Ceramic substrate, light emitting device, and method for manufacturing same

Abstract

The invention provides a ceramic substrate, a light emitting device and a manufacturing method thereof. A ceramic substrate (100) according to one embodiment of the present invention comprises: a ceramic plate (1); a seed layer (2) disposed on the upper surface of the ceramic plate (1); a Cu layer (3) disposed on the upper surface of the seed layer (2); one or more intermediate layers (4) disposed on the upper surface of the Cu layer (3) and on the side surfaces of the Cu layer (3); and an Au layer (5) disposed on the upper surface of the intermediate layer (4) and on the side surfaces of the intermediate layer (4), the upper surface of the seed layer (2) being in contact with the lower surface of the intermediate layer (4), the upper surface of the ceramic plate (1) being not in contact with the lower surface of the Au layer (5), and the Au layer (5) being in contact with the upper surface of the seed layer (2) in the horizontal direction. The edge of the upper surface of the seed layer (2) is positioned further outward than the edge of the lower surface of the Cu layer (3).

Description

Technical Field

[0001] This invention relates to a ceramic substrate and a light-emitting device, and a method for manufacturing the same. Background Technology

[0002] In recent years, in order to miniaturize, increase functionality, and integrate electronic devices or components, microchips (semiconductor integrated circuits) have also been required to be miniaturized. To make the wiring inside the semiconductor even finer, photolithography technology is used, for example (see, for example, Patent Document 1).

[0003] One method for forming wiring using photolithography involves forming a metal film on a substrate and then removing excess portions of the metal film by etching to form wiring of a desired shape. However, this method describes the possibility that etching can damage the substrate or cause changes in the composition of the conductive film, and sometimes a stripping method is used when forming wiring (for example, see Patent Document 2).

[0004] On the other hand, copper (Cu) with high conductivity is used for wiring. However, copper is also prone to corrosion in normal environments due to the influence of moisture in the air. Therefore, methods for forming plating layers such as nickel (Ni), rhodium (Rh), and gold (Au) on the surface of copper are known (see Patent Document 3).

[0005] <Prior art documents>

[0006] <Patent Documents>

[0007] Patent Document 1: Japanese Patent Application Publication No. 2023-108213

[0008] Patent Document 2: Japanese Patent Application Publication No. 2003-347706

[0009] Patent Document 3: Japanese Patent No. 4706690 Summary of the Invention

[0010] <Problem to be solved by this invention>

[0011] The purpose of this invention is to provide a ceramic substrate with a Cu layer that can suppress the corrosion of the Cu layer and has excellent reliability, as well as a light-emitting device and a method for manufacturing the same.

[0012] <Methods for solving problems>

[0013] A ceramic substrate according to one embodiment of the present invention includes: a ceramic plate; a seed layer disposed on the upper surface of the ceramic plate; a Cu layer disposed on the upper surface of the seed layer; one or more intermediate layers disposed on the upper surface of the Cu layer and the side surface of the Cu layer; and an Au layer disposed on the upper surface of the intermediate layers and the side surface of the intermediate layers. The upper surface of the seed layer is in contact with the lower surface of the intermediate layer, and the upper surface of the ceramic plate is not in contact with the lower surface of the Au layer. In the horizontal direction, the edge of the upper surface of the seed layer is located further outward than the edge of the lower surface of the Cu layer.

[0014] In addition, a light-emitting device according to one embodiment of the present invention includes a ceramic substrate according to an embodiment of the present invention and a light-emitting element disposed on the ceramic substrate.

[0015] A method for manufacturing a ceramic substrate according to an embodiment of the present invention includes: a step of providing a first resist layer on the upper surface of a ceramic plate and exposing and developing the first resist layer into a predetermined shape; a step of configuring a seed layer on the upper surface of the ceramic plate exposed from the first resist layer after exposure and development, the side surface of the first resist layer, and the upper surface of the first resist layer; a step of providing a second resist layer to cover at least a portion of the upper surface of the seed layer, and exposing and developing the second resist layer into a predetermined shape to expose at least a portion of the upper surface of the seed layer configured on the upper surface of the ceramic plate; a step of configuring a Cu layer on the upper surface of the seed layer exposed from the second resist layer after exposure and development by electrolytic plating; a step of removing a portion of the seed layer, the first resist layer, and the second resist layer; a step of configuring one or more intermediate layers on the upper surface of the Cu layer and the side surface of the Cu layer; and a step of configuring an Au layer on the upper surface of the intermediate layer and the side surface of the intermediate layer.

[0016] A method for manufacturing a ceramic substrate according to an embodiment of the present invention includes: a step of preparing a ceramic substrate according to an embodiment of the present invention; a step of disposing a light-emitting element on the ceramic substrate; a step of disposing a reflective component on the upper surface of the ceramic substrate, wherein in the step of disposing the reflective component, the reflective component is configured to contact the Au layer and the seed layer of the ceramic substrate.

[0017] <The Effects of the Invention>

[0018] According to one embodiment of the present invention, a ceramic substrate and a light-emitting device, which can suppress corrosion of the Cu layer and have excellent reliability in a ceramic substrate having a Cu layer, and a method for manufacturing the same, can be provided. Attached Figure Description

[0019] Figure 1AThis is a schematic cross-sectional view showing an example of the ceramic substrate of the first embodiment.

[0020] Figure 1B This is a schematic top view showing an example of the ceramic substrate of the first embodiment.

[0021] Figure 2 This is a schematic cross-sectional view showing an example of the ceramic substrate of the second embodiment.

[0022] Figure 3 This is a schematic cross-sectional view showing an example of the ceramic substrate of the third embodiment.

[0023] Figure 4A This is a schematic top view showing an example of the ceramic substrate of the fourth embodiment.

[0024] Figure 4B yes Figure 4A A schematic cross-sectional view of the stacking direction of the IVB-IVB lines.

[0025] Figure 4C The ceramic substrate of embodiment 4-1 is in Figure 4B An enlarged cross-section of the IVC region.

[0026] Figure 4D The ceramic substrate of embodiment 4-2 is in Figure 4B An enlarged cross-section of the IVC region.

[0027] Figure 4E This is a schematic bottom view showing an example of the ceramic substrate of the fourth embodiment.

[0028] Figure 5 This is a flowchart illustrating an example of a method for manufacturing a ceramic substrate according to the first embodiment.

[0029] Figure 6A This is a schematic cross-sectional view showing an example of a ceramic plate used in the manufacturing method of the ceramic substrate according to the first embodiment.

[0030] Figure 6B This is a schematic cross-sectional view showing an example of providing a first anti-corrosion layer on the upper surface of a ceramic substrate in the manufacturing method of the ceramic substrate according to the first embodiment.

[0031] Figure 6C This is a schematic cross-sectional view showing an example of exposing and developing the first resist layer in a specified shape during the manufacturing method of the ceramic substrate according to the first embodiment.

[0032] Figure 6D This is a schematic cross-sectional view showing an example of the arrangement of a seed layer in the manufacturing method of the ceramic substrate according to the first embodiment.

[0033] Figure 6EThis is a schematic cross-sectional view showing an example of a method for manufacturing a ceramic substrate according to the first embodiment, in which a second resist layer is provided in such a way as covering a seed layer.

[0034] Figure 6F This is a schematic cross-sectional view showing an example of exposing and developing a second resist layer to a predetermined shape in the manufacturing method of the ceramic substrate according to the first embodiment.

[0035] Figure 6G This is a schematic cross-sectional view showing an example of a Cu layer being disposed in the manufacturing method of the ceramic substrate according to the first embodiment.

[0036] Figure 6H This is a schematic cross-sectional view illustrating an example of removing a portion of the seed layer, the first resist layer, and the second resist layer in the manufacturing method of the ceramic substrate according to the first embodiment.

[0037] Figure 6I This is a schematic cross-sectional view showing an example of an intermediate layer being disposed in the manufacturing method of the ceramic substrate according to the first embodiment.

[0038] Figure 6J This is a schematic cross-sectional view showing an example of an Au layer being disposed in the manufacturing method of the ceramic substrate according to the first embodiment.

[0039] Figure 7 This is a flowchart illustrating an example of a method for manufacturing a ceramic substrate according to the second embodiment.

[0040] Figure 8A This is a schematic cross-sectional view showing an example of the arrangement of the first intermediate layer in the manufacturing method of the ceramic substrate according to the second embodiment.

[0041] Figure 8B This is a schematic cross-sectional view showing an example of the arrangement of the second intermediate layer in the manufacturing method of the ceramic substrate according to the second embodiment.

[0042] Figure 8C This is a schematic cross-sectional view showing an example of an Au layer being disposed in the manufacturing method of the ceramic substrate according to the second embodiment.

[0043] Figure 9 This is a flowchart illustrating an example of a method for manufacturing a ceramic substrate according to the third embodiment.

[0044] Figure 10A This is a schematic cross-sectional view illustrating an example of the method for manufacturing a ceramic substrate according to the third embodiment, in which the first resist layer is exposed and developed into a predetermined shape.

[0045] Figure 10B yes Figure 10A An enlarged cross-section view in region XB.

[0046] Figure 10CThis is a schematic cross-sectional view showing an example of the arrangement of a seed layer in the manufacturing method of the ceramic substrate according to the third embodiment.

[0047] Figure 10D This is a schematic cross-sectional view showing an example of the provision of a second resist layer in the manufacturing method of the ceramic substrate according to the third embodiment.

[0048] Figure 10E This is a schematic cross-sectional view illustrating an example of the process of manufacturing a ceramic substrate according to the third embodiment, in which the second resist layer is exposed and developed into a predetermined shape.

[0049] Figure 10F This is a schematic cross-sectional view showing an example of a Cu layer being disposed in the manufacturing method of the ceramic substrate according to the third embodiment.

[0050] Figure 10G This is a schematic cross-sectional view illustrating an example of removing a portion of the seed layer, the first resist layer, and the second resist layer in the manufacturing method of the ceramic substrate according to the third embodiment.

[0051] Figure 10H This is a schematic cross-sectional view showing an example of the intermediate layer being configured in the manufacturing method of the ceramic substrate according to the third embodiment.

[0052] Figure 10I This is a schematic cross-sectional view showing an example of an Au layer being disposed in the manufacturing method of the ceramic substrate according to the third embodiment.

[0053] Figure 11 This is a flowchart illustrating an example of a method for manufacturing a ceramic substrate according to the fourth embodiment.

[0054] Figure 12A This is a schematic cross-sectional view illustrating an example of the method for manufacturing a ceramic substrate according to the fourth embodiment, in which the first resist layer is exposed and developed into a predetermined shape.

[0055] Figure 12B yes Figure 12A An enlarged cross-section of region XIB.

[0056] Figure 12C This is a schematic cross-sectional view showing an example of the arrangement of a seed layer in the manufacturing method of the ceramic substrate according to the fourth embodiment.

[0057] Figure 12D This is a schematic cross-sectional view showing an example of the arrangement of the second resist layer in the manufacturing method of the ceramic substrate according to the fourth embodiment.

[0058] Figure 12E This is a schematic cross-sectional view illustrating an example of the process of manufacturing a ceramic substrate according to the fourth embodiment, in which the second resist layer is exposed and developed into a predetermined shape.

[0059] Figure 12FThis is a schematic cross-sectional view showing an example of a Cu layer being disposed in the manufacturing method of the ceramic substrate according to the fourth embodiment.

[0060] Figure 12G This is a schematic cross-sectional view showing an example of the method for manufacturing a ceramic substrate according to the fourth embodiment, in which a portion of the seed layer, the first resist layer, and the second resist layer are removed.

[0061] Figure 12H This is a schematic cross-sectional view showing an example of an intermediate layer being configured in the manufacturing method of the ceramic substrate according to the fourth embodiment.

[0062] Figure 12I This is a schematic cross-sectional view showing an example of an Au layer being disposed in the manufacturing method of the ceramic substrate according to the fourth embodiment.

[0063] Figure 13A This is a schematic top view illustrating an example of a light-emitting device according to an embodiment.

[0064] Figure 13B yes Figure 13A A schematic cross-sectional view of the stacking direction of the XIIIB-XIIIB line.

[0065] Figure 13C yes Figure 13B An enlarged cross-section of region XIIIC.

[0066] Figure 13D yes Figure 13C An enlarged cross-sectional view of region XIIID.

[0067] Figure 14 This is a flowchart illustrating an example of a method for manufacturing a light-emitting device according to an embodiment.

[0068] Figure 15A This is an SEM image obtained by magnifying the horizontal planar view of the intermediate ceramic substrate obtained by configuring a Cu layer in the ceramic substrate manufacturing method of the fourth embodiment by magnifying it 50 times from above.

[0069] Figure 15B yes Figure 15A The enlarged cross-sectional image of region XVB in the thickness direction is an SEM image observed by magnifying the cross-sectional image of the intermediate ceramic substrate obtained by configuring a Cu layer in the ceramic substrate manufacturing method of the fourth embodiment by 100 million times.

[0070] Symbol Explanation

[0071] 1. Ceramic slab

[0072] 2. Seed layer

[0073] 2a Edge of the upper surface of the seed layer

[0074] 3 Cu layers

[0075] Edge of the lower surface of the 3b Cu layer

[0076] 4. Intermediate layer

[0077] 4b The edge of the lower surface of the intermediate layer

[0078] 4-1 First Intermediate Layer

[0079] 4-2 Second Intermediate Layer

[0080] 5 Au layers

[0081] Edge of the lower surface of the 5b Au layer

[0082] 10 regions

[0083] 11. Solder pad section

[0084] 11A Pad Section

[0085] 11B pad section

[0086] 13 Heat dissipation section

[0087] 12 slots or holes

[0088] 14 Identification Markers

[0089] 20 Light-emitting elements

[0090] 30 Light-transmitting components

[0091] 40 reflective components

[0092] 50 First Anti-corrosion Layer

[0093] 51 Second Anti-corrosion Layer

[0094] 41 Frame

[0095] 42 protective components

[0096] 60 joint components

[0097] L1 Length of the lower surface of the first anti-corrosion layer

[0098] L2 Length of the upper surface of the first anti-corrosion layer

[0099] S1 Space

[0100] S2 Space

[0101] 100 ceramic substrate

[0102] 200 light-emitting devices Detailed Implementation

[0103] The ceramic substrate and light-emitting device of the present invention, and the manufacturing method thereof, are described in detail with reference to the accompanying drawings. However, the embodiments shown below are merely examples of ceramic substrates, light-emitting devices, and manufacturing methods thereof to embody the technical concept of the present invention, and the present invention is not limited thereto.

[0104] Furthermore, unless otherwise specified, the dimensions, materials, shapes, and relative arrangements of the constituent parts described in the embodiments are not intended to limit the scope of the invention, but are merely illustrative examples. Additionally, for clarity, the size and positional relationships of components shown in the accompanying drawings are sometimes exaggerated. Furthermore, in the following description, the same names and symbols denote the same or homogeneous components, and detailed descriptions are appropriately omitted. To avoid making the drawings overly complex, sometimes schematic diagrams with some elements omitted, or end views showing only cross-sections, are used as cross-sectional views.

[0105] Furthermore, in this disclosure, unless otherwise specified, polygons such as rectangles are also referred to as polygons, including shapes in which the corners of the polygon have been processed by chamfering, beveling, rounding, or other similar processes. Moreover, shapes processed in the middle portion of the sides, not limited to the corners (i.e., the ends of the sides), are also referred to as polygons. That is, shapes that have undergone localized processing while retaining the polygonal form are also included in the interpretation of "polygon" as used in this invention.

[0106] Furthermore, this interpretation applies not only to polygons, but also to terms describing specific shapes such as trapezoids, circles, and concave / convex shapes. The same applies to terms describing the sides that form the shape. That is, even if a corner or middle portion of a side is processed, the interpretation of "side" includes the processed portion. Additionally, when it is necessary to distinguish between unprocessed "polygons" and "sides," and processed shapes, the term "in a strict sense" is added, for example, it is written as "quadrilateral in a strict sense," etc.

[0107] Furthermore, in the following description, terms indicating specific directions or positions (e.g., "upper," "lower," "side," "upper surface," "lower surface," "side," "X," "Y," "Z," and other terms incorporating these terms) are used as needed. However, the use of these terms is for the purpose of facilitating understanding of the invention with reference to the accompanying drawings and does not imply an undue limitation of the technical scope of the invention based on the meaning of these terms. For example, the use of "upper surface" does not imply that the invention must always be used with the surface facing upwards. Additionally, regarding embodiments, "covering" is not limited to direct contact, but also includes indirect coverage, such as through other components.

[0108] In addition, in this specification or claims, when there are multiple constituent elements and they are distinguished separately, "first", "second", etc., may be added at the beginning of the constituent element to distinguish them.

[0109] (Ceramic substrate)

[0110] <First Implementation>

[0111] Figure 1A This is a schematic cross-sectional view showing an example of the ceramic substrate of the first embodiment. Figure 1B This is a schematic top view showing an example of the ceramic substrate of the first embodiment. Hereinafter, the structure of the ceramic substrate 100 will be described.

[0112] The ceramic substrate 100 of the first embodiment includes a ceramic plate 1, a seed layer 2 disposed on the upper surface of the ceramic plate 1, a Cu layer 3 disposed on the upper surface of the seed layer 2, an intermediate layer 4 disposed on the upper surface and side surface of the Cu layer 3, and an Au layer 5 disposed on the upper surface and side surface of the intermediate layer 4. The upper surface of the seed layer 2 is in contact with the lower surface of the intermediate layer 4, while the upper surface of the ceramic plate 1 is not in contact with the lower surface of the Au layer 5. In the horizontal direction, the edge 2a of the upper surface of the seed layer 2 is located further outward than the edge 3b of the lower surface of the Cu layer 3. The ceramic substrate 100 of the first embodiment may also have other structures as needed.

[0113] The stacking direction of the ceramic plate 1, seed layer 2, Cu layer 3, intermediate layer 4, and Au layer 5 is defined as the Z-axis. The axis perpendicular to the Z-axis is defined as the X-axis. The axis perpendicular to both the Z-axis and the X-axis is defined as the Y-axis. The X, Y, and Z axes are mutually perpendicular. The horizontal direction of the ceramic plate 1 can be any direction perpendicular to the Z-axis, which is the stacking direction; it can be either the X-axis or the Y-axis. In this specification, the XY plane is defined as the horizontal plane of the ceramic substrate 100, and both the X-axis and Y-axis are horizontal directions of the ceramic substrate 100.

[0114] In the ceramic substrate 100, the region where the seed layer 2, Cu layer 3, intermediate layer 4, and Au layer 5 are stacked is designated as region 10. That is, the upper surface of the ceramic substrate 100 is exposed in the region other than region 10. When the ceramic substrate 100 is used as a light-emitting device, the light-emitting element is preferably disposed on region 10.

[0115] There are no particular restrictions on the planar shape of region 10 in ceramic substrate 100, but when ceramic substrate 100 is used in a light-emitting device, it is preferable to have a shape that corresponds to the electrode shape, layout, etc. of the light-emitting element.

[0116] (Ceramic Plate 1)

[0117] The ceramic plate 1 serves as an insulating component, acting as a base for arranging the seed layer 2, Cu layer 3, intermediate layer 4, and Au layer 5. The ceramic plate 1 is preferably in a sintered state, rather than in a softened state before sintering.

[0118] There are no particular limitations on the planar shape of the ceramic plate 1 in the horizontal direction. It can be a circle, an ellipse, a quadrilateral, a hexagon, or other polygons with rounded corners, or a combination of these shapes. Among these, a quadrilateral is preferred, and a rectangle is more preferred. The planar shape and size of the ceramic plate 1 can be appropriately adjusted according to the required performance based on the size and quantity of the Cu layer 3 and other materials disposed thereon.

[0119] The upper surface of the ceramic plate 1 may or may not be planar, but a planar surface is preferred in order to allow for the appropriate configuration of the light-emitting element when the ceramic substrate 100 is used in a light-emitting device.

[0120] The lower surface of the ceramic plate 1 is the side opposite to the upper surface of the ceramic plate 1 where the Cu layer 3 is disposed. The lower surface of the ceramic plate 1 may or may not be planar, but a planar surface is preferred so that the ceramic substrate 100 can be properly disposed on a mounting substrate when it is used in a light-emitting device.

[0121] The upper and lower surfaces of ceramic plate 1 are, for example, parallel. Here, when describing the surfaces of ceramic plate 1 as "parallel," a difference within ±5 degrees is allowed.

[0122] As for the material of the ceramic plate 1, any insulating material is acceptable and there are no particular restrictions, but it is preferable to use a material that does not easily allow light from the light-emitting element or from the outside to pass through when the ceramic substrate 100 is used in a light-emitting device. Examples of such materials for the ceramic plate 1 include nitride ceramics such as aluminum nitride, silicon nitride, and boron nitride; oxide ceramics such as alumina, silicon oxide, calcium oxide, and magnesium oxide; silicon carbide; mullite; and borosilicate glass. One of these materials may be used alone, or two or more may be used in combination.

[0123] The ceramic plate 1 preferably contains these insulating materials as the main material, and may also include other auxiliary materials as needed. Here, "main material" means the material with the largest mass among the materials constituting the ceramic plate 1.

[0124] There are no particular restrictions on the secondary material used in ceramic plate 1; for example, glass can be used.

[0125] There are no particular limitations on the average thickness of the ceramic plate 1, but it is preferably 100 μm to 1000 μm, and more preferably 120 μm to 500 μm.

[0126] In addition, the average thickness of ceramic plate 1 is measured at two arbitrarily selected points from the corner of ceramic plate 1, and the average value of the two points is calculated. A macrometer is used to measure the thickness at the corner of ceramic plate 1.

[0127] (Seed layer 2)

[0128] The seed layer 2 is disposed on the upper surface of the ceramic plate 1.

[0129] In the seed layer 2, in the horizontal direction, the edge 2a of the upper surface of the seed layer 2 is located further outward than the edge 3b of the lower surface of the Cu layer 3. Preferably, the edge 2a of the upper surface of the seed layer 2 is disposed 1 μm or more but less than 5 μm outside the edge 3b of the lower surface of the Cu layer 3, more preferably 1.2 μm or more but less than 3 μm outside. The region inside the edge 3b of the lower surface of the Cu layer 3 is defined as the inner side of the edge 3b of the lower surface of the Cu layer 3, and the region outside the edge 3b of the lower surface of the Cu layer 3 is defined as the outer side of the edge 3b of the lower surface of the Cu layer 3. In the horizontal direction, when the edge 2a of the upper surface of the seed layer 2 is located further outward than the edge 3b of the lower surface of the Cu layer 3, corrosion of the lower surface of the Cu layer 3 can be suppressed, and a ceramic substrate 100 with excellent reliability can be obtained.

[0130] Furthermore, in the seed layer 2, in the horizontal direction, it is preferable that the edge 2a of the upper surface of the seed layer 2 is located further inward than the edge 5b of the lower surface of the Au layer 5. Specifically, in the horizontal direction, it is preferable that the edge 2a of the upper surface of the seed layer 2 is disposed 1.0 μm or more and 5.0 μm or less inward of the edge 5b of the lower surface of the Au layer 5, more preferably disposed 1.2 μm or more and 3 μm or less inward. Additionally, the inner region surrounded by the edge 5b of the lower surface of the Au layer 5 is defined as the inner side of the edge 5b of the lower surface of the Au layer 5, and the outer region surrounded by the edge 5b of the lower surface of the Au layer 5 is defined as the outer side of the edge 5b of the lower surface of the Au layer 5. In the horizontal direction, when the edge 2a of the upper surface of the seed layer 2 is located inward of the edge 5b of the lower surface of the Au layer 5, corrosion of the lower surface of the Cu layer 3 can be appropriately suppressed, resulting in a ceramic substrate 100 with excellent reliability.

[0131] Furthermore, the side surface of the seed layer 2 is preferably exposed from the Au layer 5. The side surface of the seed layer 2 refers to the surface that connects to the upper and lower surfaces of the seed layer 2 when the ceramic substrate 100 is viewed in cross-section.

[0132] In the ceramic substrate 100 of the first embodiment, the lower surface of the intermediate layer 4 is in contact with the upper surface of the seed layer 2. Therefore, when viewed in a horizontal plane, the edge 2a of the upper surface of the seed layer 2 coincides with the edge 4b ​​of the lower surface of the intermediate layer 4, but is not limited thereto.

[0133] For example, only a portion of the lower surface of the intermediate layer 4 may contact the upper surface of the seed layer 2, while another portion of the lower surface of the intermediate layer 4 may not contact the upper surface of the seed layer 2, but this other portion of the lower surface of the intermediate layer 4 may be covered by the Au layer 5. In this case, when viewed along a horizontal plane, the edge 2a of the upper surface of the seed layer 2 is positioned inside the edge 4b ​​of the lower surface of the intermediate layer 4. That is, the edge 2a of the upper surface of the seed layer 2 is located outside the edge 3b of the lower surface of the Cu layer 3 and inside the edge 4b ​​of the lower surface of the intermediate layer 4. Furthermore, the inner region surrounded by the edge 4b ​​of the lower surface of the intermediate layer 4 is defined as the inner side of the edge 4b ​​of the lower surface of the intermediate layer 4, and the outer region surrounded by the edge 4b ​​of the lower surface of the intermediate layer 4 is defined as the outer side of the edge 4b ​​of the lower surface of the intermediate layer 4.

[0134] Alternatively, for example, the entire lower surface of the intermediate layer 4 and the entire lower surface of the Au layer 5 may be in contact with the upper surface of the seed layer 2. In this case, when viewed along a horizontal plane, the edge 2a of the upper surface of the seed layer 2 coincides with the edge 5b of the lower surface of the Au layer 5, or the edge 2a of the upper surface of the seed layer 2 is located further outward than the edge 5b of the lower surface of the Au layer 5.

[0135] Furthermore, for example, if the entire lower surface of the intermediate layer 4 and a portion of the lower surface of the Au layer 5 are in contact with the upper surface of the seed layer 2, then another portion of the lower surface of the Au layer 5 may not be in contact with the upper surface of the seed layer 2. In this case, when viewed in a horizontal plane, the edge 2a of the upper surface of the seed layer 2 is positioned further outward than the edge 4b ​​of the lower surface of the intermediate layer 4 and further inward than the edge 5b of the lower surface of the Au layer 5. That is, the edge 2a of the upper surface of the seed layer 2 is positioned further outward than the edge 3b of the lower surface of the Cu layer 3, further outward than the edge 4b ​​of the lower surface of the intermediate layer 4, and further inward than the edge 4b ​​of the lower surface of the intermediate layer 4.

[0136] As for the planar shape and size of the seed layer 2 along the horizontal direction, there are no particular restrictions as long as the edge 2a of the upper surface of the seed layer 2 is located further outward than the edge 3b of the lower surface of the Cu layer 3. When the ceramic substrate 100 is used as a light-emitting device, it can be appropriately adjusted according to the shape, size and number of light-emitting elements arranged on the region 10.

[0137] While there are no particular limitations on the material used as the seed layer 2, a conductive material is preferred, such as Ti, Cu, Au, Ru, TiNi, TiW, CuNi, and NiCr. One of these materials can be used alone, or two or more can be used in combination. Preferably, the seed layer 2 is selected from one or more materials chosen from the group consisting of Ti layers, Cu layers, Au layers, Ru layers, TiNi layers, TiW layers, CuNi layers, and NiCr layers. More preferably, it is selected from any one of the groups consisting of Ti layers and Cu layers, Ti layers and Au layers, Ti layers and TiNi layers, Ti layers and TiW layers, Ti layers and TiW layers and Cu layers, Ti layers and Ru layers and Cu layers, TiW layers, CuNi layers, and NiCr layers. By using these materials as the seed layer 2, the adhesion to the Cu layer 3 is better, thereby suppressing corrosion of the Cu layer 3 and improving reliability.

[0138] The average thickness of the seed layer 2 is not particularly limited, but is preferably 0.1 μm or more and 2.0 μm or less, more preferably 0.3 μm or more and 1 μm or less. When the average thickness of the seed layer 2 is 0.1 μm or more and 2.0 μm or less, the lower surface of the intermediate layer 4 and the lower surface of the Au layer 5 can be prevented from contacting the ceramic plate 1. Therefore, no gaps are formed around the Cu layer 3, thereby suppressing the corrosion of the Cu layer 3 and obtaining a ceramic substrate 100 with excellent reliability.

[0139] In addition, the average thickness of the seed layer 2 is determined by taking a cross-section of the region containing the seed layer 2 of the ceramic substrate 100 in the Z-axis direction using a scanning electron microscope (SEM), and measuring the thickness of the seed layer 2 at three randomly selected locations in the field of view of the SEM image (for example, one location selected in the center and two locations selected at the ends), and calculating the average value of the three locations.

[0140] (Cu layer 3)

[0141] Cu layer 3 is disposed on the upper surface of seed layer 2. The lower surface of Cu layer 3 is covered by seed layer 2, and the sides and upper surface of Cu layer 3 are covered by intermediate layer 4. Since the upper surface of seed layer 2 is in contact with intermediate layer 4, Cu layer 3 is entirely covered by seed layer 2 and intermediate layer 4. Therefore, Cu layer 3 is not affected by external environment such as air, and corrosion can be suppressed, thereby obtaining a ceramic substrate 100 with excellent reliability.

[0142] There are no particular limitations on the planar shape of the Cu layer 3 in the horizontal direction. It can take various shapes, such as circles, ellipses, quadrilaterals, hexagons, polygons, polygons with rounded corners, or combinations of these shapes. The planar shape and size of the Cu layer 3 can be appropriately adjusted according to the shape, size, and number of light-emitting elements disposed on region 10 when the ceramic substrate 100 is used in a light-emitting device.

[0143] There are no particular limitations on the average thickness of Cu layer 3, but it is preferably 10 μm or more and 60 μm or less, and more preferably 15 μm or more and 30 μm or less.

[0144] In addition, the average thickness of Cu layer 3 is determined by taking a cross-section of the region containing Cu layer 3 of the ceramic substrate 100 in the Z-axis direction using a scanning electron microscope (SEM), and measuring the thickness of Cu layer 3 at three randomly selected locations in the field of view of the SEM image (for example, one location in the center and two locations at the ends), and calculating the average value of the three locations.

[0145] (Middle layer 4)

[0146] An intermediate layer 4 is disposed on the upper surface and side surface of the Cu layer 3. In the ceramic substrate 100 of the first embodiment, the intermediate layer 4 is a single layer. The upper surface of the seed layer 2 is in contact with the intermediate layer 4. The intermediate layer 4 can improve the adhesion between the Cu layer 3 and the Au layer 5.

[0147] The planar shape and size of the intermediate layer 4 in the horizontal direction can be appropriately adjusted according to the planar shape and size of the Cu layer 3.

[0148] There are no particular limitations on the material used for the intermediate layer 4, but a conductive material is preferred, such as Ti, Ni, Pd, Pt, Rh, W, Ru, etc. One material can be used alone, or two or more materials can be used in combination. Among these, Ni and Pd are preferred materials for the intermediate layer 4. When the intermediate layer 4 is fabricated by electroless electroplating, Ni, NiP, NiB, Pd, etc., are preferred.

[0149] There is no particular limitation on the average thickness of the intermediate layer 4, but it is preferably 0.03 μm or more and 1 μm or less, more preferably 0.05 μm or more and 0.1 μm or less.

[0150] In addition, the average thickness of the intermediate layer 4 is determined by taking a cross-section of the region containing the intermediate layer 4 of the ceramic substrate 100 using a scanning electron microscope (SEM), measuring the thickness of the intermediate layer 4 at three randomly selected locations in the field of view of the SEM image (e.g., one location selected in the center and two locations selected at the ends), and calculating the average value of the three locations.

[0151] (Au layer 5)

[0152] Au layer 5 is disposed on the upper surface and sides of intermediate layer 4. The upper surface of ceramic plate 1 does not contact Au layer 5. Au layer 5 is the outermost layer in region 10.

[0153] By setting the outermost surface of region 10 as an Au layer 5, the reliability of the connection with the light-emitting element can be improved when the ceramic substrate 100 is used as a light-emitting device. Typically, gold is used as the electrode of the light-emitting element. The connection reliability between the Au layer 5 in region 10 and the Au that serves as the electrode of the light-emitting element is high, so even if a high voltage is provided, it will not cause degradation and can maintain a highly reliable connection for a long time.

[0154] The planar shape and size of Au layer 5 in the horizontal direction can be appropriately adjusted according to the planar shape and size of Cu layer 3 and intermediate layer 4.

[0155] There are no particular limitations on the average thickness of the Au layer 5, but it is preferably 0.03 μm or more and 1 μm or less, and more preferably 0.05 μm or more and 0.1 μm or less.

[0156] In addition, the average thickness of the Au layer 5 is determined by taking a cross-section of the region containing the Au layer 5 of the ceramic substrate 100 in the Z-axis direction using a scanning electron microscope (SEM), and measuring the thickness of the Au layer 5 at three randomly selected locations in the field of view of the SEM image (e.g., one location selected in the center and two locations selected at the ends), and calculating the average value of the three locations.

[0157] (Other structures)

[0158] Other structures of the ceramic substrate 100 include wiring components and heat dissipation components that are different from those in region 10 and the pad component 11 described later.

[0159] When the ceramic substrate 100 is used as a light-emitting device, a wiring section for electrically connecting to the light-emitting elements may be provided, depending on the number of light-emitting elements to be installed between the multiple regions 10. For example, one or more relay wiring sections may be arranged between a pair of regions 10. Regarding the shape and arrangement of the wiring section arranged between the pair of regions 10, it may be configured to drive multiple light-emitting elements independently, or it may be configured to drive them by implementing series, parallel, or a combination thereof, depending on the shape of the pair of regions 10, their power supply control, etc.

[0160] The ceramic substrate 100 may have a heat dissipation portion on its lower surface. The heat dissipation portion is preferably configured to overlap with the area directly below the region 10 where the light-emitting element is disposed when viewed in a horizontal plane. Preferably, the heat dissipation portion has a larger area in its plan view. There are no particular limitations on the shape, structure, or size of the heat dissipation portion; it can be appropriately selected according to the purpose. The heat dissipation portion can use the same metal material as region 10.

[0161] <Second Implementation Method>

[0162] Figure 2 This is a schematic cross-sectional view showing an example of the ceramic substrate of the second embodiment. The ceramic substrate 100 of the second embodiment has the same structure as the ceramic substrate 100 of the first embodiment, except that the intermediate layer 4 is composed of two layers: a first intermediate layer 4-1 and a second intermediate layer 4-2.

[0163] The first intermediate layer 4-1 and the second intermediate layer 4-2 are each made of different materials. Ni is preferably used as the material for the first intermediate layer 4-1. Pd is preferably used as the material for the second intermediate layer 4-2.

[0164] In the ceramic substrate 100 of the second embodiment, a Ni layer as a first intermediate layer 4-1 is disposed on the upper surface and side surface of the Cu layer 3, a Pd layer as a second intermediate layer 4-2 is disposed on the upper surface and side surface of the Ni layer as the first intermediate layer 4-1, and an Au layer 5 is disposed on the upper surface and side surface of the Pd layer as the second intermediate layer 4-2.

[0165] Here, the entire lower surface of the first intermediate layer 4-1 and the entire lower surface of the second intermediate layer 4-2 are in contact with the upper surface of the seed layer 2, but this is not limited to this. For example, only the entire lower surface of the first intermediate layer 4-1 may be in contact with the upper surface of the seed layer 2, while the lower surface of the second intermediate layer 4-2 may not be in contact with the upper surface of the seed layer 2; the entire lower surface of the first intermediate layer 4-1 and a portion of the lower surface of the second intermediate layer 4-2 may be in contact with the upper surface of the seed layer 2; or only a portion of the lower surface of the first intermediate layer 4-1 may be in contact with the upper surface of the seed layer 2, while the other portion of the lower surface of the first intermediate layer 4-1 and the entire lower surface of the second intermediate layer 4-2 may not be in contact with the upper surface of the seed layer 2.

[0166] Furthermore, in the ceramic substrate 100 of the second embodiment, the case where the intermediate layer 4 has two layers is described. In the ceramic substrate 100 of the present invention, the intermediate layer 4 may also have three or more layers. There are no particular limitations on the material of each intermediate layer 4 in the case of three or more layers, and it can be appropriately selected according to the purpose.

[0167] <Third Implementation Method>

[0168] Figure 3 This is a schematic cross-sectional view showing an example of the ceramic substrate of the third embodiment. The ceramic substrate 100 of the third embodiment has the same structure as the ceramic substrate 100 of the first embodiment, except that the cross-sectional view of the seed layer 2 is different.

[0169] In the ceramic substrate 100 of the third embodiment, a seed layer 2 is continuously disposed on a portion of the side surface of the Cu layer 3 from the lower surface of the Cu layer 3, and the intermediate layer 4 is configured to cover the seed layer 2 disposed on a portion of the side surface of the Cu layer 3.

[0170] Here, "continuously arranged" seed layer 2 means that seed layer 2 is arranged not only in the horizontal direction of the XY plane, but also without interruption in the Z-axis direction, which is the stacking direction. As a result, compared with the ceramic substrate 100 of the first embodiment, no boundary is formed between the lower surface of the intermediate layer 4 and the upper surface of the seed layer 2 on the lower surface of the Cu layer 3, which can more reliably prevent the Cu layer 3 from contacting the external environment such as air, and can better suppress corrosion, thereby obtaining a ceramic substrate 100 with excellent reliability.

[0171] <Fourth Implementation>

[0172] Figure 4A This is a schematic top view showing an example of the ceramic substrate of the fourth embodiment. The ceramic substrate 100 of the fourth embodiment has the same structure as the ceramic substrate 100 of the first embodiment, except that it has a pad portion 11 electrically connected to the Au layer 5.

[0173] (Pad Section 11)

[0174] As for the layer structure of the pad portion 11, there are no particular limitations as long as it can be electrically connected to the Au layer 5 in region 10, and it can be appropriately selected according to the purpose. Hereinafter, as an example of the pad portion 11, the pad portion 11A of the ceramic substrate 100 in the 4-1 embodiment and the pad portion 11B of the ceramic substrate 100 in the 4-2 embodiment will be described. In a ceramic substrate 100, only one of the pad portion 11A and the pad portion 11B may be provided, or both may be provided in a divided region.

[0175] While there are no particular limitations on the planar shape of the pad portion 11 in the horizontal direction, it is preferable that it extends from region 10 to near the end of the ceramic substrate 100. By increasing the total area of ​​region 10 and pad portion 11, when the ceramic substrate 100 is used in a light-emitting device, a light-emitting device with easy current flow and low resistance can be obtained. Here, "near the end of the ceramic substrate 100" refers to a distance from the outer edge of the ceramic plate 1 on the surface where region 10 and pad portion 11 are disposed to region 10 or pad portion 11 that is 0.01 mm or more and 0.5 mm or less.

[0176] Furthermore, by arranging region 10 and pad portion 11 near the end of ceramic substrate 100, the connection length of the power supply component used to supply power to the external connection portion can be shortened, thereby enabling reliable and easy power supply. This power supply component, such as a wire, can be used. Preferably, the horizontal planar shape of pad portion 11 is such that, within a ceramic substrate 100 with a generally rectangular horizontal planar shape, the positive and negative pairs of external connection portions extend towards one side of the rectangle. This allows power supply components from the outside to be connected from the same direction and with the same length in both the positive and negative external connection portions.

[0177] <<Implementation Method 4-1>>

[0178] Figure 4B yes Figure 4A A schematic cross-sectional view of the stacking direction of the IVB-IVB lines. Figure 4C The ceramic substrate of embodiment 4-1 Figure 4B An enlarged cross-sectional view of the IVC region shown.

[0179] The pad portion 11A in the ceramic substrate 100 of the fourth-1 embodiment includes a ceramic plate 1, a seed layer 2 disposed on the upper surface of the ceramic plate 1, an intermediate layer 4 disposed on the upper surface of the seed layer 2, and an Au layer 5 disposed on the upper surface of the intermediate layer 4. The pad portion 11A preferably does not include a Cu layer 3. This reduces the thickness of the pad portion 11A. When the ceramic substrate 100 is used in a light-emitting device, by disposing of the Cu layer 3 only in the region 10 where the light-emitting element is disposed, the heat dissipation of the light-emitting element can be improved.

[0180] <<Implementation Method 4-2>>

[0181] Figure 4D The ceramic substrate of embodiment 4-2 Figure 4B An enlarged cross-sectional view of the IVC region shown.

[0182] The pad portion 11B in the ceramic substrate 100 of the fourth-second embodiment includes a ceramic plate 1, a seed layer 2 disposed on the upper surface of the ceramic plate 1, and an Al layer 6 disposed on the upper surface of the seed layer 2. The pad portion 11B preferably does not include a Cu layer 3. This reduces the thickness of the pad portion 11B. When the ceramic substrate 100 is used in a light-emitting device, by disposing of the Cu layer 3 only in the region 10 where the light-emitting element is disposed, the heat dissipation of the light-emitting element can be improved. Furthermore, when Al is used in the conductive wires, the same material as the surface of the pad portion 11B can be used, thereby preventing breakage or wire breakage between the solder wire and the pad portion 11B.

[0183] (Heat dissipation section 13)

[0184] Figure 4E This is a schematic bottom view showing an example of the ceramic substrate of the fourth embodiment. The heat dissipation part 13, for example, can be shaped by cutting a rectangular pattern into multiple comb-like shapes and assembling them.

[0185] [Manufacturing method of ceramic substrate]

[0186] <First Implementation>

[0187] Figure 5 This is a flowchart illustrating an example of a method for manufacturing a ceramic substrate according to the first embodiment. (Refer to...) Figures 6A to 6J The method for manufacturing the ceramic substrate according to the first embodiment will be described.

[0188] The method for manufacturing a ceramic substrate according to the first embodiment includes: a step of providing a first resist layer on the upper surface of a ceramic plate and exposing and developing the first resist layer into a predetermined shape; a step of configuring a seed layer on the upper surface of the ceramic plate exposed from the first resist layer after exposure and development, the side surface of the first resist layer, and the upper surface of the first resist layer; a step of providing a second resist layer to cover at least a portion of the upper surface of the seed layer and exposing and developing the second resist layer into a predetermined shape to expose at least a portion of the upper surface of the seed layer configured on the upper surface of the ceramic plate; a step of configuring a Cu layer on the upper surface of the seed layer exposed from the second resist layer after exposure and development by electrolytic plating; a step of removing a portion of the seed layer, the first resist layer, and the second resist layer; a step of configuring one or more intermediate layers on the upper surface of the Cu layer and the side surface of the Cu layer; and a step of configuring an Au layer on the upper surface of the intermediate layer and the side surface of the intermediate layer.

[0189] (S1) Step of exposing and developing the first resist layer into a specified shape

[0190] Figure 6AThis is a schematic cross-sectional view showing an example of a ceramic plate used in the manufacturing method of the ceramic substrate according to the first embodiment. Figure 6B This is a schematic cross-sectional view showing an example of the provision of a first resist layer in the manufacturing method of the ceramic substrate according to the first embodiment. Figure 6C This is a schematic cross-sectional view illustrating an example of the process of manufacturing a ceramic substrate according to the first embodiment, in which the first resist layer is exposed and developed into a predetermined shape.

[0191] In step S1, where the first resist layer is exposed and developed into a specified shape, the first resist layer 50 is provided on the upper surface of the ceramic plate 1, and the first resist layer 50 is exposed and developed into a specified shape.

[0192] Specifically, in step S1, which involves exposing and developing the first resist layer into a predetermined shape, a ceramic plate 1 is first prepared. The ceramic plate 1 can be a ceramic precursor before sintering or a sintered ceramic. From the perspective of avoiding dimensional changes caused by sintering, a sintered ceramic is preferred.

[0193] Next, a first anti-corrosion layer 50 is provided on the upper surface of the ceramic plate 1. At this time, the first anti-corrosion layer 50 can be provided on the entire upper surface of the ceramic plate 1, or it can be provided on a portion of the upper surface of the ceramic plate 1. Regarding the location of the first anti-corrosion layer 50 on the upper surface of the ceramic plate 1, it can be appropriately selected according to the desired location of the setting area 10.

[0194] There are no particular limitations on the first resist layer 50, and it can be formed using photoresist compositions commonly used in the field of light-emitting element technology, sheet photoresist (dry film photoresist), etc. Specifically, the first resist layer 50 can be a photoresist composition made of various materials classified as phenolic-diazonaphthoquinone (DNQ) photoresist, positive photoresist, negative photoresist, chemically amplified photoresist, photocrosslinked photoresist, photopolymerized photoresist, etc., or a dry film photoresist made of these photoresist compositions. Any commercially available product can be used for these photoresist compositions or dry film photoresist. It is preferable to use a negative photoresist to form the first resist layer 50.

[0195] Methods for forming the first resist layer 50 using a photoresist composition include, for example, screen coating, spin coating, roller coating, lamination, dip coating, and spray coating.

[0196] Next, the first resist layer 50 can be formed into a predetermined shape using, for example, photolithography and etching. When using a negative photoresist, for example, the first resist layer 50 is exposed using a mask with an opening having a desired shape corresponding to region 10.

[0197] There are no particular restrictions on the exposure level, but it is preferable to set it appropriately within the range of 10mJ to 50mJ. Baking can be performed at any temperature and for any time before and after exposure.

[0198] Then, by using a developer solution that can dissolve the photoresist present in the non-exposed portion of the first resist layer 50, the first resist layer 50 is formed into a pattern of a predetermined shape.

[0199] The developer used here can be selected appropriately depending on the type of photoresist used. For example, tetramethylammonium hydroxide (TMAH) and tetrabutylammonium hydroxide (TBAH) can be cited.

[0200] (S2) Steps for configuring the seed layer

[0201] Figure 6D This is a schematic cross-sectional view showing an example of the arrangement of a seed layer in the manufacturing method of the ceramic substrate according to the first embodiment.

[0202] In S2, a seed layer 2 is disposed on the upper surface of the ceramic plate 1 exposed from the first resist layer 50 after exposure and development, the side surface of the first resist layer 50, and the upper surface of the first resist layer 50.

[0203] The seed layer 2 can be formed by known methods in the art, such as electrolytic plating, non-electrolytic plating, vapor deposition, sputtering, etc., using the material of the seed layer 2.

[0204] The average thickness of the seed layer 2 can be adjusted by the amount of material supplied to the seed layer 2. In the configuration of the seed layer S2, the seed layer 2 is preferably configured to have a thickness of 1.0 μm or more and 5.0 μm or less, and more preferably to have a thickness of 1.2 μm or more and 3.0 μm or less.

[0205] (S3) Step of exposing and developing the second resist layer into the specified shape

[0206] Figure 6E This is a schematic cross-sectional view showing an example of the provision of a second resist layer in the manufacturing method of the ceramic substrate according to the first embodiment. Figure 6F This is a schematic cross-sectional view illustrating an example of the process of manufacturing a ceramic substrate according to the first embodiment, in which the second resist layer is exposed and developed into a predetermined shape.

[0207] In step S3, where the second resist layer is exposed and developed into a predetermined shape, the second resist layer 51 is provided in such a way that it covers at least a portion of the upper surface of the seed layer 2, and the second resist layer 51 is exposed and developed into a predetermined shape in such a way that at least a portion of the upper surface of the seed layer 2 disposed on the upper surface of the ceramic plate 1 is exposed.

[0208] Regarding the location of the second resist layer 51, it can be appropriately selected on the upper surface of the seed layer 2 according to the desired location of the setting area 10. However, it is preferable to set the second resist layer 51 at a location where the first resist layer 50 can be removed at least simultaneously when the second resist layer 51 is removed.

[0209] There are no particular limitations on the second resist layer 51, and it can be formed using photoresist compositions commonly used in the field of light-emitting element technology. For example, the same photoresist composition as the first resist layer 50 can be used. Preferably, a negative photoresist is used to form the second resist layer 51.

[0210] Methods for forming the second resist layer 51 using a photoresist composition include, for example, screen coating, spin coating, roller coating, lamination, dip coating, spray coating, etc.

[0211] Next, the second resist layer 51 can be formed into a predetermined shape using photolithography and etching methods, for example. When using a negative photoresist, the second resist layer 51 is exposed using a mask with an opening having a desired shape corresponding to region 10. For example, in S5, when a mask is provided such that the second resist layer 51 is formed on the seed layer 2 disposed on the first resist layer 50, a portion of the seed layer, the first resist layer, and the second resist layer (described later) are removed, the seed layer 2 between the first resist layer 50 and the second resist layer 51, as well as between the first resist layer 50 and the second resist layer 51, can be removed simultaneously.

[0212] There are no particular restrictions on the exposure level, but it is preferable to set it appropriately within the range of 10mJ to 50mJ. Baking can be performed at any temperature and for any time before and after exposure.

[0213] Then, by using a developer solution that can dissolve the photoresist present in the non-exposed portion of the second resist layer 51, the second resist layer 51 is formed into a pattern of a predetermined shape.

[0214] The developer used here can be selected appropriately depending on the type of photoresist used. For example, tetramethylammonium hydroxide (TMAH) and tetrabutylammonium hydroxide (TBAH) can be cited.

[0215] In the method for manufacturing a ceramic substrate according to the first embodiment, in step S3, which involves exposing and developing the second resist layer into a predetermined shape, it is preferable to perform the exposure and development in such a manner that the seed layer 2 disposed on the side surface and the upper surface of the first resist layer 50 is not exposed, while at least a portion of the upper surface of the seed layer 2 disposed on the upper surface of the ceramic substrate 1 is exposed from the second resist layer 51. That is, it is preferable to remove the second resist layer 51 between adjacent first resist layers 50.

[0216] (S4) Steps for configuring the Cu layer

[0217] Figure 6G This is a schematic cross-sectional view showing an example of a Cu layer being disposed in the manufacturing method of the ceramic substrate according to the first embodiment.

[0218] In step S4, the Cu layer is deposited by electroplating on the upper surface of the seed layer 2, which is exposed from the second resist layer 51 after exposure and development. The average thickness of the Cu layer 3 can be adjusted by the amount of Cu-containing electroplating solution provided. Here, the seed layer 2 is not deposited on the side of the Cu layer 3.

[0219] The electroplating solution may contain, for example, Cu particles and solvents, and may also contain resins as needed. The electroplating solution is bonded to the seed layer 2.

[0220] (S5) Step of removing a portion of the seed layer, the first resist layer, and the second resist layer.

[0221] Figure 6H This is a schematic cross-sectional view illustrating an example of removing a portion of the seed layer, the first resist layer, and the second resist layer in the manufacturing method of the ceramic substrate according to the first embodiment.

[0222] In step S5, which removes a portion of the seed layer, the first resist layer, and the second resist layer, it is preferable to completely remove the first resist layer 50 and the second resist layer 51. A portion of the seed layer 2 can be, for example, the seed layer 2 between the first resist layer 50 and the second resist layer 51, or the seed layer 2 disposed on the side of the first resist layer 50. This forms a stacked structure of a ceramic plate 1, a seed layer 2, and a Cu layer 3 having a predetermined shape.

[0223] For example, a portion of the seed layer 2, the first resist layer 50, and the second resist layer 51 can be removed using a stripping method. The solvent used in the stripping method can be, for example, a stripping solution. For example, a portion of the seed layer 2, the first resist layer 50, and the second resist layer 51 can be removed simultaneously by ultrasonic cleaning.

[0224] (S6) Steps to configure the intermediate layer

[0225] Figure 6I This is a schematic cross-sectional view showing an example of an intermediate layer being disposed in the manufacturing method of the ceramic substrate according to the first embodiment.

[0226] In step S6, an intermediate layer 4 is disposed on the upper surface and the side surface of the Cu layer 3. Furthermore, it is preferable that the intermediate layer 4 is disposed to cover the upper surface of the seed layer 2 disposed on the upper surface of the ceramic plate 1. The average thickness of the intermediate layer 4 can be adjusted by varying the amount of material supplied.

[0227] For example, the intermediate layer 4 can be formed by methods known in the art, such as electrolytic plating, non-electrolytic plating, vapor deposition, sputtering, etc.

[0228] (S7) Steps to configure the Au layer

[0229] Figure 6J This is a schematic cross-sectional view showing an example of an Au layer being disposed in the manufacturing method of the ceramic substrate according to the first embodiment.

[0230] In step S7, the Au layer 5 is disposed on the upper surface and the side surface of the intermediate layer 4. Specifically, the Au layer 5 can be formed by providing material for the Au layer 5 from above and on the side surface of the intermediate layer 4. The average thickness of the Au layer 5 can be adjusted by the amount of material provided.

[0231] For example, the Au layer 5 can be formed by methods known in the art, such as electrolytic plating, non-electrolytic plating, vapor deposition, sputtering, etc.

[0232] The ceramic substrate 100 formed by the method described above has a ceramic plate 1, a seed layer 2 disposed on the upper surface of the ceramic plate 1, a Cu layer 3 disposed on the upper surface of the seed layer 2, an intermediate layer 4 disposed on the upper surface and side surface of the Cu layer 3, and an Au layer 5 disposed on the upper surface and side surface of the intermediate layer 4. The upper surface of the seed layer 2 is in contact with the intermediate layer 4, and the upper surface of the ceramic plate 1 is not in contact with the Au layer 5. In the horizontal direction, the edge 2a of the upper surface of the seed layer 2 is located further outward than the edge 3b of the lower surface of the Cu layer 3, and in the horizontal direction, the edge 2a of the upper surface of the seed layer 2 is located further inward than the edge 5b of the lower surface of the Au layer 5.

[0233] In the method for manufacturing a ceramic substrate according to the first embodiment, in the final formed ceramic substrate 100, since the edge 2a of the upper surface of the seed layer 2 is located further outward than the edge 3b of the lower surface of the Cu layer 3, the upper surface of the seed layer 2 contacts the lower surface of the intermediate layer 4, and the Cu layer 3 is completely covered by the seed layer 2 and the intermediate layer 4. Therefore, corrosion of the lower surface of the Cu layer 3 can be suppressed, thereby obtaining a ceramic substrate 100 with excellent reliability.

[0234] <Second Implementation Method>

[0235] Figure 7 This is a flowchart illustrating an example of the method for manufacturing the ceramic substrate according to the second embodiment. Regarding the method for manufacturing the ceramic substrate according to the second embodiment, please refer to... Figures 8A to 8C Please provide an explanation.

[0236] The manufacturing method of the ceramic substrate in the second embodiment is the same as that in the first embodiment, except that it forms two or more intermediate layers 4.

[0237] (S16) Steps for configuring the first intermediate layer

[0238] Figure 8A This is a schematic cross-sectional view showing an example of the arrangement of the first intermediate layer in the manufacturing method of the ceramic substrate according to the second embodiment.

[0239] In step S16, the first intermediate layer 4-1 is disposed on the upper surface and the side surface of the Cu layer 3. The average thickness of the first intermediate layer 4-1 can be adjusted by the amount of material supplied to the first intermediate layer 4-1.

[0240] Although the material of the first intermediate layer 4-1 can be appropriately selected, in the configuration of the first intermediate layer S16, it is preferable to configure the Ni layer as the first intermediate layer 4-1 on the upper surface and the side surface of the Cu layer 3.

[0241] (S17) Steps for configuring the second intermediate layer

[0242] Figure 8B This is a schematic cross-sectional view showing an example of the arrangement of the second intermediate layer in the manufacturing method of the ceramic substrate according to the second embodiment.

[0243] In S17, the second intermediate layer is configured on the upper surface and the side surface of the first intermediate layer 4-1. The average thickness of the second intermediate layer 4-2 can be adjusted by the amount of material supplied to the second intermediate layer 4-2.

[0244] Although the material of the second intermediate layer 4-2 can be appropriately selected, in S17 of configuring the second intermediate layer 4-2, it is preferable to configure the Pd layer as the second intermediate layer 4-2 on the upper surface of the Ni layer as the first intermediate layer 4-1 and on the side surface of the Ni layer as the first intermediate layer 4-1.

[0245] (S18) Steps for configuring the Au layer

[0246] Figure 8C This is a schematic cross-sectional view showing an example of an Au layer being disposed in the manufacturing method of the ceramic substrate according to the second embodiment.

[0247] In S18, where the Au layer is configured, the Au layer 5 is configured on the upper surface and the side surface of the second intermediate layer 4-2. If the second intermediate layer 4-2 is a Pd layer, in S7-2, where the Au layer is configured, the Au layer 5 is configured on the upper surface and the side surface of the Pd layer that is the second intermediate layer 4-2.

[0248] The ceramic substrate 100 formed by the method described above includes a ceramic plate 1, a seed layer 2 disposed on the upper surface of the ceramic plate 1, a Cu layer 3 disposed on the upper surface of the seed layer 2, a first intermediate layer 4-1 and a second intermediate layer 4-2 disposed on the upper surface and side surface of the Cu layer 3, and an Au layer 5 disposed on the upper surface and side surface of the second intermediate layer 4-2. The upper surface of the seed layer 2 is in contact with the first intermediate layer 4-1 and the second intermediate layer 4-2. However, the upper surface of the ceramic plate 1 is not in contact with the Au layer 5. In the horizontal direction, the edge 2a of the upper surface of the seed layer 2 is located further outward than the edge 3b of the lower surface of the Cu layer 3, and in the horizontal direction, the edge 2a of the upper surface of the seed layer 2 is located further inward than the edge 5b of the lower surface of the Au layer 5.

[0249] Furthermore, in the manufacturing method of the ceramic substrate in the second embodiment, the case where the intermediate layer 4 has two layers is described. However, in the ceramic substrate 100 of the present invention, the intermediate layer 4 may also have three or more layers. When three or more layers are formed, the third intermediate layer, the fourth intermediate layer, and so on are formed sequentially according to the same method as in S17 for configuring the second intermediate layer.

[0250] <Third Implementation Method>

[0251] Figure 9 This is a flowchart illustrating an example of a method for manufacturing a ceramic substrate according to the third embodiment. Regarding the method for manufacturing a ceramic substrate according to the third embodiment, please refer to... Figures 10A to 10I Please provide an explanation.

[0252] The method for manufacturing a ceramic substrate according to the third embodiment is the same as the method for manufacturing a ceramic substrate according to the first embodiment, except that the predetermined shape of the first resist layer is such that the length L1 of the lower surface of the first resist layer 50 in the cross-section along the thickness direction of the ceramic plate 1 is shorter than the length L2 of the upper surface of the first resist layer 50, and a seed layer 2 is disposed on a portion of the side surface of the Cu layer 3.

[0253] (S21) Step of exposing and developing the first resist layer into a specified shape

[0254] Figure 10A This is a schematic cross-sectional view illustrating an example of the method for manufacturing a ceramic substrate according to the third embodiment, in which the first resist layer is exposed and developed into a predetermined shape. Figure 10B yes Figure 10A An enlarged cross-sectional view of region XB.

[0255] In step S21, which exposes and develops the first resist layer into a predetermined shape, the first resist layer 50 is exposed and developed such that the length L1 of the lower surface of the first resist layer 50 in the cross-section along the thickness direction of the ceramic plate 1 is shorter than the length L2 of the upper surface of the first resist layer 50. That is, the length L1 of the lower surface of the first resist layer 50 and the length L2 of the upper surface of the first resist layer 50 satisfy L1... <L2。

[0256] For example, in step S21, where the first resist layer 50 is exposed and developed into a predetermined shape, the first resist layer 50 is exposed and developed such that it has a main portion 50A and a protrusion 50B in a cross-section along the thickness direction of the ceramic plate 1. The main portion 50A, in cross-section, is the portion of the first resist layer that contacts the first region M of the upper surface of the ceramic plate 1. The protrusion 50B protrudes from the main portion 50A onto the second region N but does not contact the second region N of the upper surface of the ceramic plate 1 adjacent to the first region M. This creates a space S1 between the upper surface of the ceramic plate 1 and the lower surface of the protrusion 50B. Furthermore, the length of the first region M on the upper surface of the ceramic plate 1 in the X-axis direction is the length L1 of the lower surface of the first resist layer 50.

[0257] (S22) Steps for configuring the seed layer

[0258] Figure 10C This is a schematic cross-sectional view showing an example of the arrangement of a seed layer in the manufacturing method of the ceramic substrate according to the third embodiment.

[0259] In S22, a seed layer 2 is provided to continuously cover the side surface of the first resist layer 50 and the upper surface of the ceramic plate 1 exposed from the first resist layer 50. Specifically, in S22, the seed layer 2 is provided on the upper surface of the ceramic plate 1 exposed from the first resist layer 50 after exposure and development, the side surface of the first resist layer 50, and the upper surface of the first resist layer 50, thereby also providing a seed layer 2 in space S1.

[0260] (S23) Step of exposing and developing the second resist layer into a specified shape

[0261] Figure 10D This is a schematic cross-sectional view showing an example of the provision of a second resist layer in the manufacturing method of the ceramic substrate according to the third embodiment. Figure 10E This is a schematic cross-sectional view illustrating an example of the process of manufacturing a ceramic substrate according to the third embodiment, in which the second resist layer is exposed and developed into a predetermined shape.

[0262] In step S23, which exposes and develops the second resist layer into a predetermined shape, it is preferable to expose and develop the seed layer 2 disposed on the side of the first resist layer 50 in such a way that the seed layer 2 is exposed.

[0263] (S24) Steps for preparing the Cu layer

[0264] Figure 10F This is a schematic cross-sectional view illustrating an example of the Cu layer configuration in the ceramic substrate manufacturing method of the third embodiment. In the ceramic substrate manufacturing method of the third embodiment, during S24 of the Cu layer configuration, in addition to configuring the Cu layer 3 on the upper surface of the seed layer 2 exposed from the second resist layer 51 by electrolytic plating, it is preferable to also configure the Cu layer 3 on the seed layer 2 disposed on the side of the first resist layer 50 by electrolytic plating. Since the seed layer 2 is continuously provided, the Cu layer 3 can be configured by electrolytic plating.

[0265] (S25) Step of removing a portion of the seed layer, the first resist layer, and the second resist layer.

[0266] Figure 10G This is a schematic cross-sectional view illustrating an example of removing a portion of the seed layer, the first resist layer, and the second resist layer in the manufacturing method of the ceramic substrate according to the third embodiment.

[0267] In S25, when removing a portion of the seed layer, the first resist layer, and the second resist layer, the seed layer 2 disposed on the upper surface of the first resist layer 50 and the lower surface of the second resist layer 51 is removed, while the seed layer 2 disposed on the side of the first resist layer 50 and the seed layer 2 disposed on the upper surface of the ceramic plate 1 and the lower surface of the first resist layer 50 are not removed.

[0268] (S26) Steps for configuring the intermediate layer

[0269] Figure 10H This is a schematic cross-sectional view showing an example of the intermediate layer being configured in the manufacturing method of the ceramic substrate according to the third embodiment.

[0270] In step S26, the intermediate layer 4 is configured to cover the seed layer 2 disposed on the side of the Cu layer 3 and the upper surface of the Cu layer 3. The intermediate layer 4 is also configured on the side of the Cu layer 3 that is not covered by the seed layer 2.

[0271] (S27) Steps for configuring the Au layer

[0272] Figure 10I This is a schematic cross-sectional view showing an example of an Au layer being disposed in the manufacturing method of the ceramic substrate according to the third embodiment.

[0273] The ceramic substrate 100 formed by the method described above includes a ceramic plate 1, a seed layer 2 disposed on the upper surface of the ceramic plate 1, a Cu layer 3 disposed on the upper surface of the seed layer 2, an intermediate layer 4 disposed on the upper surface and side surface of the Cu layer 3, and an Au layer 5 disposed on the upper surface and side surface of the intermediate layer 4, wherein the upper surface of the seed layer 2 is in contact with the intermediate layer 4. However, the upper surface of the ceramic plate 1 is not in contact with the Au layer 5. In the horizontal direction, the edge 2a of the upper surface of the seed layer 2 is located further outward than the edge 3b of the lower surface of the Cu layer 3, and in the horizontal direction, the edge 2a of the upper surface of the seed layer 2 is located further inward than the edge 5b of the lower surface of the Au layer 5. The seed layer 2 is continuously disposed on a portion of the side surface of the Cu layer 3 starting from the lower surface of the Cu layer 3, and the intermediate layer 4 is disposed in a manner that covers the seed layer 2 disposed on a portion of the side surface of the Cu layer 3.

[0274] The ceramic substrate 100 formed by the ceramic substrate manufacturing method of the third embodiment, compared with the ceramic substrate 100 formed by the ceramic substrate manufacturing method of the first embodiment, has the advantage that, since the seed layer 2 is disposed on a portion of the side surface of the Cu layer 3, a boundary between the lower surface of the intermediate layer 4 and the upper surface of the seed layer 2 is not formed on the lower surface of the Cu layer 3, thereby more reliably preventing the Cu layer 3 from contacting the external environment such as air. Furthermore, corrosion can be suppressed, resulting in a ceramic substrate 100 with superior reliability.

[0275] <Fourth Implementation>

[0276] Figure 11 This is a flowchart illustrating an example of a method for manufacturing a ceramic substrate according to the fourth embodiment. Regarding the method for manufacturing a ceramic substrate according to the fourth embodiment, please refer to... Figures 12A to 12I Please provide an explanation.

[0277] The method for manufacturing a ceramic substrate according to the fourth embodiment is the same as the method for manufacturing a ceramic substrate according to the third embodiment, except that the first resist layer 50 is formed in such a way that the cross-sectional shape of the first resist layer 50 is a pendant shape (also called an inverted cone shape), that is, the first resist layer 50 is formed in such a way that the cross-sectional shape of the first resist layer 50 is such that the width (length in the X-axis direction) of the cross-section of the first resist layer 50 is smaller from the upper surface of the first resist layer 50 toward the lower surface of the first resist layer 50, and the seed layer 2 is not disposed on the side of the Cu layer 3.

[0278] (S31) Step of exposing and developing the first resist layer into a specified shape

[0279] Figure 12A This is a schematic cross-sectional view illustrating an example of the method for manufacturing a ceramic substrate according to the fourth embodiment, in which the first resist layer is exposed and developed into a predetermined shape. Figure 12B yes Figure 12A An enlarged cross-section of region XIB.

[0280] In step S31, where the first resist layer 50 is exposed and developed into a predetermined shape, the first resist layer 50 is exposed and developed such that its shape in a cross-section along the thickness direction of the ceramic plate 1 has a main portion 50A and a protrusion 50B. The main portion 50A is the part of the first resist layer that contacts the first region M on the upper surface of the ceramic plate 1 during cross-section. The protrusion 50B protrudes from the main portion 50A onto the second region N without contacting the second region N on the upper surface of the ceramic plate 1 adjacent to the first region M. As a result, a space S2 is formed between the upper surface of the ceramic plate 1 and the lower surface of the protrusion 50B.

[0281] (S32) Steps for preparing the seed layer

[0282] Figure 12C This is a schematic cross-sectional view showing an example of the arrangement of a seed layer in the manufacturing method of the ceramic substrate according to the fourth embodiment.

[0283] (S33) Step of exposing and developing the second resist layer into a specified shape

[0284] Figure 12D This is a schematic cross-sectional view showing an example of the provision of a second resist layer in the manufacturing method of the ceramic substrate according to the fourth embodiment. Figure 12E This is a schematic cross-sectional view illustrating an example of the process of manufacturing a ceramic substrate according to the fourth embodiment, in which the second resist layer is exposed and developed into a predetermined shape.

[0285] In step S33, where the second resist layer is exposed and developed into a predetermined shape, a sheet-like photoresist, specifically a dry film, is used as the second resist layer 51. By creating a vacuum while using the dry film, the air layer between the first resist layer 50, the seed layer 2, and the second resist layer 51 is removed, and the second resist layer 51 can also be formed in space S2.

[0286] Next, the second resist layer 51 is exposed and developed while retaining the second resist layer 51 disposed on the upper surface of the seed layer 2 and the second resist layer 51 disposed on the side of the seed layer 2 in space S2. As a result, the seed layer 2 disposed on the upper surface of the ceramic plate 1 is exposed from the second resist layer 51.

[0287] Alternatively, a photoresist composition commonly used in the field of light-emitting element technology can be used instead of a sheet photoresist as the second resist layer. The second resist layer 51 is disposed on the upper surface of the seed layer 2 disposed on the upper surface of the ceramic plate 1, on the upper surface of the seed layer 2 disposed on the upper surface of the first resist layer 50, and on the side surface of the seed layer 2 disposed on the side surface of the first resist layer 50. In this case, the second resist layer 51 is also disposed above the ceramic plate 1 and on the side surface of the first resist layer 50 between adjacent first resist layers 50, and in space S2. Next, the second resist layer 51 is exposed and developed such that the upper surface of the ceramic plate 1 is exposed. Thus, the seed layer 2 disposed on the upper surface of the ceramic plate 1 is exposed from the second resist layer 51. Furthermore, being above the ceramic plate 1 does not mean that the ceramic plate 1 is in contact with the second resist layer 51; the seed layer 2 is disposed between the ceramic plate 1 and the second resist layer 51. Furthermore, the side of the first resist layer 50 does not mean that the side of the first resist layer 50 is in contact with the second resist layer 51. A seed layer 2 is disposed between the side of the first resist layer 50 and the second resist layer 51.

[0288] (S34) Steps for configuring the Cu layer

[0289] Figure 12F This is a schematic cross-sectional view showing an example of a Cu layer being disposed in the manufacturing method of the ceramic substrate according to the fourth embodiment.

[0290] A Cu layer 3 is formed by providing a Cu-containing electroplating solution above the seed layer 2 exposed from the second resist layer 51. At this time, since the second resist layer 51 is disposed in space S2, no electroplating solution is provided.

[0291] (S35) Step of removing a portion of the seed layer, the first resist layer, and the second resist layer.

[0292] Figure 12G This is a schematic cross-sectional view illustrating an example of removing a portion of the seed layer, the first resist layer, and the second resist layer in the manufacturing method of the ceramic substrate according to the fourth embodiment.

[0293] In S35, when removing a portion of the seed layer, the first resist layer, and the second resist layer, the first resist layer 50, the seed layer 2 disposed on the upper surface of the first resist layer 50, the seed layer 2 disposed on the side surface of the first resist layer 50, the second resist layer 51 disposed on the upper surface of the seed layer 2 disposed on the upper surface of the first resist layer 50, and the second resist layer 51 disposed on the side surface of the seed layer 2 disposed on the side surface of the first resist layer 50 are removed.

[0294] (S36) Steps for configuring the intermediate layer

[0295] Figure 12HThis is a schematic cross-sectional view showing an example of an intermediate layer being configured in the manufacturing method of the ceramic substrate according to the fourth embodiment.

[0296] (S37) Steps for configuring the Au layer

[0297] Figure 12I This is a schematic cross-sectional view showing an example of an Au layer being disposed in the manufacturing method of the ceramic substrate according to the fourth embodiment.

[0298] The ceramic substrate 100 formed by the method described above has a ceramic plate 1, a seed layer 2 disposed on the upper surface of the ceramic plate 1, a Cu layer 3 disposed on the upper surface of the seed layer 2, an intermediate layer 4 disposed on the upper surface and side surface of the Cu layer 3, and an Au layer 5 disposed on the upper surface and side surface of the intermediate layer 4, wherein the upper surface of the seed layer 2 is in contact with the intermediate layer 4. Here, although the upper surface of the ceramic plate 1 is not in contact with the Au layer 5, it may still be in contact. In the horizontal direction, the edge 2a of the upper surface of the seed layer 2 of the ceramic substrate 100 is located further outward than the edge 3b of the lower surface of the Cu layer 3. By forming the first resist layer 50 as described above to provide space S2, the area of ​​the seed layer 2 extending outward from the Cu layer 3 can be increased, and by the contact between the seed layer 2 and the Au layer 5, corrosion of the lower surface of the Cu layer 3 can be further suppressed, thereby obtaining a ceramic substrate with excellent reliability.

[0299] [Light-emitting device]

[0300] The light-emitting device 200 of the embodiment includes a ceramic substrate 100 of the embodiment and a light-emitting element 20 disposed on the ceramic substrate 100. The light-emitting device 200 of the embodiment also preferably includes a reflective component 40 disposed on the upper surface of the ceramic substrate 100. The light-emitting device 200 of the embodiment may further include a bonding component 60 for electrically connecting the light-emitting element 20 and the ceramic substrate 100, a light-transmitting component 30 disposed on the upper surface of the light-emitting element 20, and a frame 41 surrounding the light-emitting element 20 on the ceramic substrate 100.

[0301] Figure 13A This is a schematic top view illustrating an example of a light-emitting device according to an embodiment. Figure 13B yes Figure 13A A schematic cross-sectional view of the stacking direction of the XIIIB-XIIIB line. Figure 13C yes Figure 13B An enlarged cross-section of region XIIIC. Figure 13D yes Figure 13C An enlarged cross-sectional view of region XIIID. The following describes the various structures of the light-emitting device 200.

[0302] The light-emitting device 200 is a device that emits light by disposing a light-emitting element 20 on a ceramic substrate 100. In the light-emitting device 200, the region 10 where the seed layer 2, Cu layer 3, intermediate layer 4 and Au layer 5 of the ceramic substrate 100 are stacked is the element placement region for placing the light-emitting element 20.

[0303] Furthermore, in the light-emitting device 200, the pad portion 11 of the ceramic substrate 100 is an external connection area used to ensure electrical connection between the light-emitting device 200 and the outside. The pad portion 11 is disposed on the outer side of the frame 41. When the light-emitting device 200 is viewed in plan view, the boundary between the region 10 and the pad portion 11 is located inside the outer edge of the frame 41.

[0304] The frame 41 has a roughly rectangular shape when viewed in plan view, and the three sides of the rectangle are formed as covering areas 10 or pad portions 11.

[0305] The light-emitting device 200 has a ceramic substrate 100, thus allowing the provision of a region 10 in the component mounting region and a pad portion 11 in the external connection region, i.e., wiring layers made of different materials can be provided respectively. Therefore, the component mounting region can become a wiring layer adapted to the bonding material of the light-emitting element 20, and the external connection region can become a wiring layer adapted to power supply components from the outside. This makes the bonding between the light-emitting element 20 and the ceramic substrate 100, and the bonding between the power supply components from the outside and the ceramic substrate 100, more robust and reliable.

[0306] (Light-emitting element 20)

[0307] The light-emitting element 20 is preferably a light-emitting diode (LED). There are no particular limitations on the composition of the light-emitting element 20; any composition can be used depending on the desired emission wavelength. For example, a nitride semiconductor (In) capable of emitting blue or green light can be used. x Al y Ga 1-x-y The light-emitting element 20 can be selected from N, 0≤X, 0≤Y, X+Y≤1) or GaP, or GaAlAs or AlInGaP that emits red light. One type can be used alone, or two or more can be used in combination. Furthermore, the size and shape of the light-emitting element 20 can be appropriately selected according to the intended use.

[0308] The light-emitting element 20 is typically formed by stacking a semiconductor layer on a support substrate (e.g., a light-transmitting substrate such as sapphire). The support substrate may have irregularities at its interface with the semiconductor layer. This allows for the intentional alteration of the critical angle at which light emitted from the semiconductor layer strikes the substrate, thereby facilitating the extraction of light to the outside of the support substrate. The support substrate can be removed after the semiconductor layer is stacked. For example, it can be removed by grinding, LLO (Laser Lift Off), or similar methods.

[0309] The light-emitting element 20 is mounted face down, with a pair of positive and negative electrodes disposed on the side that contacts the ceramic substrate 100.

[0310] When the light-emitting element 20 is mounted face down, it can be mounted on the mounting substrate in a flip-chip manner. In this case, the side of the light-emitting element 20 opposite to the side where a pair of electrodes are formed becomes the main light extraction surface. In flip-chip mounting, conductive paste-like bonding components such as solder, thin-film bonding components, or patterned connecting components are used to electrically connect the light-emitting element 20 to the region 10 of the ceramic substrate 100.

[0311] The outermost surface of the positive and negative electrodes of the light-emitting element 20 is preferably made of Au. Au has chemical stability, which can ensure reliability in long-term electrical connection. In addition, the outermost surface of region 10 of the ceramic substrate is an Au layer 5. Thus, by using the same material as the Au layer 5 of region 10 on the outermost surface of the positive and negative electrodes of the light-emitting element 20, a connection with higher reliability can be achieved.

[0312] The number of light-emitting elements 20 can be one or more. Furthermore, when there are multiple light-emitting elements 20, their arrangement is not particularly limited; for example, they can be arranged in a row or in a matrix in the first direction. In the case of a light-emitting device 200 having a horizontally elongated light distribution pattern suitable for vehicle headlights, it is preferable to arrange them in a row in the first direction. For example, if the planar shape of the ceramic substrate 100 in the horizontal direction is rectangular, taking the direction of the long side as the first direction, it is preferable to arrange multiple light-emitting elements 20 in a row along the first direction, and more preferably, to arrange multiple light-emitting elements 20 in a row at equal intervals along the first direction.

[0313] The light-emitting element 20 is disposed on region 10 of the ceramic substrate 100. Region 10 is disposed inside the frame 41 and is bonded to the light-emitting element 20. However, region 10 is not limited to the portion bonded to the light-emitting element 20, but also includes the area surrounding it.

[0314] There are no particular limitations on the planar shape of the light-emitting element 20 in the horizontal direction. Various shapes can be used, such as circles, ellipses, quadrilaterals, hexagons, polygons with rounded corners, or combinations of these shapes. Quadrilaterals are preferred, and rectangles are more preferred. Therefore, when multiple light-emitting elements 20 are arranged in the first direction, the distance between the sides of adjacent light-emitting elements 20 can be maintained at a constant level, allowing the multiple light-emitting elements 20 to be arranged close to each other. Furthermore, a rectangular light-emitting surface that is horizontally elongated when viewed in planar mode along the horizontal direction can be formed.

[0315] The vertical, horizontal, and height dimensions of the light-emitting element 20 can be arbitrarily set. However, to achieve a higher output light-emitting device 200, a large light-emitting element 20 is preferred. When viewed in a horizontal plane, the vertical and horizontal dimensions of the light-emitting element 20 are preferably 600 μm or more, more preferably 1,000 μm or more. Furthermore, from the viewpoint of uniform luminous intensity and ease of installation, the vertical and horizontal dimensions of the light-emitting element 20 are preferably 2,000 μm or less.

[0316] The light-emitting elements 20 are arranged at intervals from each other. In this case, the distance between the light-emitting elements 20 can be, for example, in the range of 0.1 times to 0.5 times one side of the light-emitting element 20 along the first direction. Specifically, when using light-emitting elements 20 with a planar shape that is approximately square and have longitudinal and lateral dimensions of about 1,000 μm, the distance between adjacent light-emitting elements 20 can be in the range of 100 μm to 500 μm.

[0317] (Jointing component 60)

[0318] The process of mounting the light-emitting element 20 onto the ceramic substrate 100 is typically performed using a bonding member 60. Examples of bonding members 60 include, for instance, solders of the Sn-Bi, Sn-Cu, Sn-Ag, and Au-Sn types; eutectic alloys, such as alloys with Au and Sn as main components, alloys with Au and Si as main components, and alloys with Au and Ge as main components; conductive pastes of Ag, Au, and Pd; bumps; anisotropic conductive materials such as anisotropic conductive films (ACF) and anisotropic conductive pastes (ACP); low-melting-point metal solders; and conductive adhesives and conductive composite adhesives made by combining these materials. One of these materials may be used alone, or two or more may be used in combination. Preferably, the light-emitting element 20 is mounted on the region 10 using a bonding member 60 containing Au. Since the outermost surface of the region 10 is the Au layer 5, using a bonding member containing Au ensures a more reliable and stable connection over a long period.

[0319] (Reflective component 40)

[0320] The reflective component 40 is a light-reflective component. The reflective component 40 is disposed on the upper surface of the ceramic substrate 100 and contacts the Au layer 5 and the seed layer 2. The reflective component 40 is preferably configured to also cover the side surface of the light-emitting element 20. In the light-emitting device 200, the reflective component 40 is, for example, disposed between the lower surface of the light-emitting element 20 and the upper surface of the ceramic substrate 100. By disposing the reflective component 40 on the upper surface of the ceramic substrate 100 and contacting the Au layer 5 and the seed layer 2, it is possible to suppress the upward movement (peeling) of the reflective component.

[0321] In order to effectively utilize the light from the light-emitting element 20, the reflective component 40 preferably has a high reflectivity. The reflective component 40 is preferably white. Regarding the reflectivity of the reflective component 40, it is preferably 90% or more, more preferably 94% or more, in the wavelength range of the light emitted by the light-emitting element 20.

[0322] The reflective component 40 can be formed using a resin material, for example. As the resin material, 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, can be used.

[0323] Furthermore, the reflective component 40 preferably contains a filler material such as a light-reflective substance in the resin material. Known materials such as titanium oxide, silicon oxide, zirconium oxide, aluminum oxide, zinc oxide, potassium titanate, aluminum nitride, boron nitride, and mullite can be used as examples of light-reflective substances. Since the amount of light reflected and transmitted by the reflective component 40 can vary, the content of the light-reflective substance can be appropriately adjusted according to the desired characteristics of the light-emitting device 200, but it is preferably 30% by mass or more relative to the total mass of the reflective component 40.

[0324] (Light-transmitting component 30)

[0325] The light-transmitting component 30 is disposed on the light extraction surface side of the light-emitting element 20, and preferably is joined to the light extraction surface of the light-emitting element 20.

[0326] The light-transmitting component 30 has an upper surface and a lower surface. Light emitted from the light-emitting element 20 enters the light-transmitting component 30 through the lower surface, and the upper surface of the light-transmitting component 30 serves as the light extraction surface, from which light is emitted to the outside. Preferably, the light-transmitting component 30 is a component that allows more than 60% of the light emitted from the light-emitting element 20 to pass through.

[0327] To effectively extract light emitted from the light-emitting element 20, the lower surface of the light-transmitting member 30 preferably covers the entire upper surface of the light-emitting element 20. That is, when viewed in a horizontal plane, the edge of the upper surface of the light-emitting element 20 is preferably covered in a manner encompassed within the edge of the lower surface of the light-transmitting member 30. Furthermore, the area of ​​the upper surface of the light-transmitting member 30 is preferably smaller than the sum of the areas of the upper surfaces of the plurality of light-emitting elements 20 included in the light-emitting device 200. Thus, light emitted from the light-emitting element 20 that enters from the lower surface of the light-transmitting member 30 can be emitted from the smaller upper surface of the light-transmitting member 30 (i.e., the light-emitting surface of the light-emitting device 200). In other words, since the light emitted from the light-emitting element 20 is concentrated through the light-transmitting member 30, the light-emitting device 200 has high brightness and can illuminate a greater distance.

[0328] The light-transmitting component 30 can individually cover the structure of multiple light-emitting elements 20, or it can integrally cover the structure of multiple light-emitting elements 20. The outer peripheral side of the light-transmitting component 30 is preferably covered by the reflective component 40.

[0329] The thickness of the light-transmitting component 30 is subject to special restrictions, but is preferably 50 μm or more and 300 μm or less.

[0330] In the case where a light-emitting device 200 includes multiple light-transmitting components 30, the upper surfaces of the multiple light-transmitting components 30 preferably form the same surface or substantially the same surface. This allows for more reliable prevention of interference between light emitted from the sides of the light-transmitting components 30. On the other hand, regardless of their number, the upper surfaces of the light-transmitting components 30 can be various shapes, such as concave-convex shapes, curved surfaces, or lens-like shapes. The lower surface of the light-transmitting components 30 is preferably a surface parallel to the light-extracting surface of the light-emitting element 20.

[0331] The light-transmitting component 30 may be formed, for example, of a material containing a phosphor, which can perform wavelength conversion on at least a portion of the light incident from the light-diffusing material or the light-emitting element 20. Examples of light-transmitting components containing phosphors include sintered bodies containing phosphors, resins, glass, phosphor powders of other inorganic materials, etc. The sintered body containing the phosphor can be a material formed by sintering only the phosphor, or a material formed by sintering a mixture of the phosphor and a sintering aid. When sintering a mixture of the phosphor and the sintering aid, inorganic materials such as silicon dioxide, aluminum oxide, or titanium dioxide are preferably used as the sintering aid. This suppresses discoloration or deformation of the sintering aid caused by light or heat, even when the light-emitting element 20 has high output. The higher the light transmittance of the light-transmitting component 30, the easier it is to generate light reflection at the interface with the reflective component 40, thereby improving brightness.

[0332] As the phosphor contained in the light-transmissive member 30, a material that can be excited by the light emitted from the light-emitting element 20 is used. For example, one of the specific examples shown below can be used alone, or two or more thereof can be used in combination. As a specific example of a fluorescent material that can be excited by a blue light-emitting element or an ultraviolet light-emitting element, a cerium-activated yttrium-aluminum-garnet-based fluorescent material (e.g., Y3(Al,Ga)5O 12 :Ce), a cerium-activated lutetium-aluminum-garnet-based fluorescent material (e.g., Lu3(Al,Ga)5O 12 :Ce), an europium and / or chromium-activated calcium aluminosilicate-based fluorescent material (e.g., CaO-Al2O3-SiO2:Eu), a terbium-aluminum-garnet-based fluorescent material (e.g., Tb3(Al,Ga)5O 12 :Ce), an europium-activated silicate-based fluorescent material (e.g., (Sr,Ba)2SiO4:Eu), a β-sialon-based fluorescent material (e.g., Si 6-z Al z O z N 8-z :Eu(0 < Z < 4.2)), an α-sialon-based fluorescent material (e.g., Mz(Si,Al) 12 (O,N) 16 (where 0 < z ≤ 2, and M is a lanthanide element other than Li, Mg, Ca, Y, La, and Ce)), a CASN-based fluorescent material (e.g., CaAlSiN3:Eu), a SCASN-based fluorescent material (e.g., (Sr,Ca)AlSiN3:Eu), etc. nitride-based fluorescent materials, a manganese-activated potassium fluorosilicate-based fluorescent material (e.g., K2SiF6:Mn, K2(Si,Al)F6:Mn, 3.5MgO·0.5MgF2·GeO2:Mn), a sulfide-based fluorescent material, a quantum dot fluorescent material (e.g., perovskite, sulfate), etc. By combining these phosphors with a blue light-emitting element or an ultraviolet light-emitting element, various color light-emitting devices (e.g., white-like light-emitting devices) can be manufactured. In the case of a light-emitting device that can emit white light, it is adjusted to white according to the type and concentration of the phosphor contained in the light-transmissive member 30. When such a phosphor is contained in the light-transmissive member 30, it is preferable to set the concentration of the phosphor to 5% or more and 50% or less.

[0333] The joining between the light-transmissive member 30 and the light extraction surface of the light-emitting element 20 can be performed, for example, through the light guide member 61. In addition, the joining between the light-transmissive member 30 and the light-emitting element 20 can also be directly joined by crimping, sintering, surface activation bonding, atomic diffusion bonding, or hydroxyl bonding without using the light guide member 61.

[0334] The light-transmitting component 30 is typically disposed on the upper surface of the light-emitting element 20, but depending on its form, it may also cover a portion of the area 10 and / or a portion of the pad portion 11.

[0335] (Frame 41)

[0336] The frame 41 is disposed around the light-emitting element 20 on the ceramic substrate 100. When viewed in a horizontal plane, the outer edge of the frame 41 preferably includes the boundary between the region 10 and the pad portion 11. Thus, the frame 41 can cover the step difference between the region 10 and the pad portion 11, and while the contact area with the frame 41 is increased, the anchoring effect provided by the step difference can be utilized.

[0337] The frame 41 can also be spaced apart from the outer edge of the upper surface of the ceramic substrate 100. Therefore, in the manufacturing process of the light-emitting device 200, on the individual processing line where each light-emitting device 200 is individually separated from the assembly of light-emitting devices 200, it is unnecessary to configure the frame 41 or the reflective component 40. That is, there is no need to cut the resin component during individualization, thus suppressing problems such as shape changes of the resin component or peeling from the ceramic substrate 100 caused by stress during cutting.

[0338] The frame 41 covers a portion of the area 10 and the pad portion 11, and is therefore formed of an insulating component. The frame 41 may, for example, be formed of an insulating resin component. Insulating resin components include, for example, silicone resin, modified silicone resin, epoxy resin, modified epoxy resin, acrylic resin, or a mixture of at least one of these resins. One of these may be used alone, or two or more may be used in combination.

[0339] The frame 41 may contain a filler material such as a light-reflective substance within the insulating resin component. The light-reflective substance may be an equivalent material to the light-reflective substance in the reflective component 40.

[0340] Furthermore, when the frame 41 is configured to contact the region 10, the region 10 preferably has a groove or hole 12 on the surface of the region that contacts the frame 41. The ceramic plate 1 is preferably exposed on the bottom surface of the groove or hole 12. This improves the fit between the frame 41 and the ceramic substrate 100, resulting in a light-emitting device 200 with superior reliability.

[0341] (Other components)

[0342] Other components, such as protective components 42 and electronic components, may also be installed in the light-emitting device 200. These other components and electronic components are preferably embedded in the reflective component 40.

[0343] Additionally, the light-emitting device 200 may have an identification mark 14 on its upper surface. The identification mark 14 is located in the outer edge of the generally rectangular ceramic substrate 100, between the area 10 and the side of the pad portion 11 that does not extend, and the outer edge of the frame 41. The identification mark 14 can be used for identifying the position of the light-emitting surface of the light-emitting device 200 during secondary mounting, and for identifying the position of the frame 41 during manufacturing. The identification mark 14 can, for example, be formed using the same metal material as the pad portion 11. By using the same material for the identification mark 14, the surface of the pad portion 11, and the identification mark 14 itself, metal corrosion caused by potential differences between different metal materials can be suppressed.

[0344] [Manufacturing method of light-emitting device]

[0345] The manufacturing method of the light-emitting device of the embodiment includes the steps of preparing the ceramic substrate 100 of the embodiment, the step of arranging the light-emitting element 20 on the ceramic substrate 100, and the step of arranging the reflective component 40 on the upper surface of the ceramic substrate 100. In the step of arranging the reflective component 40, the reflective component 40 is arranged to contact the Au layer 5 and the seed layer 2 of the ceramic substrate 100.

[0346] Figure 14 This is a flowchart illustrating an example of a method for manufacturing a light-emitting device according to an embodiment.

[0347] (S41) Steps for preparing ceramic substrate

[0348] In S41 of preparing the ceramic substrate 100, the ceramic substrate 100 of the embodiment is prepared.

[0349] Alternatively, the ceramic substrate 100 may be an area having multiple light-emitting elements 20 configured and then individually configured for each light-emitting device 200 after the reflective component 40 is configured, or it may be the size of a single light-emitting device 200.

[0350] (S42) Steps for configuring the light-emitting element

[0351] In step S42, the light-emitting element 20 is disposed on the ceramic substrate 100. In step S42, it is preferable to use a bonding member 60 to connect the electrode of the light-emitting element 20 to the upper surface of region 10. Furthermore, the light-emitting element 20 is preferably disposed in a structure in which a light-transmitting member 30 has been pre-attached to it. When bonding the light-transmitting member 30 to the light-emitting element 20, a light-transmitting bonding material is preferably used.

[0352] (S43) Steps for configuring the reflective component

[0353] In step S43, the reflective member 40 is disposed on the upper surface of the ceramic substrate 100. At this time, the reflective member 40 is configured to contact the Au layer 5 and the seed layer 2 of the ceramic substrate 100. This helps to suppress the floating (peeling) of the reflective member. Furthermore, in step S43, it is preferable that the reflective member 40 is configured to cover the side surface of the light-emitting element 20. The reflective member 40 is disposed on the ceramic substrate 100 such that the upper surface of the light-transmitting member 30 surrounding the light-emitting element 20 and disposed on the light-extracting surface of the light-emitting element 20 is exposed. It is preferable that the reflective member 40 is rectangular in plan view.

[0354] Furthermore, in the manufacturing method of the light-emitting device according to the embodiment, after S43 where the reflective component is arranged, a unitization operation is performed as needed. In the light-emitting device 200, one unit of the light-emitting device 200 is pre-set according to the number of light-emitting elements 20 used. Therefore, when manufacturing multiple light-emitting devices 200 at once, a unitization operation is performed. During the unitization operation, multiple light-emitting devices 200 are manufactured by cutting them into a grid pattern. Furthermore, as a cutting method, for example, methods using a disc-shaped rotating blade, an ultrasonic cutter, or a laser-irradiated blade can be cited.

[0355] [Example]

[0356] The following examples illustrate the present invention, but the present invention is not limited to these examples.

[0357] (Example 1)

[0358] according to Figure 11 The flowchart of the fourth embodiment shown illustrates the fabrication of a ceramic substrate 100. Using a scanning electron microscope (SEM), the upper surface and thickness cross-section of the intermediate formed after the S34 Cu layer is configured are observed under BED-C, accelerating voltage: 5.0KV, irradiation current mode: Std.-PC50.0, and high vacuum conditions.

[0359] The intermediate is cut along its thickness direction (Z-axis direction) by using focused ion beam processing (FIB) to expose a cross-section that leaves the thickness direction intact.

[0360] Figure 15A This is a plan view in the horizontal direction of the intermediate body of the ceramic substrate 100 obtained in step S34 of the ceramic substrate manufacturing method of the fourth embodiment, when the Cu layer is disposed, and an SEM image observed from the top surface at 50x magnification. Figure 15B yes Figure 15AThe enlarged cross-sectional view of region XVB in the thickness direction is an SEM image of the intermediate body of the ceramic substrate 100 obtained in step S34 of the ceramic substrate manufacturing method of the fourth embodiment, when viewed at 10,000x magnification.

[0361] In the SEM image, the ceramic plate 1, the first resist layer 50 with a pendant (inverted cone) cross-sectional shape disposed on the upper surface of the ceramic plate 1, the seed layer 2 disposed on the upper surface of the ceramic plate 1, the upper surface of the first resist layer 50, and the side surface of the first resist layer 50, the Cu layer disposed on the upper surface of the seed layer 2, and the space S2 between the upper surface of the ceramic plate 1 and the lower surface of the protrusion 50B are observed. Furthermore, although not clearly observed in the SEM image, the sketch film of the second resist layer 51 is configured to contact the upper surface of the seed layer 2 disposed on the upper surface of the first resist layer 50 and the side surface of the Cu layer 3.

[0362] As described above, the present invention has been illustrated with specific embodiments, but these are merely illustrative and the invention is not limited to the described embodiments. These embodiments can be implemented in various other forms, and various combinations, omissions, substitutions, additions, modifications, etc., can be made without departing from the spirit of the invention. These embodiments and their variations are also included in the scope and spirit of the invention, and are included within the same scope as the invention described in the claims.

[0363] In addition to the above implementation methods, the following notes are further disclosed.

[0364] (Appendix 1) A ceramic substrate includes: a ceramic plate; a seed layer disposed on the upper surface of the ceramic plate; a Cu layer disposed on the upper surface of the seed layer; one or more intermediate layers disposed on the upper surface of the Cu layer and the side surface of the Cu layer; an Au layer disposed on the upper surface of the intermediate layers and the side surface of the intermediate layers, wherein the upper surface of the seed layer is in contact with the lower surface of the intermediate layer, and the upper surface of the ceramic plate is not in contact with the lower surface of the Au layer, and in the horizontal direction, the edge of the upper surface of the seed layer is located further outward than the edge of the lower surface of the Cu layer.

[0365] (Note 2) According to the ceramic substrate of Note 1, in the horizontal direction, the edge of the upper surface of the seed layer is located further inward than the edge of the lower surface of the Au layer.

[0366] (Note 3) The ceramic substrate according to Note 1 or 2, wherein the side of the seed layer is exposed from the Au layer.

[0367] (Note 4) The ceramic substrate according to any one of Notes 1 to 3, wherein the seed layer is continuously disposed from the lower surface of the Cu layer to a portion of the side surface of the Cu layer, and the intermediate layer is disposed in such a way as to cover the seed layer disposed on a portion of the side surface of the Cu layer.

[0368] (Note 5) The ceramic substrate according to any one of Notes 1 to 4, wherein the intermediate layer comprises a Ni layer and a Pd layer, the Ni layer is disposed on the upper surface of the Cu layer and the side surface of the Cu layer, the Pd layer is disposed on the upper surface of the Ni layer and the side surface of the Ni layer, and the Au layer is disposed on the upper surface of the Pd layer and the side surface of the Pd layer.

[0369] (Note 6) The ceramic substrate according to any one of Notes 1 to 5, wherein the seed layer is selected from one or more of the group consisting of Ti layer, Cu layer, Au layer, Ru layer, TiNi layer, TiW layer, CuNi layer and NiCr layer.

[0370] (Note 7) The ceramic substrate according to any one of Notes 1 to 6, wherein the seed layer has an average thickness of 0.1 μm or more and 2.0 μm or less.

[0371] (Note 8) The ceramic substrate according to any one of Notes 1 to 7, wherein, in the horizontal direction, the edge of the upper surface of the seed layer is disposed at a position 1.0 μm or more and 5.0 μm or less inward than the edge of the lower surface of the Au layer.

[0372] (Note 9) The ceramic substrate according to any one of Notes 1 to 8, wherein the ceramic substrate further has pads electrically connected to the Au layer.

[0373] (Note 10) According to the ceramic substrate of Note 9, the pad portion includes the ceramic plate, the seed layer disposed on the upper surface of the ceramic plate, the intermediate layer disposed on the upper surface of the seed layer, and the Au layer disposed on the upper surface of the intermediate layer.

[0374] (Note 11) According to Note 9 or 10, the ceramic substrate includes the ceramic plate, the seed layer disposed on the upper surface of the ceramic plate, and the Al layer disposed on the upper surface of the seed layer.

[0375] (Note 12) A light-emitting device comprising: a ceramic substrate according to any one of Notes 1 to 11; and a light-emitting element disposed on the ceramic substrate.

[0376] (Note 13) The light-emitting device according to Note 12, wherein the light-emitting device includes a reflective component disposed on the upper surface of the ceramic substrate, the reflective component being in contact with the Au layer and the seed layer.

[0377] (Appendix 14) A method for manufacturing a ceramic substrate includes: a step of depositing a first resist layer on the upper surface of a ceramic plate and exposing and developing the first resist layer into a predetermined shape; a step of depositing a seed layer on the upper surface of the ceramic plate exposed from the first resist layer after exposure and development, the side surface of the first resist layer, and the upper surface of the first resist layer; a step of depositing a second resist layer to cover at least a portion of the upper surface of the seed layer and exposing and developing the second resist layer into a predetermined shape to expose at least a portion of the upper surface of the seed layer deposited on the upper surface of the ceramic plate; a step of depositing a Cu layer on the upper surface of the seed layer exposed from the second resist layer after exposure and development by electrolytic plating; a step of removing a portion of the seed layer, the first resist layer, and the second resist layer; a step of depositing one or more intermediate layers on the upper surface of the Cu layer and the side surface of the Cu layer; and a step of depositing an Au layer on the upper surface of the intermediate layer and the side surface of the intermediate layer.

[0378] (Note 15) According to the method for manufacturing a ceramic substrate as described in Note 14, in the step of exposing and developing the first resist layer into a predetermined shape, the length of the lower surface of the first resist layer in the cross-section of the ceramic plate in the thickness direction is shorter than the length of the upper surface of the first resist layer, and in the step of configuring the seed layer, the seed layer is configured to continuously cover the side surface of the first resist layer and the upper surface of the ceramic plate exposed from the first resist layer.

[0379] (Note 16) According to the method for manufacturing a ceramic substrate as described in Note 15, in the step of exposing and developing the first resist layer into a predetermined shape, the first resist layer is formed in such a way that the cross-sectional image of the first resist layer is in a hanging shape, and in the step of exposing and developing the second resist layer into a predetermined shape, the second resist layer is a sheet-like resist.

[0380] (Appendix 17) A method for manufacturing a ceramic substrate according to any one of Appendices 14 to 16, wherein, in the step of exposing and developing the second resist layer into a predetermined shape, the exposure and development are performed such that the seed layer disposed on the side surface of the first resist layer and the upper surface of the first resist layer are not exposed, while at least a portion of the upper surface of the seed layer disposed on the upper surface of the ceramic substrate is exposed from the second resist layer.

[0381] (Note 18) A method for manufacturing a ceramic substrate according to any one of Notes 14 to 17, wherein, in the step of configuring the seed layer, the seed layer has a thickness of 1.0 μm or more and 2.0 μm or less.

[0382] (Note 19) A method for manufacturing a ceramic substrate according to any one of Notes 14 to 18, wherein, in the step of configuring the intermediate layer, the intermediate layer is configured such that it covers the upper surface of the seed layer disposed on the upper surface of the ceramic substrate.

[0383] (Appendix 20) A method for manufacturing a ceramic substrate according to any one of Appendices 14 to 19, wherein the step of configuring the intermediate layer includes configuring a Ni layer on the upper surface of the Cu layer and the side surface of the Cu layer, and configuring a Pd layer on the upper surface of the Ni layer and the side surface of the Ni layer, and configuring the Au layer in the step of configuring the Au layer, wherein the Au layer is configured on the upper surface of the Pd layer and the side surface of the Pd layer.

[0384] (Appendix 21) A method for manufacturing a ceramic substrate according to any one of Appendices 14 to 20, wherein, in the step of exposing and developing the second resist layer, the exposure and development are performed in such a way that the seed layer disposed on the side of the first resist layer is exposed, and in the step of configuring the Cu layer, the Cu layer is configured on the seed layer disposed on the side of the first resist layer by electrolytic plating.

[0385] (Note 22) A method for manufacturing a ceramic substrate according to any one of Notes 14 to 21, wherein the step of configuring the intermediate layer includes configuring the intermediate layer in such a way that it covers the seed layer disposed on the side of the Cu layer and the upper surface of the Cu layer.

[0386] (Note 23) According to the method for manufacturing a ceramic substrate as described in Note 14, after the step of removing the first resist layer and the second resist layer, in the horizontal direction, the edge of the upper surface of the seed layer is disposed further outward than the edge of the lower surface of the Cu layer.

[0387] (Note 24) A method for manufacturing a ceramic substrate according to any one of Notes 14 to 23, wherein the first resist layer and the second resist layer are composed of a negative photoresist.

[0388] (Appendix 25) A method for manufacturing a light-emitting device, comprising: a step of preparing a ceramic substrate as described in any one of Appendices 1 to 11; a step of disposing a light-emitting element on the ceramic substrate; a step of disposing a reflective component on the upper surface of the ceramic substrate, wherein, in the step of disposing the reflective component, the reflective component is configured to contact the Au layer and the seed layer of the ceramic substrate.

Claims

1. A ceramic substrate comprising: Ceramic slab; A seed layer is disposed on the upper surface of the ceramic plate; A Cu layer is disposed on the upper surface of the seed layer; One or more intermediate layers are disposed on the upper surface of the Cu layer and the side surface of the Cu layer; and An Au layer is disposed on the upper surface of the intermediate layer and the side surface of the intermediate layer. The upper surface of the seed layer is in contact with the lower surface of the intermediate layer. The upper surface of the ceramic plate is not in contact with the lower surface of the Au layer. In the horizontal direction, the edge of the upper surface of the seed layer is located further outward than the edge of the lower surface of the Cu layer.

2. The ceramic substrate according to claim 1, wherein, In the horizontal direction, the edge of the upper surface of the seed layer is located further inward than the edge of the lower surface of the Au layer.

3. The ceramic substrate according to claim 1 or 2, wherein, The side of the seed layer is exposed from the Au layer.

4. The ceramic substrate according to any one of claims 1 to 3, wherein, The seed layer is continuously disposed from the lower surface of the Cu layer to a portion of the side surface of the Cu layer. The intermediate layer is configured such that the seed layer is disposed on a portion of the side surface of the Cu layer.

5. The ceramic substrate according to any one of claims 1 to 4, wherein, The intermediate layer comprises a Ni layer and a Pd layer. The Ni layer is disposed on the upper surface of the Cu layer and the side surface of the Cu layer. The Pd layer is disposed on the upper surface of the Ni layer and the side surface of the Ni layer. The Au layer is disposed on the upper surface of the Pd layer and the side surface of the Pd layer.

6. The ceramic substrate according to any one of claims 1 to 5, wherein, The seed layer is selected from one or more of the following: Ti layer, Cu layer, Au layer, Ru layer, TiNi layer, TiW layer, CuNi layer and NiCr layer.

7. The ceramic substrate according to any one of claims 1 to 6, wherein, The seed layer has an average thickness of more than 0.1 μm and less than 2.0 μm.

8. The ceramic substrate according to any one of claims 1 to 7, wherein, In the horizontal direction, the edge of the upper surface of the seed layer is disposed at a position 1.0 μm or more and 5.0 μm or less inward than the edge of the lower surface of the Au layer.

9. The ceramic substrate according to any one of claims 1 to 8, wherein, The ceramic substrate also has pads that are electrically connected to the Au layer.

10. The ceramic substrate according to claim 9, wherein, The pad portion includes the ceramic plate, the seed layer disposed on the upper surface of the ceramic plate, the intermediate layer disposed on the upper surface of the seed layer, and the Au layer disposed on the upper surface of the intermediate layer.

11. The ceramic substrate according to claim 9 or 10, wherein The pad portion includes the ceramic plate, the seed layer disposed on the upper surface of the ceramic plate, and the Al layer disposed on the upper surface of the seed layer.

12. A light-emitting device, comprising: The ceramic substrate according to any one of claims 1 to 11; and A light-emitting element is disposed on the ceramic substrate.

13. The light-emitting device according to claim 12, wherein, The light-emitting device includes a reflective component disposed on the upper surface of the ceramic substrate. The reflective component is in contact with the Au layer and the seed layer.

14. A method for manufacturing a ceramic substrate, comprising: The steps include: setting a first resist layer on the upper surface of a ceramic plate, and exposing and developing the first resist layer into a specified shape; The step of depositing a seed layer on the upper surface of the ceramic plate exposed from the first resist layer after exposure and development, the side surface of the first resist layer, and the upper surface of the first resist layer; The steps include: providing a second resist layer in a manner that covers at least a portion of the upper surface of the seed layer, and exposing and developing the second resist layer into a predetermined shape so that at least a portion of the upper surface of the seed layer disposed on the upper surface of the ceramic plate is exposed; The step of electroplating a Cu layer on the upper surface of the seed layer exposed from the second resist layer after exposure and development; The step of removing a portion of the seed layer, the first resist layer, and the second resist layer; The step of configuring one or more intermediate layers on the upper surface of the Cu layer and the side surface of the Cu layer; and The step of depositing an Au layer on the upper surface and the side surface of the intermediate layer.

15. The method for manufacturing a ceramic substrate according to claim 14, wherein, In the step of exposing and developing the first resist layer into a predetermined shape, the length of the lower surface of the first resist layer in the cross-section along the thickness direction of the ceramic plate is shorter than the length of the upper surface of the first resist layer. In the step of configuring the seed layer, the seed layer is configured to continuously cover the side surface of the first resist layer and the upper surface of the ceramic plate exposed from the first resist layer.

16. The method for manufacturing a ceramic substrate according to claim 15, wherein, In the step of exposing and developing the first resist layer into a predetermined shape, the first resist layer is formed in such a way that the cross-sectional image of the first resist layer is in a suspended shape. In the step of exposing and developing the second resist layer into a specified shape, the second resist layer is a sheet-like resist.

17. The method for manufacturing a ceramic substrate according to any one of claims 14 to 16, wherein, In the step of exposing and developing the second resist layer into a predetermined shape, the seed layer disposed on the side surface of the first resist layer and the upper surface of the first resist layer is not exposed, but at least a portion of the upper surface of the seed layer disposed on the upper surface of the ceramic plate is exposed from the second resist layer.

18. The method for manufacturing a ceramic substrate according to any one of claims 14 to 17, wherein, In the step of configuring the seed layer, the seed layer has a thickness of 1.0 μm or more and 2.0 μm or less.

19. The method for manufacturing a ceramic substrate according to any one of claims 14 to 18, wherein, In the step of configuring the intermediate layer, the intermediate layer is configured such that it covers the upper surface of the seed layer disposed on the upper surface of the ceramic plate.

20. The method for manufacturing a ceramic substrate according to any one of claims 14 to 19, wherein, The step of configuring the intermediate layer includes configuring a Ni layer on the upper surface and the side surface of the Cu layer, and configuring a Pd layer on the upper surface and the side surface of the Ni layer. In the step of configuring the Au layer, the Au layer is configured on the upper surface of the Pd layer and the side surface of the Pd layer.

21. The method for manufacturing a ceramic substrate according to any one of claims 14 to 20, wherein, In the step of exposing and developing the second resist layer, the exposure and development are performed in a manner that exposes the seed layer disposed on the side surface of the first resist layer. In the step of configuring the Cu layer, the seed layer configured on the side of the first resist layer is configured into the Cu layer by electrolytic plating.

22. The method for manufacturing a ceramic substrate according to any one of claims 14 to 21, wherein, The step of configuring the intermediate layer includes configuring the intermediate layer in a manner that covers the seed layer disposed on the side surface of the Cu layer and the upper surface of the Cu layer.

23. The method for manufacturing a ceramic substrate according to claim 14, wherein, After removing the first and second resist layers, in the horizontal direction, the edge of the upper surface of the seed layer is positioned further outward than the edge of the lower surface of the Cu layer.

24. The method for manufacturing a ceramic substrate according to any one of claims 14 to 23, wherein, The first and second resist layers are composed of negative photoresist.

25. A method for manufacturing a light-emitting device, comprising: The steps of preparing the ceramic substrate according to any one of claims 1 to 11; The step of configuring light-emitting elements on the ceramic substrate; and The step of configuring a reflective component on the upper surface of the ceramic substrate. In the step of configuring the reflective component, the reflective component is configured to contact the Au layer and the seed layer of the ceramic substrate.

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