be low as a result of the transmitted light being reflected by the surface of the depression and confined inside the sealing layer. It was.

  In order to improve the decrease in light extraction efficiency due to the spread of the potted resin material, an annular member is attached on the base so as to surround the mounting portion of the light emitting element, and the height is higher than the annular member. There has been proposed a light emitting device in which a light emitting element is mounted on a mounting portion formed so as to protrude and a translucent member is provided inside the annular member so as to cover the light emitting element (see, for example, Patent Document 1). .

  However, in the light emitting device described in Patent Document 1, the annular member is made of a metal such as an Fe—Ni—Co alloy or an Fe—Ni alloy, or a ceramic material such as alumina ceramics. Since the annular member reflects or absorbs part of the transmitted light, the light extraction efficiency cannot be sufficiently increased.

  In recent years, in a substrate on which a light emitting element of a type having an electrode on the back surface and connected by flip chip bonding is mounted, a conductive layer (hereinafter, referred to as a reflective layer) made of silver or a silver alloy formed on the light emitting element mounting surface. The heat radiation performance is improved by increasing the area of the silver layer. In such a substrate, it is considered that the silver layer surface is subjected to gold plating or the like to prevent silver oxidation or corrosion. However, gold is emitted from the LED element (for example, blue light having a wavelength of 460 nm). ) Is absorbed, a light emitting device with high light extraction efficiency cannot be obtained.

  In order to prevent silver oxidation and corrosion, a substrate for a light-emitting element has been proposed in which a glass layer is coated on the surface of the silver layer to improve weather resistance such as corrosion resistance and prevent a decrease in reflectance. (For example, refer to Patent Document 2). Hereinafter, the light emitting element substrate is simply referred to as an element substrate.

  However, the element substrate of Patent Document 2 is not applicable to a substrate on which the above-described flip chip bonding type light emitting element is mounted because the mounting portion of the light emitting element is also covered with a glass layer. In addition, even in a structure equipped with a wire bonding type light emitting element, if a resin sealing layer is formed by potting so as to cover the light emitting element, the resin material spreads on the glass coating layer, forming a hemispherical lens-shaped sealing layer There was a problem that I could not.

JP 2005-340543 A JP 2009-231440 A

  The present invention has been made to solve the above-described problem, and is a device in which a decrease in reflectance is prevented by preventing corrosion of a silver layer, and a sealing layer having a desired shape can be formed, and light extraction efficiency is improved. The purpose is to provide a substrate. It is another object of the present invention to provide a light-emitting device that has a sealing layer of a desired shape and can emit light with high luminance with improved color unevenness and light collection rate.

  The element substrate of the present invention is made of an inorganic insulating material, and is composed of a substrate having a light emitting element mounting surface, an element connection terminal formed on the mounting surface, and silver or a silver alloy formed on the mounting surface. A coating layer formed of a first glass ceramic sintered body, which is formed to cover the reflective layer and a region excluding the element connection terminal on the mounting surface so as to cover a surface and an edge of the reflective layer; A damming layer made of a second sintered ceramic glass material is provided on the covering layer so as to surround the element connection terminal.

In the element substrate of the present invention, the damming layer has an annular planar shape, and the width and height are 0.091 to 0.182 and 0.009 to 0.009 to 0.009, respectively, in proportion to the inner diameter of the annular shape. It is preferable to be in the range of 0.030. Further, the first glass ceramic sintered body is preferably a sintered body of a glass ceramic composition containing the first glass powder and the first ceramic powder. Then, the first glass powder, as represented by mol% based on oxides, the _{SiO 2 57~65%, B 2 O} 3 and 13 to 18%, the _{Al 2 O 3 3~8%, Na} 2 O And a composition containing 0.5 to 6% in total and at least 9 to 23% CaO selected from K ₂ O.

Further, the second glass ceramic sintered body is preferably a sintered body of a glass ceramic composition containing a second glass powder and a second ceramic powder. Then, the second glass powder, as represented by mol% based on oxides terms of SiO _{2 78-83%,} B 2 _{O 3} 16 to 18%, the _Al 2 _{O 3} 0 to 0.5%, Na A composition containing 0.9 to 4% in total of at least one selected from ₂ O and K ₂ O and 0 to 0.6% in total of at least one selected from CaO, SrO and BaO is preferable.

  The light emitting device of the present invention includes the element substrate of the present invention, a light emitting element mounted on the mounting surface of the element substrate and electrically connected to the element connection terminal, and the weir on the mounting surface. A sealing layer made of a resin provided so as to cover the light emitting element is provided in a region inside the layer.

According to the element substrate of the present invention, the corrosion of the silver layer is prevented to prevent the reflectance from being lowered, and the lens-shaped sealing layer can be formed in a desired shape, thereby improving the light extraction efficiency.
According to the light-emitting device of the present invention, it is possible to obtain high-luminance light emission with high light extraction efficiency and improved color unevenness and light collection rate.

1 shows an embodiment of an element substrate of the present invention, (a) is a plan view seen from the upper surface (mounting surface) side, (b) is a plan view seen from the lower surface (non-mounting surface) side, (c ) Is a cross-sectional view taken along line XX in (a). In the element substrate of the present invention, it is an enlarged cross-sectional view showing the relationship between the width and height of the damming layer and the shape of the sealing layer formed in the region inside the damming layer. 1 shows an embodiment of a light emitting device according to the present invention, wherein (a) is a plan view seen from the upper surface (mounting surface) side, and (b) is a cross-sectional view taken along line YY in (a).

Hereinafter, although an embodiment of the present invention is described, the present invention is not limited to this.
The element substrate according to the embodiment of the present invention is made of an inorganic insulating material, has a base having a mounting surface for a light emitting element, an element connection terminal formed on the mounting surface, and silver or silver formed on the mounting surface. A reflective layer made of an alloy, and a coating layer made of a first glass ceramic sintered body that is formed on the mounting surface so as to cover the surface and edge of the reflective layer in a region excluding the element connection terminal And a blocking layer made of a second glass ceramic sintered body formed on the covering layer so as to surround the element connection terminal.
The reflective layer made of silver or a silver alloy has a function as a heat dissipation layer. In addition, this layer can function as a wiring layer depending on the planar shape and formation position, and in this case, it can also be referred to as a wiring conductor layer. .

  The light emitting device of the embodiment of the present invention includes the element substrate of the above-described embodiment, a light emitting element mounted on the mounting surface and electrically connected to the element connection terminal in the element substrate, A sealing layer made of a resin provided so as to cover the light emitting element is provided in a region inside the blocking layer on the mounting surface.

  In the element substrate of the embodiment, the first glass ceramic sintered body is formed so as to cover the surface and the edge of the reflective layer made of silver or silver alloy in a region excluding the element connection terminal on the mounting surface of the base. Since the coating layer to be formed is formed, it is possible to prevent the reflectance from being lowered due to oxidation or corrosion of silver or the like. Further, since this coating layer does not absorb light from the light emitting element mounted on the substrate, the light extraction efficiency is not lowered. Furthermore, since the damming layer made of the second glass ceramic sintered body is formed on the coating layer made of the first glass ceramic sintered body, the flowable resin material for sealing Wetting and spreading can be prevented, and a sealing layer having a desired shape can be formed.

  That is, the flow of the resin material constituting the sealing layer is blocked by the damming layer made of the second glass ceramic sintered body, and the resin material gets wet on the mounting surface of the base to the outer region. Since spreading is suppressed, a resin sealing layer having a hemispherical lens shape can be easily formed by a simple and inexpensive potting method, and a light-emitting device having stable and good optical characteristics can be obtained.

In addition, the damming layer is made of a sintered glass ceramic, and the damming layer hardly reflects or absorbs the light transmitted through the sealing layer. A device is obtained. Furthermore, by adjusting the glass composition of the first glass ceramic sintered body constituting the coating layer and the second glass ceramic sintered body constituting the barrier layer, the content of the ceramic powder, etc., respectively, the barrier layer The shape, height, and the width that becomes a barrier in the direction of wetting and spreading can be formed so as to be suitable for preventing the sealing resin material from spreading.
Furthermore, since both the covering layer and the blocking layer can be formed by a method such as simultaneous firing with the substrate, the light emitting device as a whole can be easily manufactured.

<Light emitting element substrate (element substrate)>
Hereinafter, embodiments of an element substrate of the present invention will be described with reference to the drawings. FIG. 1A is a plan view of the element substrate of the embodiment as viewed from the upper surface (mounting surface) side, and FIG. 1B is a plan view of the element substrate as viewed from the lower surface (non-mounting surface) side. Moreover, FIG.1 (c) is sectional drawing cut | disconnected by the XX line of Fig.1 (a).

The element substrate 1 of the embodiment includes a base 2 having a substantially flat plate shape in a square shape. The base 2 is made of an inorganic insulating material, and the upper surface on which the light emitting element is mounted is a mounting surface 21. The opposite surface is referred to as a non-mounting surface 22. The shape, thickness, size and the like of the substrate 2 are not particularly limited, and can be generally the same as that used as a substrate for mounting a light emitting element.
In the present specification, the “substantially flat substrate” means a flat surface at a level at which the upper main surface and the lower main surface, that is, the mounting surface 21 and the non-mounting surface 22 can be recognized as a flat plate shape at the visual level. It refers to a certain substrate. Similarly, the abbreviations indicate levels that can be recognized at the visual level unless otherwise specified.

  Examples of the inorganic insulating material constituting the substrate 2 include an aluminum oxide sintered body (alumina ceramic), an aluminum nitride sintered body, a mullite sintered body, and a glass ceramic composition containing glass powder and ceramic powder. Body (Low Temperature Co-fired Ceramics. Hereinafter, may be referred to as LTCC). In the present invention, from the viewpoints of high reflectivity, ease of manufacture, easy processability, economy and the like, the inorganic insulating material constituting the substrate 2 is preferably LTCC. The raw material composition, sintering conditions, and the like of the sintered body of the glass ceramic composition constituting the substrate 2 will be described in the manufacturing method described later.

  The base body 2 preferably has a bending strength of, for example, 250 MPa or more from the viewpoint of suppressing damage or the like when the light emitting element is mounted and when it is used thereafter. And the base | substrate 2 has the mounting part for mounting a light emitting element in the approximate center part of the mounting surface 21. FIG.

A pair of (anode and cathode) element connection terminals 3 are provided on the mounting portion of the base 2. These element connection terminals 3 are arranged so as to face the substantially central portion of the mounting surface 21 so that a metal-to-metal connection is possible via a pair of electrodes on the lower surface of the mounted light emitting element and gold-tin solder or the like. Has been. On the mounting surface 21 of the base 2, a reflection layer (hereinafter referred to as a silver reflection layer) 4 made of silver or a silver alloy is connected to the element in a region excluding the mounting portion where the element connection terminals 3 are formed. It is formed to be connected to the terminal 3.
In FIG. 1, the silver reflection layer 4 is formed so as to be connected to the element connection terminal 3, and the silver reflection layer 4 has a function as a wiring conductor layer. The formation position is not limited and may be formed in the peripheral region separately from the element connection terminal 3. Further, a wiring conductor layer may be formed separately from the silver reflection layer 4.

  On the non-mounting surface 22 of the base 2, a pair of external connection terminals 5 serving as an anode and a cathode electrically connected to an external circuit are provided. The element connection terminals 3 on the anode side and the cathode side are connected to a pair of connection vias 6 embedded in the base body 2 via a silver reflection layer 4 as a wiring conductor layer. 6 are electrically connected to the pair of external connection terminals 5 formed on the non-mounting surface 22.

  The element connection terminal 3, the external connection terminal 5, and the connection via 6 embedded in the base 2 are the element connection terminal 3 → (silver reflection layer 4 as a wiring conductor layer) → connection via 6 → external connection terminal 5. → As long as the anode and the cathode are electrically connected to the external circuit without short-circuiting, the position and shape of the arrangement are not limited.

As described above, the silver reflection layer 4 that has a heat dissipation function and also functions as a wiring conductor layer is a layer made of a silver alloy such as silver, a silver palladium alloy, or a silver platinum alloy. From the viewpoint of reflectance, the silver alloy is preferably an alloy mainly composed of silver, and the silver content is more preferably 90% by mass or more. Specifically, in the case of a silver palladium alloy, palladium can be contained up to 10% by mass, and in the case of a silver platinum alloy, platinum can be contained up to 3% by mass. The silver reflection layer 4 preferably has a high reflectance, and a silver layer is particularly preferable.
The silver reflecting layer 4 is obtained by adding a vehicle such as ethyl cellulose to a silver powder or a powder of the silver alloy, and adding a solvent or the like, if necessary, to a paste (silver paste) by a method such as screen printing. 2 can be formed by printing on the mounting surface 21 and baking. As for the thickness of the silver reflection layer 4, 5-20 micrometers is preferable.

  The constituent material of the element connection terminal 3, the external connection terminal 5, and the connection via 6 can be used without particular limitation as long as it is the same constituent material as the conductor used for wiring of the element substrate. Specifically, a conductive metal material whose main component is copper, silver, gold, or the like can be given. Among such metal materials, silver, a silver alloy such as a silver palladium alloy or a silver platinum alloy is preferably used, and the same material as the silver reflective layer 4 is more preferable. In particular, since the element connection terminal 3 is formed so as to be connected to the silver reflection layer 4, it is preferable that the element connection terminal 3 is made of the same material as the silver reflection layer 4. The element connection terminal 3 is preferably formed in the same process as the formation of the silver reflective layer 4 using a silver paste containing the conductive metal material. The thickness of the element connection terminal 3 and the external connection terminal 5 is preferably in the range of 5 to 15 μm.

  In the element connection terminal 3 and the external connection terminal 5, a conductive protective layer (not shown) is formed on the layer made of the conductive metal material to protect the layer from oxidation and sulfurization. It is preferable. The conductive protective layer is not particularly limited as long as it is made of a conductive material having a function of protecting the conductive metal layer. Specific examples include layers made of nickel plating, chromium plating, silver plating, nickel / silver plating, gold plating, nickel / gold plating, and the like.

  In the element substrate 1 of the embodiment, as the conductive protective layer for protecting the element connection terminals 3 and the external connection terminals 5, for example, for the element connection terminals 3, the light emitting element solder, gold, and gold-tin eutectic crystal described later are used. For example, a gold plating layer is preferable as at least the outermost layer from the viewpoint that a good metal-to-metal connection can be obtained. The conductive protective layer may be formed only of a gold plating layer, but a nickel / gold plating layer obtained by performing gold plating on nickel plating is more preferable. In this case, the thickness of the conductive protective layer is preferably 2 to 20 μm for the nickel plating layer and 0.1 to 1 μm for the gold plating layer.

  A covering layer 7 made of the first glass ceramic sintered body is formed on the mounting surface 21 of the base 2 in a region excluding the element connection terminal 3 covered with the conductive protective layer. The covering layer 7 is formed on the mounting surface 21 of the base 2 so as to cover the entire surface including the edge of the silver reflecting layer 4. The thickness of the coating layer 7 is preferably 8 to 30 μm.

The first glass ceramic sintered body constituting the coating layer 7 is preferably a sintered body of the first glass ceramic composition containing the first glass powder and the first ceramic powder. Then, the glass composition of the first glass powder, as represented by mol% based on oxides, the _{SiO 2 57~65%, B 2 O} 3 and 13 to 18%, the _Al 2 _{O 3 3~8%,} Na It is preferable that a total of at least one selected from ₂ O and K ₂ O is 0.5 to 6% and CaO is 9 to 23%. By using the glass powder having such a composition, the width, height, etc. of the weir layer described later can be controlled to a desired value. That is, it is possible to form a damming layer having a width and height suitable for preventing the expansion of the sealing resin material.
Next, the composition of the first glass powder will be described. Hereinafter, in the description of the glass composition, “%” represents an oxide conversion mol% unless otherwise specified.

SiO ₂ is a glass network former. When the content of SiO ₂ is less than 57%, it is difficult to obtain a stable glass and the chemical durability may be lowered. On the other hand, when the content of SiO ₂ exceeds 65%, the glass melting temperature (Ts) and the glass transition temperature (Tg) may be excessively increased. The content of SiO ₂ is preferably 58% or more, more preferably 59% or more, and particularly preferably 60% or more. Further, the content of SiO ₂ is preferably 64% or less, more preferably 63% or less.

In addition, the first glass ceramic composition containing the first glass powder and the first ceramic powder is fired in contact with the silver or silver alloy constituting the silver reflective layer 4, so that the silver reflective layer 4 Also from the viewpoint of ease of diffusion of silver ions migrated from, the content of SiO ₂ is preferably 57 to 65%. That is, in the composition of the first glass powder, when the content of SiO ₂ is too large (exceeds 65%), the silver ions migrated from the silver reflecting layer 4 are the first glass constituting the coating layer 7. Without reaching the glass phase of the ceramic sintered body, it reaches the surface of the coating layer 7 along the surface of the first ceramic powder (for example, alumina powder) contained in the first glass ceramic sintered body. . And the silver ion which reached | attained the coating layer 7 surface contacts with the silicone resin etc. which comprise the sealing layer, and is reduced by the platinum catalyst etc. which are contained in a silicone resin, and becomes silver. As a result, coloration due to silver occurs at the interface between the coating layer 7 and the silicone resin sealing layer, and the amount of light flux decreases.

On the other hand, when the content of SiO ₂ is too small (less than 57%) in the composition of the first glass powder, a large amount of silver is contained in the glass phase of the first glass ceramic sintered body constituting the coating layer 7. Since ions diffuse, the glass is colored yellow or brown and the amount of light flux decreases.

B ₂ O ₃ is a glass network former. When the content of B ₂ O ₃ is less than 13%, Ts and Tg may be excessively high. On the other hand, when the content of B ₂ O ₃ exceeds 18%, it is difficult to obtain a stable glass and the chemical durability may be lowered. The content of B ₂ O ₃ is preferably 14% to 17%, more preferably 15% to 16%.

Al ₂ O ₃ is added to increase the stability, chemical durability and strength of the glass. If the content of Al ₂ O ₃ is less than 3%, the glass may become unstable. On the other hand, when the content of Al ₂ O ₃ exceeds 8%, Ts and Tg may be excessively high. The content of Al ₂ O ₃ is preferably 4% or more and 7% or less, more preferably 5% or more and 6% or less.

  CaO is added to increase the stability of the glass and the crystal precipitation, and to decrease Ts and Tg. If the CaO content is less than 9%, Ts may be excessively high. On the other hand, if the CaO content exceeds 23%, the glass may become unstable. The content of CaO is preferably 12% or more and 22% or less, more preferably 13% or more and 21% or less, and particularly preferably 14% or more and 20% or less.

Na ₂ O and K ₂ O are added to lower Tg. When the total content of Na ₂ O and K ₂ O is less than 0.5%, Ts and Tg may be excessively high. On the other hand, when the total content of Na ₂ O and K ₂ O exceeds 6%, chemical durability, particularly acid resistance may be lowered, and electrical insulation may be lowered. The total content of Na ₂ O and K ₂ O is preferably 0.8% or more and 5% or less.

  In addition, the composition of the first glass powder is not necessarily limited to the one composed only of the above components, and other components can be contained within a range satisfying various characteristics such as Tg. In this embodiment, lead oxide is not contained. When other components are contained, the total content is preferably 10% or less.

  The first glass powder is obtained by manufacturing glass having the above composition by a melting method and pulverizing it by a dry pulverization method or a wet pulverization method. In the case of the wet pulverization method, it is preferable to use water or ethyl alcohol as a solvent. Examples of the pulverizer include a roll mill, a ball mill, and a jet mill.

The 50% particle size (D ₅₀ ) of the first glass powder is preferably 0.5 μm or more and 4 μm or less. In this specification, D ₅₀ is a value measured using a laser diffraction / scattering particle size distribution measuring apparatus. If the first D ₅₀ of the glass powder is less than 0.5μm, the handling glass powder is likely to agglomerate are not only difficult, fear is the time required for pulverization is too long. On the other hand, if D ₅₀ of the first glass powder exceeds 4 μm, Ts may increase or sintering may be insufficient. The particle size is adjusted by, for example, classification as necessary after pulverization. The maximum particle size of the first glass powder is preferably 20 μm or less. When the maximum particle size exceeds 20 μm, the sinterability of the glass powder is lowered, and undissolved components remain in the sintered body, which may reduce the reflectivity of the coating layer 7. The maximum particle size of the first glass powder is more preferably 10 μm or less.

As a 1st ceramic powder mix | blended with a 1st glass ceramic composition with such a 1st glass powder, an alumina powder, a zirconia powder, a silica powder, a titania powder etc. are mentioned, for example. The D ₅₀ of the first ceramic powder is preferably 0.3 to 5.0 μm.

  The blend ratio of the first glass powder and the first ceramic powder in the first glass ceramic composition is 60 to 80% by mass for the first glass powder and 20 to 40% by mass for the first ceramic powder. It is preferable to do so. When the blending ratio of the first ceramic powder is equal to or higher than the lower limit, the surface flatness of the coating layer 7 is improved and the heat dissipation is improved. Further, when the blending ratio of the first ceramic powder is not more than the above upper limit value, a glass ceramic sintered body having a uniform composition can be obtained.

  The method for forming the covering layer 7 is not particularly limited as long as it is a method capable of forming the above-described layer having a predetermined thickness flat. For example, a paste of a mixture of the first glass powder and the first ceramic powder can be printed by screen printing or the like and fired.

  A damming layer 8 made of a second glass ceramic sintered body is provided on the mounting surface 21 of the substrate 2 and on the covering layer 7 so as to surround the element connection terminals 3 formed in the light emitting element mounting portion. Is formed. The sintered glass ceramic body constituting the damming layer 8 is preferably a sintered body of the second glass ceramic composition containing the second glass powder and the second ceramic powder.

Then, the glass composition of the second glass powder, as represented by mol% based on oxides terms of SiO _{2 78-83%,} B 2 _{O 3} 16 to 18%, the _Al 2 _{O 3} 0 to 0.5% It is preferable that 0.9 to 4% in total of at least one selected from Na ₂ O and K ₂ O and 0 to 0.6% in total of at least one selected from CaO, SrO and BaO are contained. By making the glass composition of the second glass powder in this way, the width and height of the blocking layer 8 can be set to desired values suitable for preventing the sealing resin material from spreading.
Hereinafter, the composition of the second glass powder will be described.

SiO ₂ serves as a glass network former and is an essential component for increasing chemical durability, particularly acid resistance. If the SiO ₂ content is less than 78%, the acid resistance may be insufficient. On the other hand, if the content of SiO ₂ exceeds 83%, Ts and Tg may be excessively high.

B ₂ O ₃ is an essential component that becomes a glass network former. If the content of B ₂ O ₃ is less than 16%, the softening point may become excessively high, and the glass may become unstable. On the other hand, if the content of B ₂ O ₃ exceeds 18%, it is difficult to obtain a stable glass, and chemical durability may be lowered.

Al ₂ O ₃ is an optional component that may be added in a range of 0.5% or less in order to enhance the stability and chemical durability of the glass. When the content of Al ₂ O ₃ exceeds 0.5%, the transparency of the glass may be lowered.

Na ₂ O and K ₂ O are essential components to be added in a range where the total content becomes 0.9 to 4% in order to lower the softening point and Tg. If the total content of Na ₂ O and K ₂ O is less than 0.9%, the softening point and Tg may be too high. On the other hand, when the total content of Na ₂ O and K ₂ O exceeds 4%, chemical durability, particularly acid resistance may be lowered, and electrical insulation may be lowered.
Na ₂ O and K ₂ O preferably contain at least one selected from these.

  CaO, SrO and BaO are optional components that may be added within a range where the total content of these does not exceed 0.6% in order to lower the softening point and Tg and increase the stability of the glass. is there. If the total content of CaO, SrO and BaO exceeds 0.6%, the acid resistance may be lowered.

  In addition, the 2nd glass powder is not necessarily limited to what consists only of the said component, In the range which does not impair the effect of this invention, it can contain components other than the above. In this embodiment, lead oxide is not contained. When it contains components other than the above, the total content is preferably 10% or less.

The second glass powder is obtained by producing a glass having the above composition by a melting method in the same manner as the first glass powder and pulverizing it by a dry pulverization method or a wet pulverization method. The D ₅₀ of the second glass powder is preferably 0.5 μm or more and 4 μm or less. When the D ₅₀ of the second glass powder is less than 0.5 μm, the glass powder tends to aggregate and difficult to handle, and uniform dispersion becomes difficult. On the other hand, if D ₅₀ of the second glass powder exceeds 4 μm, Ts may increase or sintering may be insufficient. The particle size is adjusted by, for example, classification as necessary after pulverization.

Examples of the second ceramic powder blended in the second glass ceramic composition together with the second glass powder include alumina powder, silica powder, and zirconia powder. The D ₅₀ of the second ceramic powder is preferably 0.3 to 5.0 μm.

  The blending ratio of the second glass powder and the second ceramic powder in the second glass ceramic composition varies depending on the type of the second ceramic powder and the formation method of the weir layer 8.

  The method for forming the blocking layer 8 is not particularly limited as long as it can form a layer having a predetermined height, which will be described later, flatly. For example, a paste of a mixture containing the second glass powder and the second ceramic powder (hereinafter referred to as a damming paste) can be printed by screen printing or the like and fired.

  When the damming layer 8 is formed by firing a printed layer of paste containing alumina powder as the second ceramic powder, the blending ratio of the second glass powder and alumina powder is 70: A range of 30 to 85:15 is preferred. That is, the blending amount of the alumina powder is preferably 15 to 30% by mass with respect to the total amount of the second glass powder and the alumina powder. Moreover, when the damming layer 8 is formed by baking the printing layer of the paste containing a silica powder, the compounding ratio of the 2nd glass powder and a silica powder is 85: 15-90: A range of 10 is preferred. That is, the blending amount of the silica powder is preferably 10 to 15% by mass with respect to the total amount of the second glass powder and the silica powder. When the content of the second ceramic powder is within the above range, a glass ceramic sintered body having a uniform composition can be obtained, and the surface flatness is high and the desired width and height described later in a desired shape are obtained. A damming layer 8 having a thickness can be formed.

The damming layer 8 can be formed by firing a green sheet containing the second glass powder and the second ceramic powder in addition to the firing of the paste printing layer. When such a forming method is adopted, it is preferable to use alumina powder as the second ceramic powder. And as for content of an alumina powder, 30-60 mass% is preferable with respect to the total amount of a 2nd glass powder and an alumina powder. When the content of alumina powder contained in the green sheet is within the above range, a glass ceramic sintered body having a uniform composition can be obtained, and the desired width described later in a desired shape with high surface flatness. The damming layer 8 having a height or the like can be formed.
A method for forming the blocking layer 8 will be described in the method for manufacturing the element substrate 1.

  The planar shape of the damming layer 8 is not particularly limited as long as it has a predetermined width and a frame shape or an annular shape surrounding the light emitting element mounting portion. Moreover, you may have a notch partially. A rectangular frame shape or an annular shape is preferable, and an annular shape is particularly preferable from the viewpoint of forming a hemispherical lens-shaped sealing layer.

  The height H and the width W of the blocking layer 8 shown in an enlarged manner in FIG. That is, by potting a curable resin material having fluidity, in order to form the hemispherical lens-shaped sealing layer 9 whose height to the top is close to ½ of the diameter, The height H is preferably in the range of 0.009 to 0.03, more preferably in the range of 0.012 to 0.018 in terms of the ratio to the inner diameter (hereinafter referred to as the inner diameter) D of the annular shape. When the ratio (H / D) of the height H of the damming layer 8 to the inner diameter D is less than 0.009, the fluid resin material exceeds the upper surface of the damming layer 8 and spreads to the outer region during potting. Thus, the hemispherical lens shape cannot be maintained. Further, in order to suppress an excessive increase in the number of steps such as screen printing for forming the damming layer 8 and increase productivity, the ratio of the height H of the damming layer 8 to the inner diameter D is 0.03 or less. Is preferred.

  The width W of the blocking layer 8 serving as a barrier in the direction of wetting and spreading is not particularly limited, but the ratio (W / D) to the inner diameter D of the annular shape is preferably in the range of 0.091 to 0.182, 0.121 to 0 A range of .152 is more preferred. If the ratio of the width W of the dam layer 8 to the inner diameter D is less than 0.091, it is difficult to form the dam layer 8 by screen printing. When the ratio of the width W of the damming layer 8 to the inner diameter D exceeds 0.182, the dividing groove when the damming layer 8 contacts the cathode mark formed on the base 2 or is formed as a connecting substrate. There is a risk that glass will flow into. The width W of the blocking layer 8 is the width of the upper surface of the blocking layer 8 as shown in FIG.

  For example, when the annular inner diameter D of the blocking layer 8 is 1.65 mm (1650 μm), the height H of the blocking layer 8 is preferably in the range of 15 to 50 μm, and more preferably 20 to 30 μm. The width W of the blocking layer 8 is preferably in the range of 150 to 300 μm, and more preferably 200 to 250 μm.

  In the element substrate 1 of the embodiment, thermal vias (not shown) can be further embedded in the base 2 in order to reduce the thermal resistance of the base 2. The thermal via is, for example, a columnar shape smaller than the mounting portion of the light emitting element, and is preferably disposed from the non-mounting surface 22 to an intermediate position in the thickness direction of the base 2. With such an arrangement, the flatness of the entire mounting surface 21, particularly the mounting portion, can be improved, the thermal resistance can be reduced, and the inclination when the light emitting element is mounted can be suppressed.

  In the element substrate 1 of such an embodiment, the silver reflection layer 4 and the element connection terminal 3 connected to the silver reflection layer 4 are formed on the mounting surface 21 of the base 2, except on the element connection terminal 3 on the mounting surface 21. Since the coating layer 7 made of the first glass ceramic sintered body is formed in the region, it is possible to prevent the reflectance from being lowered due to corrosion of silver or the like constituting the silver reflective layer 4, and this coating layer 7 does not absorb light from the light emitting element mounted on the substrate 2, and therefore does not reduce the light extraction efficiency. In addition, since the damming layer 8 made of the second glass ceramic sintered body is formed on the coating layer 7 made of the first glass ceramic sintered body, the resin material for forming the sealing layer 9 The wetting and spreading can be satisfactorily prevented by the damming layer 8 and a sealing layer having a desired shape can be formed. Further, by adjusting the glass composition of the first glass ceramic sintered body constituting the coating layer 7 and the second glass ceramic sintered body constituting the blocking layer 8, the content of the ceramic powder, etc., respectively, The shape and height of the stopper layer 8 and a width that becomes a barrier in the direction of spreading can be formed so as to be suitable for preventing the resin material for sealing from spreading.

  The element substrate 1 of the present invention has been described above. However, the configuration can be changed as appropriate as long as it does not contradict the spirit of the present invention. Next, a light emitting device according to an embodiment of the present invention will be described.

<Light emitting device>
3A is a plan view of the light emitting device according to the embodiment as viewed from the upper surface (mounting surface) side, and FIG. 3B is a cross-sectional view taken along line YY in FIG. 3A. . FIG. 3A shows a state where the sealing layer is removed.

  The light emitting device 20 of the embodiment has the element substrate 1 of the above embodiment, and the light emitting element 10 such as two LED elements is mounted on the mounting portion provided on the mounting surface 21 of the base 2 of the element substrate 1. Has been. Each light emitting element 10 has a pair of electrodes such as bumps on the lower surface, and these electrodes are joined to the element connection terminal 3 by an intermetallic connection 3a through solder, gold, gold-tin eutectic solder or the like. Yes. The two light emitting elements 10 are connected in parallel.

  In addition, the connection method of the light emitting element 10 is not limited to the said method, What is necessary is just the method by flip chip bonding, such as connection by bump. Further, the number of light emitting elements 10 to be connected is not limited to two as long as it can be arranged in the element connection terminal 3.

  Then, a sealing layer 9 made of a translucent resin formed in a substantially hemispherical shape so as to cover the light emitting element 10 is provided in a region inside the blocking layer 8 on the mounting surface 21 of the base 2. Yes. As the resin constituting the sealing layer 9, a silicone resin is preferably used because it is excellent in terms of light resistance and heat resistance. However, the use of an epoxy resin other than the silicone resin, a fluorine resin, or the like is not limited. . As the silicone resin, a known silicone resin as a sealing resin for the light emitting device is used without particular limitation.

  Moreover, the light obtained as the light-emitting device 20 can be appropriately adjusted to a desired light-emitting color by mixing or dispersing a phosphor or the like in such a light-transmitting resin. That is, by mixing and dispersing the phosphor in a translucent resin such as silicone resin that constitutes the sealing layer 9, the phosphor excited by the light emitted from the light emitting element 10 emits visible light, The visible light and the light emitted from the light emitting element 10 are mixed to obtain a desired light emitting color as the light emitting device 20. The type of the phosphor is not particularly limited, and is appropriately selected according to the type of light emitted from the light emitting element 10 and the target emission color.

  In the light emitting device of the embodiment, the flow of the resin material constituting the sealing layer 9 is blocked by the blocking layer 8 made of the second glass ceramic sintered body, and the resin material is placed on the mounting surface 21 of the base 2. Since it is possible to suppress the wetting and spreading to the outer region (peripheral region) on the coating layer 7 formed in this manner, the hemispherical lens-shaped sealing layer 9 can be stably formed. The damming layer 8 is composed of a light-transmitting glass ceramic sintered body, and the damming layer 8 does not reflect or absorb the light transmitted through the sealing layer 9, so that the light extraction efficiency is excellent, and the light emission A light emitting device 20 with high luminance is obtained.

Next, a method for manufacturing the element substrate and the light emitting device according to the embodiment of the present invention will be described by taking as an example the manufacture of the element substrate 1 shown in FIG. 1 having a base made of LTCC and the light emitting device 20 shown in FIG. To do.
The method for producing the element substrate 1 shown in FIG. 1 includes, for example, the following (A) green sheet production process for base, (B) silver paste layer and conductor paste layer formation process, and (C1) coating glass paste layer formation. A step, (C2) an unfired blocking layer forming step, (D) a laminating step, and (E) a firing step. 3 can be manufactured through the (F) light emitting element mounting process and then the (G) sealing layer forming process using the element substrate 1 manufactured in this way. In addition, about the member used for manufacture, the same code | symbol as the member of a finished product is attached | subjected and demonstrated.

(A) Green sheet production process for substrate A green sheet (green sheet for substrate) for forming a substrate is produced using a glass ceramic composition containing glass powder and ceramic powder. The base green sheet includes an upper layer green sheet for forming an upper layer, an inner layer green sheet for forming an inner layer, and a lower layer green sheet for forming a lower layer.

  A green sheet for a substrate is prepared by adding a binder, and if necessary, a plasticizer, a dispersant, a solvent, etc. to a glass ceramic composition containing glass powder and ceramic powder. It can be manufactured by molding into a sheet and drying.

  As a glass powder for a substrate for producing a green sheet for a substrate, those having a Tg of 550 ° C. or more and 700 ° C. or less are preferable. When Tg is less than 550 ° C., degreasing may be difficult, and when it exceeds 700 ° C., the shrinkage start temperature becomes high and the dimensional accuracy may be lowered. Moreover, the glass powder for base | substrate is preferable that a crystal | crystallization precipitates when it bakes at 800 degreeC or more and 930 degrees C or less. If the crystal does not precipitate, sufficient mechanical strength may not be obtained.

Such base glass powder, as represented by mol% based on oxides, the _{SiO 2 57~65%, B 2 O} 3 and 13 to 18%, the CaO 9 to 23%, the _Al 2 _{O 3} 3 It is preferable to contain at least 0.5 to 6% of at least one selected from ˜8%, Na ₂ O and K ₂ O. By using a material having such a composition, the surface flatness of the substrate 2 can be easily improved.

  The glass powder for a substrate is obtained by producing a glass having the above composition by a melting method and pulverizing it by a dry pulverization method or a wet pulverization method. In the case of the wet pulverization method, it is preferable to use water or ethyl alcohol as a solvent. Examples of the pulverizer include a roll mill, a ball mill, and a jet mill.

D ₅₀ of the glass powder for substrate is preferably 0.5 μm or more and 2 μm or less. If D ₅₀ of the glass powder for substrate is less than 0.5 [mu] m, handling the glass powder is likely to agglomerate are not only difficult, uniform dispersion becomes difficult. On the other hand, if the D ₅₀ of the glass powder for substrate exceeds 2μm, there is a possibility that increase and insufficient sintering of the glass softening temperature is generated. For example, the particle size may be adjusted by classification as necessary after pulverization.

  As the ceramic powder for the substrate, those conventionally used for the production of LTCC substrates can be used. For example, alumina powder, zirconia powder, or a mixture of alumina powder and zirconia powder can be suitably used. In particular, it is preferable to use a ceramic powder having a higher refractive index than alumina (hereinafter referred to as a high refractive index ceramic powder) together with the alumina powder.

The high refractive index ceramic powder is a component for improving the reflectance of the base body 2 that is a sintered body, and examples thereof include titania powder, zirconia powder, and stabilized zirconia powder. While the refractive index of alumina is about 1.8, the refractive index of titania is about 2.7 and the refractive index of zirconia is about 2.2, which is higher than that of alumina. . D ₅₀ of these ceramic powders for substrates is preferably 0.5 μm or more and 4 μm or less.

  Such a ceramic powder for a substrate and the glass powder for a substrate are blended so that, for example, the glass powder for the substrate is 30% by mass to 50% by mass and the ceramic powder for the substrate is 50% by mass to 70% by mass. Then, a glass ceramic composition for a substrate is obtained by mixing. In addition, a slurry can be obtained by adding a binder and, if necessary, a plasticizer, a dispersant, a solvent, and the like to the glass ceramic composition for a substrate.

  As the binder, for example, polyvinyl butyral, acrylic resin and the like can be suitably used. As the plasticizer, for example, dibutyl phthalate, dioctyl phthalate, butyl benzyl phthalate and the like can be used. As the solvent, organic solvents such as toluene, xylene, 2-propanol and 2-butanol can be suitably used.

  The slurry thus obtained is formed into a sheet by a doctor blade method or the like, and dried to produce, for example, three base sheet green sheets (upper layer green sheet, lower layer green sheet and inner layer green sheet). To do. Further, via holes for interlayer connection are formed at predetermined positions of these green sheets for the substrate using a punching die or a punching machine, and holes for thermal vias are further formed as necessary.

(B) Silver paste layer and conductor paste layer forming step,
By forming a silver paste layer at a predetermined position on the main surface of the upper layer green sheet, the unsintered silver reflecting layer 4 is formed. Further, by forming a conductive paste layer at predetermined positions of the upper layer green sheet and the lower layer green sheet, the unfired element connection terminals 3 and the unfired external connection terminals 5 are formed, respectively. Furthermore, the unfired connection via 6 is formed by filling the via hole with a conductive paste. When holes for thermal vias are formed, an unfired thermal via is formed by filling the holes with a metal paste.

  Examples of the method for forming the silver paste layer include a method of applying a silver paste by screen printing. Moreover, as a formation method of a conductor paste layer and a conductor paste filling layer, the method of apply | coating or filling a conductor paste by screen printing is mentioned. The film thicknesses of the silver paste layer and the conductor paste layer to be formed are adjusted so that the film thicknesses of the finally obtained silver reflection layer 4, element connection terminal 3, external connection terminal 5, etc. become a predetermined film thickness. . Moreover, as a formation method of a metal paste filling layer, the method of filling a metal paste by screen printing is mentioned.

As described above, the silver paste is made into a paste by adding a vehicle such as ethyl cellulose to a powder of silver or a silver alloy (a silver-platinum alloy or a silver-palladium alloy) and, if necessary, a solvent. Things can be used.
Further, as the conductive paste, for example, a paste obtained by adding a vehicle such as ethyl cellulose to a conductive metal powder mainly composed of copper, silver, gold or the like, and a solvent or the like as required can be used. Here, as the conductive metal powder, it is preferable to use the silver or silver alloy (silver and platinum alloy or silver and palladium alloy) powder. That is, from the viewpoint of simplification of the process, the unfired element connection terminal 3, the unfired external connection terminal 5 and the unfired connection via 6 are formed using a silver paste used for forming the unfired silver reflecting layer 4. Is preferred.

  As the metal paste used for forming the unfired thermal via, a paste made by adding a silver powder or a silver-based alloy powder to a vehicle such as ethyl cellulose and, if necessary, a solvent or the like can be used. . From the viewpoint of simplification of the process, it is preferable to form an unfired thermal via using a silver paste used for the unfired silver reflective layer 4. That is, it is preferable to form the unsintered silver reflection layer 4, the unsintered element connection terminal 3, the unsintered external connection terminal 5, the unsintered connection via 6, and the unsintered thermal via using a silver paste having the same composition. .

(C1) Coating glass paste layer forming step In the upper layer green sheet in which the unsintered silver reflecting layer 4 and the unsintered element connection terminals 3 are formed at predetermined positions on the main surface in the step (B), the unsintered element connection is performed. The coating glass paste, which is the unsintered coating layer 7, is printed by a method such as screen printing so that the entire surface including the end face of the unsintered silver reflecting layer 4 is covered in the region except on the terminals 3. A paste layer is formed. As the glass paste for coating, a paste obtained by adding a vehicle such as ethyl cellulose and, if necessary, a solvent to the mixture of the first glass powder and the first ceramic powder is used.

(C2) Unfired blocking layer forming step The unfired blocking layer 8 is formed by forming a glass paste layer for blocking. That is, in the upper layer green sheet, the unfired element connection terminals 3 formed in the step (B) are surrounded on the coating glass paste layer which is the unfired coating layer 7 formed in the step (C1). In this way, the damming glass paste is screen-printed to form the damming glass paste layer 8 having an annular shape in plan view.

  As the damming glass paste, a vehicle such as ethyl cellulose and a solvent or the like are added to the mixture (second glass ceramic composition) containing the second glass powder and the second ceramic powder as described above. The paste is used. The thickness of the damming glass paste layer 8 to be formed is preferably adjusted so that the height H of the finally obtained damming layer 8 is a predetermined ratio with respect to the annular inner diameter D. . The thickness of the damming glass paste layer 8 and the width of the pattern can be adjusted by adjusting the fluidity of the damming glass paste and the number of screen printing steps.

  In addition, the unfired damming layer 8 can be formed by stacking green sheets (damping green sheets). That is, a slurry is prepared by adding a binder, and if necessary, a plasticizer, a solvent, etc., to a mixture containing the second glass powder and the second ceramic powder, and this is formed into a sheet by a doctor blade method or the like. And drying to prepare a green sheet for a blocking layer. In addition, as a binder, a plasticizer, a solvent, etc., the thing similar to what was described in the preparation process of the green sheet for base | substrates can be used. Then, the green sheet for damming produced in this way is die-cut and molded into a predetermined shape, and is laminated and disposed on the glass paste layer for coating formed in the step (C1), so that it is not fired. A damming layer 8 is formed.

  In any case, the thickness of the unfired blocking layer 8 to be formed is preferably adjusted to be the height H of the finally obtained blocking layer 8.

(D) Laminating step Green sheet with covering glass paste layer 7 and unfired weir blocking layer 8 obtained in step (C2), and green sheet with conductor paste layer obtained in step (B) After overlapping in a predetermined order, they are integrated by thermocompression bonding. In this way, the unfired substrate 2 is obtained.

(E) Firing step The green substrate 2 obtained in the step (D) is degreased with a binder or the like as necessary, and then fired to sinter the glass ceramic composition or the like to obtain the element substrate 1. .

  Degreasing is performed, for example, under the condition of holding at a temperature of 500 ° C. to 600 ° C. for 1 hour to 10 hours. When the degreasing temperature is less than 500 ° C. or the degreasing time is less than 1 hour, the binder or the like may not be sufficiently removed. On the other hand, if the degreasing temperature is about 600 ° C. and the degreasing time is about 10 hours, the binder and the like can be sufficiently removed, and if it exceeds this, productivity and the like may be lowered.

  In addition, in the firing, the time can be appropriately adjusted in a temperature range of 800 ° C. to 930 ° C. in consideration of obtaining a dense structure of the base 2 and productivity. Specifically, it is preferable to hold at a temperature of 850 ° C. or more and 900 ° C. or less for 20 minutes or more and 60 minutes or less, and a temperature of 860 ° C. or more and 880 ° C. or less is particularly preferable. If the firing temperature is less than 800 ° C., the substrate 2 may not be obtained as a dense structure. On the other hand, if the firing temperature exceeds 930 ° C., the productivity and the like may be lowered due to deformation of the substrate 2. On the other hand, when the firing temperature exceeds 880 ° C., the silver paste layer is excessively softened, so that the predetermined shape may not be maintained.

  In this way, the element substrate 1 is obtained. After firing, nickel plating, chrome plating, silver plating, nickel / silver plating, so as to cover the whole of the element connection terminals 3 and the external connection terminals 5 as necessary. Conductive protective layers, such as gold plating and nickel / gold plating, which are usually used for protecting conductors in the element substrate 1 can be formed. Among these, nickel / gold plating is preferably used. For example, the nickel / gold plating can be formed by electrolytic plating using a nickel sulfamate bath for the nickel plating layer and a potassium gold cyanide bath for the nickel plating layer.

(F) Light-Emitting Element Mounting Step In the element substrate 1 obtained in the step (E), a light-emitting element 10 such as an LED element having a pair of bump electrodes on the lower surface is provided at a substantially central portion of the mounting surface 21 of the base 2. The light emitting element 10 is electrically connected to the element connection terminal 3 by inter-metal connection via solder, gold, gold-tin eutectic solder or the like.

(G) Sealing Layer Forming Step In this manner, a thermosetting silicone resin material having fluidity is potted to form a substantially hemispherical resin layer so as to cover the light emitting element 10 mounted on the mounting portion of the substrate 2. And cured by heating or the like. In this way, a substantially hemispherical lens-shaped sealing layer 9 is formed in the inner region of the annular damming layer 8 made of the second glass ceramic sintered body formed on the mounting surface 21 of the substrate 2.

  In the above manufacturing method, the number of base green sheets used in the manufacturing process of the element substrate 1 is not necessarily three, and may be two or four or more. In addition, the order of forming each part can be appropriately changed as long as the element substrate 1 can be manufactured. Furthermore, the element substrate 1 may be manufactured by a method in which a multi-piece connection substrate is manufactured according to its size, and a process of dividing the substrate is performed to manufacture individual substrates. In that case, the division timing may be before the light emitting element 10 is mounted or after the light emitting element 10 is mounted as long as it is after the firing.

  According to such an embodiment of the present invention, the coating layer 7 made of the first glass ceramic sintered body so as to cover the surface and the edge of the silver reflecting layer 4 formed on the mounting surface 21 of the substrate 2. Therefore, a reduction in reflectance due to oxidation or corrosion of silver or the like can be prevented, and a desired shape blocking layer 8 made of the second glass ceramic sintered body can be easily formed on the coating layer 7. Can be formed. The flow of the curable resin material for forming the sealing layer 9 is blocked by the blocking layer 8 made of the second glass ceramic sintered body. As a result, the resin material is placed on the mounting surface 21 of the base 2. Is prevented from spreading to the region outside the damming layer 8, so that a stable hemispherical lens-shaped sealing layer 9 is formed. Further, since the blocking layer 8 is made of a light-transmitting material and light transmitted through the sealing layer 9 is not reflected or absorbed by the blocking layer 8, the light emission is excellent in light extraction efficiency and has high emission luminance. A device is obtained.

  Examples of the present invention will be described below. In addition, this invention is not limited to an Example.

Examples 1-11
The element substrate 1 shown in FIG. 1 was manufactured by the method shown below, and the light-emitting device 20 shown in FIG. 3 was manufactured using it.

(Preparation of glass paste for coating)
First, glass powder B was manufactured. That is, in terms of oxide-based mol%, SiO ₂ is 60.4%, B ₂ O ₃ is 16.6%, Al ₂ O ₃ is 6.0%, CaO is 13.0%, and K ₂ O is The glass raw material was prepared and mixed so that 2.0% and Na ₂ O would be 2.0%, and this raw material mixture was put in a platinum crucible and melted at 1500 to 1600 ° C. for 60 minutes. The glass was poured out and cooled. The obtained glass was pulverized with an alumina ball mill for 20 to 60 hours to obtain glass powder B. In addition, ethyl alcohol was used as a solvent for pulverization.

The _{D 50} of the resulting glass powder B ([mu] m), a laser diffraction / scattering particle size distribution analyzer (manufactured by Shimadzu Corporation, trade name: SALD2100) was measured using a was 2.5 [mu] m. Then, the mixed powder 70 mass% and the D ₅₀ is obtained by mixing the alumina powder 30 mass% of 2μm of the obtained glass powder B, and a resin component, the mixed powder is 60 mass%, the proportion of the resin component is 40 mass% The mixture was kneaded in a porcelain mortar for 1 hour, and further dispersed three times with three rolls to obtain a coating glass paste. In addition, the resin component used what prepared and disperse | distributed ethyl cellulose and alpha terpineol by the mass ratio of 85:15.

(Preparation of glass paste for damming)
First, glass powder A and glass powder B were produced. In the production of the glass powder A, the glass raw material is used so that SiO ₂ is 81.6%, B ₂ O ₃ is 16.6%, and K ₂ O is 1.8% in terms of mol% in terms of oxide. After mixing and mixing, this raw material mixture was put in a platinum crucible and melted at 1500 to 1600 ° C. for 60 minutes, and then the molten glass was poured out and cooled. The obtained glass was pulverized by an alumina ball mill for 20 to 60 hours to obtain glass powder A. In addition, ethyl alcohol was used as a solvent for pulverization. The glass powder B was produced in the same manner as the glass powder B used for the preparation of the coating glass paste.

The _{D 50} of the resulting glass powder A ([mu] m), a laser diffraction / scattering particle size distribution analyzer (manufactured by Shimadzu Corporation, trade name: SALD2100) was measured using a was 2.5 [mu] m. Further, _{D 50} of the glass powder B was the similar to the 2.5 [mu] m. Next, the resin component is mixed with the mixed powder obtained by mixing the glass powder A or glass powder B obtained above and the ceramic powder shown in Table 1 at a mass ratio shown in the same table. Was mixed in a porcelain mortar for 1 hour, and further dispersed three times with three rolls to obtain a glass paste for damming. In addition, the resin component used what prepared and disperse | distributed ethyl cellulose and alpha terpineol by the mass ratio of 85:15. Moreover, in Example 6 and Example 7, ceramic powder was not mix | blended, but the said resin component was mix | blended with glass powder A or glass powder B, and the glass paste for damming was prepared.

(Preparation of green sheet molded body for damming)
In Example 5, an organic solvent (toluene, xylene, 2-propanol, 2-butanol was mixed at a mass ratio of 4: 2: 2: 1 to a mixed powder obtained by mixing glass powder B and alumina powder at a mass ratio of 50:50. 15 g, 2.5 g of plasticizer (di-2-ethylhexyl phthalate), 5 g of polyvinyl butyral (manufactured by Denka Co., Ltd., trade name: PVK # 3000K) as a binder, and a dispersant (manufactured by Big Chemie Co., Ltd.) (Name: BYK180) 0.5 g was mixed and mixed to prepare a slurry, which was then applied onto a PET film by the doctor blade method and dried. Next, the obtained green sheet was processed into an annular shape, and a damming green sheet molded body having an inner diameter D of 1.65 mm (1650 μm)), a width of 210 μm and a thickness of 25 μm was produced.

(Production of element substrate)
An upper layer green sheet, an inner layer green sheet, and a lower layer green sheet for preparing the substrate 2 were prepared.
First, in terms of oxide-based mol%, SiO ₂ is 60.4%, B ₂ O ₃ is 15.6%, Al ₂ O ₃ is 6%, CaO is 15%, K ₂ O is 1%, Na _The raw materials were blended and mixed so that ₂ O would be 2%. The raw material mixture was put in a platinum crucible and melted at 1600 ° C. for 60 minutes, and then the molten glass was poured out and cooled. This glass was pulverized with an alumina ball mill for 40 hours to produce a glass powder for a substrate. Note that ethyl alcohol was used as a solvent for grinding.

  35% by mass of the glass powder for the substrate, 40% by mass of alumina powder (manufactured by Showa Denko KK, trade name: AL-45H), zirconia powder (manufactured by Daiichi Rare Element Chemical Co., Ltd., trade name: HSY-3F-J) ) Was mixed so as to be 25% by mass, and mixed to produce a glass ceramic composition. 50 g of this glass ceramic composition, 15 g of an organic solvent (toluene, xylene, 2-propanol, 2-butanol mixed at a mass ratio of 4: 2: 2: 1), plasticizer (di-2-ethylhexyl phthalate) 2.5 g of polyvinyl butyral (trade name: PVK # 3000K, manufactured by Denka Co., Ltd.) as a binder, 5 g, and 0.5 g of a dispersant (trade name: BYK180, manufactured by Big Chemie) were blended and mixed to prepare a slurry. .

  This slurry is coated on a PET film by a doctor blade method, dried green sheets are laminated, and the upper layer and inner layer are flat and have a size after baking of 205 mm × 205 mm and a thickness of 0.15 mm. Green sheets for the lower layer and the lower layer were manufactured. Then, in each of the green sheets for the upper layer, the inner layer, and the lower layer, through holes for connection vias were formed at predetermined positions using a hole puncher. In this embodiment, the element substrate is manufactured as a multi-piece connecting substrate, divided into pieces after firing, which will be described later, and a substantially square element substrate having an outer dimension of 2.8 mm × 2.8 mm. It was set to 1. The following description will explain one section of the multi-piece connecting board that becomes one element board after division.

  Silver powder (Daiken Chemical Industry Co., Ltd., trade name: S400-2) and ethyl cellulose as a vehicle are blended at a mass ratio of 85:15, and α-terpineol as a solvent so that the solid content is 85% by mass. Then, the mixture was kneaded in a porcelain mortar for 1 hour and further dispersed three times with a three roll to produce a silver paste.

  The silver paste obtained above was filled in the through-holes for connection vias formed in each of the green sheets by a screen printing method to form unfired connection vias. Further, the silver paste was screen-printed in a predetermined pattern at a predetermined position on the upper main surface of the upper layer green sheet, thereby forming an unfired silver reflecting layer and an unfired element connection terminal. Furthermore, the silver paste was screen-printed in a predetermined pattern at a predetermined position on the lower main surface of the lower layer green sheet, thereby forming unfired external connection terminals.

  Next, on the upper main surface of the upper layer green sheet, the above-described coating glass paste is screen-printed so as to cover the entire surface of the unsintered silver reflecting layer 4 in a region except on the unsintered element connection terminals, and unsintered coating A coating glass paste layer as layer 7 was formed. Further, on the upper main surface of the upper layer green sheet, the above-described damming glass paste was screen-printed on the covering glass paste layer so as to surround the unfired element connection terminals. Then, a glass paste layer for damming having an annular shape (inner diameter D is 1.65 mm (1650 μm)) in plan view was formed.

  In Example 5, the damming glass paste layer was not formed, and the damming green sheet molded body was laminated on the covering glass paste layer. The green sheet molding for damming was arranged so as to surround the unfired element connection terminal.

  Next, these green sheets for substrates were superposed and integrated by thermocompression bonding to obtain an unsintered connection substrate. After putting a dividing line (cut line) such that each section has an outer dimension of 2.8 mm × 2.8 mm after firing on this unfired connection substrate, degreasing is performed by holding at 550 ° C. for 5 hours, Firing was performed by holding at 870 ° C. for 30 minutes to produce a multi-piece connected substrate. The obtained multi-piece connection substrate was divided along a dividing line to manufacture an element substrate.

In the element substrate thus obtained, the width W and the height H of the weir layer after firing were measured using a contact-type film thickness meter (trade name: Surfcom 1400D, manufactured by Tokyo Seimitsu Co., Ltd.). The measurement results are shown in Table 1. In Table 1, along with the width W and height H of the blocking layer, the ratio of these values to the inner diameter D of the blocking layer is also shown.
In Examples 7, 8 and 10, the glass ceramic sintered body forming the weir layer is integrated with the glass ceramic sintered body forming the coating layer immediately below, so that no boundary is formed, and the width W cannot be measured. As a result, the width W dimension and its ratio to the diameter D were not shown.

<Manufacture and evaluation of light emitting device>
Next, two LED elements (trade name: DA350, manufactured by CREE) having a pair of electrodes on the lower surface are arranged on the mounting portion of the element substrate thus obtained, and the pair of electrodes is used as an element connection terminal. It was connected by gold tin solder adhesion. Thereafter, a curable silicone resin material (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: KER-6075) is dispensed to the inner region of the blocking layer formed on the mounting surface in the firing step. , Trade name: ML-5000XII) to form a layer covering the LED element. And after heating this layer at 100 degreeC for 1 hour, it heated and hardened at 150 degreeC for 3 hours, and formed the translucent sealing layer.

  It was examined whether or not the sealing layer thus formed had a hemispherical lens shape that was a desired shape. The shape of the sealing layer was evaluated based on whether the height h to the top of the sealing layer was ½ of the diameter d of the bottom. The height h to the top of the sealing layer was measured using a contact film thickness meter (trade name: Surfcom 1400D, manufactured by Tokyo Seimitsu Co., Ltd.), and the diameter d of the bottom of the sealing layer was measured using a length measuring microscope (Olympus). It was measured using a product name, STM6). The evaluation results are shown in Table 1. In addition, (circle) shows that the sealing layer is exhibiting the substantially hemispherical lens shape, and x shows that the shape of the sealing layer is far from the hemispherical lens shape.

As can be seen from Table 1, the glass A having a composition containing 81.6% of SiO ₂ , 16.6% of B ₂ O ₃ and 1.8% of K ₂ O in terms of mol% in terms of oxide. In Examples 1 to 4 in which the weir layer was formed by firing a paste of a glass ceramic composition obtained by mixing powder and alumina powder or silica powder at a mass ratio of 90:10 to 70:30, A blocking layer is formed in which the ratio of the width W to the inner diameter D of the annular shape is 0.091 to 0.182 and the ratio of the height H to the inner diameter D is in the range of 0.009 to 0.03. .
Further, in terms of oxide-based mol%, SiO ₂ is 60.46%, B ₂ O ₃ is 16.6%, Al ₂ O ₃ is 6.0%, CaO is 13.0%, and K ₂ O is A green sheet of a glass ceramic composition obtained by mixing glass B powder having a composition containing 2.0% and Na ₂ O at a ratio of 2.0% and alumina powder in a mass ratio of 50:50. Also in Example 5 in which the damming layer was formed by firing, the ratio of the width W to the inner diameter D was 0.091 to 0.182, and the ratio of the height H to the inner diameter D was 0.009 to 0. A blocking layer in the range of .03 is obtained.

  And the LED element is arranged and connected to the mounting portion of the element substrate obtained in Examples 1 to 5 having such a damming layer, and a curable silicone resin material is provided in a region inside the damming layer. In a light-emitting device in which a sealing layer is formed by injecting heat and curing, a silicone resin material does not spread to the outside of the region surrounded by the blocking layer, and has a desired hemispherical lens shape A layer is formed. In addition, by forming the sealing layer having such a hemispherical lens shape, the path length through which the light emitted from the LED element passes through the sealing layer becomes equal in all directions, and the light emission has stable and good optical characteristics. A device is obtained.

  On the other hand, Examples 6 and 7 in which a damming layer was formed by firing a glass paste containing glass A or glass B and not containing ceramic powder, or glass B and alumina powder or silica powder In Examples 8 to 11 in which the damming layer was formed by firing a paste of a glass ceramic composition obtained by mixing the above at a mass ratio of 90:10 to 70:30, the boundary portion of the damming layer was formed. Or the ratio of the width W of the blocking layer to the inner diameter D is less than 0.091, and a blocking layer having a predetermined width W is not obtained.

  And LED element is arrange | positioned and connected to the mounting part of the element substrate obtained in Examples 6-11 which has such a blocking layer, and a curable silicone resin material is provided in the area inside the blocking layer. In the sealing layer that is injected and cured by heating, the wetting layer cannot sufficiently suppress the wetting and spreading of the curable silicone resin material to the outside, so that the path length of the transmitted light is equal in all directions. It can be seen that such a stable hemispherical lens-shaped sealing layer is not formed.

DESCRIPTION OF SYMBOLS 1 ... Element substrate, 2 ... Base | substrate, 3 ... Element connection terminal, 4 ... Silver reflection layer, 5 ... External electrode terminal, 6 ... Connection via, 7 ... Covering layer, 8 ... Damping layer, 9 ... Sealing layer, 10 ... light emitting element, 20 ... light emitting device, 21 ... mounting surface, 22 ... non-mounting surface.

Claims (7)

A substrate made of an inorganic insulating material and having a light-emitting element mounting surface;
An element connection terminal formed on the mounting surface;
A reflective layer made of silver or a silver alloy formed on the mounting surface;
A coating layer formed of a first glass ceramic sintered body, which is formed so as to cover a surface and an edge of the reflective layer in a region excluding the element connection terminal on the mounting surface;
A light emitting element substrate comprising: a second glass ceramic sintered body formed on the covering layer so as to surround the element connection terminal.   The blocking layer has an annular planar shape, and the width and height are in the range of 0.091 to 0.182 and 0.009 to 0.030, respectively, in ratio to the inner diameter of the annular shape. The light emitting element substrate according to claim 1.   The substrate for a light-emitting element according to claim 1, wherein the first glass ceramic sintered body is a sintered body of a glass ceramic composition containing a first glass powder and a first ceramic powder. The first glass powder is expressed by mol% on the basis of oxide, SiO ₂ is 57 to 65%, B ₂ O ₃ is 13 to 18%, Al ₂ O ₃ is ₃ to 8%, Na ₂ O and K. _The substrate for a light-emitting element according to claim 3, having a composition containing at least one selected from ₂ O in a total amount of 0.5 to 6% and CaO of 9 to 23%.   The light emitting device according to any one of claims 1 to 4, wherein the second glass ceramic sintered body is a sintered body of a glass ceramic composition containing a second glass powder and a second ceramic powder. Substrate. The second glass powder is expressed in mol% in terms of oxide, and SiO ₂ is 78 to 83%, B ₂ O ₃ is 16 to 18%, Al ₂ O ₃ is 0 to 0.5%, Na ₂ O. And at least one selected from K ₂ O in a total of 0.9 to 4%, and a composition containing at least one selected from CaO, SrO and BaO in a total of 0 to 0.6%. The board | substrate for light emitting elements of description. A substrate for a light emitting device according to any one of claims 1 to 6,
A light emitting element mounted on the mounting surface of the light emitting element substrate and electrically connected to the element connection terminal;
A light emitting device comprising: a sealing layer made of a resin provided so as to cover the light emitting element in a region inside the blocking layer on the mounting surface.

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