Ceramic substrate, method for producing same, light-emitting device, and method for producing same

Abstract

The present invention addresses the problem of providing a highly reliable ceramic substrate and a method for manufacturing the same, and a light-emitting device and a method for manufacturing the same, whereby adhesion between a ceramic plate and a conductive member inside a through-hole or a recess of the ceramic plate can be improved, and migration of metal in the conductive member can be suppressed. A method of manufacturing a ceramic substrate according to an embodiment of the present disclosure includes: forming a through hole or a recess in a ceramic plate including aluminum nitride, the ceramic plate including a first surface and a second surface positioned on an opposite side to the first surface, by irradiating the ceramic plate with a laser such that aluminum is precipitated; removing the aluminum deposited on the inner surface of the through hole or the recess; and disposing a conductive paste inside the through-hole or the recess.

Description

Technical Field

[0001] The present disclosure relates to a ceramic substrate and a method for manufacturing the same, as well as a light-emitting device and a method for manufacturing the same. Background Art

[0002] In recent years, in order to achieve miniaturization, high functionality, and integration of electronic devices or components, it has been proposed to form through-holes (also referred to as "hole portions," "through-holes," etc.) in insulating substrates. In order to provide electrical conductivity between the two sides of the substrate, a conductive material such as copper or silver is disposed in the through-holes. For example, a through-hole-filled substrate is known, comprising: an insulating substrate having a hole portion; and a conductive through-hole portion formed by a conductor filled in the hole portion. The conductive through-hole portion has a porosity of 10% by volume or less, and substantially no gap exists between the conductive through-hole portion and the wall of the hole portion. The conductive through-hole portion is formed by an active metal film present at the interface between a conductive through-hole body having a sea-island structure comprising a continuous phase and a dispersed phase and the hole portion wall (for example, see Patent Document 1).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2022-13766 Summary of the Invention

[0006] Problems to be solved by the invention

[0007] The purpose of the present disclosure is to provide a high-reliability ceramic substrate and its manufacturing method, as well as a light-emitting device and its manufacturing method, which can improve the tightness between the ceramic plate and the conductive component inside the through hole or recess of the above-mentioned ceramic plate and can suppress the migration of metal in the above-mentioned conductive component.

[0008] Methods for solving problems

[0009] One embodiment of the present disclosure relates to a method for manufacturing a ceramic substrate, comprising: irradiating a ceramic plate containing aluminum nitride and having a first surface and a second surface located opposite to the first surface with a laser so as to precipitate aluminum, forming a through hole or a recess in the ceramic plate, removing the aluminum precipitated on the inner surface of the through hole or the recess, and disposing a conductive paste inside the through hole or the recess.

[0010] In addition, one embodiment of the present disclosure relates to a ceramic substrate comprising: a ceramic plate containing aluminum nitride, having a first surface and a second surface located on the opposite side of the above-mentioned first surface, a through hole connecting the above-mentioned first surface and the above-mentioned second surface, or a recess located on at least one of the above-mentioned first surface and the above-mentioned second surface, and a conductive component formed inside the above-mentioned through hole or the above-mentioned recess, wherein the inner surface defining the above-mentioned through hole or the above-mentioned recess has a nitride film with an average thickness of not less than 10 μm and not more than 35 μm.

[0011] In addition, a method for manufacturing a light-emitting device according to an embodiment of the present disclosure includes preparing the ceramic substrate manufactured by the method for manufacturing the ceramic substrate according to an embodiment of the present disclosure, disposing a light-emitting element having an electrode on the ceramic substrate, and electrically connecting the electrode to a conductive member.

[0012] Furthermore, a light-emitting device according to one embodiment of the present disclosure includes the ceramic substrate according to one embodiment of the present disclosure, and a light-emitting element having an electrode disposed on the ceramic substrate, wherein the electrode and the conductive member are electrically connected.

[0013] Effects of the Invention

[0014] According to one embodiment of the present disclosure, a highly reliable ceramic substrate and its manufacturing method, as well as a light-emitting device and its manufacturing method can be provided, which can improve the tightness between the ceramic plate and the conductive component inside the through hole or recess of the above-mentioned ceramic plate and can inhibit the migration of metal in the above-mentioned conductive component. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1A It is a schematic plan view showing an example of the ceramic substrate according to the first embodiment.

[0016] Figure 1B It is a schematic bottom view showing an example of the ceramic substrate according to the first embodiment.

[0017] Figure 1C As an example Figure 1A and Figure 1B Schematic cross-sectional view of a cross section of the IC-IC line.

[0018] Figure 2 It is a schematic cross-sectional view showing a modification of the ceramic substrate according to the first embodiment.

[0019] Figure 3A It is a schematic plan view showing an example of a ceramic substrate according to the second embodiment.

[0020] Figure 3B It is a schematic bottom view showing an example of a ceramic substrate according to the second embodiment.

[0021] Figure 3C As an example Figure 3A and Figure 3B Schematic cross-sectional view of the cross section taken along line IIIC-IIIC.

[0022] Figure 4 It is a schematic cross-sectional view showing a modification of the ceramic substrate according to the second embodiment.

[0023] Figure 5 It is a flowchart showing an example of the method for manufacturing the ceramic substrate according to the first embodiment.

[0024] Figure 6A This is a schematic cross-sectional view showing an example of a ceramic plate used in the method for manufacturing a ceramic substrate according to the first embodiment.

[0025] Figure 6B It is a schematic cross-sectional view showing an example of forming a through hole in the method for manufacturing the ceramic substrate according to the first embodiment.

[0026] Figure 6C It is a schematic cross-sectional view showing an example of removing precipitated aluminum in the method for producing the ceramic substrate according to the first embodiment.

[0027] Figure 6D It is a schematic cross-sectional view showing an example of polishing or grinding a ceramic plate in the method for manufacturing a ceramic substrate according to the first embodiment.

[0028] Figure 6E It is a schematic cross-sectional view showing an example of disposing the conductive paste in the method for manufacturing the ceramic substrate according to the first embodiment.

[0029] Figure 6F It is a schematic cross-sectional view showing an example of a conductive member in the method for manufacturing the ceramic substrate according to the first embodiment.

[0030] Figure 6G It is a schematic cross-sectional view showing an example of polishing or grinding the conductive member in the method for manufacturing the ceramic substrate according to the first embodiment.

[0031] Figure 7A For the general Figure 6E The region VIIA is enlarged and schematically shown in the enlarged cross-sectional view.

[0032] Figure 7B For the general Figure 6F The region VIIB is enlarged and schematically shown in the enlarged cross-sectional view.

[0033] Figure 8 It is a schematic cross-sectional view showing an example of a light-emitting device according to an embodiment.

[0034] Figure 9A It is a perspective view showing an application example of the light emitting device according to the embodiment.

[0035] Figure 9B To express Figure 9A Cross-sectional view of section IXB-IXB.

[0036] Figure 10 This is a flowchart showing an example of a method for manufacturing a light-emitting device according to an embodiment.

[0037] Figure 11A This is a cross-sectional observation image of the through-hole formed in Example 1 after laser irradiation.

[0038] Figure 11B This is a cross-sectional observation image of the through hole after etching to remove aluminum in Example 1.

[0039] Figure 12A This is an observation image of the cross section of the ceramic substrate of Example 1 obtained using a scanning electron microscope (SEM).

[0040] Figure 12B This is an observation image of the cross section of the ceramic substrate of Example 1 obtained by fluorescent X-ray spectroscopy (Ti-Ka).

[0041] Figure 13A This is an observation image of a region including the inner surface defining the through-hole on the first surface of the ceramic substrate of Example 1, obtained using a metallurgical microscope.

[0042] Figure 13B This is an observation image of a region including the inner surface defining the through-hole on the first surface of the ceramic substrate of Example 1, obtained using a scanning electron microscope (SEM). DETAILED DESCRIPTION

[0043] The ceramic substrate and its manufacturing method, and the light-emitting device and its manufacturing method according to the embodiments of the present disclosure are described in detail with reference to the accompanying drawings. However, the embodiments described below are merely examples of the ceramic substrate and its manufacturing method, and the light-emitting device and its manufacturing method that embody the technical concept of the present disclosure, and are not limited thereto.

[0044] In addition, the dimensions, materials, shapes, and relative configurations of the components described in the embodiments are not limited to the scope of the present disclosure unless otherwise specified, and are merely illustrative examples. In addition, the sizes and positional relationships of the components shown in the drawings may sometimes be exaggerated for clarity. In addition, in the following description, for components with the same name or symbol, the same or homogeneous components are appropriately omitted for detailed description. In order to avoid over-complication of the drawings, schematic diagrams with some elements omitted are sometimes used as cross-sectional views, and end views showing only cross-sections are sometimes used.

[0045] Furthermore, in this disclosure, polygons such as rectangles, triangles, and quadrilaterals, including shapes with corners that have been processed, such as fillets, chamfers, angled corners, and rounded corners, are also referred to as polygons. Furthermore, shapes that have been processed in the middle of a side, not just the corners (edges), are also referred to as polygons. In other words, shapes that have been partially processed while retaining the polygonal base are included in the definition of "polygon" as described in this disclosure.

[0046] Furthermore, this applies not only to polygons but also to terms that denote specific shapes, such as trapezoids, circles, and concave-convex shapes. This also applies to the processing of the individual sides that form that shape. That is, even if processing is applied to a corner or the middle of a side, the interpretation of "side" includes that processed portion. Furthermore, when distinguishing a "polygon" or "side" that has not been partially processed from the processed shape, the term "strict" is used, such as "strict quadrilateral."

[0047] In addition, in the following description, terms indicating specific directions or positions (for example, "upper", "lower", "X", "Y", "Z" and other terms containing these terms) are used as needed. However, the use of these terms is to facilitate understanding of the invention with reference to the accompanying drawings, and the meaning of these terms does not unduly limit the technical scope of the present invention. For example, when it is recorded as "above", the invention does not necessarily always face upward. In addition, parts with the same symbols appearing in multiple drawings represent the same or equivalent parts or components. In addition, for the embodiments, "covering" is not limited to direct contact, but also includes indirect contact, such as covering via other components.

[0048] In the present specification or claims, when a plurality of components are provided and each component is to be distinguished from the others, the components may be distinguished by adding "first," "second," etc. at the beginning of the components.

[0049] 〔Ceramic Substrate〕

[0050] <First embodiment>

[0051] Figure 1A It is a schematic plan view showing an example of the ceramic substrate according to the first embodiment. Figure 1B It is a schematic bottom view showing an example of the ceramic substrate according to the first embodiment. Figure 1C This is an example Figure 1A and Figure 1B Hereinafter, each structure of the ceramic substrate 100 will be described.

[0052] The ceramic substrate 100 according to the first embodiment includes a ceramic plate 1 made of aluminum nitride and a conductive member 2 formed inside a through-hole 3. The ceramic plate 1 made of aluminum nitride includes a first surface 1a and a second surface 1b located opposite to the first surface 1a, and has the through-hole 3 connecting the first surface 1a and the second surface 1b.

[0053] In the through hole 3 , an inner surface 3 a defining the through hole 3 has a nitride film 4 having an average thickness of 10 μm to 35 μm.

[0054] (Ceramic plate 1)

[0055] The ceramic plate 1 is an insulating member serving as a base for forming the conductive member 2. The ceramic plate 1 is sintered, but is preferably not in a softened state before sintering.

[0056] The ceramic plate 1 preferably comprises aluminum nitride as a main material, and may further comprise other auxiliary materials as required. Here, the so-called "main material" refers to the material with the highest content among the materials constituting the ceramic plate 1.

[0057] The auxiliary material in the ceramic plate 1 is not particularly limited, and examples thereof include ceramics other than aluminum nitride, glass, etc. These may be used alone or in combination of two or more.

[0058] Ceramics other than aluminum nitride are not particularly limited, and examples thereof include nitride-based ceramics such as silicon nitride and boron nitride; oxide-based ceramics such as aluminum oxide, silicon oxide, calcium oxide, and magnesium oxide; silicon carbide; mullite; borosilicate glass, etc. These may be used alone or in combination of two or more.

[0059] The ceramic plate 1 is preferably a plate-like member that is rectangular in plan view. The rectangle may be a rectangle having a long side and a short side. Unless specifically excluded, a square may be included. Furthermore, the shape of the ceramic plate 1 in plan view is not limited to a rectangle and may also be a circle, an ellipse, a polygon, or the like.

[0060] The first surface 1 a may or may not be a plane. When the ceramic substrate 100 is used in a light-emitting device, the light-emitting elements can be preferably arranged on a plane, which is preferable.

[0061] The second surface 1b is the surface opposite to the first surface 1a in the ceramic plate 1. The second surface 1b may or may not be a flat surface. When the ceramic substrate 100 is used in a light-emitting device, it is preferable to configure the mounting substrate to be flat.

[0062] In the ceramic substrate 100 according to the first embodiment, Figure 1CThe upper surface of the ceramic plate 1 is set as the first surface 1a, and the lower surface of the ceramic plate 1 is set as the second surface 1b. This is just for the convenience of separate recording. When the ceramic substrate 100 is used for a light-emitting device, the mounting substrate can be arranged on the first surface 1a, and the light-emitting element can be arranged on the second surface 1b.

[0063] The first surface 1a and the second surface 1b are parallel to each other, for example. Here, when the surfaces of the ceramic plate 1 are expressed as "parallel", a difference within ±5 degrees is allowed.

[0064] The through hole 3 connects the first surface 1a and the second surface 1b. The through hole 3 is, for example, a through hole.

[0065] The shape of the opening of through hole 3 in a plan view of ceramic plate 1 is preferably circular or elliptical. The shape of the opening of through hole 3 in a plan view of ceramic plate 1 is not limited to circular or elliptical and may be polygonal including rectangular.

[0066] In the ceramic substrate 100 involved in the first embodiment, the opening diameter of the opening portion of the through hole 3 formed on the first surface 1a in the top view of the ceramic plate 1 and the opening diameter of the opening portion of the through hole 3 formed on the second surface 1b are not particularly limited and can be appropriately selected according to the purpose, but are preferably not less than 50 μm and not more than 500 μm, and more preferably not less than 50 μm and not more than 200 μm.

[0067] In the ceramic substrate 100 according to the first embodiment, the opening diameters of the through-holes 3 formed on the first surface 1a of the ceramic plate 1 are the same as the opening diameters of the through-holes 3 formed on the second surface 1b. Here, when the opening diameters of the through-holes 3 of the ceramic plate 1 are described as "the same," a difference within ±5% is permitted.

[0068] When the opening of through hole 3 is circular or elliptical, the "opening diameter" is the maximum diameter of the opening. When the opening of through hole 3 is rectangular in a plan view of ceramic plate 1, the "opening diameter" is the diagonal length of the opening.

[0069] The number of through holes 3 in the ceramic plate 1 is not particularly limited and may be one or more. However, from the viewpoint of mounting in a light-emitting device, a plurality is preferred.

[0070] When a plurality of through holes 3 are provided, the arrangement of the plurality of through holes 3 in a plan view of the ceramic plate 1 , the pitch between one through hole 3 and other adjacent through holes 3 , etc. are not particularly limited and can be appropriately selected according to the purpose.

[0071] In through-hole 3, inner surface 3a defining through-hole 3 has nitride film 4 having an average thickness of not less than 10 μm and not more than 35 μm. Specifically, nitride film 4 is disposed at the interface between inner surface 3a defining through-hole 3 and conductive member 2. Nitride film 4 improves adhesion between ceramic plate 1 and conductive member 2 formed within through-hole 3, thereby providing a highly reliable ceramic substrate 100.

[0072] The inner surface 3a defining the through-hole 3 in the ceramic plate 1 has unevenness and is roughened. The recessed portion defining the inner surface 3a of the through-hole 3 is an irregular microstructure. In the present disclosure, the irregular microstructure of the recessed portion defining the inner surface 3a of the through-hole 3 can be referred to as, for example, a tree root shape or a tree shape. Nitride exists within the tree root-shaped recessed portion. Therefore, the nitride film 4 includes the tree root-shaped inner surface 3a defining the through-hole 3 and the nitride existing within the inner surface 3a. More specifically, the nitride film 4 includes the material constituting the ceramic plate 1 and the nitride, and may also include components from the conductive member 2.

[0073] The arithmetic mean roughness Ra of the inner surface 3a defining the through-hole 3 is not particularly limited and can be appropriately selected depending on the intended purpose, but is preferably 1.0 μm to 3.5 μm. The arithmetic mean roughness Ra of the inner surface 3a defining the through-hole 3 is measured in accordance with JIS B 0601 using a stylus-type surface roughness meter (e.g., SE3500 manufactured by Kosaka Laboratory Co., Ltd.) equipped with a diamond stylus having a tip curvature radius r of 2 μm.

[0074] As the nitride in the nitride film 4 , for example, titanium nitride can be mentioned.

[0075] The average thickness of the nitride film 4 is not less than 10 μm and not more than 35 μm, and preferably not less than 10 μm and not more than 25 μm.

[0076] In the ceramic substrate 100 according to the first embodiment, the average thickness of the nitride film 4 is measured as follows. A scanning electron microscope (SEM) image is obtained at 250x magnification, observing a region X encompassing at least a portion of the conductive member 2 and at least 50 μm in the depth direction of the recess from the inner surface 3 a defining the through-hole 3 in the ceramic plate 1, on a cross section through the center of gravity of the opening of the through-hole 3 in the thickness direction of the ceramic substrate 100. In the SEM image of region X, the maximum length l of the root-like recess toward the ceramic plate 1 is measured from the inner surface 3 a defining the through-hole 3. Similarly, the maximum length l is measured at five randomly selected locations on the ceramic substrate 100, and the average maximum length L at the five locations is calculated. This average maximum length L represents the average thickness of the nitride film 4 of the ceramic substrate 100 according to the first embodiment.

[0077] The inner surface 3 a defining the through-hole 3 may have the nitride film 4 discontinuously or continuously.

[0078] Here, "non-continuously" having the nitride film 4 means that the nitride film 4 on the inner surface 3 a defining the through-hole 3 has a region where it is at least partially interrupted within the average thickness of the nitride film 4. In this case, in the region where the nitride film 4 is interrupted on the inner surface 3 a defining the through-hole 3, that is, in the region where the nitride film 4 is not present, no nitride is present within the tree-root-like recess on the inner surface 3 a defining the through-hole 3.

[0079] Furthermore, when the inner surface 3a defining the through-hole 3 has a discontinuous nitride film 4, the region without the nitride film 4 can have an aluminum film from the ceramic plate 1 on the inner surface 3a defining the through-hole 3. In other words, when the inner surface 3a defining the through-hole 3 has a discontinuous nitride film 4, the inner surface 3a defining the through-hole 3 can have a discontinuous aluminum film. In this case, the inner surface 3a defining the through-hole 3 includes regions having the nitride film 4 and regions having the aluminum film. Therefore, when the inner surface 3a defining the through-hole 3 has a discontinuous nitride film 4, the inner surface 3a defining the through-hole 3 does not have a continuous aluminum film.

[0080] Furthermore, "continuously" having the nitride film 4 means that the nitride film 4 on the inner surface 3a defining the through-hole 3 is disposed without interruption within the average thickness of the nitride film 4. In other words, when the inner surface 3a defining the through-hole 3 continuously has the nitride film 4, the inner surface 3a defining the through-hole 3 does not have an aluminum film originating from the ceramic plate 1.

[0081] (Conductive member 2)

[0082] The conductive member 2 is responsible for electrical wiring in the ceramic substrate 100. The conductive member 2 is, for example, a through-hole. In the ceramic substrate 100 according to the first embodiment, the conductive member 2 is formed inside the through-hole 3. Preferably, the conductive member 2 is formed so as to be flush with the first surface 1a of the ceramic plate 1 on the first surface 1a side and flush with the second surface 1b on the second surface 1b side.

[0083] The conductive member 2 preferably includes a eutectic structure of silver and copper. The eutectic structure of the conductive member 2 can be confirmed by observing a cross section of the ceramic substrate 100 in the thickness direction including the cross section of the conductive member 2 with a SEM.

[0084] The ceramic substrate 100 according to the first embodiment can be preferably manufactured by the method for manufacturing the ceramic substrate according to the first embodiment, which will be described later.

[0085] <<Modification of the first embodiment>>

[0086] Figure 2 It is a schematic cross-sectional view showing a modification of the ceramic substrate according to the first embodiment.

[0087] The modification of the ceramic substrate 100 according to the first embodiment differs from the ceramic substrate 100 according to the first embodiment in that the opening diameter of the through-hole 3 in the first surface 1a of the ceramic plate 1 is larger than the opening diameter of the through-hole 3 in the second surface 1b. When the opening diameter of the through-hole 3 in the ceramic plate 1 is described as "large," it means that the opening diameter of the through-hole 3 in the second surface 1b is greater than 5% of the opening diameter of the through-hole 3 in the first surface 1a of the ceramic plate 1.

[0088] in addition, Figure 2 An example is shown in which the opening diameter of the through hole 3 in the first surface 1a of the ceramic plate 1 is larger than the opening diameter of the through hole 3 in the second surface 1b. The first surface 1a and the second surface 1b are described only for the convenience of distinguishing the surfaces in the drawings. The opening diameter of the through hole 3 in the second surface 1b of the ceramic plate 1 can be larger than the opening diameter of the through hole 3 in the first surface 1a.

[0089] The ratio of the opening diameter of the through-hole 3 in the first surface 1 a to the opening diameter of the through-hole 3 in the second surface 1 b is not particularly limited.

[0090] <Second embodiment>

[0091] Figure 3A It is a schematic plan view showing an example of a ceramic substrate according to the second embodiment. Figure 3B It is a schematic bottom view showing an example of a ceramic substrate according to the second embodiment. Figure 3C As an example Figure 3A and Figure 3B Schematic cross-sectional view of the cross section taken along line IIIC-IIIC.

[0092] The ceramic substrate 100 involved in the second embodiment has a ceramic plate 1 containing aluminum nitride and a conductive component 2 formed inside a recess 5. The ceramic plate 1 containing aluminum nitride has a first surface 1a and a second surface 1b located on the opposite side of the first surface 1a, and has a recess 5 located on at least one of the first surface 1a and the second surface 1b. In the recess 5, the inner surface defining the recess 5 has a nitride film 4 with an average thickness of not less than 10 μm and not more than 35 μm.

[0093] Figure 3A , an example is shown in which the first surface 1 a has the recess 5 . The first surface 1 a and the second surface 1 b are described only for the convenience of distinguishing the surfaces in the drawings. The second surface 1 b may have the recess 5 .

[0094] The ceramic substrate 100 according to the second embodiment differs from the ceramic substrate 100 according to the first embodiment in that the through-hole 3 is replaced by a recess 5 . The configuration other than the recess 5 is the same as that of the ceramic substrate 100 according to the first embodiment.

[0095] Recess 5 is a bottomed hole that does not penetrate from the first surface 1a to the second surface 1b. Recess 5 has side surfaces 5a and a bottom 5b that connect the opening and the bottom in the Z-axis direction. In other words, the inner surface of recess 5 is defined by side surfaces 5a and bottom 5b. Recess 5 has the same structure as through-hole 3, except for a different cross-sectional shape in the Z-axis direction.

[0096] The maximum depth of the recess 5, that is, the maximum length in the Z-axis direction of the inner surface defining the recess 5 in the cross-sectional view, is not particularly limited and can be appropriately selected according to the thickness of the ceramic plate 1, but is preferably between 25 μm and 300 μm, preferably between 50 μm and 200 μm, and more preferably between 50 μm and 100 μm.

[0097] <<Modification of the second embodiment>>

[0098] Figure 4 It is a schematic cross-sectional view showing a modified example of the ceramic substrate according to the second embodiment.

[0099] The modification of the ceramic substrate 100 according to the second embodiment differs from the ceramic substrate 100 according to the first embodiment in that the opening diameter of the recess 5 is larger than the bottom diameter of the bottom 5b of the recess 5. When the opening diameter of the recess 5 of the ceramic plate 1 is described as "large," it means that the bottom diameter of the bottom 5b of the recess 5 is larger than 5% of the opening diameter of the recess 5.

[0100] The ratio of the opening diameter of the recess 5 to the bottom diameter of the bottom 5 b of the recess 5 is not particularly limited.

[0101] The cross-sectional shape of the recess 5 of the ceramic substrate 100 according to the second embodiment in the Z-axis direction is not limited to a rectangle, and may be, for example, a triangle, a trapezoid, a U-shape, or the like.

[0102] [Method for manufacturing ceramic substrate]

[0103] <First embodiment>

[0104] Figure 5 1 is a flowchart showing an example of a method for manufacturing a ceramic substrate according to the first embodiment. Figures 6A to 7B To explain.

[0105] The method for manufacturing a ceramic substrate according to the first embodiment includes: (S1) irradiating a ceramic plate 1 containing aluminum nitride and having a first surface 1a and a second surface 1b opposite to the first surface 1a with a laser beam L so as to deposit aluminum 11, thereby forming a through-hole 3 in the ceramic plate 1; (S2) removing the deposited aluminum 11 from an inner surface 3a defining the through-hole 3; and (S3) disposing a conductive paste 30 within the through-hole 3. The method for manufacturing a ceramic substrate according to the first embodiment preferably further includes (S2-1) grinding or polishing the ceramic plate 1, (S4) forming the conductive member 2, and (S5) grinding or polishing the conductive member 2.

[0106] (S1) Forming a through hole

[0107] Figure 6A This is a schematic cross-sectional view showing an example of a ceramic plate used in the method for manufacturing a ceramic substrate according to the first embodiment. Figure 6B It is a schematic cross-sectional view showing an example of forming a through hole in the method for manufacturing the ceramic substrate according to the first embodiment.

[0108] A ceramic plate 1 comprising aluminum nitride is prepared, comprising a first surface 1a and a second surface 1b opposite to the first surface 1a. The ceramic plate 1 may be a pre-sintered ceramic precursor or a sintered ceramic. Sintered ceramics are preferred because they do not experience dimensional changes due to sintering.

[0109] In forming through-hole S1, the ceramic plate 1 is irradiated with laser light L to precipitate aluminum 11, thereby forming through-hole 3 in the ceramic plate 1. The laser light L is not particularly limited as long as the aluminum 11 from the ceramic plate 1 can precipitate at the irradiated portion 20 of the through-hole 3, but a laser light L capable of thermal processing is preferred.

[0110] In the method for manufacturing a ceramic substrate according to the first embodiment, a wave that maximizes the pulse width of the laser light L in a pulse repetition period is a continuous wave (CW), and the pulse width of the laser light L includes the CW.

[0111] The laser light L capable of thermal processing preferably has a pulse width in the microsecond region or the nanosecond region, more preferably in the nanosecond region, and even more preferably in the range of 1 nanosecond to 23 nanoseconds.

[0112] Examples of the laser L capable of thermal processing include lasers having an oscillation wavelength of 750 nm or greater and lasers having an output of 500 W or greater. Specific examples of the laser L capable of thermal processing include fiber lasers, disk lasers, and CO2 lasers.

[0113] There are no particular restrictions on the pulse width, output, and wavelength of the laser L capable of thermal processing. For example, processing can be performed using fiber laser (CW: 1 nanosecond, wavelength: 532nm, output: 1,500W), disk laser (CW: 3 nanoseconds, wavelength: 1,064nm, output: 1,000W), CO2 laser (pulse: 16 nanoseconds × 200 times, wavelength: 10,600nm, output conversion: 300W~700W), etc. Aluminum 11 only needs to be precipitated and is not limited to these conditions.

[0114] When laser light L is irradiated along the Z-axis direction onto a predetermined area of ​​first surface 1a of ceramic plate 1 and thermally processed, the ceramic is primarily removed by melting and sublimation from irradiated areas 20 that have absorbed the irradiated laser light L, forming through-holes 3 extending from first surface 1a to second surface 1b. At this point, aluminum 11 is deposited in areas 20 of ceramic plate 1 irradiated with laser light L. Through-holes 3 can be formed by a single irradiation with laser light L, or by gradually removing the ceramic through multiple irradiations with laser light L.

[0115] In the ceramic plate 1 irradiated with the laser light L, the heat generated by the irradiation with the laser light L diffuses not only from the portion 20 irradiated with the laser light L but also from the portion 20 irradiated with the laser light L to the surrounding portion 21. Therefore, the aluminum 11 precipitated from the ceramic plate 1 is generated not only in the portion 20 irradiated with the laser light L but also in the surrounding portion 21 within the ceramic plate 1 in the X-axis direction from the portion 20 irradiated with the laser light L.

[0116] (S2) Removal of aluminum

[0117] Figure 6C It is a schematic cross-sectional view showing an example of removing precipitated aluminum in the method for producing the ceramic substrate according to the first embodiment.

[0118] In the method for manufacturing the ceramic substrate according to the first embodiment, “removing the precipitated aluminum 11 ” includes not only completely removing the precipitated aluminum 11 but also removing only the surface side of the precipitated aluminum 11 and / or partially removing it.

[0119] There are no particular restrictions on the partial removal of the precipitated aluminum 11, as long as it does not affect the effects of the present disclosure. However, it is preferably removed by at least 70%, more preferably at least 80%, and even more preferably at least 90%, relative to the total area of ​​the inner surface 3a defining the through-hole 3. The removal ratio of the precipitated aluminum 11 can be confirmed by SEM observation of a cross section of the ceramic plate 1 in the thickness direction, including the cross section of the through-hole 3, or by electrical testing.

[0120] When only the surface side of the precipitated aluminum 11 is removed, it is preferable to remove 50% or more of the precipitated aluminum 11 along the thickness direction, more preferably 70% or more, and even more preferably 90% or more. The precipitated aluminum 11 may not have a uniform thickness across the entire inner surface 3a defining the through-hole 3, and aluminum nitride may be exposed on a portion of the inner surface 3a defining the through-hole 3. Here, "the thickness direction of the precipitated aluminum 11" refers to the direction from the inner surface 3a defining the through-hole 3 toward the through-hole 3, i.e., the YX axis direction.

[0121] The method for removing the aluminum 11 deposited on the irradiated portion 20 defining the inner surface 3a of the through-hole 3 in S1 for forming the through-hole is not particularly limited, but it is preferable to bring a solvent into contact with the irradiated portion 20 defining the inner surface 3a of the through-hole 3. Examples of the method for bringing the solvent into contact with the irradiated portion 20 defining the inner surface 3a of the through-hole 3 include etching and immersing the ceramic plate 1 containing the aluminum deposited on the irradiated portion 20 defining the inner surface 3a of the through-hole 3 in a solvent.

[0122] The solvent is not particularly limited as long as it can remove the precipitated aluminum 11. Examples thereof include alkaline solvents such as sodium hydroxide, potassium hydroxide, and lithium hydroxide; and acidic solvents such as phosphoric acid, hydrochloric acid, sulfuric acid, nitric acid, and acetic acid. These may be used alone or in combination of two or more.

[0123] The temperature and time for bringing the solvent into contact with the irradiated portion 20 defining the inner surface 3 a of the through-hole 3 are not particularly limited as long as the precipitated aluminum 11 can be removed.

[0124] When the aluminum 11 deposited from the ceramic plate 1 is removed, the roughened, uneven inner surface 3a defining the through-hole 3 is exposed. At this time, the aluminum 11 deposited in the peripheral area 21 of the area irradiated by the laser light L is also removed, revealing the root-like recessed portion 21a defining the inner surface 3a of the through-hole 3. Therefore, the aluminum nitride of the ceramic plate 1 is exposed on the inner surface 3a defining the through-hole 3.

[0125] Furthermore, when the aluminum 11 deposited from the ceramic plate 1 is removed, burrs 12 are generated around the openings of the through holes 3 on the first surface 1 a and the second surface 1 b of the ceramic plate 1 .

[0126] (S2-1) Grinding or grinding ceramic plate

[0127] Figure 6D It is a schematic cross-sectional view showing an example of polishing or grinding a ceramic plate in the method for manufacturing a ceramic substrate according to the first embodiment.

[0128] In S2-1 of grinding or polishing the ceramic plate, burrs 12 formed on the first surface 1a and the second surface 1b of the ceramic plate 1 are ground or polished and removed. When burrs 12 are formed in S2-1 of grinding or polishing the ceramic plate, it is preferable to remove the burrs 12 so that the periphery of the opening of the through hole 3 is substantially flush with the first surface 1a and the second surface 1b.

[0129] Alternatively, instead of performing S2-1 of grinding or polishing the ceramic plate, the burrs 12 may be removed simultaneously with grinding or polishing the conductive member 2 in S5 of grinding or polishing the conductive member.

[0130] (S3) Prepare conductive paste

[0131] Figure 6E It is a schematic cross-sectional view showing an example of disposing the conductive paste in the method for manufacturing the ceramic substrate according to the first embodiment. Figure 7A For the general Figure 6E The region VIIA is enlarged and schematically shown in the enlarged cross-sectional view.

[0132] In step S3 of placing the conductive paste, the conductive paste 30 is filled into the through-hole 3 , so that the conductive paste 30 can be placed inside the through-hole 3 . At this time, the tree-root-shaped recess 21 a is also filled with the conductive paste 30 .

[0133] In S3 of disposing the conductive paste, the conductive paste 30 is filled into the through-hole 3 by, for example, screen printing, metal mask printing, or nozzle injection so that the conductive paste 30 and the first and second surfaces 1a, 1b of the ceramic plate 1 have substantially the same surface height.

[0134] In step S3 of disposing the conductive paste, in addition to filling the through-holes 3 with the conductive paste 30, the conductive paste 30 is preferably disposed so as to further cover the openings of the through-holes 3 and at least a portion of at least one of the first surface 1a and the second surface 1b of the ceramic plate 1. Therefore, in step S4 of forming the conductive member, a decrease in dimensional accuracy due to volume shrinkage during sintering of the conductive paste 30 can be prevented.

[0135] As a specific example, in step S3 of disposing the conductive paste, when filling the through-hole 3 with the conductive paste 30, the conductive paste 30 is preferably filled into the through-hole 3 from the first surface 1a of the ceramic plate 1, for example, using a squeegee, a tool used for screen printing. The conductive paste 30 is then filled into the through-hole 3 from the second surface 1b of the ceramic plate 1 using the same squeegee as used for the first surface 1a, thereby covering the opening of the through-hole 3 and at least a portion of at least one of the first surface 1a and the second surface 1b of the ceramic plate 1. In other words, the conductive paste 30 can be disposed so as to continuously cover at least a portion of at least one of the first surface 1a and the second surface 1b of the ceramic plate 1 from the through-hole 3.

[0136] Furthermore, in step S3 of applying the conductive paste, after applying the conductive paste 30 and before sintering, the conductive paste 30 is preferably dried and pressurized. For example, the conductive paste 30 can be dried by placing it in an electric furnace at a temperature above room temperature and below 100°C. Furthermore, when the ceramic plate 1 with the conductive paste 30 applied is placed in the furnace, it is preferably dried and pressurized simultaneously using a mold that applies pressure. The drying and pressurization process allows the conductive paste 30 to be formed into the conductive member 2, making it less susceptible to volume shrinkage in step S4.

[0137] -Conductive paste 30-

[0138] Conductive paste 30, preferably containing active metal solder, can appropriately form nitride film 4 on inner surface 3a defining through-hole 3 and improve adhesion between ceramic plate 1 and conductive member 2. Active metal solder contains eutectic powder 14 of silver and copper, active metal powder 15, and solvent 16, and preferably further includes inorganic filler 17 and other components as needed.

[0139] Furthermore, the active metal brazing material has fluidity and can be freely filled into the through-hole 3 of any shape. Furthermore, it can be arranged by applying it to any shape and thickness and then solidifying it.

[0140] --Eutectoid powder 14--

[0141] The eutectic powder 14 is a eutectic powder of silver and copper. The melting point of the eutectic powder of silver and copper is about 780°C.

[0142] The content of the eutectic powder 14 in the conductive paste 30 is not particularly limited, but is preferably 40% by mass or more and 95% by mass or less, when the total amount of the eutectic powder 14, the active metal powder 15, and the inorganic filler 17 is 100% by mass.

[0143] --Active metal powder 15--

[0144] The active metal powder 15 is a metal compound 18 that is disposed on at least a portion of the surface defining the inner surface 3 a of the through-hole 3 and the inorganic filler 17 after sintering.

[0145] There are no particular restrictions on the active metal powder 15. For example, titanium hydride (TiH2), cerium hydride (CeH2), zirconium hydride (ZrH2), magnesium hydride (MgH2), etc. can be cited. One of them can be used alone, or two or more of them can be used in combination. Among these, the active metal powder 15 preferably contains TiH2. If the active metal powder 15 contains TiH2, it reacts with the aluminum nitride exposed on the inner surface 3a that defines the through hole 3, and titanium nitride (TiN) as the metal compound 18 can be obtained. Titanium nitride is known as a barrier metal. Therefore, the migration of the metal in the conductive member 2 can be suppressed, and a highly reliable ceramic substrate 100 can be produced.

[0146] The content of active metal powder 15 in conductive paste 30 is not particularly limited, but is preferably 2% by mass or more and 15% by mass or less, relative to the combined amount of eutectic powder 14, active metal powder 15, and inorganic filler 17, taking the total amount of eutectic powder 14, active metal powder 15, and inorganic filler 17 as 100% by mass. When the content of active metal powder 15 is 2% by mass or more relative to the combined amount of eutectic powder 14, active metal powder 15, and inorganic filler 17, a nitride coating 4 of suitable thickness can be formed. Furthermore, hydrogen derived from active metal powder 15 can create a reducing atmosphere in the reaction phase, enabling proper sintering of conductive paste 30. If the content of active metal powder 15 exceeds 15% by mass relative to the combined amount of eutectic powder 14, active metal powder 15, and inorganic filler 17, there is a high likelihood that the generated hydrogen will not be eliminated and will remain as voids within conductive member 2.

[0147] --Solvent 16--

[0148] As the solvent 16, there is no particular restriction, and an organic binder is preferably used. As the organic binder, there is no particular restriction, for example, thermosetting resins, thermoplastic resins, etc. can be mentioned. As specific examples of organic binders, epoxy resins, silicone resins, acrylic resins, carbamate resins, polyvinyl resins, ethyl cellulose resins, phenol resins, polyimide resins, polyurethane resins, melamine resins, polyurea resins, etc. can be mentioned. In addition, as the organic binder, solvents and resin materials used as general through-hole materials can be used. They can be used alone or in combination of two or more. The organic binder acts as a sintering binder, so in S4 forming the conductive member 2, it is decomposed, evaporated and removed.

[0149] The content of the solvent 16 in the conductive paste 30 is not particularly limited and can be appropriately selected according to the contents of the eutectic powder 14 , the active metal powder 15 , and the inorganic filler 17 .

[0150] --Inorganic filler 17--

[0151] The inorganic filler 17 is not particularly limited. Examples include ceramic fillers such as silica fillers, metal fillers, and glass fillers. These may be used alone or in combination. Among these, ceramic fillers are preferred. The inclusion of the inorganic filler 17 in the conductive paste 30 improves the thermal conductivity and heat dissipation properties of the conductive member 2.

[0152] The ceramic filler is not particularly limited, and examples thereof include aluminum nitride (AlN), silicon nitride (Si 3 N 4 ), aluminum oxide (Al 2 O 3 ), and silicon carbide (SiC).

[0153] Furthermore, the inorganic filler 17 is preferably a material having a linear expansion coefficient of 8 ppm or less. This can reduce the linear coefficient of the conductive member 2 and improve thermal shock resistance.

[0154] The median particle size of the inorganic filler 17 is not particularly limited, but is preferably 1 μm or more and 50 μm or less, and more preferably 2 μm or more and 15 μm or less.

[0155] Furthermore, the inorganic filler 17 is preferably a material with a linear expansion coefficient of 5 ppm or less and a high thermal conductivity of 100 W / m·K or greater. Examples of such materials include the aforementioned ceramic fillers. Dispersing such a material within the conductive member 2 can mitigate differences in linear expansion coefficients and improve reliability, such as thermal shock resistance.

[0156] The thermal conductivity of the inorganic filler 17 is not particularly limited, but is preferably 20 W / (m / K) or higher, and more preferably 30 W / (m / K) or higher at a measurement temperature of 300 K.

[0157] The content of the inorganic filler 17 in the conductive paste 30 is not particularly limited, but is preferably 4% by mass or more and 50% by mass or less, based on 100% by mass of the total amount of the eutectic powder 14 , the active metal powder 15 , and the inorganic filler 17 .

[0158] --Other ingredients--

[0159] There are no particular limitations on other components in the conductive paste 30 , and examples thereof include reducing agents such as organic acids, and eutectic alloy powders other than the eutectic powder of silver and copper. These may be used alone or in combination of two or more.

[0160] Examples of eutectic alloy powders other than the silver and copper eutectic powder include copper and zinc eutectic alloys, copper and tin eutectic alloys, etc. These may be used alone or in combination of two or more.

[0161] The melting point of the other eutectic alloy powder is not particularly limited, but is preferably 700°C to 1,200°C, more preferably 720°C to 1,100°C, and even more preferably 780°C to 850°C.

[0162] The content of other eutectic alloy powders is not particularly limited as long as the effects of the present disclosure are not impaired.

[0163] (S4) Forming a conductive member

[0164] Figure 6F It is a schematic cross-sectional view showing an example of forming a conductive member in the method for manufacturing a ceramic substrate according to the first embodiment. Figure 7B For the general Figure 6F The region VIIB is enlarged and schematically shown in the enlarged cross-sectional view.

[0165] In step S4 of forming the conductive member, the conductive member 2 is formed inside the through-hole 3 , and the nitride film 4 is formed on the inner surface 3 a defining the through-hole 3 .

[0166] In S4 for forming the conductive member, the conductive member is formed by sintering the active metal solder serving as the conductive paste 30. The sintering can be performed using a sintering furnace such as an electric furnace.

[0167] The sintering temperature for sintering conductive paste 30 is not particularly limited, but is preferably 700°C to 1200°C, more preferably 720°C to 1000°C, and even more preferably 750°C to 900°C. Sintering conductive paste 30 at this preferred sintering temperature melts the eutectic of silver and copper, achieving conductivity in conductive member 2.

[0168] The sintering atmosphere when sintering the conductive paste 30 is not particularly limited, but is preferably an Ar atmosphere of 99.9% or more or an Ar atmosphere of 10 -5 Vacuum atmosphere below Pa.

[0169] The sintering time for sintering the conductive paste 30 is not particularly limited, but is preferably 5 minutes to 60 minutes, more preferably 10 minutes to 50 minutes, and even more preferably 15 minutes to 45 minutes.

[0170] The conductive member 2 produced using the conductive paste 30 contains, for example, a metal compound 18, a metal 19, and an inorganic filler 17. The solvent 16 is removed by sintering the conductive paste 30 and evaporating.

[0171] For example, when the combined content of the metal compound 18, the metal 19, and the inorganic filler 17 in the conductive member 2 is 100 mass%, it is preferred that the metal compound 18 be present in an amount of 1 mass% to 10 mass%, the metal 19 be present in an amount of 40 mass% to 95 mass%, and the inorganic filler 17 be present in an amount of 4 mass% to 50 mass%. The conductive member 2 contains the inorganic filler 17 at a predetermined ratio, thereby reducing volume shrinkage. Furthermore, the conductive member 2 contains the metal 19 at a predetermined ratio, thereby dispersing the inorganic filler 17 throughout the continuous metal 19.

[0172] The metal 19 is a metal member that serves as the core of the conductive member 2 together with the inorganic filler 17 when the conductive member 2 is formed. The metal 19 is disposed in a state where the inorganic filler 17 is dispersed.

[0173] In S4 of forming the conductive member, the silver and copper eutectic powder 14 in the conductive paste 30 is sintered to form the metal 19. Therefore, the metal 19 includes the silver and copper eutectic, and further includes the metal eutectic when the conductive paste 30 includes other metal eutectic powder.

[0174] The inorganic filler 17 is disposed in a state where a plurality of particles are dispersed in the conductive member 2. Here, a plurality of inorganic fillers 17 means that the inorganic filler 17 is not a single particle but a plurality of particles.

[0175] In addition, the inorganic filler 17 is preferably 100 μm thick in the cross-sectional view of the conductive member 2 in the Z-axis direction b. 2 , with 10μm 2 Above 75μm 2 The following ranges can be configured.

[0176] Active metal powder 15 is sintered to form metal compound 18. Conductive paste 30 is sintered to form a reaction phase between inorganic filler 17 and active metal powder 15 on the surface of inorganic filler 17. Metal compound 18 is primarily disposed on at least a portion or all of the surface of inorganic filler 17 and on at least a portion of inner surface 3a defining through-hole 3. Metal compound 18 includes filler surface metal compound 18a disposed on the surface of inorganic filler 17 and wall metal compound 18b disposed on at least a portion of inner surface 3a defining through-hole 3. It is preferred that active metal powder 15, inorganic filler 17, and the components of inner surface 3a defining through-hole 3 be sintered to form filler surface metal compound 18a and wall metal compound 18b as reactants.

[0177] The filler surface metal compound 18a is a metal compound 18 that is arranged to cover at least a portion or all of the surface of the inorganic filler 17. For example, when the inorganic filler 17 is aluminum nitride (AlN) or silicon nitride (Si3N4), the filler surface metal compound 18a reacts with titanium hydride (TiH2) in the active metal powder 15 before sintering to form titanium nitride (TiN) on the surface of the inorganic filler 17. Moreover, the filler surface metal compound 18a is formed continuously in a jagged pattern on its surface, and the surface of the inorganic filler 17 also becomes jagged. Moreover, the inorganic filler 17 with the filler surface metal compound 18a arranged on the surface becomes dispersed in the continuous conductive member 2.

[0178] The wall metal compound 18b is configured as the metal compound 18 on at least a portion of the inner surface 3a defining the through-hole 3. For example, if the inner surface 3a defining the through-hole 3 contains silicon nitride, the active metal powder 15 before sintering is, for example, titanium hydride, and a reactant is generated, forming a compound on the inner surface 3a defining the through-hole 3. The wall metal compound 18b is formed in a state where concavities and convexities are continuously formed in a zigzag pattern on the inner surface 3a defining the through-hole 3. The wall metal compound 18b is also formed in the root-shaped recesses of the inner surface 3a defining the through-hole 3, forming a nitride film 4. This improves the adhesion between the inner surface 3a defining the through-hole 3 and the conductive member 2. Furthermore, heat conducted from the conductive member 2 to the ceramic plate 1 can be efficiently released via the inner surface 3a defining the through-hole 3.

[0179] As described above, ceramic substrate 100 is obtained, which includes ceramic plate 1 and conductive member 2 having nitride film 4 on inner surface 3a defining through-hole 3. The average thickness of nitride film 4 in ceramic substrate 100 is preferably 10 μm to 35 μm, more preferably 10 μm to 25 μm.

[0180] (S5) Grinding or grinding the conductive member

[0181] Figure 6G It is a schematic cross-sectional view showing an example of polishing or grinding the conductive member in the method for manufacturing the ceramic substrate according to the first embodiment.

[0182] In S5 of polishing or grinding the conductive member, the conductive member 2 is polished or ground so that at least one of the first surface 1 a and the second surface 1 b of the ceramic plate 1 in the portion covered by the conductive member 2 is exposed.

[0183] The ceramic substrate 100 obtained in forming the conductive component S4 can be used directly, for example, when only the through hole 3 of the ceramic plate 1 is filled with the conductive paste 30 in S3 in which the conductive paste is configured. However, when it is configured to cover the opening of the through hole 3 and at least a portion of at least one of the first surface 1a and the second surface 1b of the ceramic plate 1, by further grinding or grinding the conductive component S5, the first surface 1a and the second surface 1b of the ceramic plate 1 and the surface (exposed surface) of the conductive component 2 can be made approximately the same surface.

[0184] In addition, in S4 of forming the conductive member, the first surface 1 a and the second surface 1 b of the ceramic plate 1 may be blackened, but these can be removed in S5 of polishing or grinding the conductive member.

[0185] <<First Modification of the First Embodiment>>

[0186] The first variant of the method for manufacturing a ceramic substrate involved in the first embodiment differs from the method for manufacturing a ceramic substrate involved in the first embodiment in that, in S1 of forming a through hole, the laser L is irradiated in such a manner that the opening diameter of the through hole 3 in the first surface 1a of the ceramic plate 1 is larger than the opening diameter of the through hole 3 in the second surface 1b.

[0187] By changing the pulse width of the laser light L and the output as needed, the cross-sectional shape of the through-hole 3 can be adjusted to a desired shape. For example, compared with the method for manufacturing the ceramic substrate according to the first embodiment, this can achieve a lower output of the laser light L and shorten the irradiation time of the laser light L. Furthermore, it is preferred that the laser light L be irradiated from the first surface 1a side of the ceramic plate 1.

[0188] <Second embodiment>

[0189] The method for manufacturing a ceramic substrate according to the second embodiment differs from the method for manufacturing a ceramic substrate according to the first embodiment in that in step S1 of forming a through-hole, the through-hole 3 and the recess 5 are formed in the ceramic plate 1 in step S1A.

[0190] By changing the pulse width of the laser light L and changing the output as needed, the recess 5 can be formed and the depth of the recess 5 can be adjusted. For example, compared with the method for manufacturing a ceramic substrate according to the first embodiment, the output of the laser light L can be lowered, and the irradiation time of the laser light L can be shortened.

[0191] <<First Modification of Second Embodiment>>

[0192] The first variant of the method for manufacturing a ceramic substrate involved in the second embodiment differs from the method for manufacturing a ceramic substrate involved in the second embodiment in that: in S1A where a recess 5 is formed on the ceramic plate 1, laser L is irradiated in such a manner that the opening diameter of the recess 5 in the first surface 1a of the ceramic plate 1 is larger than the bottom diameter of the recess 5.

[0193] The cross-sectional shape of the recess 5 can be adjusted to a desired shape by changing the pulse width and output of the laser light L as needed. For example, compared to the method for manufacturing a ceramic substrate according to the second embodiment, lower output of the laser light L and shorter irradiation time of the laser light L can be achieved.

[0194] <<Second Modification of the First or Second Embodiment>>

[0195] The second variant of the method for manufacturing a ceramic substrate according to the first embodiment or the method for manufacturing a ceramic substrate according to the second embodiment differs from the method for manufacturing a ceramic substrate according to the first embodiment or the method for manufacturing a ceramic substrate according to the second embodiment in that the conductive paste 30 further contains at least one powder 31 selected from the group consisting of copper powder, silver powder, powder of an alloy of silver and copper, and ceramic powder.

[0196] The content of at least one powder 31 selected from the group consisting of copper powder, silver powder, powder of an alloy of silver and copper, and ceramic powder in the conductive paste 30 is not particularly limited as long as the effects of the present disclosure are not impaired. When the total amount of the eutectic powder 14, the active metal powder 15, the inorganic filler 17, and the powder 31 is 100 mass%, it is preferably 5 mass% or more and 20 mass% or less.

[0197] Copper powder, silver powder, and silver-copper alloy powder have superior electrical conductivity compared to silver-copper eutectic powder. Furthermore, copper powder has a melting point of 1,084°C, and silver powder has a melting point of 962°C. Therefore, during the sintering step S4 to form the conductive member, the conductive paste 30 is less likely to melt and remains dispersed in the conductive member 2 as a powder. This further improves the electrical conductivity of the ceramic substrate 100.

[0198] Furthermore, since ceramic powder also has a high melting point, it is difficult to melt into the conductive paste 30 even when sintering S4 to form the conductive member, and may exist as a powder dispersed in the conductive member 2. This can reduce the difference in linear expansion coefficient between the ceramic plate 1 and the conductive member 2, further improving the reliability of the ceramic substrate 100.

[0199] 〔Light-emitting device〕

[0200] The light-emitting device 200 according to the embodiment includes the ceramic substrate 100 according to the embodiment and a light-emitting element 202 provided with an electrode 205 disposed on the ceramic substrate 100 . The electrode 205 is electrically connected to the conductive member 2 .

[0201] Figure 8 2 is a schematic cross-sectional view showing an example of a light emitting device 200 according to an embodiment. Components of the light emitting device 200 will be described below.

[0202] The light emitting device 200 is a device that emits light by arranging light emitting elements 202 on a ceramic substrate 100. The number of light emitting elements 202 may be one or more. In the case of a plurality of light emitting elements 202, their arrangement is not particularly limited, and for example, they may be arranged in a row.

[0203] As an example, the light-emitting device 200 is configured with a light-transmitting component 203 to cover the light-taking surface of the light-emitting element 202; a light-reflecting component 204 to cover the side surfaces of the light-emitting element 202 and the first surface 1a of the ceramic plate 1 in the ceramic substrate 100; and a metal bump 206 electrically connected to the light-emitting element 202 and the conductive component 2 of the ceramic substrate 100.

[0204] In the ceramic substrate 100, wiring of various patterns can be formed according to the application. However, in the light-emitting device 200 involved in the embodiment, the light-emitting element 202 has a pair of electrodes 205 on the same side and is mounted face down with the surface having the electrodes 205 facing the first surface 1a of the ceramic plate 1 in the ceramic substrate 100.

[0205] In the light emitting device 200 according to the embodiment, the pair of electrodes 205 of the light emitting element 202 can be placed on the side opposite to the surface in contact with the ceramic substrate 100 and can be mounted face up and connected to the conductive member 2 of the ceramic substrate 100 via wires.

[0206] (Light-emitting element 202)

[0207] The light-emitting element 202 includes a pair of electrodes 205 , a semiconductor stack 207 , and an element substrate 208 .

[0208] The light emitting element 202 includes, as an example, a semiconductor stack 207 on the bottom surface side of an element substrate 208 and a pair of electrodes 205 on the semiconductor stack 207 side.

[0209] As the semiconductor stack 207, any composition can be used depending on the desired emission wavelength. For example, a nitride semiconductor (Indium nitride) capable of emitting blue or green light can be used. x Al y Ga 1-x-yN, 0≤X, 0≤Y, X+Y≤1) or GaP, or GaAlAs or AlInGaP capable of red light emission. These can be used alone or in combination of two or more. Furthermore, the size and shape of light-emitting element 202 can be appropriately selected depending on the intended use.

[0210] As the element substrate 208 , a sapphire substrate or a silicon substrate is used as an example.

[0211] Electrode 205 is connected to conductive member 2 of ceramic substrate 100 via metal bump 206 via bonding member 209. Electrodes 205 are arranged so that one side is a p-electrode and the other side is an n-electrode, maintaining a distance that prevents electrical shorting. As an example, while electrodes 205 are configured so that the p-electrode and the n-electrode are each located at one position, either electrode may be located at two positions, while the other electrode may be located at one position.

[0212] (Translucent member 203)

[0213] The light-transmitting member 203 is arranged on the plane side of the element substrate 208, which is the light-extracting surface. The light-transmitting member 203 can be made of, for example, a light-transmitting resin material, epoxy resin, silicone resin, or a resin mixed therewith. The light-transmitting member 203 can include a phosphor, for example, a phosphor that absorbs blue light from the light-emitting element 202 and emits yellow light, thereby emitting white light. In addition, the light-transmitting member 203 can include multiple types of phosphors, for example, a phosphor that absorbs blue light from the semiconductor stack 207 and emits green light, and a phosphor that emits red light, thereby emitting white light from the light-emitting element 202.

[0214] As such a phosphor, for example, a yttrium-aluminum-garnet phosphor (for example, Y3(Al, Ga)5O 12 :Ce), lutetium-aluminum-garnet phosphors (e.g., Lu3(Al, Ga)5O 12 :Ce), terbium-aluminum-garnet phosphor (for example, Tb3(Al, Ga)5O 12 :Ce), βSialon phosphor (for example, (Si,Al)3(O,N)4:Eu), αSialon phosphor (for example, Mz(Si,Al) 12 (O, N) 16(wherein, 0<z≤2, M is a lanthanide element other than Li, Mg, Ca, Y, and La and Ce)), nitride-based phosphors such as CASN-based phosphors (e.g., CaAlSiN3:Eu) or SCASN-based phosphors (e.g., (Sr, Ca)AlSiN3:Eu), fluoride-based phosphors such as KSF-based phosphors (e.g., K2SiF6:Mn), KSAF-based phosphors (e.g., K2(Si, Al)F6:Mn), or MGF-based phosphors (e.g., 3.5MgO-0.5MgF2-GeO2:Mn), or quantum dot phosphors such as perovskite and chalcopyrite, etc.

[0215] (Metal bump 206)

[0216] The metal bumps 206 electrically connect the electrode 205 to the conductive member 2. The metal bumps 206 can be located on either the electrode 205 side or the conductive member 2 side. The shape, size, and number of the metal bumps 206 can be appropriately set as long as they can be located within the electrode 205. The size of the metal bumps 206 can be adjusted appropriately based on the size of the semiconductor stack 207 and the required light output of the light-emitting element. For example, a diameter of tens to hundreds of μm is possible.

[0217] Metal bumps 206 can be formed, for example, from Au, Ag, Cu, Al, Sn, Pt, Zn, Ni, or alloys thereof. Metal bumps 206 can be formed, for example, in this region using a known bumping method. The bumping method can be formed using a bump bonder, a wire bonding device, or the like. Furthermore, metal bumps 206 can be formed in this region using known methods such as electrolytic plating, electroless plating, vapor deposition, and sputtering.

[0218] The metal bumps 206 are bonded here, for example, via a bonding member 209. Examples of the bonding member 209 used here include solders such as tin-bismuth, tin-copper, tin-silver, and gold-tin; eutectic alloys such as alloys mainly composed of Au and Sn, alloys mainly composed of Au and Si, and alloys mainly composed of Au and Ge; paste materials such as silver, gold, and palladium; anisotropic conductive materials such as ACP and ACF; solders of low-melting-point metals; conductive adhesives in combination thereof; and conductive composite adhesives.

[0219] (Light reflecting member 204)

[0220] The light-reflecting member 204 is a light-reflecting member. The light-reflecting member 204 is positioned to cover the first surface 1a of the ceramic plate 1 in the ceramic substrate 100 while also covering the side surfaces of the light-emitting element 202. Furthermore, the light-reflecting member 204 is positioned to expose the light-extraction surface of the light-emitting element 202 and to be flush with the light-reflecting member 204 of the light-emitting element 202. Furthermore, the light-reflecting member 204 is positioned, for example, between the lower surface of the light-emitting element 202 and the first surface 1a of the ceramic plate 1 in the ceramic substrate 100.

[0221] The light reflecting member 204 preferably has a high reflectivity in order to effectively utilize the light from the light emitting element 202. The light reflecting member 204 is preferably white. The reflectivity of the light reflecting member 204 at the wavelength of the light emitted by the light emitting element 202 is preferably 90% or higher, and more preferably 94% or higher.

[0222] The light reflecting member 204 may be made of a resin such as a thermoplastic resin, such as an acrylic resin, a polycarbonate resin, a cyclic polyolefin resin, a polyethylene terephthalate resin, a polyethylene naphthalate resin, or a polyester resin, or a thermosetting resin such as an epoxy resin or a silicone resin. A known light diffusing material such as titanium oxide, silicon oxide, aluminum oxide, zinc oxide, or glass may be used.

[0223] Furthermore, the light-emitting device 200 uses one light-emitting element 202 as a unit to control brightness and dimming. The number of light-emitting elements 202 included in a unit can be one or more. For example, a unit can contain four light-emitting elements 202 in one row and four columns, or two rows and two columns, or nine light-emitting elements 202 in three rows and three columns. The number of light-emitting elements 202 is not limited.

[0224] Application examples of light-emitting devices

[0225] Figure 9A It is a perspective view showing an application example of the light emitting device according to the embodiment. Figure 9B To express Figure 9A The IXB-IXB section of FIG. Figure 9B Omit Figure 9A It is expressed as a part of .

[0226] The light emitting device 200 may be provided with a plurality of ( Figure 9A The light emitting module 300 (11 in FIG. 1 ) may be a structure in which 11 light emitting devices 200 are mounted on one ceramic substrate 100. The structure of the light emitting module 300 will be described.

[0227] The light-emitting module 300 includes 11 light-emitting devices 200 in a row, a light-reflecting member 204 on the periphery of the light-emitting device 200, a frame 301 on the outside of the light-reflecting member 204, and a module substrate 302 connected to the surface opposite to the first surface 1a of the ceramic plate 1 in the ceramic substrate 100.

[0228] The frame 301 is a member for surrounding the light reflecting member 204 covering the plurality of light emitting devices 200. The frame 301 is formed in a rectangular ring shape, for example, a rectangular shape in a plan view, and is arranged so as to surround the light reflecting member 204.

[0229] The frame 301 can be formed using a frame-shaped member made of metal, alloy, or ceramic. Examples of metals include Fe, Cu, Ni, Al, Ag, Au, Al, Pt, Ti, W, and Pd. Examples of alloys include alloys containing at least one selected from the group consisting of Fe, Cu, Ni, Al, Ag, Au, Al, Pt, Ti, W, and Pd.

[0230] Alternatively, a resin material may be used as the frame 301. In this case, the metal, alloy, or ceramic member may be embedded in the frame 301 formed of the resin material, or a portion of the frame 301 may be formed of the resin material and another portion of the metal, alloy, or ceramic member.

[0231] The module substrate 302 is a member for mounting the light emitting device 200 and is a substrate for electrically connecting the light emitting device 200 to the outside. The module substrate 302 is formed into a substantially rectangular shape in a plan view, for example. The module substrate 302 includes a substrate portion 303 and a wiring board portion 304.

[0232] As a material for substrate portion 303, for example, an insulating material is preferably used, and a material that is not easily permeable to light emitted from light-emitting element 202 or external light is preferably used. For example, ceramics such as alumina, aluminum nitride, and mullite; thermoplastic resins such as polyamide, polyphthalamide, polyphenylene sulfide, and liquid crystal polymer; and resins such as epoxy resin, silicone resin, modified epoxy resin, urethane resin, and phenol resin can be used. Among these, ceramics having excellent heat dissipation properties are preferably used as the material for substrate portion 303.

[0233] Furthermore, the wiring board portion 304 is formed on the substrate portion 303 at a position facing the conductive member 2 on the surface opposite to the first surface 1a of the ceramic board 1 in the ceramic substrate 100 of the light-emitting device 200. Examples of the material for the wiring board portion 304 include the materials exemplified as the materials used for the conductive member 2.

[0234] Furthermore, the module substrate 302 is bonded to the frame 301 via a conductive adhesive 305, and the conductive member 2 is bonded to the wiring board portion 304. Conductive adhesive 305 can be, for example, eutectic solder, conductive paste, or bumps. Furthermore, in the light-emitting device 200, protective elements 306 are arranged on the ceramic substrate 100 in parallel with the light-emitting elements 202.

[0235] The light emitting module 300 is configured as described above, and therefore operates as follows when driven.

[0236] In the light-emitting module 300, current is supplied from an external power source to the light-emitting element 202 via the wiring board portion 304, the conductive member 2, and the electrode 205, causing the light-emitting element 202 to emit light. Of the light emitted by the light-emitting element 202, light traveling upward is extracted externally above the light-emitting device 200 via the translucent member 203. Furthermore, light traveling downward is reflected by the ceramic substrate 100 and extracted externally via the translucent member 203. Furthermore, light traveling between the light-emitting element 202 and the housing 301 is reflected by the light-reflecting member 204 and the housing 301 and extracted externally via the translucent member 203. Furthermore, light traveling between the light-emitting elements 202 is reflected by the light-reflecting member 204 and extracted externally via the translucent member 203. In this case, by narrowing the space between the light-transmitting members 203 (for example, 0.2 mm or less), the optical system can be simplified and compacted when the light-emitting module 300 is used as a light source for a vehicle headlight.

[0237] Furthermore, when manufacturing the light-emitting module 300, the light-emitting devices 200 are arranged on a sheet member, the frame 301 is disposed around them, and in this state, the light-reflecting member 204 is placed in the space surrounded by the frame 301 and the sheet member. The light-emitting devices 200 supported by the frame 301 and the light-reflecting member 204 are then placed on a module substrate 302 equipped with a wiring board portion 304 and a conductive adhesive 305. The conductive member 2 and the wiring board portion 304 are then electrically connected, thereby manufacturing the light-emitting module 300.

[0238] [Method for manufacturing a light-emitting device]

[0239] The method for manufacturing a light emitting device according to the embodiment includes preparing a ceramic substrate 100 manufactured by the method for manufacturing a ceramic substrate 100 according to the embodiment, and disposing a light emitting element 202 having an electrode 205 on the ceramic substrate 100 , wherein the electrode 205 is electrically connected to a conductive member 2 .

[0240] Figure 101 is a flowchart showing an example of a method for manufacturing a light emitting device according to an embodiment. In addition, the method for manufacturing a light emitting device according to an embodiment includes, as an example, disposing a light reflecting member.

[0241] (S11) Preparing a ceramic substrate

[0242] In S11 of preparing the ceramic substrate 100 , the ceramic substrate 100 according to the embodiment is prepared.

[0243] Furthermore, the ceramic substrate 100 has a plurality of regions for arranging the light emitting elements 202 , and can be sized to be singulated into individual light emitting devices 200 after the light reflecting member 204 is arranged.

[0244] (S12) Configuring Light-Emitting Elements

[0245] In step S12 of arranging the light-emitting element, a light-emitting element 202 having an electrode 205 is arranged on a ceramic substrate 100. In step S12 of arranging the light-emitting element, the electrode 205 of the light-emitting element 202 is connected to a bonding member 209 disposed on the conductive member 2 using a metal bump 206. The light-emitting element 202 is already in a state where a translucent member 203 is connected to an element substrate 208. When bonding the translucent member 203 to the element substrate 208, a translucent bonding material is used.

[0246] (S13) Arrangement of light reflecting member

[0247] In S13 of arranging the light-reflecting member, the light-reflecting member 204 is arranged so as to cover the first surface 1a of the ceramic plate 1 in the ceramic substrate 100 and the side surfaces of the light-emitting element 202. The light-reflecting member 204 is arranged on the ceramic substrate 100 so as to surround the light-emitting element 202 and expose the upper surface of the light-transmitting member 203, which serves as the light extraction surface of the light-emitting element 202. The light-reflecting member 204 is arranged so as to form a rectangular shape when viewed from above.

[0248] In addition, in the manufacturing method of the light-emitting device according to the embodiment, after S13 of configuring the light-reflecting member, a singulation operation is performed as needed. The light-emitting device 200 is pre-set as a single unit of the light-emitting device 200 according to the number of light-emitting elements 202 used. Therefore, when manufacturing a plurality of light-emitting devices 200, a singulation operation is performed. When performing the singulation operation, a plurality of light-emitting devices 200 are produced by cutting in a grid pattern. In addition, as a cutting method, for example, a method using a disk-shaped rotating blade, an ultrasonic cutter, a laser irradiation scraper, etc. can be cited.

[0249] Example

[0250] The present invention is described in detail below with reference to the following examples, but the present invention is not limited by these examples.

[0251] (Example 1)

[0252] 84 parts by mass of eutectic powder of silver and copper, 10 parts by mass of titanium hydride powder, 1 part by mass of polyvinyl butyral (PVB) resin, and 5 parts by mass of aluminum nitride powder were mixed to prepare a conductive paste 30. Using this conductive paste 30, based on Figure 5 The flowchart shown in FIG. 1 shows a method for manufacturing a ceramic substrate according to an embodiment of the present invention. A fiber laser (CW: 1 nanosecond, wavelength: 532 nm, output: 1,500 W) is used in step S1 for forming the through-holes. Furthermore, in step S4 for forming the conductive member, the ceramic plate 1 with the conductive paste 30 disposed in the through-holes 3 is sintered at 850°C for 30 minutes.

[0253] After performing S1 for forming the through-holes and S2 for removing the aluminum, each ceramic plate 1 was cut in the thickness direction by laser irradiation and observed with a metal microscope at a magnification of 250 times. Figure 11A The cross-sectional observation image of the through-hole 3 after irradiation with the laser light L in S1 for forming the through-hole is shown. Aluminum 11 deposited on the inner surface defining the through-hole 3 is confirmed. Figure 11B The cross-sectional observation image of the through-hole 3 after etching in S2 in which aluminum is removed is shown. After the precipitated aluminum 11 is removed, burrs 12 are confirmed to be generated on the inner surface 3a defining the through-hole 3.

[0254] The manufactured ceramic substrate 100 was cut in the thickness direction by laser irradiation, and a region including the inner surface 3 a defining the through-hole 3 in the cut cross section was observed using an SEM at a magnification of 250 times. Figure 12A The cross-section of the ceramic substrate 100 is observed using a SEM. Figure 12B An observation image of a cross section of the ceramic substrate 100 obtained by fluorescent X-ray spectroscopy (Ti-Ka) is shown.

[0255] Furthermore, a region including the inner surface 3 a defining the through-hole 3 in the first surface 1 a of the manufactured ceramic substrate 100 was observed using a metallographic microscope and an SEM at a magnification of 250 times. Figure 13A Observation image obtained using a metallographic microscope is shown of a region including the inner surface 3 a defining the through-hole 3 on the first surface 1 a of the ceramic substrate 100 . Figure 13B The image obtained by SEM observation shows a region of the inner surface 3 a defining the through-hole 3 on the first surface 1 a of the ceramic substrate 100 including the cross section of the ceramic substrate 100 .

[0256] These observation images confirmed the nitride film 4 including the root-like inner surface 3a defining the through-hole 3 and the nitride present in the inner surface 3a. The average thickness of the nitride film 4 was 20 μm, and the opening diameter of the through-hole 3 was 100 μm.

[0257] As described above, the present invention has been described based on specific embodiments. However, these are merely examples, and the present invention is not limited to the above embodiments. The above embodiments can be implemented in various other forms, and various combinations, omissions, substitutions, additions, and modifications can be made without departing from the scope of the invention. These embodiments and their modifications are included in the scope and spirit of the invention and are included in the scope equivalent to the invention described in the claims.

[0258] In addition to the above embodiments, the following supplementary notes are further disclosed.

[0259] (Note 1)

[0260] A method for manufacturing a ceramic substrate, comprising:

[0261] A ceramic plate including aluminum nitride and having a first surface and a second surface opposite to the first surface is irradiated with laser light so as to precipitate aluminum, thereby forming a through hole or a recess in the ceramic plate.

[0262] removing the aluminum deposited on the inner surface of the through hole or the recess, and

[0263] A conductive paste is disposed inside the through hole or the recess.

[0264] (Note 2)

[0265] According to the method for manufacturing a ceramic substrate as described in Supplementary Note 1,

[0266] When configuring the above conductive paste, the above conductive paste is active metal solder,

[0267] The manufacturing method includes: filling the through hole or the recess with the active metal brazing material, and then sintering the active metal brazing material to form a conductive member.

[0268] (Note 3)

[0269] According to the method for manufacturing a ceramic substrate described in Appendix 2, when the conductive paste is arranged, the conductive paste is arranged so as to cover the opening of the through hole or the recess and at least a portion of at least one of the first surface and the second surface of the ceramic plate.

[0270] (Note 4)

[0271] According to the method for producing a ceramic substrate according to Supplementary Note 2 or Supplementary Note 3, the active metal solder contains eutectic powder of silver and copper, an active metal, and a solvent.

[0272] (Note 5)

[0273] The method for producing a ceramic substrate according to Supplementary Note 4, wherein the active metal solder further contains at least one powder selected from the group consisting of copper powder, silver powder, powder of an alloy of silver and copper, and ceramic powder.

[0274] (Note 6)

[0275] According to the method for producing a ceramic substrate according to Supplementary Note 4 or Supplementary Note 5, the content of the active metal in the active metal brazing filler metal is 2% by mass or more and 15% by mass or less.

[0276] (Note 7)

[0277] According to any one of Notes 3 to 6, the manufacturing method of the ceramic substrate includes: when forming the above-mentioned conductive component, grinding or polishing the above-mentioned conductive component in such a manner that at least one of the above-mentioned first surface and the above-mentioned second surface of the above-mentioned ceramic plate in the portion covered by the above-mentioned conductive component is exposed.

[0278] (Note 8)

[0279] The method for producing a ceramic substrate according to any one of Supplementary Notes 1 to 7, further comprising: bringing a solvent into contact with the inner surface of the through-hole or the recess when removing the aluminum.

[0280] (Note 9)

[0281] According to the method for manufacturing a ceramic substrate described in any one of Notes 1 to 8, when forming the through hole or the recess, the opening diameter of the through hole formed on the first surface of the ceramic plate is larger than the opening diameter of the through hole formed on the second surface.

[0282] (Note 10)

[0283] According to the method for manufacturing a ceramic substrate according to any one of Supplementary Notes 2 to 9, when forming the conductive member, the average thickness of the nitride film formed on the inner surface defining the through hole or the recess is 10 μm to 35 μm.

[0284] (Note 11)

[0285] According to the method for manufacturing a ceramic substrate according to any one of Supplementary Notes 1 to 10, when forming the through-hole or the recess, the ceramic plate is heat-processed by irradiation with the laser beam to precipitate the aluminum on the inner surface of the through-hole or the recess.

[0286] (Note 12)

[0287] According to the method for manufacturing a ceramic substrate according to Supplementary Note 11, the laser light is a laser light having an oscillation wavelength of 750 nm or more or a laser light having an output of 500 W or more.

[0288] (Note 13)

[0289] According to the method for manufacturing a ceramic substrate according to any one of Supplementary Notes 1 to 12, when forming the through-hole or the recessed portion, the ceramic plate is a sintered ceramic plate.

[0290] (Note 14)

[0291] A method for manufacturing a light-emitting device, comprising:

[0292] preparing the ceramic substrate manufactured by the method for manufacturing the ceramic substrate according to any one of Supplementary Notes 1 to 13, and

[0293] A light-emitting element having electrodes is arranged on the ceramic substrate.

[0294] The electrodes are electrically connected to the conductive members.

[0295] (Note 15)

[0296] A ceramic substrate comprising:

[0297] A ceramic plate comprising aluminum nitride, comprising a first surface and a second surface located opposite to the first surface, and having a through hole connecting the first surface and the second surface or a recess located on at least one of the first surface and the second surface; and

[0298] The conductive member formed inside the through hole or the recess,

[0299] In the through hole or the recess, an inner surface defining the through hole or the recess has a nitride film having an average thickness of 10 μm to 35 μm.

[0300] (Note 16)

[0301] The ceramic substrate according to Supplementary Note 15, wherein the conductive member includes a eutectic structure of silver and copper.

[0302] (Note 17)

[0303] The ceramic substrate according to Supplementary Note 16, wherein the conductive member further contains at least one powder selected from the group consisting of copper powder, silver powder, powder of an alloy of silver and copper, and ceramic powder.

[0304] (Note 18)

[0305] According to Supplementary Note 15 or Supplementary Note 16, the inner surface defining the through hole or the recess has the discontinuous nitride film and does not have a continuous aluminum film.

[0306] (Note 19)

[0307] The ceramic substrate according to any one of Supplementary Notes 15 to 18, wherein the inner surface defining the through hole or the recess has the continuous nitride film.

[0308] (Note 20)

[0309] A light emitting device comprising:

[0310] The ceramic substrate according to any one of Supplementary Notes 15 to 19, and

[0311] A light emitting element having electrodes disposed on the ceramic substrate,

[0312] The electrode and the conductive member are electrically connected.

[0313] Explanation of symbols

[0314] 1 ceramic plate

[0315] 1a Page 1

[0316] 1b Side 2

[0317] 2 conductive components

[0318] 3 through holes

[0319] 3a inner surface

[0320] 4 Nitride film

[0321] 5 recesses

[0322] 11 Aluminum

[0323] 12 Fly

[0324] 14 eutectic powder

[0325] 15Active metal powder

[0326] 16 solvents

[0327] 17Inorganic fillers

[0328] 18 Metal compounds

[0329] 18a Metal compounds on the filler surface

[0330] 18b Wall metal compounds

[0331] 19 Metal

[0332] 20 irradiation sites

[0333] 21 peripheral areas

[0334] 30 conductive paste

[0335] 31 powder

[0336] 100 ceramic substrate

[0337] 200 light-emitting devices

[0338] 202 light-emitting element

[0339] 203 Translucent Components

[0340] 204 light reflecting component

[0341] 205 electrode

[0342] 206 metal bumps

[0343] 207 semiconductor stack

[0344] 208 component substrate

[0345] 209 joint components

[0346] 300 light-emitting modules

[0347] 301 frame

[0348] 302 module substrate

[0349] 303 Substrate Department

[0350] 304 wiring board

[0351] 305 conductive adhesive

[0352] 306 protection element

Claims

1. A method for manufacturing a ceramic substrate, comprising: A ceramic plate including aluminum nitride and having a first surface and a second surface located opposite to the first surface is irradiated with laser light so as to deposit aluminum, thereby forming through holes or recesses in the ceramic plate. removing the aluminum deposited on the inner surface of the through hole or the recess, and A conductive paste is disposed inside the through hole or the recess.

2. The method for manufacturing a ceramic substrate according to claim 1, When configuring the conductive paste, the conductive paste is an active metal solder. The manufacturing method comprises: After the active metal solder is filled in the through hole or the recess, the active metal solder is sintered to form a conductive member.

3. The method for manufacturing a ceramic substrate according to claim 2, When the conductive paste is disposed, the conductive paste is disposed so as to cover the opening of the through hole or the recess and at least a portion of at least one of the first surface and the second surface of the ceramic plate.

4. The method for manufacturing a ceramic substrate according to claim 2 or 3, The active metal solder contains eutectic powder of silver and copper, active metal and solvent.

5. The method for manufacturing a ceramic substrate according to claim 4, The active metal solder further contains at least one powder selected from the group consisting of copper powder, silver powder, powder of an alloy of silver and copper, and ceramic powder.

6. The method for manufacturing a ceramic substrate according to claim 4 or 5, The content of the active metal in the active metal brazing filler metal is 2 mass % or more and 15 mass % or less.

7. The method for manufacturing a ceramic substrate according to any one of claims 3 to 6, comprising: When forming the conductive member, the conductive member is ground or polished so that at least one of the first surface and the second surface of the ceramic plate in the portion covered by the conductive member is exposed.

8. The method for manufacturing a ceramic substrate according to any one of claims 1 to 7, further comprising: When removing the aluminum, a solvent is brought into contact with the inner surface of the through-hole or the recess.

9. The method for producing a ceramic substrate according to any one of claims 1 to 8, When forming the through-hole or the recess, the opening diameter of the through-hole formed on the first surface of the ceramic plate is larger than the opening diameter of the through-hole formed on the second surface.

10. The method for producing a ceramic substrate according to any one of claims 2 to 9, When forming the conductive member, the average thickness of the nitride film formed on the inner surface defining the through hole or the recess is 10 μm to 35 μm.

11. The method for producing a ceramic substrate according to any one of claims 1 to 10, When forming the through-hole or the recess, the ceramic plate is thermally processed by irradiation with the laser beam, so that the aluminum is deposited on the inner surface of the through-hole or the recess.

12. The method for manufacturing a ceramic substrate according to claim 11, The laser light is a laser light having an oscillation wavelength of 750 nm or more or a laser light having an output of 500 W or more.

13. The method for producing a ceramic substrate according to any one of claims 1 to 12, When forming the through hole or the recess, the ceramic plate is a sintered ceramic plate.

14. A method for manufacturing a light-emitting device, comprising: The ceramic substrate manufactured by the method for manufacturing a ceramic substrate according to any one of claims 1 to 13 is prepared, and A light emitting element having electrodes is arranged on the ceramic substrate. The electrode is electrically connected to the conductive member.

15. A ceramic substrate comprising: A ceramic plate comprising aluminum nitride, comprising a first surface and a second surface located opposite to the first surface, and having a through hole connecting the first surface and the second surface or a recess located on at least one of the first surface and the second surface; and The conductive member formed inside the through hole or the recess, In the through hole or the recessed portion, an inner surface defining the through hole or the recessed portion has a nitride film having an average thickness of 10 μm to 35 μm.

16. The ceramic substrate according to claim 15, The conductive member contains a eutectic structure of silver and copper.

17. The ceramic substrate according to claim 16, The conductive member further contains at least one powder selected from the group consisting of copper powder, silver powder, powder of an alloy of silver and copper, and ceramic powder.

18. The ceramic substrate according to claim 15 or 16, The inner surface defining the through hole or the recess has the discontinuous nitride film and does not have a continuous aluminum film.

19. The ceramic substrate according to any one of claims 15 to 18, An inner surface defining the through hole or the recess has the continuous nitride film.

20. A light emitting device comprising: The ceramic substrate according to any one of claims 15 to 19, and a light-emitting element provided with electrodes and disposed on the ceramic substrate; The electrode and the conductive member are electrically connected.

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