Sintered substrate, light-emitting device, and method for producing a sintered substrate and a light-emitting device

Abstract

A method for producing a sintered substrate comprises: preparing a ceramic substrate (1) having a first surface (1A) and a second surface (1B) on the opposite side of the first surface, the ceramic substrate having a through-hole (2) penetrating such that the through-hole connects the first surface and the second surface; arranging in the through-hole a conductive paste (3A) containing at least one metal powder (45A), a first active metal powder (6A1), and an organic solvent (7B); arranging a second active metal powder (6A2) on a surface of the arranged conductive paste; and firing the conductive paste on which the second active metal powder is arranged.

Description

Technical field

[0001] The present disclosure relates to a sintered substrate, a light-emitting device and methods for producing the sintered substrate and the light-emitting device. State of the art

[0002] Traditionally, a ceramic substrate, such as a Si3N4 substrate which has excellent high thermal conductivity, uses an active metal soldering material for a through-hole material or a wiring conductor. Citation list of patent literature Patent document 1: JP 5693940 B Patent document 2: JP 6541530 B Overview of the invention Technical problem

[0003] However, a ceramic substrate can develop protrusions and indentations on the surface of an active metal soldering material during firing, which can make assembly difficult.

[0004] One object of embodiments of the present disclosure is to provide a sintered substrate which has good mountability, a light-emitting device and methods for producing the sintered substrate and the light-emitting device. Solution to the problem

[0005] A method for producing a sintered substrate, disclosed in embodiments, comprises: preparing a ceramic substrate having a first surface and a second surface on opposite sides of the first surface, the ceramic substrate comprising a through-hole penetrating the substrate such that the through-hole connects the first surface and the second surface; arranging, in the through-hole, a conductive paste comprising at least one metal powder, a first active metal powder, and an organic solvent; arranging a second active metal powder on a surface of the arranged conductive paste; and firing the conductive paste on which the second active metal powder is arranged.

[0006] A method for manufacturing a light-emitting device, disclosed in embodiments, includes: preparing the sintered substrate, which was produced by the above-described method for manufacturing a sintered substrate; and arranging a light-emitting element, comprising an element electrode, in the sintered substrate, wherein, in preparing the sintered substrate, a conductive paste arranged in the through-hole becomes a conductive area by firing the conductive paste, and, in arranging the light-emitting element, the conductive area and the element electrode are electrically connected.

[0007] A sintered substrate disclosed in embodiments comprises a ceramic substrate having a first surface and a second surface on opposite sides of the first surface, wherein the ceramic substrate comprises: a through-hole penetrating such that the through-hole connects the first surface and the second surface; and a conductive region arranged in the through-hole, wherein the conductive region comprises a metal and a reaction layer of a metal compound arranged on inner walls defining the through-hole;and in a surface side of the conductive area a first metal layer, a second metal layer and a metal compound-rich layer between the first metal layer and the second metal layer are provided, wherein the metal compound-rich layer has a higher content of the metal compound than the first metal layer and the second metal layer, and wherein the second metal layer is arranged in a surface side of the conductive area;

[0008] A sintered substrate, disclosed in other embodiments, comprises a ceramic substrate having a first surface and a second surface on opposite sides of the first surface, the ceramic substrate comprising: a through-hole penetrating such that the through-hole connects the first surface and the second surface; and a conductive region arranged in the through-hole, the conductive region comprising a metal and a reaction layer of a metal compound arranged on inner walls defining the through-hole;and a first metal layer and a metal compound-rich layer on the first metal layer are provided on a surface side of the conductive region, the metal compound-rich layer having a higher content of the metal compound than the first metal layer and being arranged on a surface side of the conductive region.

[0009] Furthermore, a light-emitting device, disclosed in one embodiment, includes the sintered substrate described above and a light-emitting element comprising an element electrode, wherein the conductive area of ​​the sintered substrate and the element electrode are electrically connected. Advantageous effects of the invention

[0010] Embodiments of the present disclosure can provide a sintered substrate which has good mountability, a light-emitting device, as well as methods for producing the sintered substrate and the light-emitting device. Brief description of drawings [ Fig. 1] Fig. Figure 1 is a top view schematically representing a sintered substrate in accordance with an embodiment. [ Fig. 2] Fig. 2 is a schematic perspective cross-sectional view, taken along line II-II in Fig. 1. [ Fig. 3A] Fig. Figure 3A is an enlarged photographic image of a cross-section illustrating a cross-section in part of a conductive area of ​​a sintered substrate in accordance with an embodiment. [ Fig. 3B] Fig. Figure 3B is an enlarged planar view that schematically represents part of a conductive area of ​​a sintered substrate in accordance with an example. [ Fig. 3C] Fig. 3C is a magnified planar photographic image showing a portion of a known conductive region for comparison with Fig. 3B illustrates this. [ Fig. 3D] Fig. 3D is an enlarged photographic image of a cross-section, showing a portion of a cross-section of a known conductive area for comparison with Fig. 3A illustrates this. [ Fig. 4] Fig. Figure 4 is a flowchart illustrating a process for producing a sintered substrate in accordance with one embodiment. [ Fig. 5A] Fig. Figure 5A is a cross-sectional view schematically representing a ceramic substrate in a method for producing a sintered substrate in accordance with one embodiment. [ Fig. 5B] Fig. Figure 5B is an end view that schematically represents a state of a ceramic substrate in a process for producing a sintered substrate in accordance with an embodiment. [ Fig. 5C] Fig. Figure 5C is an end view illustrating a state in which a recessed area formed in a ceramic substrate and a conductive paste to be arranged in a through-hole are prepared in a method for producing a sintered substrate in accordance with an embodiment. [ Fig. 5D] Fig. 5D is an end view that schematically represents a state in which a recessed area is arranged in a ceramic substrate and a conductive paste is arranged in a through-hole, in a method for producing a sintered substrate in accordance with an embodiment. [ Fig. 5E] Fig. Figure 5E is an end view that schematically represents a state in which a second active metal powder is arranged in a conductive paste in a method for producing a sintered substrate according to one embodiment. [ Fig. 5F] Fig. 5F is an end view that schematically represents a state in which the conductive paste is fired in a process for producing a sintered substrate according to an embodiment. [ Fig. 6] Fig. Figure 6 is a cross-sectional view that schematically represents a light-emitting device in accordance with one embodiment. [ Fig. 7] Fig. Figure 7 is a flowchart illustrating a method for manufacturing a light-emitting device in accordance with one embodiment. [ Fig. 8A] Fig. Figure 8A is a cross-sectional view illustrating a state in which a connecting component is arranged on a sintered substrate in a method for manufacturing a light-emitting device according to one embodiment. [ Fig. 8B] Fig. Figure 8B is a cross-sectional view showing a state in which a light-emitting element is arranged in a method for manufacturing a light-emitting device in accordance with an embodiment. [ Fig. 8C] Fig. Figure 8C is a cross-sectional view illustrating a state in which a light-reflecting component is arranged in a method for manufacturing a light-emitting device in accordance with an embodiment. [ Fig. 9] Fig. Figure 9 is a cross-sectional view that schematically represents a sintered substrate in accordance with another embodiment. [ Fig. 10] Fig. Figure 10 is a flowchart illustrating a process for producing a sintered substrate in accordance with another embodiment. [ Fig. 11A] Fig. Figure 11A is a cross-sectional view schematically representing a ceramic substrate in which a through-hole is formed in a method for producing a sintered substrate in accordance with another embodiment. [ Fig. 11B] Fig. Figure 11B is a cross-sectional view that schematically represents a state in which a first conductive paste is arranged in a through-hole in a method for producing a sintered substrate in accordance with another embodiment. [ Fig. 11C] Fig. Figure 11C is a cross-sectional view schematically representing a state in which a second conductive paste is arranged in such a way that it is in contact with a first conductive paste in a method for producing a sintered substrate in accordance with another embodiment. [ Fig. 11D] Fig. Figure 11D is a cross-sectional view that schematically represents a state in which a second active metal powder is arranged in a second conductive paste in a method for producing a sintered substrate in accordance with another embodiment. [ Fig. 11E] Fig. Figure 11E is a cross-sectional view that schematically represents a state in which a first conductive paste and a second conductive paste are fired in a process for producing a sintered substrate in accordance with another embodiment. [ Fig. 12] Fig. Figure 12 is a cross-sectional view schematically representing a light-emitting device using a sintered substrate in accordance with another embodiment. Description of embodiments

[0011] Embodiments according to the present disclosure are described below with reference to the drawings. The embodiments described below serve only to embody the technical concepts according to the present disclosure, and the invention is not limited to the following unless otherwise specified. The content described in one embodiment may also be applied to other embodiments or variations. The drawings schematically represent some embodiments. For clarity in the description, scales, intervals, positional relationships, and the like of each component may be exaggerated, or some components may be omitted from the drawings. Directions shown in each of the drawings indicate relative positions between components and are not intended to indicate absolute positions.To simplify the description, the term "cross-section" can also mean a final surface and vice versa. Components with the same names and reference numerals generally represent the same components or components of the same quality, and a detailed description may be omitted. In some embodiments, the term "covering" includes not only covering by direct contact but also covering by indirect contact, for example, with another interposed component. Furthermore, the term "arranging" includes not only covering by direct contact but also covering by indirect contact, for example, with another interposed component. [Sintered substrate]

[0012] A sintered substrate 10 is described with reference to Fig. 1, 2 and 3A to 3D are described in accordance with an embodiment. It should be noted that Fig. 1 is a top view schematically representing a sintered substrate in accordance with an embodiment. Fig. 2 is a schematic perspective cross-sectional view, taken along line II-II in Fig. 1. Fig. Figure 3A is an enlarged photographic image illustrating a cross-section in part of a conductive area of ​​a sintered substrate in accordance with an embodiment. Fig. Figure 3B is a magnified planar view schematically illustrating part of the conductive area of ​​the sintered substrate, in accordance with an example. It should be noted that Fig. 3C is an enlarged planar photographic image that shows part of a conventional conductive area for comparison with Fig. 3B illustrates this. Fig. 3D is an enlarged photographic image of a cross-section, showing a cross-section of part of a conventional conductive area for comparison with Fig. 3A illustrates this.

[0013] The sintered substrate 10 comprises: a ceramic substrate 1 having a first surface 1A and a second surface 1B on the opposite side of the first surface 1A, wherein the ceramic substrate 1 includes a through-hole 2 penetrating the first surface 1A and the second surface 1B; and a conductive region 3 located within the through-hole 2. The conductive region 3 contains a metal 45 and a reaction layer 6a of a metal compound 6, arranged on inner walls defining the through-hole 2.Furthermore, the conductive region 3 on its surface includes a first metal layer 4, a second metal layer 5, and, between the first metal layer 4 and the second metal layer 5, a metal compound-rich layer 6c, which has a higher content of the metal compound 6 than the first metal layer 4 and the second metal layer 5. The second metal layer 5 is located on the surface of the conductive region 3. It should be noted that the ceramic substrate 1 is described assuming that the first surface 1A and / or the second surface 1B includes a recessed region 9, which has a larger hole size than the through-hole 2 and is connected to the through-hole 2.

[0014] Each component of the sintered substrate 10 is described below. (ceramic substrate)

[0015] The ceramic substrate 1 is a plate-shaped component that serves as the base for the sintered substrate 10. The ceramic substrate 1 has, for example, a rectangular shape in a top view. It should be noted that the shape of the ceramic substrate 1 in a top view is not particularly limited. The ceramic substrate 1 preferably uses a ceramic substrate that has already been fired and cured. The ceramic substrate 1 preferably comprises, for example, at least one selected from silicon nitride, aluminum nitride, boron nitride, magnesium oxide, and aluminum oxide. It should be noted that the ceramic substrate 1 is preferably made of a nitride ceramic, such as silicon nitride, aluminum nitride, or boron nitride, but can also be made of an oxide ceramic, such as aluminum oxide, silicon oxide, calcium oxide, or magnesium oxide. The ceramic substrate 1 can be made of beryllium oxide, silicon carbide, mullite, borosilicate glass, or an equivalent thereof.

[0016] In the ceramic substrate 1, the through-hole 2 is formed at a predetermined position in the thickness direction of the plate such that the through-hole 2 is connected to the first surface 1A and the second surface 1B, and the conductive area 3 is located within the through-hole 2. The ceramic substrate 1 includes the recessed area 9, which has a larger hole size than the through-hole 2 and is connected to the through-hole 2, on the first surface 1A and / or the second surface 1B. For example, the through-hole 2 of the ceramic substrate 1 is located at a position within the recessed area 9, which is located on both the first surface 1A and the second surface 1B.The recessed area 9 comprises a first recessed area 9a, located on the first surface 1A, and a second recessed area 9b, located on the second surface 1B. The through-hole 2 is located at the positions of the first recessed area 9a and the second recessed area 9b. The first recessed area 9a and the second recessed area 9b are arranged such that they face each other and have an inner dimension larger than that of the through-hole 2. It should be noted that, with respect to the through-hole 2 and the recessed area 9, the inner dimensions, sizes, or diameters refer to the length of a diagonal line in the case of a rectangle.The through-hole 2 is located in the recessed area 9 at a point where an electrical conductor is required, and is also located in the recessed area 9 at a point that becomes a wiring pad arranged on the ceramic substrate 1. Wiring pads are areas that serve as electrodes on which electronic components or the like are arranged. It should be noted that the recessed area 9 is preferably also located at a point where a wiring conductor is connected to a wiring pad. Because the recessed area 9 is located at a point that serves as a wiring conductor, the contact quality between the ceramic substrate 1 and the wiring conductor can be improved.The through-hole 2 is an area that serves as a contacting hole for the electrical connection between an element electrode 24 of a light-emitting element 20 and the wiring pad or wiring lead on the opposite side with respect to the sintered substrate 10 via the conductive area 3 that is located inside the through-hole 2.

[0017] The ceramic substrate 1 is shown as an example such that it has a through-hole 2 for each of the recessed areas 9, the through-hole being located essentially at the center of a recessed area 9. A plurality of through-holes 2 can be arranged with respect to a recessed area 9. Although the through-hole 2 is shown to be the same size from one end to the other, the size on the side to which the element electrode is connected can be smaller than the size of the hole on the opposite side. The opening shape of the through-hole 2 in a plan view can be a circle or a polygon, or it can be a trapezoid or a parallelogram, as long as it is a quadrilateral in a plan view, or it can be a triangle, a pentagon, or a hexagon.By forming the opening shape of the through-hole 2 as a polygonal shape, it is possible to create a form that corresponds to the shape of an electrode of the light-emitting element, thereby increasing the electrical conductivity and improving the heat dissipation properties. In the case where the opening shape of the through-hole 2 is a polygon, it is preferred that the corner region of the opening shape is rounded. The through-hole 2, which has the opening shape of a polygon, can have a continuously increasing opening area up to the recessed area 9. The maximum diameter (size or length of the diagonal line) of the through-hole 2 is preferably in the range of 0.05 mm to 0.5 mm. If the through-hole 2 is 0.05 mm or larger, the injection of a conductive paste 3A before firing can be easily carried out, thus improving the conductivity.If the through-hole 2 is 0.5 mm or smaller, its strength can be maintained and the amount of conductive paste 3A that needs to be filled can be reduced. (Conductive area)

[0018] The conductive area 3 is located in the through-hole 2 of the ceramic substrate 1, in the recessed area 9, or in both the through-hole 2 and the recessed area 9. The conductive component 3 is a component that is electrically connected to the light-emitting element 20, either alone or together with a wiring lead. The conductive area 3 comprises a first area 13, which is located in the through-hole 2, and a second area (wiring area) 8. The second area 8 is in contact with the first area 13 and is located on the first surface 1A and / or the second surface 1B such that it is partially exposed by the ceramic substrate 1. In the drawings, the second area 8 is provided on both the first surface 1A and the second surface 1B.In the conductive area 3, the second area 8 is positioned such that it protrudes relative to the front surface of the ceramic substrate 1 from both the first recessed area 9a of the first surface 1A and the second recessed area 9b of the second surface 1B. It is possible to reduce the electrical resistance and increase the electrical conductivity by increasing the thickness of the conductive area 3. This second area 8 can function as a wiring conductor or a wiring pad.

[0019] The conductive region 3 includes, for example, the metal 45 and the reaction layer 6a of a metal compound, arranged on the inner walls that define the through-hole 2. On the surface side (surface of the second region), which serves as the end surface of the conductive region 3, the following are provided from the inner side towards the surface side of the conductive region 3: the first metal layer 4; on the first metal layer 4, the metal compound-rich layer 6c, which has a higher content of the metal compound 6 than the first metal layer 4; and on the metal compound-rich layer 6c, the second metal layer 5. In the conductive region 3, the second metal layer 5 is arranged, for example, on the surface side of the conductive region 3.It should be noted that in the conductive region 3, the first metal layer 4 can be located on the surface side of the conductive region 3 by polishing or grinding the second metal layer 5 and the metal compound-rich layer 6c. Furthermore, the conductive region 3 can be formed by polishing or grinding the second metal layer 5 such that the metal compound-rich layer 6c is located on the surface side of the conductive region 3. If the sintered substrate 10 is produced by a manufacturing process to be described later, the protrusions and recesses on the surfaces of the first metal layer 4 and the second metal layer 5 can be reduced, and the amount of polishing or grinding required on the surfaces of the first metal layer 4 and the second metal layer 5 can be reduced.

[0020] The second metal layer 5, the metal compound-rich layer 6c, and the first metal layer 4 are arranged in that order from the surface side of the conductive region 3 in the metal 45. Furthermore, the conductive region 3 includes the reaction layer 6a of the metal compound 6, which is arranged on the inner walls that define the recessed region 9 and the through-hole 2 of the ceramic substrate 1. The conductive region 3 preferably contains a plurality of inorganic fillers 7, excluding metals. As shown in Fig. As shown in Figure 3A, the first metal layer 4 is divided into a region containing the inorganic filler 7 and a region not containing inorganic filler 7. The region not containing inorganic filler 7 is separated from the metal-compound layer 6c. The first metal layer 4 not containing inorganic filler 7 is positioned between the metal-compound layer 6c and the first metal layer 4 containing inorganic filler 7. However, the boundary between these layers is not clearly defined, and the thickness of the region not containing inorganic filler 7 varies depending on the content of the inorganic filler 7. That is, as shown in Fig. As shown in Figure 3A, the metal 45 includes a region where the inorganic filler 7 is absent from the upper and lower layers of the metal compound-rich layer 6c. The first metal layer 4, which contains the inorganic filler 7, includes a layer in which the inorganic filler 7 is dispersed almost uniformly. Note that a reactant 6b of the metal compound 6 is located on the surface of the inorganic filler 7.

[0021] Metal 45 preferably contains at least one selected from Ag, Al, Zn, Sn, and Ag-Cu alloys. Metal 45 may further contain at least one selected from Cu, Cr, and Ni.

[0022] In the conductive region 3, the arithmetic mean roughness Ra of the end surface (the surface of the second region 8) exposed by the ceramic substrate is preferably in the range of 0.01 µm to 1.5 µm. The arithmetic mean roughness Ra of the end surface of the conductive region 3 is preferably 1.0 µm or less, more preferably 0.5 µm or less, and most preferably 0.1 µm or less. If the arithmetic mean roughness Ra is 1.5 µm or less, the element electrode connected to the end surface of the conductive region 3 (the surface of the second region 8) can be stably connected.It should be noted that for the arithmetic mean roughness (Ra) of the final surface of the conductive area 3 (the surface of the second area 8), the ISO 25178 surface texture (measurement of surface roughness) as defined in the international standard (according to JIS B 0601) can be measured by a stylus-type measuring instrument using a stylus or by a non-stylus-type measuring instrument using a laser.

[0023] For the conductive region 3, the final surface exhibiting a surface roughness in one of the areas described above can be the surface of the first metal layer 4, the surface of the second metal layer 5, or the surface of the metal compound-rich layer 6c. If the first metal layer 4 is the final surface of the conductive region 3, the second metal layer 5 and the metal compound-rich layer 6c have been removed by polishing or grinding. If the metal compound-rich layer 6c is the final surface of the conductive region 3, the second metal layer 5 has been removed by polishing or grinding.

[0024] The conductive area 3 contains, as a metal compound 6, for example the reaction layer 6a of the metal compound 6, the reactant 6b of the metal compound 6, and the metal compound-rich layer 6c. Before firing, the metal compound 6 is an active metal powder 6A consisting of a first active metal powder 6A1 and a second active metal powder 6A2 (see Fig. 5C), each of which preferably contains at least one selected from TiH2, CeH2, ZrH2, and MgH2. After firing, the metal compound 6 comprises: the reaction layer 6a, which is arranged on the inner walls defining the recessed area 9 and the through-hole 2 of the ceramic substrate 1; the metal compound-rich layer 6c, which has a high content of the metal compound 6; a reactant of the metal compound 6, which is arranged on the surface of the second metal layer 5; and the reactant 6b, which is localized around the inorganic filler 7, if the inorganic filler 7 is included.

[0025] TiH2 (titanium hydride) is particularly preferred for the metal compound 6. When TiH2 is present, the metal compound 6 reacts with a nitride in the ceramic components, in a case where the nitride is contained in the ceramic substrate 1, and the reaction layer 6a, which serves as the active layer, is formed at the interface with the ceramic substrate 1, thereby improving the contact quality between the conductive area 3 and the ceramic substrate 1, such that the conductive area 3 can be firmly in close contact with the inner walls of the through holes 2. (Inorganic filler)

[0026] The inorganic filler 7 is dispersed in the conductive region 3 to reduce the occurrence of cracks. An example of an inorganic filler 7A prior to firing is a plurality of granular components, excluding metals. Examples of the ceramic filler include crystalline fillers, such as aluminum oxide and silicon dioxide, and amorphous fillers such as glass. It should be noted that the inorganic filler 7A prior to firing, contained in the conductive region 3, is present in the conductive paste 3A at a concentration that does not interfere with the effects of the other materials contained therein. (Organic solvent)

[0027] An organic solvent 7B (see Fig. 5C) is a component contained in the conductive paste 3A before firing. The organic solvent 7B evaporates after firing and does not remain in the conductive area 3. The organic solvent 7B can be, for example, a solvent and / or a resin material generally used as a through-hole material. (Wiring area)

[0028] The wiring area is, for example, the second area 8 of the conductive area 3 in Fig. 1 and Fig. 2. It should be noted that the wiring area is a wiring pattern arranged in the ceramic substrate 1, which has been pre-set as the second area 8 of the conductive area 3 and forms a wiring pad, an external connecting electrode, or the equivalent thereof. For example, the conductive area is arranged prior to firing as a second conductive paste 3A2 (see Fig. 5D). The wiring area is arranged as the second area 8 of the conductive area 3 such that it is continuous with the first area 13 of the conductive area 3, and here the wiring area is arranged in each of the recessed areas 9 on the side of the first surface 1A and on the side of the second surface 1B of the ceramic substrate 1. The thickness of the second area 8, as the wiring area, which protrudes from the surface of the ceramic substrate 1, is preferably in a range of, for example, 12 µm to 35 µm. It should be noted that the wiring area, which is the second area 8, is shown as a rectangle in a top view; however, any shape and / or placement of it can be assumed and is not limited. The wiring area can be arranged in the recessed area 9 such that the second area 8 is at the same level as the surface of the ceramic substrate 1.

[0029] For example, the same component used for the first area 13 of the conductive area 3 can be used for the second area 8, which is the wiring area. For instance, a metal component, such as copper foil or plating, can be placed as a connecting component 11 on the second area 8, which is the wiring area. Examples of the metal component material used as connecting component 11 include an elemental metal, such as gold, silver, copper, platinum, and aluminum; an alloy thereof; and a mixture of powder and resin binder using a resin. Furthermore, tin-silver-copper (SAC)-based solder or tin-bismuth (SnBi)-based solder can be used as connecting component 11. Examples of the resin used as the binder include a thermosetting resin, such as an epoxy resin or a silicone resin.The connecting component 11 preferably contains a reducing agent such as an organic acid. This allows a reduction of oxidation in the connecting component 11 and a reduction of the electrical resistance value in the connection.

[0030] Since the sintered substrate 10 with the configuration described above has the first metal layer 4 or the second metal layer 5 or the metal compound-rich layer 6c in the final surface of the conductive region 3, the final surface of the conductive region 3 is not in a stone-wall-like state, as in Fig. 3C is shown, and due to the reduction and narrowing of a gap g, it has a flat surface, such that, for example, the contact condition with the element electrode 24 of the light-emitting element 20 is improved, thereby increasing the reliability of the substrate. The sintered substrate 10 has the reaction layer 6a of the metal compound, which is arranged on the inner walls that define the recessed area 9 and the through-hole 2 of the ceramic substrate 1, and it is thus possible to increase the bond strength of the conductive area 3 to improve performance, such as the reliability of the substrate. [Method for producing a sintered substrate]

[0031] The following describes a method for producing a sintered substrate according to one embodiment with reference to Fig. 4 and 5A to 5F described. Fig. Figure 4 is a flowchart illustrating a process for producing a sintered substrate in accordance with one embodiment. Fig. Figure 5A is a cross-sectional view that schematically represents a ceramic substrate in a method for producing a sintered substrate according to one embodiment. Fig. Figure 5B is an end view that schematically represents a state of the ceramic substrate in a method for producing a sintered substrate according to one embodiment. Fig. Figure 5C is an end view illustrating a state in which a recessed area formed in a ceramic substrate and a conductive paste to be arranged in a through-hole are prepared in a method for producing a sintered substrate according to an embodiment. Fig. 5D is an end view that schematically represents a state in which a recessed area is arranged in a ceramic substrate and a conductive paste is arranged in a through-hole, in a method for producing a sintered substrate according to an embodiment. Fig. Figure 5E is an end view that schematically represents a state in which a second active metal powder is arranged in a conductive paste in a process for producing a sintered substrate according to an embodiment. Fig. 5F is an end view that schematically represents a state in which a conductive paste is fired in a process for producing a sintered substrate according to an embodiment.

[0032] The process S10 for producing a sintered substrate comprises: S11 of preparing the ceramic substrate 1, which has the first surface 1A and the second surface 1B on the opposite side of the first surface 1A, wherein the ceramic substrate 1 includes the through-hole 2, which penetrates such that the through-hole 2 connects the first surface 1A and the second surface 1B; S12 of arranging, in the through-hole 2, the conductive paste 3A, which contains at least one metal powder 45A, the first active metal powder 6A1 and the organic solvent 7B; S13 of arranging the second active metal powder 6A2 on a surface of the arranged conductive paste 3A; and firing the conductive paste 3A on which the second active metal powder 6A2 is arranged.S11, Preparation of the ceramic substrate 1, is described here, assuming that the recessed area 9, which is located on the first surface 1A and / or the second surface 1B, is provided, and the through-hole 2 is provided at the position where the recessed area 9 is located. (Preparing the ceramic substrate)

[0033] Step S11, Preparing the Ceramic Substrate (hereinafter referred to as step S11), consists of providing a ceramic substrate that has a through-hole 2 penetrating the first surface 1A and the second surface 1B, and which has already been fired and cured. In this step S11, the first recessed area 9a is formed in the ceramic substrate 1 to be prepared, such that it is larger than the opening area of ​​the through-hole 2 on the first surface 1A, and the second recessed area 9b is formed such that it is larger than the opening area of ​​the through-hole 2 on the second surface 1B. That is, a substrate is prepared that includes the first recessed area 9a and the second recessed area 9b, and furthermore includes the through-hole 2 that connects the first recessed area 9a and the second recessed area 9b.In this step S11, the first recessed area 9a, the second recessed area 9b, and the through-hole 2 are formed in the prepared ceramic substrate 1, e.g., by laser processing or the equivalent, which is irradiation with laser light from the sides of the first surface 1A and the second surface 1B of the ceramic substrate 1. It should be noted that the ceramic substrate 1 can be prepared with a number of through-holes 2 formed on it, the number being determined based on the size of the area to accommodate a plurality of light-emitting elements 20 and the number of element electrodes 24, or it can be prepared by cutting it to a size to accommodate a predetermined number of light-emitting elements 20.

[0034] In this step S11, the through-hole 2 formed in the ceramic substrate 1 is shaped into a polygonal form in a top view and has a rectangular shape when cut vertically with respect to the ceramic substrate 1. The through-hole 2 has a constant width. It should be noted that the maximum size of the through-hole 2 is preferably in the range of 0.05 mm to 0.5 mm. Furthermore, the through-hole 2 can be formed such that the opening area on the side of the second surface 1B is larger than the side connected to the element electrode 24 of the light-emitting element 20. If the opening area of ​​the through-hole 2 on the side of the second surface 1B is larger than that on the side of the first surface 1A, the heat dissipation property will be excellent. (Arranging a conductive paste)

[0035] Step S12, the placement of the conductive paste (hereinafter referred to as step S12), consists of placing the conductive paste 3A in the through-hole 2 and the recessed area 9 formed in the ceramic substrate 1. In this step S12, the conductive paste 3A is placed in the through-hole 2, for example, by applying screen printing or injection using a nozzle. It should be noted that in the conductive paste 3A, an area placed in the through-hole 2, which serves as the first area 13 after firing, and an area which serves as the second area 8 after firing, are formed, for example, from the same component.The conductive paste 3A is arranged, for example, such that a first conductive paste 3A1, serving as the first area 13, is arranged in the through-hole 2, and the second conductive paste 3A2, serving as the second area 8, is arranged such that it protrudes from the surfaces of the first surface 1A and the second surface 1B of the ceramic substrate 1 by means of a mask or the like.

[0036] In the conductive paste 3A, it is desirable that the first conductive paste 3A1 of the area that serves as the first area 13 after firing, and the second conductive paste 3A2 of the area that serves as the second area 8 after firing, are arranged alternately by the same series of screen printing or the like. As in Fig. As shown in Figure 5C, the conductive paste 3A comprises, for example, at least the metal powder 45A, the active metal powder 6A, and the organic solvent 7B. The conductive paste 3A contains, for example, the metal powder 45A in a range of 63 wt% to 85 wt%, the first active metal powder 6A1 in a range of 1 wt% to 15 wt%, the organic solvent 7B in a range of 5 wt% to 15 wt%, and contains the inorganic filler 7A, excluding metals, in an acceptable range of wt%. It should be noted that the first active metal powder 6A1 is preferably present in a range of 1 part by weight to 5 parts by weight when the total of the other components is taken as 100.The conductive paste 3A (the first conductive paste 3A1 and the second conductive paste 3A2) used in step S12 has fluidity due to the organic solvent 7B it contains and can freely fill the through hole 2 and the recessed area 9, each of which can have any shape, and can also be arranged in any shape and thickness by curing after application.

[0037] In this step S12, the metal powder 45A can contain at least one selected from Ag, Al, Zn, Sn, and Ag-Cu alloy powder. Ag-Cu alloy powder is used as an example. The metal powder 45A preferably contains at least one selected from Cu, Cr, and Ni. Cu powder is used as an example. The metal powder 45A preferably has a medium particle size in the range of 1 µm to 50 µm. If the metal powder 45A is at least one selected from Cu, Cr, and Ni, its melting point is preferably in the range of 200°C to 1000°C. In this step S12, if the metal powder 45A is at least one selected from Ag, Al, Zn, Sn, and Ag-Cu alloy powder, its melting point is preferably in the range of 1050°C to 2500°C.

[0038] In this step S12, the active metal powder 6A preferably contains at least one of the following, selected from TiH2, CeH2, ZrH2, and MgH2, as the first active metal powder 6A1. TiH2 is used as an example. The content of the first active metal powder 6A1 is preferably in the range of 1 part by weight to 5 parts by weight, as described above. If the content of the first active metal powder 6A1 is set to 1 part by weight or more, the reaction layer 6a, the reactant 6b, and the metal compound-rich layer 6c of the metal compound 6 can be formed in a required minimum amount after firing. Furthermore, it is possible to form the reaction layer 6a, the reactant 6b, and the metal compound-rich layer 6c of the metal compound 6 cost-effectively after firing if the content of the first active metal powder 6A1 is 5 parts by weight or less.

[0039] It should be noted that when the conductive paste 3A is placed in the through-hole 2 in step S12, it is preferred to place a mask in a different area than the first recessed area 9a, for example, from the first surface 1A as one surface of the ceramic substrate 1, to place the conductive paste 3A in the through-hole 2 and the first recessed area 9a using a squeegee as a screen printing tool, and furthermore to place the conductive paste 3A in the second recessed area 9b and the through-hole 2 from the second surface 1B as the other surface of the ceramic substrate 1 through the mask using a squeegee as for the first surface 1A. When the placement of the conductive paste 3A is complete, the masks placed on the first surface 1A and the second surface 1B of the ceramic substrate 1 are removed.

[0040] Step S13, the placement of the second active metal powder, consists of placing the second active metal powder 6A2 on the surface of the placed conductive paste (second conductive paste 3A2) 3A (hereinafter referred to as step S13). In this step S13, the second active metal powder 6A2 is placed on the surface of the second conductive paste 3A2, which is exposed by the first surface 1A and the second surface 1B of the ceramic substrate 1, by printing the paste or spraying the liquid obtained by causing the second active metal powder 6A2 to be contained in the organic solvent and formed into the paste or liquid state.It should be noted that when the second active metal powder 6A2 is arranged on the surface of the second conductive paste 3A2, the second active metal powder 6A2 is preferably pressed so that it is embedded in the second conductive paste 3A2. The second active metal powder 6A2 is arranged on the surface of the conductive paste 3A (surface of the second conductive paste 3A2), which is an area that serves as a wiring lead or wiring pad, and serves as a protruding area that extends from the first surface 1A and the second surface 1B of the ceramic substrate 1 by means of a mask by screen printing, metal mask printing, spraying, or the like. It should be noted that the second active metal powder 6A2 being in a liquid state means a state in which the second active metal powder 6A2 is contained in an organic solvent while being dispersed and mixed in the organic solvent.

[0041] Subsequently, step S14, the firing of the conductive paste (hereinafter referred to as step S14), is performed. In this step S14, a firing oven, such as an electric oven, is used, and the firing is carried out at a temperature of 850°C or higher. It should be noted that in step S14, when the firing process is carried out, the firing atmosphere is preferably an Ar atmosphere of 99.9% or higher or a vacuum atmosphere of 10 -5The conductivity of the conductive paste 3A is less than 850°C or higher, and more preferably 900°C or higher. In this step S14, the firing temperature is preferably 850°C or higher, and more preferably 900°C or higher. By performing this step S14, the region of the conductive paste 3A located in the ceramic substrate 1 is cured to a state that contains the second active metal powder 6A2. It should be noted that the ceramic substrate 1 has already been fired and cured in step S11 and is not fired and cured in this step S14. It should also be noted that a drying step of the conductive paste 3A can be performed before carrying out step S14. The drying step of the conductive paste 3A is preferably carried out in air or at a temperature in the range of 20°C to 60°C, which is lower than the firing temperature, before firing in the electric furnace.

[0042] Step S14 produces the sintered substrate 10. In the sintered substrate 10, the firing of the conductive paste 3A, which contains the second active metal powder 6A2, does not form the area (second area, protruding area) of the conductive region 3 exposed by the ceramic substrate 1 in a stone-wall-like state, but rather a smooth, flat surface, as shown in Fig. 3A and Fig. 3B is shown, with few protrusions, recesses, and cracks. As in Fig. 3C and Fig. In 3D representation, a known conductive region 300 has a stone-wall-like shape and is in a state where the clefts (a large number of foam-like holes) g are formed. Meanwhile, in the sintered substrate 10, the first metal layer 4, the metal-compound layer 6c of the metal compound 6, and the second metal layer 5 are formed to smooth the surface of the conductive region 3 by placing the second active metal powder 6A2 on the surface of the second region (protruding area) 8 of the conductive region 3 and performing a firing. Therefore, in the sintered substrate 10, the bond strength of the element electrode 24 connected to the conductive region 3 is improved.It should be noted that in the conductive area 3 the reaction layer 6a of the metal compound 6 is formed on the inner side surface of the through hole 2 and furthermore the reactant 6b of the metal compound 6 is localized around the second metal layer 5 in which a second metal powder 5A is fired and is also localized around the inorganic filler 7 if the inorganic filler 7 is included.

[0043] Therefore, in the sintered substrate 10, the bond strength between the inner walls of the through-hole 2 and the recessed area 9 and the conductive area 3 is improved by the reaction layer 6c of the metal compound 6 or the like. It should be noted that if the final surface of the conductive area 3 is the second metal layer 5, the conductive area 3 is in a fired condition in step S14, and if the metal compound-rich layer 6c or the first metal layer 4 is the final surface of the conductive area 3, the conductive area 3 is in a polished or ground condition after step S14. Even if the first metal layer 4 becomes the final surface of the conductive area 3, if the second metal layer 5 becomes the final surface of the conductive area 3, or if the metal compound-rich layer 6c becomes the final surface of the conductive area 3, the stone-walled condition, as described in Fig. 3C is shown, improved, and the gap g is reduced, smaller, or eliminated, such that the final surface of the conductive area 3 becomes a smooth, flat surface without protrusions, indentations, or cracks, as shown in Fig. 3B is shown. [Light-emitting device]

[0044] A light-emitting device 100 is described below with reference to Fig. 6 in accordance with an embodiment. Fig. Figure 6 is a cross-sectional view that schematically represents a light-emitting device in accordance with one embodiment.

[0045] The light-emitting device 100 is a device configured to emit light by arranging the light-emitting element 20 on the sintered substrate 10, includes the sintered substrate 10 and the light-emitting element 20 having the element electrode 24, and electrically connects the conductive area 3 of the sintered substrate 10 and the element electrode 24.

[0046] The light-emitting device 100 comprises the sintered substrate 10 described above and the light-emitting element 20, which is electrically connected to the second region 8, serving as the wiring area of ​​the conductive region 3, which in turn serves as the wiring area of ​​the sintered substrate 10. It should be noted that the light-emitting device 100 is described assuming, as an example, that a light-reflecting component 30, covering the lateral surfaces of the light-emitting element 20 and the sintered substrate 10, is arranged. Additionally, the light-emitting device 100 is described as a configuration in which the connecting component 11 is arranged on the conductive region 3 of the sintered substrate 10 and electrically connected to it.

[0047] In the light-emitting device 100, the light-emitting element 20, which is a mounting component comprising the element electrode 24, is arranged on the sintered substrate 10. In the light-emitting device 100, a plating, acting as the connecting component 11, is arranged on the second region 8 of the conductive region 3, which is continuously connected to the first region located in the ceramic substrate 1, and projects from the first surface 1A and the second surface 1B to form the wiring area. In the light-emitting device 100, the second region 8, which is part of the conductive region 3, projects from the first surface 1A and the second surface 1B of the ceramic substrate 1 to form a protruding area.This means that the protruding area is a wiring area connected to the element electrode 24 and, in this example, is the second area 8 of the conductive area 3. A plating is applied to the second area 8, which is the protruding area. It should be noted that the surface of the second area 8, which is the end surface of the conductive area 3, is a smooth, flat surface with almost no protrusions, recesses, or cracks. When the second area 8 is plated to form the connecting component 11, the surface of the plating also becomes a smooth, flat surface without protrusions, recesses, or cracks. Therefore, when the element 24 is connected, the connection is easily made, and the connection strength is improved. (Light-emitting element)

[0048] The light-emitting element 20 includes a pair of element electrodes 24, a light-transmitting component 23 arranged on a light extraction surface of the light-emitting element 20, an element substrate 22 and a semiconductor stack 21.

[0049] The light-emitting element 20 includes, for example, the semiconductor stack 21 on the element substrate 22. In the present embodiment, the light-transmitting component 23 is arranged on one side of the upper surface of the element substrate 22, which serves as the light extraction surface. The semiconductor stack 21 is provided on one side of the lower surface of the element substrate 22, and the pair of element electrodes 24 is provided on the side of the semiconductor stack 21. The semiconductor stack 21 can have any composition according to the desired emission wavelength. For example, a nitride semiconductor capable of emitting blue or green light (InXAlYGa1-X-YN, 0 ≤ X, 0 ≤ Y, X + Y ≤ 1), GaP, GaAlAs, or AllnGaP capable of emitting red light, or the like, can be used. The size and shape of the light-emitting element 20 can be selected to suit the intended use.

[0050] As an example, a sapphire substrate, a silicon substrate, or a GaN substrate is used as the element substrate 22. The thickness of the element substrate 22 is, for example, 20 µm to 2 mm, preferably 50 µm to 500 µm, and even more preferably 80 µm to 160 µm. The element substrate 22 is arranged such that its lower surface faces the semiconductor stack 21 and its upper surface faces the light-transmitting component 23. It should be noted that it is preferred that the element substrate 22 and the light-transmitting component 23 are directly connected to each other or connected to each other via a connecting component.

[0051] The light-transmitting component 23 can be made, for example, from a light-transmitting resin material or an inorganic material such as glass, aluminum oxide, or a phosphor. An epoxy resin, a silicone resin, a resin obtained by mixing an epoxy resin and a silicone resin, or the like can be used for the light-transmitting component 23. The light-transmitting component 23 can contain a phosphor in the resin material or the inorganic material, or it can contain only a phosphor. The light-transmitting component 23 includes a phosphor that absorbs blue light from the light-emitting element 20 and emits yellow light, thus emitting white light.The light-transmitting component 23 can contain a plurality of types of phosphors, and also, for example, by including a phosphor that absorbs blue light from the semiconductor stack 21 and emits green light, and a phosphor that emits red light, white light can be emitted by light from the light-emitting element 20 via the light-transmitting component 23.

[0052] Examples of the phosphor include a phosphor based on yttrium aluminum garnet (for example, Y3(Al,Ga)5O). 12 :Ce), a phosphor based on lutetium aluminum garnet (for example Lu3(Al,Ga)5O 12 :Ce), a phosphor based on terbium aluminum garnet (for example Tb3(Al,Ga)5O 12 :Ce), nitride phosphors, such as a β-SiAlON phosphor (for example (Si,Al)3(O,N)4:Eu), an α-SiAlON phosphor (Mz(Si,Al) 12 (O,N) 16(where 0 < z ≤ 2, and M is Li, Mg, Ca, Y, and a lanthanide element other than La and Ce)), a CASN-based phosphor (e.g., CaAlSiN3:Eu) and a SCASN-based phosphor (e.g., (Sr,Ca)AlSiN3:Eu), fluoride phosphors such as a KSF-based phosphor (e.g., K2SiF6:Mn), a KSAF-based phosphor (e.g., K2(Si,Al)F6:Mn), and an MGF-based phosphor (e.g., 3.5MgO·0.5MgF2·GeO2:Mn), quantum dot phosphors such as perovskite and chalcopyrite, and the like.

[0053] The element electrodes 24 are connected to the second regions 8 of the conductive regions 3, which serve as the wiring regions of the sintered substrate 10, via metal bumps 12 and / or the connecting components 11. One of the element electrodes 24 is a p-electrode, and the p-electrode is arranged at a distance from the other element electrode 24, i.e., an n-electrode, such that no electrical short circuit occurs with it. For example, the element electrodes 24 have a configuration in which a p-electrode and an n-electrode are arranged one after the other, but can also have a configuration in which, for the p-electrode and the n-electrode, one is arranged in two positions and the other in one position.

[0054] The metal bumps 12 and / or the connecting components 11 electrically connect the element electrodes 24 and the second regions 8 of the conductive regions 3, which serve as wiring areas. The metal bumps 12 can be arranged either on the side of the element electrodes 24 or on the side of the second region 8 of the conductive region 3 that serves as a wiring area. The shape, size, and number of the metal bumps 12 can be adjusted as appropriate, provided that the metal bumps 12 can be arranged within the area of ​​a region of the element electrodes 24. The size of the metal bump 12 can be adjusted as appropriate according to the size of the semiconductor stack, the required light emission output of the light-emitting element, and the like. For example, the metal bump 12 can have a diameter ranging from a few tens of micrometers to a few hundred micrometers.

[0055] The metal bumps 12 can be made, for example, from Au, Ag, Cu, Al, Sn, Pt, Zn, Ni, or an alloy thereof, and can be produced from bolt bumps known in this field. The bolt bumps can be formed using a bolt bump connector, a wiring connection device, or the like. The metal bumps can also be formed by a process known in the art, such as electroplating, electroless plating, vapor deposition, or sputtering.

[0056] Examples of the connecting component 11 include solder, such as tin-bismuth-based solder, tin-copper-based solder, tin-silver-based solder, and gold-tin-based solder; eutectic alloys, such as alloys containing Au and Sn as major components, alloys containing Au and Si as major components, and alloys containing Au and Ge as major components; paste materials made of silver, gold, palladium, and the like; anisotropic conductive materials, such as ACP and ACF; hard solders made of low-melting-point metals; and conductive adhesives and conductive composite adhesives made of a combination of these materials. The connecting component 11 is applied to the second area 8 of the conductive area 3, which serves as the wiring area, for example, by plating. (Light-reflecting component)

[0057] The light-reflecting component 30 is a component that exhibits light reflectivity. The light-reflecting component 30 is positioned such that it covers the upper surface of the sintered substrate 10 and the lateral surfaces of the light-emitting element 20. The light-reflecting component 30 is positioned such that it exposes a light-reflecting surface of the light-emitting element 20 and is flush with the light-transmitting component 23 of the light-emitting element 20. It should be noted that the reflective component 30 is also positioned, for example, between the lower surface of the light-emitting element 20 and the surface (first surface) of the sintered substrate 10.

[0058] The light-reflecting component 30 preferably has a high reflectance and is preferably white in order to effectively utilize the light from the light-emitting element 20. The reflectance of the light-reflecting component 30 is, for example, preferably 90% or more, and even more preferably 94% or more at the wavelength of the light emitted by the light-emitting element 20.

[0059] The light-reflecting component 30 can use a resin containing a light-diffusing material. Examples of resins used for the light-reflecting component include thermoplastic resins, such as acrylic resin, polycarbonate resin, cyclic polyolefin resin, polyethylene terephthalate resin, polyethylene naphthalate resin, or polyester resin, or thermosetting resins, such as epoxy resin or silicone resin. A well-known material, such as titanium dioxide, silicon dioxide, aluminum oxide, zinc oxide, or glass, can be used as the light-diffusing material.

[0060] The sintered substrate 10 is connected to an external wiring substrate or the like. The external wiring substrate is electrically connected via the connecting component 11 to the wiring area, which is the second area 8 of the conductive area 3 located on the second surface 1B of the ceramic substrate 1. The configuration of the external wiring substrate is not particularly limited as long as it is used in this type of light-emitting device 100.

[0061] In the light-emitting device 100, which has the configuration described above, the connection strength with the electrode areas 24 can be improved, and the reliability of the device can be enhanced, since the surfaces of the second areas 8 of the conductive areas 3, which protrude from the first surface 1A and the second surface 1B of the conductive areas 3 in the sintered substrate 10, are smooth, flat surfaces without protrusions, recesses, or cracks. Furthermore, in the light-emitting device 100, it is possible to stabilize the connection of the element electrodes without increasing the amount of the connecting component 11, which will be a plating layer.

[0062] It should be noted that, although the light-emitting device 100 uses a single light-emitting element 20 to control the brightness and switching on and off, a plurality of light-emitting elements 20 can be contained in a single unit to control the switching on and off for each of the contained light-emitting elements 20, and that the size and number of light-emitting elements 20 can be one type with two elements or two or more types with multiple elements. For example, light-emitting elements 20 of the same size arranged in one row and four columns, four light-emitting elements 20 arranged in two rows and two columns, or nine light-emitting elements 20 arranged in three rows and three columns can be used as a single unit.Additionally, a configuration in which the light-emitting elements 20, which have different sizes, are arranged in an arbitrary arrangement for each size, can be set as one unit. [Method for manufacturing a light-emitting device]

[0063] The following describes a method for manufacturing a light-emitting device in accordance with an embodiment with reference to Fig. 8A to 8C described. Fig. Figure 8A is a cross-sectional view illustrating a state in which a connecting component is arranged on a sintered substrate in a method for manufacturing a light-emitting device according to one embodiment. Fig. Figure 8B is a cross-sectional view showing a state in which a light-emitting element is arranged in a method for manufacturing a light-emitting device according to one embodiment. Fig. Figure 8C is a cross-sectional view illustrating a state in which a light-reflecting component is arranged in a method for manufacturing a light-emitting device according to one embodiment.

[0064] The process S20 for manufacturing the light-emitting device comprises S21, a preparation of the sintered substrate, which is produced by the above-described process S10 for manufacturing the sintered substrate, and S22, an arrangement of the light-emitting element, which has the element electrode on the sintered substrate. Subsequently, the conductive paste 3A, which is filled into the through-holes 2 in S21, the preparation of the sintered substrate, is fused to the conductive areas 3 by firing the ceramic substrate 1, and the conductive areas 3 and the element electrodes 24 are electrically connected to each other in S22, the arrangement of the light-emitting element.It should be noted that in the following description it is assumed that S23, the arrangement of the light-reflecting component 30, which covers the lateral surfaces of the light-emitting element 20 and the sintered substrate 10, is carried out after S22, the arrangement of the light-emitting element. (Preparing the sintered substrate)

[0065] Step S21, the preparation of the sintered substrate (hereinafter referred to as step S21), consists of preparing the sintered substrate 10, which was produced by the sintered substrate fabrication process S10 described above. In the sintered substrate 10, the surfaces of the second regions 8 of the conductive regions 3, which serve as the protruding regions extending from the first surface 1A and the second surface 1B, are in a smooth, planar state without protrusions, indentations, or cracks, as shown in Fig. 3B is shown, in which the stone-wall-like condition and the cleft (a large number of foam-like holes) g, as in Fig. 3C is shown, not formed. It should be noted that the sintered substrate 10 can contain a plurality of regions in which the light-emitting elements 20 are arranged, and can have a singulation size to separate the light-emitting devices 100 after the light-reflecting component 30 described below is arranged, or a size for each light-emitting device 100. (Arrangement of the light-emitting element)

[0066] Step S22, the arrangement of the light-emitting element (hereinafter referred to as step S22), consists of arranging the light-emitting element 20 on the sintered substrate 10. It should be noted that the light-emitting element 20 is arranged in a state in which the light-transmitting component 23 is pre-connected to the element substrate 22. When connecting the light-transmitting component 23 to the element substrate 22, a light-transmitting connecting material is used. In this step S22, the element electrodes 24 of the light-emitting element 20 are connected to the wiring areas via the connecting components 11, which are located on the second areas (wiring areas) 8 of the conductive areas 3 that serve as wiring areas, or via the metal bumps 12. (Arrangement of the light-reflecting component)

[0067] Step S23, the arrangement of the light-reflecting component (hereinafter referred to as step S23), consists of arranging the light-reflecting component 30, which covers the first surface 1A as the top surface of the sintered substrate 10 and covers the lateral surfaces of the light-emitting element 20. In this step S23, the light-reflecting component 30 is arranged on the sintered substrate 10 such that it surrounds the light-emitting element 20 and exposes the top surface of the light-transmitting component 23, which serves as the light extraction surface of the light-emitting element 20. The light-reflecting component 30 is arranged so that it has a rectangular shape in a top view.

[0068] In process S20 for manufacturing the light-emitting device, a singulation operation is optionally performed after the operation of step S23 is completed. In the light-emitting device 100, the number of light-emitting elements 20 used is preset. Therefore, if multiple light-emitting devices 100 are manufactured at once, the singulation operation is performed. During the singulation operation, the multiple light-emitting devices 100 are produced by cutting in a grid pattern. For example, a rotary blade with a disc shape, an ultrasonic cutter, laser irradiation, or the like can be used as the cutting method.

[0069] According to method S20 for manufacturing the light-emitting device, which has the configuration described above, the surfaces of the second regions 8, which serve as the protruding regions of the conductive regions 3 of the sintered substrate 10, become smooth, flat surfaces without protrusions, recesses, or cracks, in which the stone-wall-like condition and the gap g, as described in Fig. 3C is shown, which is not formed by the process S10 for producing the sintered substrate, such that the connection strength with the element electrodes 24 is improved and the reliability is improved by improving the connection strength of the conductive areas 3 arranged in the through holes 2, thereby enabling stable control of the light-emitting element 20.

[0070] The following describes how in Fig. Figure 9 shows a sintered substrate 10A described, which shows an application example. Fig. Figure 9 is a cross-sectional view showing an application example of a sintered substrate.

[0071] The sintered substrate 10A differs from the sintered substrate 10 described above in that the recessed area 9 is not provided and the conductive area 3 is the first area 13 and the wiring area 8 connected to the conductive area 3 is provided as the second area on the surface of the ceramic substrate 1.

[0072] The sintered substrate 10A comprises the ceramic substrate 1, which has the first surface 1A and the second surface 1B on the opposite side of the first surface 1A. The ceramic substrate 1 comprises: the through-hole 2, which penetrates the first surface 1A and the second surface 1B; the conductive area 3, which is arranged in the through-hole 2; and the wiring area 8, which is arranged to be in contact with at least a portion of the conductive area 3. The conductive area 3 comprises the metals 45 and the reaction layer 6a of the metal compound, which are arranged on the inner walls defining the through-hole 2.Furthermore, the following are provided on the surface side of the conductive region 3: the first metal layer 4, the second metal layer 5, and the metal compound-rich layer 6c, which has a higher content of the metal compound 6 than the first metal layer 4 and the second metal layer 5, wherein the metal compound-rich layer 6c is located between the first metal layer 4 and the second metal layer 5, and the second metal layer 5 is arranged on the surface side of the conductive region 3. It should be noted that in the sintered substrate 10, either the metal compound-rich layer 6c or the first metal layer 4 can be located on the surface side of the conductive region 3.

[0073] The ceramic substrate 1 has the same configuration and components as those described above, except that the recessed area 9 is not provided. The ceramic substrate 1 includes the through holes 2 of the same size, which extend between the first surface 1A and the second surface 1B.

[0074] The conductive area 3 comprises the area (first area) 13, which is arranged in the through-hole 2 of the ceramic substrate 1, and the wiring area (second area) 8, which is arranged on the surface of the ceramic substrate 1. The conductive area 3 includes the first area 13 described above within the ceramic substrate 1, within the thickness of the ceramic substrate 1. The conductive area 3 includes the second area, which is arranged to be in contact with at least a portion of the first area 13, namely the wiring portion 8, which is located on the surface of the ceramic substrate 1. Within the conductive area 3, the first area 13 and the wiring portion 8 are preferably formed from the same component.The conductive area 3, which includes the first area 13 and the wiring area 8, includes: the metal 45; and the reaction layer 6a of the metal compound on the inner walls defining the through-hole 2 and on the connection surfaces where the wiring area 8 is in contact with the surface of the ceramic substrate 1.

[0075] On the surface side of the conductive area 3, i.e., on the surface side of the wiring area 8, the first metal layer 4 is provided, the metal compound-rich layer 6c, which has a higher content of the metal compound 6 than the first metal layer 4, is provided on the first metal layer 4, and the second metal layer 5 is provided on the metal compound-rich layer 6c (see Fig. 3) It should be noted that the surface side of the wiring area 8 can be the first metal layer 4, the metal compound-rich layer 6c, or the second metal layer 5. If the first metal layer 4 or the metal compound-rich layer 6c is located on the surface side of the wiring area 8, the second metal layer 5, or the second metal layer and the metal compound-rich layer 6c, are polished or cut. As described above, in the conductive area 3, the arithmetic mean roughness Ra on the surface side of the wiring area 8, which serves as the final surface exposed by the ceramic substrate 1, is preferably in the range of 0.01 µm to 1.5 µm. The method for measuring the arithmetic mean roughness Ra on the surface side of the wiring area 8 is the same as the method already described.The components of conductive area 3 and the components contained therein are the same as described above.

[0076] In the sintered substrate 10A, the surfaces of the wiring areas 8, which serve as the end surfaces of the conductive areas 3, are smooth, flat surfaces without protrusions, recesses, or cracks, such that the element electrodes 24 and the like can be stably connected. Furthermore, the sintered substrate 10A includes the reaction layer 6a of the metal compound 6 in the area where the ceramic substrate 1 and the conductive area 3 are in contact. This allows the bond strength between the conductive area 3, which includes the wiring area 8, and the ceramic substrate 1 to be improved. Additionally, the opening area of ​​the through-hole 2 on the side of the second surface 1B is larger than on the side of the first surface 1A, such that excellent heat dissipation properties of the light-emitting element 20 can be achieved.

[0077] The following describes a process SA10 for the production of the sintered substrate 10A with reference to Fig. Sections 10 and 11A to 11E are described. It should be noted that if the same procedure or configuration is used in the already described procedure S10 for producing the sintered substrate, the description is omitted. Fig. Figure 11A is a cross-sectional view schematically representing a ceramic substrate in which a through-hole is formed in a method for producing a sintered body substrate according to another embodiment. Fig. Figure 11B is a cross-sectional view schematically representing a state in which a first conductive paste is arranged in a through-hole in a method for producing a sintered substrate according to another embodiment. Fig. Figure 11C is a cross-sectional view that schematically represents a state in which a second conductive paste is arranged to be in contact with a first conductive paste in a method for producing a sintered substrate according to another embodiment. Fig. Figure 11D is a cross-sectional view that schematically represents a state in which a second active metal powder is arranged in a second conductive paste in a process for producing a sintered substrate according to another embodiment. Fig. Figure 11E is a cross-sectional view that schematically represents a state in which a first conductive paste and a second conductive paste are fired in a process for producing a sintered substrate according to another embodiment.

[0078] The method SA10 for producing a sintered substrate comprises: SA11 preparing the ceramic substrate 1, which has the first surface 1A and the second surface 1B on the opposite side of the first surface 1A, wherein the ceramic substrate 1 includes the through-hole 2, which penetrates the first surface 1A and the second surface 1B; S12 arranging the first conductive paste 3A1, which contains at least the metal powder 45A, the first active metal powder 6A1 and the organic solvent 7B, in the through-hole 2; S13 arranging the second conductive paste 3A2 on the surface of the ceramic substrate 1 such that it is in contact with the first conductive paste 3A1; S14 arranging the second active metal powder 6A2 on the surface of the second conductive paste;and S15 of the firing of the second conductive paste 3A2, on which the second active metal powder 6A2 is arranged, and the first conductive paste 3A1 arranged in the through-hole 2.;

[0079] SA11, the preparation of the ceramic substrate (hereinafter referred to as step SA11), consists of preparing the ceramic substrate 1, which includes the through-hole 2 that penetrates the first surface 1A and the second surface 1B, with the ceramic substrate 1 having already been fired and cured. In this step SA11, the through-hole 2 is formed, but the recessed area 9 is not formed. The ceramic substrate 1 has the same configuration and material as those described above, except that the recessed area 9 is not formed.

[0080] SA12, the placement of the first conductive paste (hereinafter referred to as step SA12), consists of placing the first conductive paste 3A1 in the through-hole 2 of the ceramic substrate 1. In this step SA12, the first conductive paste 3A1 is placed in the through-hole 2, for example, by screen printing or injection using a nozzle. The first conductive paste 3A1 used in this step SA12 has the same components as the conductive paste 3A described above.

[0081] SA13, the application of the second conductive paste (hereinafter referred to as step SA13), consists of applying the second conductive paste 3A2 to the first surface 1A and / or the second surface 1B of the ceramic substrate 1 (on both in Fig. 11B) such that it is in contact with the first conductive paste 3A1. In this step SA13, for example, a mask is arranged on the ceramic substrate 1, different from the area where the second conductive paste 3A2 is arranged, and the second conductive paste 3A2 is arranged by applying screen printing or by applying it using a nozzle. In this step SA13, the second conductive paste 3A2 has the same components as the conductive paste 3A described above.

[0082] It should be noted that in steps SA12 and SA13, the first conductive paste 3A1 and the second conductive paste 3A2 can have the same components and can be arranged in the same step as conductive paste 3A. That is, as an arrangement of conductive paste 3A, a mask can be placed on the ceramic substrate 1, and the conductive paste 3A can be placed in the through-hole 2 and on the first surface 1A and the second surface 1B of the ceramic substrate 1 by screen printing or the like.

[0083] SA14, the placement of the second active metal powder (hereinafter referred to as step SA14), serves to place the second active metal powder 6A2 on the surface of the second conductive paste 3A2. In this step SA14, when the conductive paste 3A is placed as described above, the second active metal powder 6A2 is placed on the surfaces of the conductive paste 3A exposed by the ceramic substrate 1.

[0084] In this step SA14, the second active metal powder 6A2, in paste or liquid form as described above, is applied to the second conductive paste 3A2 or the conductive paste 3A by pressing or spraying through the mask. When the second active metal powder 6A2 is applied to the surfaces of the second conductive paste 3A2 or the conductive paste 3A, it is preferably pressed so that it becomes embedded in the second conductive paste 3A2 or the conductive paste 3A.

[0085] SA15, the firing of the conductive paste (hereinafter referred to as step SA15), serves to carry out the firing process under the same conditions as those described in the preceding step. Before firing the conductive paste 3A, drying can be carried out in the same manner as described above.

[0086] In the sintered substrate 10A, the connection strength of the element electrodes 24 and the like, which are connected to the wiring areas 8, is better than in the second area 8 of the sintered substrate 10. In the conductive area 3 and the wiring area 8, the reaction layer 6a of the metal compound 6 is formed on the inner walls of the through-hole 2 and in an area that is in contact with the surface of the ceramic substrate 1. Furthermore, the reactant 6b of the metal compound 6 is localized around the second metal layer 5, in which the second metal powder 5A is fired, and also around the inorganic filler 7 if the inorganic filler 7 is present. Therefore, in the sintered substrate 10A, the connection strength between the through-hole 2 and the ceramic substrate 1, as well as between the conductive area 3 and the wiring area 8, is improved.

[0087] Below, a light-emitting device 100A, which uses the sintered substrate 10A, is described with reference to Fig. 12 described. Fig. Figure 12 is a cross-sectional view illustrating an application example of a light-emitting device. It should be noted that an explanation of the same configurations described above is omitted.

[0088] The light-emitting device 100A comprises the sintered substrate 10A and the light-emitting element 20, which has the element electrodes 24, and electrically connects the conductive areas 3 (wiring areas 8) of the sintered substrate 10A and the element electrodes 24. In the sintered substrate 10A, the element electrodes 24 are connected, for example, via plating layers representing the connecting components 11, to the wiring areas 8, which are in contact with the conductive areas 3. The light-emitting device 100A comprises the light-reflecting component 30 as described above in the light-emitting device 100. It should be noted that the surfaces of the wiring area 8 are smooth, flat surfaces without protrusions, recesses, or cracks, in which the stone-wall-like condition and the gap g, as in Fig.3C is shown, but not formed. Therefore, the flat state without cracks, protrusions, or recesses can be maintained even when the connecting component 11, which serves as a plating layer, is in place. Therefore, in the light-emitting device 100A, it is possible to stabilize the connection of the element electrodes without increasing the amount of the plating layer.

[0089] The method for manufacturing the light-emitting device 100A performs the same steps as the method S20 described above for manufacturing the light-emitting device 100. That is, the steps of preparing the sintered substrate 10A, arranging the conductive areas 3 in the through-holes 2 of the ceramic substrate 1, and electrically connecting the element electrodes 24 to the conductive areas 3 are carried out. When arranging the conductive area 3, the element electrode 24 is electrically connected to the conductive area 3 via a connecting component, such as the wiring area 8 or the plating layer applied to the wiring area 8. Furthermore, the light-reflecting component 30 is arranged for the manufacture of the light-emitting device 100A.

[0090] It should be noted that by making the opening area of ​​the second surface 1B of the through-hole 2 of the sintered substrate 10 larger than the opening area of ​​the first surface 1A on the side where the mounting component electrodes are connected, the thermal conductivity of the sintered substrate 10 can be improved to enhance heat dissipation, strength can be maintained while stiffness is preserved, thickness can be reduced, and performance characteristics such as reliability can be improved. For example, the through-hole 2 can be formed by laser processing, mechanical machining, or chemical processing such as etching.It should be noted that, although the through-hole 2 preferably has a polygonal shape, the polygonal shape here can be different from a shape in which the vertex angles of two continuous sides are strictly formed by connecting straight lines. For example, the through-hole 2 can have a polygon-like shape with rounded corners, in which straight lines are connected by a small arc.

[0091] In the present application, the relationship between the individual terms can be constructed as follows. [Clause 1] Method for producing a sintered substrate, comprising: Preparing a ceramic substrate having a first surface and a second surface on opposite sides of the first surface, wherein the ceramic substrate includes a through-hole penetrating such that the through-hole connects the first surface and the second surface; Arrange, in the through-hole, a conductive paste containing at least one metal powder, a first active metal powder and an organic solvent; Arranging a second active metal powder on a surface of the arranged conductive paste; and Burning of the conductive paste on which the second active metal powder is arranged. [Clause 2] Method for producing a sintered substrate according to Clause 1, wherein, in preparing the ceramic substrate, a recessed area is provided which is arranged on the first surface and / or the second surface, and the through-hole is provided at a position of the recessed area. [Clause 3] Method for producing a sintered substrate according to Clause 1 or 2, wherein the conductive paste is arranged in a manner in which the content of the first active metal powder is in a range of 1 part by weight to 5 parts by weight. [Clause 4] Method for producing a sintered substrate according to any one of Clauses 1 to 3, wherein, in the arrangement of the conductive paste, the metal powder contains at least one selected from Ag, Al, Zn, Sn and Ag-Cu alloy powder. [Clause 5] Method for producing a sintered substrate according to any one of Clauses 1 to 4, wherein, in the arrangement of the conductive paste, the metal powder further comprises at least one selected from Cu, Cr and Ni. [Clause 6] Method for producing a sintered substrate according to any one of Clauses 1 to 5, wherein, in the arrangement of the conductive paste, the first active metal powder contains at least one selected from TiH2, CeH2, ZrH2 and MgH2. [Clause 7] Method for producing a sintered substrate according to any one of Clauses 1 to 6, wherein in the arrangement of the second active metal powder the second active metal powder contains at least one selected from TiH2, CeH2, ZrH2 and MgH2. [Clause 8] Method for producing a sintered substrate according to any one of Clauses 1 to 7, wherein the second active metal powder is contained in an organic solvent when arranging the second active metal powder. [Clause 9] Method for producing a sintered substrate according to any one of Clauses 1 to 8, wherein, in the arrangement of the conductive paste, the conductive paste further contains a resin. [Clause 10] Method for producing a sintered substrate according to any one of Clauses 1 to 9, wherein, in the arrangement of the conductive paste, the conductive paste further contains a plurality of inorganic fillers excluding metals. [Clause 11] Method for producing a sintered substrate according to any one of Clauses 1 to 10, wherein during the firing of the conductive paste a firing atmosphere is an Ar atmosphere of 99.9% or more or a vacuum atmosphere of 10 -5 Pa or less. [Clause 12] Method for producing a sintered substrate according to any one of Clauses 1 to 11, wherein, in preparing the ceramic substrate, the through-hole is formed by irradiating with laser light from one side of the first surface of the ceramic substrate. [Clause 13] Method for producing a sintered substrate according to any of Clauses 2 to 12, which refers to Clause 2, wherein, in preparing the ceramic substrate, the ceramic substrate is irradiated with laser light to form the recessed area. [Clause 14] Method for producing a sintered substrate according to any one of Clauses 1 to 13, wherein in arranging the conductive paste the conductive paste comprises a first conductive paste which is arranged in the through-hole and a second conductive paste which is arranged on the first surface and / or the second surface in such a way that it is in contact with the first conductive paste. [Clause 15] Method for producing a sintered substrate according to any one of Clauses 2 to 12, which refers to Clause 2, wherein When arranging the conductive paste, the conductive paste is placed in the recessed area, and the conductive paste contains: a first conductive paste arranged in the recessed area and in the through-hole; and a second conductive paste arranged on the first surface and / or the second surface in such a way that it is in contact with the first conductive paste. [Clause 16] Method for manufacturing a light-emitting device, the method comprising: Preparing the sintered substrate produced by the process for producing a sintered substrate according to any one of clauses 1 to 15; and Arranging a light-emitting element comprising an element electrode in the sintered substrate, wherein, during the preparation of the sintered substrate, a conductive paste arranged in the through-hole becomes a conductive area by firing the conductive paste, and When arranging the light-emitting element, the conductive area and the element electrode are electrically connected. [Clause 17] Sintered substrate, comprising: a ceramic substrate having a first surface and a second surface on opposite sides of the first surface, wherein the ceramic substrate includes a through-hole penetrating such that the through-hole connects the first surface and the second surface; and a conductive area located within the through-hole, wherein the conductive area contains a metal and a reaction layer of a metal compound arranged on inner walls defining the through-hole, and in a surface side of the conductive region a first metal layer, a second metal layer and a metal compound-rich layer between the first metal layer and the second metal layer are provided, wherein the metal compound-rich layer has a higher content of the metal compound than the first metal layer and the second metal layer, and wherein the second metal layer is arranged in a surface side of the conductive region. [Clause 18] Sintered substrate, comprising: a ceramic substrate having a first surface and a second surface on opposite sides of the first surface, wherein the ceramic substrate includes a through-hole penetrating such that the through-hole connects the first surface and the second surface; and a conductive area located within the through-hole, wherein the conductive area contains a metal and a reaction layer of a metal compound arranged on inner walls defining the through-hole, and In a surface side of the conductive region, a first metal layer and a metal compound-rich layer on the first metal layer are provided, wherein the metal compound-rich layer has a higher content of the metal compound than the first metal layer and is arranged in a surface side of the conductive region. [Clause 19] Sintered substrate according to Clause 17 or 18, wherein the first surface and / or the second surface comprises a recessed area, the recessed area having a hole size larger than the through-hole and connected to the through-hole. [Clause 20] Sintered substrate according to one of Clauses 17 to 19, wherein an arithmetic mean roughness Ra of a final surface of the conductive area exposed by the ceramic substrate is in the range of 0.01 µm to 1.5 µm. [Clause 21] Sintered substrate according to one of Clauses 17 to 20, wherein the conductive region comprises a first region localized in a substrate of the ceramic substrate and a second region continuous with the first region and partially exposed by the ceramic substrate. [Clause 22] Sintered substrate according to one of Clauses 17 to 21, wherein the metal contains at least one selected from Ag, Al, Zn, Sn and an Ag-Cu alloy. [Clause 23] Sintered substrate according to one of Clauses 17 to 22 or according to Clause 18, wherein the metal further comprises at least one selected from Cu, Cr and Ni. [Clause 24] Sintered substrate according to one of Clauses 17 to 23, wherein the ceramic substrate contains at least one selected from silicon nitride, aluminium nitride, boron nitride, magnesium oxide and aluminium oxide. [Clause 25] Light-emitting device comprising the sintered substrate according to any one of Clauses 17 to 24 and a light-emitting element comprising an element electrode, wherein the conductive area of ​​the sintered substrate and the element electrode are electrically connected. [Clause 26] Light-emitting device according to Clause 25, wherein the conductive area comprises a first area that is localized in a substrate of the ceramic substrate, and a second area that is continuous with the first area and partially exposed by the ceramic substrate, and the second area and the element electrode are electrically connected via a connecting component. Commercial applicability

[0092] A light-emitting device according to embodiments of the present disclosure can be used for a headlight with variable light distribution. Furthermore, the light-emitting devices according to embodiments of the present disclosure can be used, for example, as a light source for the backlighting of a liquid crystal display, for various types of lighting fixtures, for a large display, for various types of display devices for advertising, destination information and the like, as well as for a digital video camera, for display reading devices in a facsimile, a copying machine, a scanner and the like, and for a projector device. Reference symbol list 1 ceramic substrate 1A First surface 1B Second surface 2 through holes 2a Inclined surface 3 Conductive area 3A Conductive Paste 3A1 First conductive paste 3A2 Second conductive paste 4 First metal layer 5 Second metal layer 6 Metal connection 6A Active Metal Powder 6A1 First active metal powder 6A2 Second active metal powder 6a Reaction layer 6b Reactant 6c Metal compound-rich layer 7 Inorganic filler: after firing 7A Inorganic filler: before firing 7B Organic solvent 8 Second area (wiring area) 9 Recessed area 9a First recessed area 9b Second recessed area 10 Sintered substrate 11 Connecting component 12 metal bumps 13 First area 20 light-emitting elements 21 Semiconductor layer 22 element substrate 23 light-transmitting component 24-element electrode 30 Light-reflecting component 45 Metal 100 light-emitting devices S10 Method for producing a sintered substrate S11 Preparing a ceramic substrate S12 Performing the filling with through-flow paste S13 Arranging a conductive paste S14 Firing of the ceramic substrate S20 Method for manufacturing a light-emitting device S21 Preparing a sintered substrate S22 Arrangement of the light-emitting element S23 Arrangement of the light-reflecting component QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] JP 5693940

[0002] JP 6541530 B

[0002]

Claims

[1] Method for producing a sintered substrate, comprising: Preparing a ceramic substrate having a first surface and a second surface on opposite sides of the first surface, wherein the ceramic substrate includes a through-hole penetrating such that the through-hole connects the first surface and the second surface; Arrange, in the through-hole, a conductive paste containing at least one metal powder, a first active metal powder and an organic solvent; Arranging a second active metal powder on a surface of the arranged conductive paste; and Burning of the conductive paste on which the second active metal powder is arranged. [2] Method for producing a sintered substrate according to claim 1, wherein in the preparation of the ceramic substrate a recessed area is provided which is arranged on the first surface and / or the second surface, and the through-hole is provided at a position of the recessed area. [3] Method for producing a sintered substrate according to claim 1 or 2, wherein the conductive paste contains a content of the first active metal powder in a range of 1 part by weight to 5 parts by weight. [4] Method for producing a sintered substrate according to any one of claims 1 to 3, wherein, in the arrangement of the conductive paste, the metal powder contains at least one selected from Ag, Al, Zn, Sn and Ag-Cu alloy powder. [5] Method for producing a sintered substrate according to any one of claims 1 to 4, wherein, in the arrangement of the conductive paste, the metal powder further comprises at least one selected from Cu, Cr and Ni. [6] Method for producing a sintered substrate according to any one of claims 1 to 5, wherein in the arrangement of the conductive paste the first active metal powder contains at least one selected from TiH2, CeH2, ZrH2 and MgH2. [7] Method for producing a sintered substrate according to any one of claims 1 to 6, wherein in the arrangement of the second active metal powder the second active metal powder contains at least one selected from TiH2, CeH2, ZrH2 and MgH2. [8] Method for producing a sintered substrate according to any one of claims 1 to 7, wherein in the arrangement of the second active metal powder the second active metal powder is contained in an organic solvent. [9] Method for producing a sintered substrate according to any one of claims 1 to 8, wherein the conductive paste further contains a resin when arranging the conductive paste. [10] Method for producing a sintered substrate according to any one of claims 1 to 9, wherein, in the arrangement of the conductive paste, the conductive paste further contains a plurality of inorganic fillers that exclude metals. [11] Method for producing a sintered substrate according to any one of claims 1 to 10, wherein during the firing of the conductive paste a firing atmosphere is an Ar atmosphere of 99.9% or more or a vacuum atmosphere of 10 -5 Pa or less. [12] Method for producing a sintered substrate according to any one of claims 1 to 11, wherein, in the preparation of the ceramic substrate, the through-hole is formed by irradiating with laser light from one side of the first surface of the ceramic substrate. [13] Method for producing a sintered substrate according to one of claims 2 to 12, which relates to claim 2, wherein in the preparation of the ceramic substrate the ceramic substrate is irradiated with laser light to form the recessed area. [14] Method for producing a sintered substrate according to any one of claims 1 to 13, wherein in arranging the conductive paste the conductive paste comprises a first conductive paste which is arranged in the through-hole and a second conductive paste which is arranged on the first surface and / or the second surface in such a way that it is in contact with the first conductive paste. [15] Method for producing a sintered substrate according to any one of claims 2 to 12, which relates to claim 2, wherein When arranging the conductive paste, the conductive paste is placed in the recessed area, and the conductive paste contains: a first conductive paste arranged in the recessed area and in the through-hole; and a second conductive paste arranged on the first surface and / or the second surface in such a way that it is in contact with the first conductive paste. [16] Method for manufacturing a light-emitting device, the method comprising: Preparing the sintered substrate produced by the process for producing a sintered substrate according to any one of claims 1 to 15; and Arranging a light-emitting element comprising an element electrode in the sintered substrate, wherein, during the preparation of the sintered substrate, a conductive paste arranged in the through-hole becomes a conductive area by firing the conductive paste, and When arranging the light-emitting element, the conductive area and the element electrode are electrically connected. [17] Sintered substrate, comprising: a ceramic substrate having a first surface and a second surface on opposite sides of the first surface, wherein the ceramic substrate includes a through-hole penetrating such that the through-hole connects the first surface and the second surface; and a conductive area located within the through-hole, wherein the conductive area contains a metal and a reaction layer of a metal compound arranged on inner walls defining the through-hole, and in a surface side of the conductive region a first metal layer, a second metal layer and a metal compound-rich layer between the first metal layer and the second metal layer are provided, wherein the metal compound-rich layer has a higher content of the metal compound than the first metal layer and the second metal layer, and wherein the second metal layer is arranged in a surface side of the conductive region. [18] Sintered substrate, comprising: a ceramic substrate having a first surface and a second surface on opposite sides of the first surface, wherein the ceramic substrate includes a through-hole penetrating such that the through-hole connects the first surface and the second surface; and a conductive area located within the through-hole, wherein the conductive area contains a metal and a reaction layer of a metal compound arranged on inner walls defining the through-hole, and In a surface side of the conductive region, a first metal layer and a metal compound-rich layer on the first metal layer are provided, wherein the metal compound-rich layer has a higher content of the metal compound than the first metal layer and is arranged in a surface side of the conductive region. [19] Sintered substrate according to claim 17 or 18, wherein the first surface and / or the second surface comprises a recessed area, wherein the recessed area has a hole size larger than the through-hole and is connected to the through-hole. [20] Sintered substrate according to any one of claims 17 to 19, wherein an arithmetic mean roughness Ra of an end surface of the conductive area exposed by the ceramic substrate is in a range of 0.01 µm to 1.5 µm. [21] Sintered substrate according to any one of claims 17 to 20, wherein the conductive region comprises a first region located in a substrate of the ceramic substrate and a second region which is continuous with the first region and is partially exposed from the ceramic substrate. [22] Sintered substrate according to any one of claims 17 to 21, wherein the metal contains at least one selected from Ag, Al, Zn, Sn and an Ag-Cu alloy. [23] Sintered substrate according to one of claims 17 to 22 or according to claim 18, wherein the metal further comprises at least one selected from Cu, Cr and Ni. [24] Sintered substrate according to any one of claims 17 to 23, wherein the ceramic substrate contains at least one selected from silicon nitride, aluminium nitride, boron nitride, magnesium oxide and aluminium oxide. [25] Light-emitting device comprising the sintered substrate according to one of claims 17 to 24 and a light-emitting element comprising an element electrode, wherein the conductive area of ​​the sintered substrate and the element electrode are electrically connected. [26] Light-emitting device according to claim 25, wherein the conductive area comprises a first area that is localized in a substrate of the ceramic substrate, and a second area that is continuous with the first area and partially exposed by the ceramic substrate, and the second area and the element electrode are electrically connected via a connecting component.

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