Light-emitting device

Abstract

The present invention provides a light-emitting device that suppresses short circuits caused by ion migration between conductive layers. [Solution] The light-emitting device comprises a substrate and a light source unit disposed on the substrate, the substrate having first and second surfaces, the second surface having one or more grooves including a first groove and first and second regions on both sides of the first groove, a resin layer comprising at least a plurality of fiber bundles and resin, and first and second conductive layers disposed in the first and second regions of the resin layer, one or more continuous fiber bundles of a plurality of fiber bundles shallower than the bottom of the first groove in cross-sectional view being arranged in the resin layer to traverse the first and second regions and the first groove in plan view, the resin layer having a first portion overlapping the first or second conductive layer and a second portion overlapping one or more grooves, the density of the plurality of fiber bundles in the second portion being greater than in the first portion, and the light source unit includes an electrode-forming surface on which first and second electrodes electrically connected to the first and second conductive layers are disposed, the electrode-forming surface facing the substrate.

Description

[Technical Field]

[0001] This application relates to a light-emitting device. [Background technology]

[0002] Light-emitting devices are known in which light-emitting elements such as LEDs (Light Emitting Diodes) are mounted on a substrate. In such light-emitting devices, the substrate on which the light-emitting elements are mounted (hereinafter referred to as the "substrate for light-emitting elements") has, for example, a plurality of conductive layers on the side opposite to the side on which the light-emitting elements are mounted, which are electrically connected to the positive and negative electrodes of the light-emitting elements. (See, for example, Patent Document 1). [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2010-040801 [Overview of the project] [Problems that the invention aims to solve]

[0004] When the distance between multiple conductive layers on a substrate for a light-emitting element becomes small, ion migration is more likely to occur between the conductive layers. When ion migration occurs, there is a risk of short circuits between the conductive layers, which can cause malfunctions or failure of the light-emitting element.

[0005] The purpose of this disclosure is to provide a substrate for a light-emitting element that suppresses short circuits due to ion migration between conductive layers, a light-emitting device using the substrate for the light-emitting element, and a method for manufacturing the substrate for the light-emitting element. [Means for solving the problem]

[0006] A substrate for a light-emitting element according to one embodiment of the present disclosure has a first surface and a second surface located opposite to the first surface, wherein the second surface has at least one groove including a first groove and a first region and a second region located on both sides of the first groove, and comprises a sheet-like resin layer containing at least a plurality of fiber bundles and resin, a first conductive layer disposed in the first region of the resin layer, and a second conductive layer disposed in the second region of the resin layer, wherein in a cross-sectional view passing through the first conductive layer, the first groove and the second conductive layer, at least one continuous fiber bundle of the plurality of fiber bundles located at a position shallower than the bottom of the first groove is arranged in a plan view to traverse the first region, the first groove and the second region.

[0007] A light-emitting device according to one embodiment of the present disclosure comprises a light-emitting substrate as described above, wherein the first conductive layer is a first lower conductive layer, the second conductive layer is a second lower conductive layer, and the first surface side of the resin layer comprises a first upper conductive layer and a second upper conductive layer arranged at intervals from each other, the first upper conductive layer being electrically connected to the first lower conductive layer, and the second upper conductive layer being electrically connected to the second lower conductive layer; and at least one light-emitting device disposed on the first surface side of the resin layer, wherein the at least one light-emitting device includes a first light-emitting device having a first electrode electrically connected to the first upper conductive layer and a second electrode electrically connected to the second upper conductive layer.

[0008] A method for manufacturing a light-emitting element substrate according to one embodiment of the present disclosure involves preparing a sheet-like metal plate having at least one protrusion on its first surface, and a prepreg having a plurality of fiber bundles and resin. The process includes: a step of bonding the first surface of the metal plate and the prepreg; a step of curing the prepreg to form a resin layer; a step of forming a resist on the metal plate; a step of etching the at least one protrusion of the metal plate; and a step of removing the resist. [Effects of the Invention]

[0009] According to an embodiment of the present disclosure, it is possible to provide a substrate for a light-emitting element that suppresses a short circuit due to ion migration between conductive layers, a light-emitting device using the substrate for a light-emitting element, and a method for manufacturing the substrate for a light-emitting element.

Brief Description of the Drawings

[0010] [Figure 1A] FIG. 1A is a schematic top view of a substrate for a light-emitting element according to an embodiment of the present disclosure. [Figure 1B] FIG. 1B is a schematic bottom view of the substrate for a light-emitting element shown in FIG. 1A. [Figure 1C] FIG. 1C is a schematic cross-sectional view taken along line 1C-1C shown in FIGS. 1A and 1B. [Figure 1D] FIG. 1D is a schematic enlarged cross-sectional view showing a part of FIG. 1C in an enlarged manner. [Figure 2A] FIG. 2A is a schematic top view of a light-emitting device according to an embodiment of the present disclosure. [Figure 2B] FIG. 2B is a schematic cross-sectional view taken along line 2B-2B shown in FIG. 2A. [Figure 3A] FIG. 3A is a schematic enlarged cross-sectional view showing a part of a resin layer in an embodiment. [Figure 3B] FIG. 3B is a schematic enlarged top view showing an example of a fiber layer. [Figure 3C] FIG. 3C is a schematic diagram for explaining the arrangement of the first fiber bundle, and is a schematic enlarged bottom view showing a part of the substrate for a light-emitting element. [Figure 4A] FIG. 4A is a schematic bottom view of a first substrate in an embodiment. [Figure 4B] FIG. 4B is a schematic enlarged bottom view showing a part of the first substrate shown in FIG. 4A. [Figure 4C] FIG. 4C is a schematic cross-sectional view taken along line 4C-4C shown in FIG. 4B. [Figure 5] FIG. 5 is a schematic enlarged bottom view showing a part of another first substrate in an embodiment. [Figure 6] FIG. 6 is a cross-sectional view showing another example of a light source unit. [Figure 7A]FIG. 7A is a schematic top view showing a light-emitting device of an embodiment. [Figure 7B] FIG. 7B is a schematic bottom view of the light-emitting device shown in FIG. 7A. [Figure 7C] FIG. 7C is a schematic cross-sectional view taken along the line 7C-7C shown in FIGS. 7A and 7B. [Figure 7D] FIG. 7D is a schematic side view of the light-emitting device shown in FIG. 7A. [Figure 8A] FIG. 8A is a schematic enlarged top view showing a part of a metal plate used in the manufacture of a substrate for a light-emitting element of an embodiment. [Figure 8B] FIG. 8B is a schematic cross-sectional view taken along the line 8B-8B shown in FIG. 8A. [Figure 8C] FIG. is a schematic enlarged cross-sectional view showing a part of a prepreg used in the manufacture of a substrate for a light-emitting element of an embodiment. [Figure 9A] FIG. 9A is a process cross-sectional view showing the manufacturing process of a substrate for a light-emitting element of an embodiment. [Figure 9B] FIG. 9B is a process cross-sectional view showing the manufacturing process of a substrate for a light-emitting element of an embodiment. [Figure 9C] FIG. 9C is a process cross-sectional view showing the manufacturing process of a substrate for a light-emitting element of an embodiment. [Figure 9D] FIG. 9D is a process cross-sectional view showing the manufacturing process of a substrate for a light-emitting element of an embodiment. [Figure 9E] FIG. 9E is a process cross-sectional view showing the manufacturing process of a substrate for a light-emitting element of an embodiment. [Figure 9F] FIG. 9F is a process cross-sectional view showing the manufacturing process of a substrate for a light-emitting element of an embodiment. [Figure 9G] FIG. 9G is a process cross-sectional view showing the manufacturing process of a substrate for a light-emitting element of an embodiment. [Figure 10A] FIG. 10A is a schematic top view of a substrate for a light-emitting element of Modification 1. [Figure 10B] FIG. 10B is a schematic bottom view of the substrate for a light-emitting element shown in FIG. 10A. [Figure 10C] FIG. 10C is a schematic cross-sectional view taken along the line 10C-10C shown in FIGS. 10A and 10B. [Figure 11] Figure 11 is a schematic enlarged bottom view showing a portion of the first substrate of the modified example 1. [Figure 12A] Figure 12A is a schematic top view showing the light-emitting device of Modification 1. [Figure 12B] Figure 12B is a schematic bottom view of the light-emitting device shown in Figure 12A. [Figure 12C] Figure 12C is a schematic cross-sectional view along the line 12C-12C shown in Figures 12A and 12B. [Figure 13] Figure 13 is a cross-sectional view of the light-emitting device shown in Figure 12C, with the lens removed. [Figure 14A] Figure 14A is a schematic top view of the light-emitting element substrate of the modified example 2. [Figure 14B] Figure 14B is a schematic bottom view of the light-emitting element substrate shown in Figure 14A. [Figure 14C] Figure 14C is a schematic cross-sectional view along the line 14C-14C shown in Figures 14A and 14B. [Figure 15] Figure 15 is a schematic enlarged bottom view showing a portion of the first substrate of the modified example 2. [Figure 16] Figure 16 is a schematic bottom view showing another substrate for a light-emitting element in the modified example 2. [Figure 17A] Figure 17A is a schematic bottom view of the light-emitting element substrate of Modification 3. [Figure 17B] Figure 17B is a schematic bottom view of another light-emitting substrate for the modified example 3. [Figure 18] Figure 18 is a schematic bottom view of yet another light-emitting substrate of the modified example 3. [Figure 19A] Figure 19A is a schematic cross-sectional view of the light-emitting element substrate of the modified example 4. [Figure 19B] Figure 19B is a schematic cross-sectional view of another light-emitting element substrate for the modified example 4. [Figure 19C] Figure 19C is a schematic cross-sectional view of another light-emitting substrate for the modified example 4. [Figure 20] Figure 20 is a schematic bottom view of another light-emitting element substrate for the modified example 4. [Figure 21] Figure 21 is a schematic enlarged cross-sectional view showing a reference example of a processing method for forming grooves in a resin layer. [Modes for carrying out the invention]

[0011] Embodiments of the invention will be described below with reference to the drawings as appropriate. However, the light-emitting substrate and light-emitting device described below are intended to embody the technical concept of the present invention, and unless otherwise specified, the present invention is not limited to these. Furthermore, the content described in one embodiment is applicable to other embodiments and modifications. In addition, the size and positional relationships of the components shown in the drawings may be exaggerated for the sake of clarity in the explanation.

[0012] In the following descriptions, components having substantially the same function are indicated by a common reference numeral, and their descriptions may be omitted. Alternatively, components not referenced in the descriptions may not be given a reference numeral. In the following descriptions, terms indicating specific directions or positions (e.g., "up," "down," "right," "left," and other terms including these terms) may be used. However, these terms are used only for clarity to indicate the relative direction or position in the referenced drawings. If the relative direction or position relationship using terms such as "up" and "down" in the referenced drawings is the same, the arrangement in drawings other than those disclosed, actual products, manufacturing equipment, etc., does not have to be the same as in the referenced drawings. In this disclosure, "parallel" includes cases where two lines, edges, planes, etc., are within a range of approximately 0° to ±5°, unless otherwise specified. Also, in this disclosure, "perpendicular" or "orthogonal" includes cases where two lines, edges, planes, etc., are within a range of approximately 90° to ±5°, unless otherwise specified.

[0013] In the following diagram, arrows indicating the mutually orthogonal x, y, and z axes are shown together. In the x-direction, the direction the arrow points is denoted as the +x direction, and the opposite direction of the +x direction is denoted as the -x direction. In the y-direction, the direction the arrow points is denoted as the +y direction, and the opposite direction of the +y direction is denoted as the -y direction. In the z-direction, the direction the arrow points is denoted as the +z direction, and the opposite direction of the +z direction is denoted as the -z direction. In the embodiment, the light-emitting element is assumed to emit light in the +z direction as an example. However, this does not restrict the orientation of the light-emitting device and light-emitting element when used, and the orientation of the light-emitting device and light-emitting element is arbitrary. Furthermore, in the claims and specification, "planar view" means viewing the object from the +z direction or the -z direction, and "planar shape" means the shape of the object when viewed from the z direction.

[0014] Furthermore, in this specification or the claims, when there are multiple components and each is to be expressed separately, the components may be distinguished by adding "1st," "2nd," etc., to their names. Also, the objects being distinguished may differ between this specification and the claims. Therefore, even if a component with the same prefix as in this specification is described in the claims, the objects identified by this component may not be the same in this specification and the claims.

[0015] For example, if there are components in this specification that are distinguished by being appended with "1st," "2nd," and "3rd," and the components appended with "1st" and "3rd" in this specification are described in the claims, then, from the standpoint of readability, the claims will be described as "1st," "2nd," etc. The components may be distinguished by adding the following note. In this case, the claim may state “First The components designated as "1st" and "2nd" refer to the components designated as "1st" and "3rd" in this specification, respectively. This rule is not limited to components; it can be applied to other subjects in a reasonable and flexible manner.

[0016] (Embodiment) Figures 1A to 1D show a substrate for a light-emitting element according to one embodiment of the present disclosure (hereinafter abbreviated as "substrate"). This may happen.) This is a diagram of 100. Figure 1A is a schematic top view of substrate 100, and Figure 1B is a schematic bottom view of substrate 100. Figure 1C is a schematic cross-sectional view of substrate 100 along the line 1C-1C shown in Figures 1A and 1B. Figure 1D is an enlarged cross-sectional view of a part of Figure 1C.

[0017] The substrate 100 comprises a sheet-like resin layer 10 and a plurality of conductive layers 20, including a first conductive layer 21 and a second conductive layer 22. The resin layer 10 has a first surface 10a and a second surface 10b located on the opposite side of the first surface 10a. The second surface 10b has at least one groove 30 including a first groove 31, and a first region R1 and a second region R2 located on both sides of the first groove 31, respectively. The resin layer 10 also contains at least a plurality of fiber bundles and resin. In the resin layer 10, in a cross-sectional view passing through the first conductive layer 21, the first groove 31, and the second conductive layer 22, at least one continuous first fiber bundle of the plurality of fiber bundles located shallower than the bottom P of the first groove 31 is arranged in a plan view to traverse the first region R1, the first groove 31, and the second region R2.

[0018] The substrate 100 has an upper surface 100a and a lower surface 100b located on the opposite side of the upper surface 100a. The first surface 10a of the resin layer 10 is located on the same side as the upper surface 100a of the substrate 100, and the second surface 10b is located on the same side as the lower surface 100b of the substrate 100.

[0019] Multiple conductive layers 20, including a first conductive layer 21 and a second conductive layer 22, are arranged on the second surface 10b of the resin layer 10. The first conductive layer 21 is located in the first region R1 of the resin layer 10, and the second conductive layer 22 is located in the second region R2 of the resin layer 10. In this specification, the resin layer 10 The conductive layer 20 provided on the second surface 10b is sometimes called the "lower conductive layer".

[0020] In the substrate 100 of this embodiment, by providing the first groove 31 on the second surface 10b of the resin layer 10, the distance between the first conductive layer 21 and the second conductive layer 22 along the second surface 10b of the resin layer 10 (hereinafter sometimes referred to as the "creepage distance") can be increased, thereby suppressing short circuits between the conductive layers caused by ion migration between the first conductive layer 21 and the second conductive layer 22.

[0021] Figure 2A is a schematic top view of a light-emitting device according to one embodiment of the present disclosure, and Figure 2B is a schematic cross-sectional view taken along the line 2B-2B shown in Figure 2A.

[0022] The light-emitting device 400 of this embodiment comprises a light-emitting element substrate 100 and at least one light-emitting element 70. The light-emitting element substrate 100 comprises a first lower conductive layer 21, a second lower conductive layer 22, and a first upper conductive layer 41 and a second upper conductive layer 42 arranged at intervals from each other on the first surface 10a side of the resin layer 10. Here, the first conductive layer 21 shown in Figures 1B and 1C is the first lower conductive layer 21, and the second conductive layer 22 is the second lower conductive layer 22. The first upper conductive layer 41 is electrically connected to the first lower conductive layer 21, and the second upper conductive layer 42 is electrically connected to the second lower conductive layer 22. Furthermore, the light-emitting device 400 of this embodiment comprises a light-emitting element substrate 100 and at least one light-emitting element 70 arranged on the first surface 10a side of the resin layer 10. At least one light-emitting element 70 includes a first light-emitting element 71 having a first electrode 81 electrically connected to a first upper conductive layer 41 and a second electrode 82 electrically connected to a second upper conductive layer 42.

[0023] The following describes each component in detail.

[0024] [Resin layer 10] As described later, the resin layer 10 includes at least a plurality of fiber bundles 11 and a resin 12. In the configuration illustrated in Figures 1A to 1C, the resin layer 10 is sheet-like and has a first surface 10a and a second surface 10b parallel to the xy plane, and a side surface 10c located between the first surface 10a and the second surface 10b. The side surface 10c may be perpendicular to the xy plane. The thickness d1 of the resin layer 10 is, for example, 200 μm or more and 900 μm or less. Here, the thickness d1 of the resin layer 10 is, for example, 300 μm. "Thickness of the resin layer" is the distance in the z direction between the portion of the second surface 10b of the resin layer 10 in which the groove 30 is not formed and the first surface 10a.

[0025] The planar shape of the resin layer 10, that is, the shape of the first surface 10a and the second surface 10b, is, for example, a quadrilateral. Each side of the quadrilateral is parallel to the x-axis or the y-axis. In the example shown in Figure 1B, the second surface 10b is a rectangle having four corners c1 to c4 and four sides s1 to s4. Sides s1 and s3 are parallel to the x-axis, and side s3 is located on the +y side of side s1. Sides s2 and s4 are parallel to the y-axis, and side s4 is located on the -x side of side s2. The angle between side s1 and side s2 is corner c1. Corner c2 is the angle between side s2 and side s3, corner c3 is the angle between side s3 and side s4, and corner c4 is the angle between side s4 and side s1. The first surface 10a shown in Figure 1A is also a rectangle similar to the second surface 10b. The dimensions of the first surface 10a and the second surface 10b are, for example, 6 mm x 6 mm. The planar shape of the resin layer 10 may be a polygon other than a quadrilateral, such as a triangle, pentagon, or hexagon. In this specification, the term "polygon" includes shapes in which the corners of the polygon have been processed, such as rounded corners, chamfers, or rounded edges. Similarly, shapes in which processing has been applied not only to the corners (ends of the sides) but also to the middle parts of the sides will also be called polygons. In other words, shapes that retain a polygonal base but have been partially processed are included in the interpretation of "polygon" as described in this specification. Furthermore, the planar shape of the resin layer 10 may also be a curved shape such as a circular or elliptical shape.

[0026] As shown in Figure 1B, the second surface 10b of the resin layer 10 has at least one groove 30 and a plurality of conductive layer placement regions. The conductive layer placement regions are regions where the conductive layer 20 is placed. A groove 30 is located between two adjacent conductive layer placement regions. In this embodiment, the plurality of conductive layer placement regions include a first region R1 and a second region R2. The groove 30 includes a first groove 31 located between the first region R1 and the second region R2.

[0027] In the example shown in Figure 1B, the second surface 10b includes a first groove 31, a first region R1 located on the -x side of the first groove 31, and a second region R2 located on the +x side of the first groove 31. The first groove 31 is a groove that extends linearly in the y-axis direction between the first region R1 and the second region R2. The first region R1 is the region enclosed by the first groove 31 and the periphery of the second surface 10b (here, sides s3, s4, and s1), and the second region R2 is the region enclosed by the first groove 31 and the periphery of the second surface 10b (here, sides s1, s2, and s3). In this example, both ends of the first groove 31 are in contact with sides s1 and s3 of the second surface 10b, respectively, but there may be gaps between the first groove 31 and side s1, or between the first groove 31 and side s3. Furthermore, depending on the planar shape and positional relationship of the first region R1 and the second region R2, the first groove 31 may be arranged parallel to the x-axis or in a direction intersecting the x-axis and y-axis (for example, in a direction inclined ±45° with respect to the x-axis). If the resin layer 10 has a polygonal planar shape such as a square, the first groove 31 may be arranged between two vertices of the polygon, along the diagonal connecting these vertices.

[0028] Preferably, the first groove 31 is positioned in a plan view so as to intersect the line segment connecting the shortest distance L1 between the first conductive layer 21 and the second conductive layer 22. This more effectively suppresses short circuits caused by ion migration between the first conductive layer 21 and the second conductive layer 22.

[0029] The second surface 10b of the resin layer 10 may be divided (partitioned) into multiple regions, including a first region R1 and a second region R2, by at least one groove 30. "Divided by a groove" or "partitioned by a groove" means that the second surface 10b is divided into multiple regions, and the groove 30 is positioned to define at least a portion of the periphery of each region. The groove 30 does not have to be positioned to completely separate the conductive layer regions. For example, there may be a portion between two conductive layer regions where no groove 30 is formed.

[0030] The number of grooves 30 and conductive layer placement regions is not particularly limited. The second surface 10b of the resin layer 10 may have a plurality of grooves 30 and three or more conductive layer placement regions. For example, the second surface 10b may be divided into three or more conductive layer placement regions by a plurality of grooves 30. By placing one conductive layer 20 in each of the plurality of conductive layer placement regions divided by the grooves 30, short circuits due to ion migration between two adjacent conductive layers 20 can be suppressed. In this case, in a plan view, at least one of the plurality of grooves 30 may be placed between two adjacent conductive layers 20.

[0031] <Groove 30> The grooves 30 on the second surface 10b of the resin layer 10 may include straight portions extending in a straight line and / or curved portions extending in a curved shape when viewed from above. The curved portions may be circular, elliptical, or arc-shaped portions that are part of these shapes.

[0032] The groove 30 has an edge at the boundary between the groove 30 and the conductive layer arrangement region (here, the first region R1 and the second region R2). In the example shown in Figures 1B and 1C, the first groove 31 has a first edge e1 located on the first region R1 side and a second edge e2 located on the second region R2 side. The first edge e1 and the second edge e2 face each other. The first edge e1 and the second edge e2 may be substantially parallel. The first edge e1 and the second edge e2 are parallel to the y-axis. The width w of the groove 31, that is, the distance between the first edge e1 and the second edge e2, is preferably 50 μm or more and 1000 μm or less, and more preferably 100 μm or more and 500 μm or less.

[0033] As shown in Figures 1C and 1D, the groove 30 has a bottom P including a bottom surface f3 in a cross-sectional view. In this specification, "bottom of the groove" refers to the portion of the groove 30 located furthest to the +z side in a cross-sectional view along the width direction of the groove 30. The depth (maximum depth) d2 of the groove 30 is preferably, for example, 1 / 3 or more and 2 / 3 or less of the thickness d1 of the resin layer 10, for example, about 1 / 2. If the depth d2 of the groove 30 is within the above range, the creepage distance between the conductive layers 20 located on both sides of the groove 30 can be increased, thereby effectively suppressing ion migration. On the other hand, if the depth d2 of the groove 30 is 2 / 3 or less of the thickness d1 of the resin layer 10, the reduction in the strength of the substrate 100 due to the partial thinning of the resin layer 10 by the groove 30 can be suppressed. The depth d2 of the groove 30 may be, for example, 130 μm or more and 600 μm or less.

[0034] The cross-sectional shape of the groove 30 is not particularly limited, but in the example shown in Figure 1D, the cross-sectional shape of the first groove 31 includes a part of a rectangle. The first groove 31 has a bottom surface f3, a side surface f1 located between the bottom surface f3 and the first edge e1, and a side surface f2 located between the bottom surface f3 and the second edge e2. The bottom surface f3 may be substantially parallel to the portion of the second surface 10b other than the groove 30 (substantially parallel to the xy plane). The side surfaces f1 and f2 may each be substantially perpendicular to the bottom surface f3 (perpendicular to the xy plane).

[0035] Note that groove 30 may include grooves other than the first groove 31. The width w, depth d2, and cross-sectional shape of the grooves other than the first groove 31 may be the same as or different from those of the first groove 31.

[0036] <Structure and materials of resin layer 10> Figure 3A is an enlarged cross-sectional view showing a part of the resin layer 10, including the first groove 31, the first conductive layer 21, and the second conductive layer 22. Figure 3B is an enlarged top view showing an example of the fiber layer 13 in the resin layer 10. Figure 3C is an enlarged bottom view showing a part of the substrate 100.

[0037] The resin layer 10 comprises at least a plurality of fiber bundles 11 and resin 12. The resin layer 10 is formed by reinforcing the resin 12 with fiber bundles 11. Each fiber bundle 11 is a bundle containing multiple fibers. The thickness of a single fiber is, for example, 4 μm to 10 μm. In this example, the fiber bundle 11 includes a plurality of longitudinal fiber bundles 112 substantially parallel to the y-axis and a plurality of transverse fiber bundles 113 substantially parallel to the x-axis. The longitudinal fiber bundles 112 and transverse fiber bundles 113 are arranged to intersect each other in a plan view. In the illustrated example, the longitudinal fiber bundles 112 are arranged along the y-axis and the transverse fiber bundles 113 are arranged along the x-axis, but this is not limited to this.

[0038] The resin layer 10 may include at least one fiber layer 13 composed of a plurality of fiber bundles 11. Each fiber layer 13 may be a woven fabric made of longitudinal fiber bundles 112 and transverse fiber bundles 113, as illustrated in Figure 3B. It is preferable that the resin layer 10 includes a plurality of fiber layers 13. As shown in Figure 3A, the plurality of fiber layers 13 may be stacked at predetermined intervals in the thickness direction (z direction) of the resin layer 10.

[0039] The plurality of fiber bundles 11 include at least one continuous first fiber bundle 11Y located shallower than the bottom P of the first groove 31. The first fiber bundle 11Y is a fiber bundle in a portion of the resin layer 10 (here, the portion of the resin layer 10 in which the groove 30 is not formed) whose depth along the +z direction from the second surface 10b of the resin layer 10 is less than the depth of the bottom P. The resin layer 10 preferably includes a plurality of first fiber bundles 11Y.

[0040] As shown in Figures 3A and 3C, the first fiber bundle 11Y is arranged to traverse the first region R1, the first groove 31, and the second region R2 in cross-sectional and plan views. In other words, in cross-sectional and plan views, the portion of the first fiber bundle 11Y that overlaps with the first region R1, the first groove 31, and the second region R2 are arranged to traverse the first region R1, the first groove 31, and the second region R2. The portion overlapping with region 1 and the portion overlapping with region 2 R2 are connected (continuous). In the illustrated example, the first fiber bundle 11Y intersects the first edge e1 and the second edge e2 of the first groove 31.

[0041] In this specification, in a plan view, the portion p1 of the resin layer 10 that overlaps with the conductive layer 20 is referred to as the "first portion," and the portion p2 that overlaps with the groove 30 is referred to as the "second portion." In this example, the portion of the resin layer 10 that overlaps with the first conductive layer 21 and the portion that overlaps with the second conductive layer 22 is the first portion p1, and the portion that overlaps with the first groove 31 is the second portion p2. The second portion p2 is thinner than the first portion p1 by, for example, the depth d2 of the first groove 31.

[0042] The first fiber bundle 11Y may traverse the first portion p1 and the second portion p2 in a plan view. As can be seen from Figure 3A, in the first portion p1 of the resin layer 10, the first fiber bundle 11Y is located shallower than the bottom P of the first groove 31, but in the second portion p2, it is located between the bottom P of the first groove 31 and the first surface 10a of the resin layer 10. As a result, only resin 12 is placed on the surface of at least one groove 30. In a cross-sectional view, the first fiber bundle 11Y is bent along the first groove 31 in the depth direction (+z direction) of the first groove 31. As shown in the figure, in a cross-sectional view passing through the first conductive layer 21, the first groove 31 and the second conductive layer 22, the first fiber bundle 11Y is bent in the +z direction along the sides f1 and f2 of the first groove 31, thereby having a recess 11Yd that is indented in the +z direction.

[0043] The multiple fiber layers 13 may include at least one first fiber layer 13Y located shallower than the bottom P of the first groove 31. The first fiber layer 13Y may be arranged continuously across the first region R1, the first groove 31, and the second region R2 in a plan view. Furthermore, for example, three or more fiber layers 13 may be stacked within the resin layer 10. This can more effectively increase the strength of the resin layer 10. Among the multiple fiber layers 13, the fiber layer 13 located deeper than the bottom P of the first groove 31 may have fiber bundles 11 that bend in the +z direction along the sides f1 and f2 of the first groove 31.

[0044] The second surface 10b of the resin layer 10 may have a plurality of grooves 30, including the first groove 31. In the above description, the structure of the fiber bundle 11 overlapping the first groove 31 and the first and second regions R1 was explained as an example in a plan view, but in a plan view, the fiber bundle 11 overlapping each of the plurality of grooves 30 and the conductive layer arrangement regions located on both sides of the groove 30 may have the same structure as described above. That is, the plurality of fiber bundles 11 include at least one continuous first fiber bundle located shallower than the bottom P of each groove 30, and the first fiber bundle may be arranged so as to traverse the groove 30 and the two conductive layer arrangement regions located on both sides of the groove 30 in a plan view. In addition, the first fiber bundle may be curved in the depth direction (+z direction) along the groove 30 in a cross-sectional view.

[0045] The resin layer 10 includes, in plan view, a first portion p1 that overlaps the first conductive layer 21 or the second conductive layer 22, and a second portion p2 that overlaps at least one groove 30. Although the second portion p2 of the resin layer 10 is thinner than the first portion p1, it may contain a similar number of fiber bundles 11 or a similar number of fiber layers 13 as the first portion p1. Therefore, the density of the fiber bundles 11 in the second portion p2 of the resin layer 10 can be made greater than the density of the fiber bundles 11 in the first portion p1. This ensures the strength of the second portion p2 of the resin layer 10.

[0046] At least one fiber bundle 11 may include two or more fiber bundles 11 stacked in the thickness direction of the resin layer 10 between the first surface 10a and the second surface 10b of the resin layer 10. When the resin layer 10 includes, in a plan view, a first portion 1p that overlaps the first conductive layer 21 or the second conductive layer 22 and a second portion p2 that overlaps at least one groove 30, it is preferable that the stacking interval of the fiber bundles 11 in the second portion p2 of the resin layer 10 is smaller than the stacking interval of the fiber bundles 11 in the first portion p1. For example, two or more fiber layers 1 each containing a fiber bundle 11. 3 is stacked in the thickness direction of the resin layer 10, and it is preferable that the spacing between the fiber layers 13 in the second portion p2 is smaller than the spacing between the fiber layers 13 in the first portion p1.

[0047] In the resin layer 10 of this embodiment, the first fiber bundle 11Y, which is located shallower than the bottom P of the groove 30, is continuously arranged so as to traverse the groove 30 in a plan view. That is, a portion of the first fiber bundle 11Y is located between the groove 30 and the first surface 10a of the resin layer 10. On the surface of the groove 30, only resin 12 is arranged, similar to the second surface 10b of the resin layer 10 excluding the groove 30, and the fiber bundle 11 is not exposed. Therefore, the entire second surface 10b of the resin layer 10 is smooth. A method for forming a resin layer 10 having such a structure will be described later.

[0048] The resin layer 10 is a layer formed by curing a prepreg, as will be described later. In this specification, a prepreg is a component in which a fiber bundle is impregnated with a thermosetting resin. The thermosetting resin in the prepreg is in a state called the B stage, which is not completely cured. The B stage is a state in which the thermosetting resin is semi-cured. When the temperature is raised, it melts temporarily, but then when heat is applied and the curing reaction of the resin occurs, it has the characteristic of becoming completely cured.

[0049] The type of resin 12 in the resin layer 10 is not particularly limited. Epoxy resin, polyimide resin, phenolic resin, melamine resin, and combinations thereof can be used as the resin 12.

[0050] The material of the fiber bundle 11 is not particularly limited. Glass fibers, ceramic fibers, carbon fibers, aramid fibers, and combinations thereof can be used as the material of the fiber bundle 11. In this embodiment, the resin layer 10 is preferably a glass epoxy resin obtained by impregnating a glass fiber cloth with epoxy resin and subjecting it to a heat-curing treatment.

[0051] The resin layer 10 may further contain an inorganic filler with high thermal conductivity to provide heat dissipation functionality. Examples of inorganic fillers that can be used include silica, alumina, aluminum nitride, boron nitride, silicon carbide, magnesium oxide, zinc oxide, and aluminum hydroxide.

[0052] [Conductive layer 20] The conductive layer 20 includes at least one positive and negative pair and supplies power to the light source unit, described later, which is placed on the first surface 10a side of the resin layer 10. The conductive layer 20 is electrically connected to, for example, an external circuit or power supply.

[0053] In the examples shown in Figures 1B and 1C, the planar shape of each conductive layer 20 is approximately rectangular. The size of the rectangle in plan view is, for example, 6 mm × 6 mm. The size of the conductive layer 20 only needs to be smaller than the conductive layer placement area (here, the first area R1 and the second area R2) where the conductive layer 20 is placed. The planar shape of the conductive layer 20 is not limited to a rectangle. As shown in the figure, notches may be provided at the corners of some of the conductive layers 20 so that the polarity of the conductive layer 20 can be identified. Each conductive layer 20 may have a planar shape that is approximately similar to or similar to the corresponding conductive layer placement areas R1 and R2. Furthermore, the planar shapes and sizes of multiple conductive layers 20 may be the same or different from each other.

[0054] As shown in Figure 1B, the multiple conductive layers 20 are arranged on the second surface 10b of the resin layer 10, spaced apart from each other. In this example, the conductive layers 20 consist of a first conductive layer 21 and a second conductive layer 22. Note that three or more conductive layers 20 may be arranged on the second surface 10b. Each conductive layer 20 is located in one of the multiple conductive layer arrangement regions on the second surface 10b. It is preferable that one conductive layer 20 is located in each conductive layer arrangement region. In a plan view, it is preferable that each conductive layer 20 is located away from the edge of the groove 30.

[0055] In a plan view, the shortest distance L1 between two adjacent conductive layers 20 is preferably, for example, 50 μm or more. This more effectively suppresses the occurrence of short circuits due to ion migration between these conductive layers 20. The upper limit of the shortest distance L1 between the conductive layers 20 is not particularly limited, but from the viewpoint of miniaturizing the light-emitting device, it may be, for example, 1000 μm or less.

[0056] [Upper conductive layer 40] As shown in Figures 1A and 1C, the substrate 100 may further include a plurality of upper conductive layers 40 on the first surface 10a of the resin layer 10.

[0057] The multiple upper conductive layers 40, including at least one positive and one negative pair, can be electrically connected to electrodes of a light source unit described later, which is placed on the upper surface 100a side of the substrate 100. Each upper conductive layer 40 is electrically connected to the corresponding conductive layer 20, for example, via a conductive member 50 placed in a through-hole in the resin layer 10. In a plan view, each upper conductive layer 40 may be arranged to at least partially overlap the corresponding conductive layer 20.

[0058] In the example shown in Figure 1A, the planar shape of each upper conductive layer 40 is approximately rectangular. The size of the rectangle is, for example, 3 mm × 1 mm. The planar shape, size, and arrangement of the upper conductive layers 40 can be selected according to the shape, size, and arrangement of the positive and negative electrodes of the light-emitting element. The planar shapes and sizes of multiple upper conductive layers 40 may be the same or different from each other.

[0059] In this embodiment, the plurality of upper conductive layers 40 include a first upper conductive layer 41 and a second upper conductive layer 42. The first upper conductive layer 41 and the second upper conductive layer 42 are arranged on the first surface 10a of the resin layer 10 with space between them. The first upper conductive layer 41 is electrically connected to the first conductive layer 21, which is located on the second surface 10b of the resin layer 10. Similarly, the second upper conductive layer 42 is electrically connected to the second conductive layer 22. Examples of materials for the lower conductive layer 20 and the upper conductive layer 40 include metals selected from Cu, Ag, Au, Ni, Fe, and Al, or at least one alloy containing these metals as the main component. In this embodiment, the lower conductive layer 20 is, for example, a layer of Cu with Au plating. The thickness of the conductive layer 20 is, for example, 10 μm to 110 μm. The upper conductive layer 40 is, for example, a Cu layer coated with an Au film. The thickness of the upper conductive layer 40 is, for example, 10 μm to 110 μm.

[0060] [Conductive member 50] As shown in Figures 1A to 1C, the substrate 100 may further comprise a plurality of conductive members 50. Each conductive member 50 is positioned in a through-hole that penetrates the resin layer 10 in the thickness direction. Each conductive member 50 is in contact with one of the conductive layers 20 and one of the upper conductive layers 40, electrically connecting them. The conductive member 50 is, for example, a Cu layer. It is preferable that the conductive member 50 fills the through-hole in the resin layer 10, but it may also be formed only on the side walls of the through-hole.

[0061] In the illustrated example, the conductive member 50 includes a first conductive member 51 and a second conductive member 52. The first conductive member 51 electrically connects the first conductive layer 21 and the first upper conductive layer 41. The second conductive member 52 electrically connects the second conductive layer 22 and the second upper conductive layer 42.

[0062] (First substrate 1000) The substrate in this embodiment may be a substrate having multiple unit regions (hereinafter referred to as the "first substrate"). Multiple substrates 100 can be obtained by separating the first substrate 1000 into individual unit regions. Note that the "substrate for light-emitting element" in this specification refers not only to the substrate after separation, but also to... This includes the first substrate before individual pieceization.

[0063] Figure 4A is a schematic bottom view showing an example of the first substrate 1000. Figure 4B is an enlarged bottom view showing a part of the first substrate 1000, and Figure 4C is an enlarged cross-sectional view along the line 4C-4C shown in Figure 4B.

[0064] The first substrate 1000 includes a plurality of unit regions U arranged in two dimensions. In the illustrated example, the plurality of unit regions U are aligned in the x and y directions.

[0065] The first substrate 1000 comprises a resin layer 10 having a first surface 10a and a second surface 10b. The resin layer 10 is continuous across a plurality of unit regions U. In each unit region U, a plurality of upper conductive layers 40 are arranged on the first surface 10a of the resin layer 10, and a first conductive layer 21 and a second conductive layer 22 are arranged on the second surface 10b. In addition, a first groove 31 is formed on the second surface 10b of the resin layer 10 in each unit region U. In the illustrated example, the shape and arrangement of the conductive layers 20, upper conductive layers 40 and grooves 30 in each unit region U are the same as those of the substrate 100 illustrated in Figures 1A to 1C.

[0066] The grooves 30 in each unit region U may be connected to the grooves 30 of adjacent unit regions U. In this example, the first grooves 31 of two adjacent unit regions U in the y-direction are connected to each other. As shown in the figure, the first grooves 31 may be arranged continuously along the y-direction of the first substrate 1000. Alternatively, as illustrated in Figure 5, the first grooves 31 of each unit region U may be spaced apart from each other. Note that in the first substrate 1000 shown in Figures 4A to 4C and Figure 5, through holes penetrating the resin layer 10 in the thickness direction and conductive members 50 are omitted.

[0067] (Light-emitting device 400) Next, with reference again to Figures 2A and 2B, an example of a light-emitting device 400 using the substrate 100 of this embodiment will be described.

[0068] The light-emitting device 400 comprises a substrate 100 and a light source unit 200.

[0069] [Light source section 200] The light source unit 200 is located on the upper surface 100a side of the substrate 100. The light source unit 200 has an emitting surface 200a located on the opposite side from the substrate 100.

[0070] In this embodiment, the light source unit 200 includes at least one light-emitting element 70, including a first light-emitting element 71. The light-emitting element 70 is arranged on the upper surface 100a side of the substrate 100, that is, on the first surface 10a side of the resin layer 10. In the illustrated example, only the first light-emitting element 71 is arranged on the upper surface 100a of the substrate 100, but two or more light-emitting elements 70 may be arranged in two dimensions.

[0071] <light-emitting element 70> As shown in Figure 2B, the light-emitting element 70 comprises a light-emitting surface 70a that primarily extracts light, an electrode-forming surface 70b located opposite the light-emitting surface 70a, a side surface 70c continuous with the light-emitting surface 70a and the electrode-forming surface 70b, and at least a pair of positive and negative electrodes 81 and 82 located on the electrode-forming surface 70b. In the illustrated example, the light-emitting surface 70a of the light-emitting element 70 is the light-emitting surface 200a of the light source unit 200. The electrodes 81 and 82 are each electrically connected to a corresponding upper conductive layer 40 by a bonding member such as solder or conductive paste. In this example, electrode 81 is electrically connected to a first upper conductive layer 41, and electrode 82 is electrically connected to a second upper conductive layer 42.

[0072] The shape of the light-emitting element 70 in plan view is, for example, rectangular. There are no particular restrictions on the size of the light-emitting element 70. The length and width of the light-emitting element 70 are, for example, 5 mm or less, preferably 4 mm or less. It is even more preferable that they be 3 mm or less. In this embodiment, the light-emitting element 70 has a square shape with sides of 3 mm in plan view.

[0073] Various types of light-emitting elements can be used as the light-emitting element 70, such as semiconductor lasers and light-emitting diodes. In this embodiment, the light-emitting element 70 is, for example, a light-emitting diode having a translucent substrate such as sapphire and a semiconductor stacked structure laminated on the translucent substrate. The wavelength of light emitted by the light-emitting element 70 can be arbitrarily selected. For example, as blue and green light-emitting elements, nitride-based semiconductors (In x Al y Ga 1-x-yLight-emitting elements made of semiconductors such as N, 0≦X, 0≦Y, X+Y≦1), ZnSe, and GaP can be used. For red light-emitting elements, light-emitting elements made of semiconductors such as GaAlAs and AlInGaP can be used. Furthermore, semiconductor light-emitting elements made of other materials can also be used. The composition, emission color, size, and number of light-emitting elements can be appropriately selected according to the purpose. As described later, when the light source unit 200 includes a wavelength conversion layer, it is preferable that the light-emitting layer of the light-emitting element 70 emits short-wavelength light that can efficiently excite the wavelength conversion material contained in the wavelength conversion layer.

[0074] The electrodes 81 and 82 are made of known metallic materials that can be electrically connected to the semiconductor multilayer structure. As the material for electrodes 81 and 82, at least one of the following metals can be used: Ni, Pt, Cu, Au, Ag, AuSn, etc. The shape of electrodes 81 and 82 in plan view is not particularly limited and can be appropriately selected from rectangular, polygonal, circular, elliptical, etc.

[0075] [Other examples of light sources] The structure of the light source is not limited to the examples shown in Figures 2A and 2B. Figure 6 is a cross-sectional view illustrating the substrate 100 and other light source units 201 in this embodiment.

[0076] The light source unit 201 comprises a light-emitting element 70 (in this case, a first light-emitting element 71), a wavelength conversion layer 90, a diffusion layer 92, and a light-reflecting member 94. The light source unit 201 has a light-emitting surface 201a located above (in the +x direction) the light-emitting surface 70a of the light-emitting element 70. In this example, the light source unit 201 has only one light-emitting element 70, but it may have a plurality of light-emitting elements 70 arranged in two dimensions.

[0077] <Wavelength conversion layer 90> The wavelength conversion layer 90 is positioned above (in the +z direction) the light-emitting surface 70a of the light-emitting element 70. The wavelength conversion layer 90 absorbs at least a portion of the light emitted by the light-emitting element 70 and emits light with a different wavelength from the light emitted from the light-emitting element 70.

[0078] The wavelength conversion layer 90 may have a substantially rectangular shape in a plan view. Preferably, in a plan view, the wavelength conversion layer 90 is larger than the light-emitting surface 70a of the light-emitting element 70 and covers the entire light-emitting surface 70a. This makes it possible to efficiently direct the light emitted from the light-emitting element 70 into the wavelength conversion layer 90 and convert the wavelength of the light emitted from the wavelength conversion layer 90.

[0079] In this embodiment, the wavelength conversion layer 90 is, for example, a square with sides of 3.2 mm in a plan view. The thickness of the wavelength conversion layer 90 in the z-axis direction is, for example, 40 μm.

[0080] The wavelength conversion layer 90 includes, for example, a base resin and a wavelength conversion substance dispersed in the resin. As the base material, for example, epoxy resin, silicone resin, a resin mixture thereof, or a light-transmitting material such as glass can be used. From the viewpoint of light resistance and ease of molding, It is preferable to select a silicone resin as the base material for the wavelength conversion layer 90. In particular, it is preferable to use phenyl silicone resin as the main component of the base material. The wavelength conversion layer 90 may also be made mainly of ceramics or glass and contain a wavelength conversion substance.

[0081] The wavelength-converting material is excited by the light emitted by the light-emitting element 70 and emits light of a different wavelength than the light emitted by the light-emitting element 70. Examples of wavelength-converting materials include cerium-activated yttrium aluminum garnet (YAG) phosphors (e.g., Y3(Al,Ga)5O 12 :Ce), cerium-activated lutetium aluminum garnet (LAG) phosphors (e.g., Lu3(Al,Ga)5O 12 Ce), terbium aluminum garnet phosphors (e.g., Tb3(Al,Ga)5O 12:(Ce), nitrogen-containing calcium aluminosilicate (CaO-Al2O3-SiO2) phosphors activated with europium and / or chromium, silicate ((Sr,Ba)2SiO4) phosphors activated with europium, β-sialon phosphors (e.g., (Si,Al)3(O,N)4:Eu), α-sialon phosphors (e.g., M z (Si,Al) 12 (O,N) 16 (where 0 < z ≤ 2, and M is Li, Mg, Ca, Y, and lanthanoid elements excluding Ce)), nitride-based phosphors such as CASN-based phosphors (e.g., CaAlSiN3:Eu) or SCASN-based phosphors (e.g., (Sr,Ca)AlSiN3:Eu), KSF-based phosphors (e.g., K2SiF6:Mn 4+ ) or fluoride-based phosphors such as MGF-based phosphors (e.g., 3.5MgO·0.5MgF2·GeO2:Mn), sulfide-based phosphors, perovskites, chalcopyrites, quantum dots, etc. Phosphors other than these phosphors, which have similar performance, functions, and effects, can also be used. The wavelength conversion layer 90 may contain one type of the above wavelength conversion materials alone, but preferably contains a plurality of types of wavelength conversion materials. For example, the wavelength conversion layer 90 preferably contains an LAG-based phosphor that produces green light emission and a CASN-based phosphor that produces red light emission. Thereby, a light source unit 201 that can emit white light can be realized. Also, by including a plurality of types of wavelength conversion materials, the wavelength band can be widened and the occurrence of a wavelength region with weak emission intensity can be suppressed. The content of the wavelength conversion material in the wavelength conversion layer 90 is, for example, 10 to 80% by weight. In this specification, % by weight means the ratio of the weight of the contained substance (here, the wavelength conversion material) to the total weight including the base material and the contained substance.

[0082] The wavelength conversion layer 90 may contain materials other than the wavelength conversion material. For example, a material having a different refractive index from the base material may be dispersed in the wavelength conversion layer 90. For example, particles having a light diffusion effect such as titanium oxide and silicon oxide can be dispersed in the base material of the wavelength conversion layer 90.

[0083] <Diffusion layer 92> The diffusion layer 92 is positioned above the wavelength conversion layer 90 (in the +z direction). The diffusion layer 92 diffuses the light emitted from the light-emitting element 70.

[0084] The diffusion layer 92 may have a substantially rectangular shape in a plan view. In a plan view, it is preferable that the diffusion layer 92 is larger than the light-emitting surface 70a of the light-emitting element 70 and covers the entire light-emitting surface 70a. The size of the diffusion layer 92 may be substantially the same as the size of the wavelength conversion layer 90. In this embodiment, the diffusion layer 92 is, for example, a square with sides of 3.2 mm in a plan view. The thickness of the diffusion layer 92 in the z-axis direction is, for example, 30 μm.

[0085] The diffusion layer 92 comprises a base resin and a diffusion material dispersed in the resin. As the base material, epoxy resin, silicone resin, a mixture thereof, or a light-transmitting material such as glass can be used. From the viewpoint of light resistance and ease of molding, it is preferable to select silicone resin as the base material for the diffusion layer 92. In particular, it is preferable to use phenyl silicone resin as the main component of the base material. Furthermore, by using the same resin as the wavelength conversion layer 90 for the base material of the diffusion layer 92, the adhesion between the wavelength conversion layer 90 and the diffusion layer 92 can be improved. Note that the diffusion layer 92 is... It may be made primarily from ceramics or glass, and may also contain a diffusing agent.

[0086] The diffusing material is a material with high light reflectivity, such as a white filler such as titanium dioxide, silicon dioxide, alumina, or zinc oxide. The concentration of the diffusing material is preferably 0.1% by weight or more and 3.0% by weight or less. The diffusion layer 92 may also contain glass filler or the like to suppress thermal expansion and contraction of the base resin. The concentration of glass filler is preferably 50% by weight or more and 80% by weight or less. However, the concentrations of the diffusing material, glass filler, etc. are not limited to these. The diffusion layer 92 preferably contains titanium dioxide and glass filler.

[0087] <Light-reflecting member 94> The light-reflecting member 94 covers at least the side surface 70c of the light-emitting element 70, the electrode-forming surface 70b, the side surfaces of the electrodes 81 and 82, the side surfaces of the wavelength conversion layer 90, and the side surfaces of the diffusion layer 92.

[0088] The light-reflecting member 94 reflects light emitted from the side surface 70c of the light-emitting element 70 and guides it upward (in the +z direction) of the light-emitting element 70. In addition, the light-reflecting member 94 can reflect light directed from the electrode-forming surface 70b of the light-emitting element 70 toward the substrate 100 and guide it upward (in the +z direction) of the light-emitting element 70. This improves the utilization efficiency of the light emitted from the light-emitting element 70.

[0089] The light-reflecting member 94 includes, for example, a base resin and a light-reflecting substance dispersed in the resin. Translucent materials such as epoxy resin, silicone resin, or resins mixed therewith can be used as the base material. From the viewpoint of light resistance and ease of molding, it is preferable to select silicone resin as the base material of the light-reflecting member 94. Furthermore, by using the same resin as the wavelength conversion layer 90 and the diffusion layer 92 for the base material of the light-reflecting member 94, the adhesion to the wavelength conversion layer 90 and the diffusion layer 92 can be improved.

[0090] Examples of light-reflecting materials that can be used include titanium dioxide, silicon dioxide, zirconium oxide, yttrium oxide, yttria-stabilized zirconia, potassium titanate, alumina, aluminum nitride, boron nitride, and mullite. The concentration of the light-reflecting material in the light-reflecting member 94 is preferably 10% by weight or more and 70% by weight or less. The light-reflecting member 94 may also contain glass fillers to suppress thermal expansion and contraction of the base resin. The concentration of the glass filler is preferably greater than 0% by weight and less than 30% by weight, and more preferably 5% by weight or more and 20% by weight or less. The concentrations of the light-reflecting material, glass filler, etc. are not limited thereto. The light-reflecting member 94 preferably contains titanium dioxide and glass fillers.

[0091] [Lens 300] The light-emitting device of this embodiment may further include a lens 300. An example of a light-emitting device 500 using the substrate 100 of this embodiment will be described. Figure 7A is a schematic top view of the light-emitting device 500, and Figure 7B is a schematic bottom view of the light-emitting device 500. Figure 7C is a schematic cross-sectional view taken along the line 7C-7C shown in Figures 7A and 7B. Figure 7D is a schematic side view of the light-emitting device 500 as seen in the direction of the +y axis.

[0092] The lens 300 includes a lens portion 310 and a lens retaining portion 320 positioned outside the lens portion 310 along the outer circumference of the lens portion 310. The lens retaining portion 320 is formed continuously (integrally) with the lens portion 310.

[0093] As shown in Figures 7A to 7C, the lens 300 is positioned to cover the light source unit 200. As shown in the figures, the lens 300 may cover the top surface 100a and side surfaces of the substrate 100, while exposing the bottom surface 100b of the substrate 100.

[0094] The lens 300 is formed from a light-transmitting resin. The resin can be a thermoplastic resin such as polycarbonate, acrylic, cyclic polyolefin, polyethylene terephthalate, or polyester, or a thermosetting resin such as phenolic resin, urea resin, melamine resin, epoxy resin, silicone resin, or polyurethane. Of these, polycarbonate is preferred.

[0095] <Lens section 310> The lens portion 310 is located above (in the +z direction) the light-emitting surface 200a of the light source portion 200 (here, the light-emitting surface 70a of the light-emitting element 70), and is an optical functional portion that refracts the light emitted from the light source portion 200 and transmitted through the lens portion 310, and emits it in the +z direction. Preferably, the lens portion 310 covers the entire light-emitting surface 200a in a plan view. The lens portion 310 may be a convex lens such as a biconvex lens, plano-convex lens, or convex meniscus lens, a concave lens such as a biconcave lens, plano-concave lens, or concave meniscus lens, or a Fresnel lens.

[0096] In this embodiment, the outer shape of the lens portion 310 in plan view is preferably approximately circular, with a diameter of 6 mm to 8 mm, for example, about 6.8 mm. The thickness of the lens portion 310 is preferably 1 mm to 2 mm, for example, about 1.5 mm. The outer shape of the lens portion 310 in plan view is not particularly limited and may be a polygon such as a square, hexagon, or octagon.

[0097] The lens portion 310 has a light incident surface 310b located on the side of the light-emitting surface 200a of the light source portion 200, and a light-emitting surface 310a located on the opposite side (+z side) of the light incident surface 310b. In this embodiment, the lens portion 310 has a Fresnel shape on the light incident surface 310b. The center of the lens portion 310 coincides with the center of the light-emitting surface 200a (here, the light-emitting surface 70a of the first light-emitting element 71). On the other hand, the light-emitting surface 310a of the lens portion 310 is substantially flat. In this example, the "light-emitting surface of the lens portion" is the portion of the upper surface of the lens 300 that overlaps with the light incident surface 310b in a plan view. Having a Fresnel shape in the lens portion 310 makes it possible to make the lens 300 thinner. This makes it possible to make the light-emitting device 500 thinner.

[0098] <Lens holder part 320> The lens holder portion 320 is a member that holds the lens portion 310. The lens holder portion 320 is continuous with the periphery of the lens portion 310 and extends downward (in the -Z direction). In this example, the lens holder portion 320 is cylindrical in plan view. The thickness of the lens holder portion 320 in the x-axis or y-axis direction is, for example, 0.3 mm or more and 1.0 mm or less. The height of the lens holder portion 320 in the z direction, i.e., the length from the upper end of the lens holder portion 320 (in other words, the light-emitting surface 310a) to the lower end of the lens holder portion 320, is, for example, 1.0 mm or more and 5.0 mm or less, and can be adjusted so that an air layer is formed between the light-incident surface 310b of the lens portion 310 and the light-emitting surface 200a of the light source portion 200.

[0099] The lower surface 320b of the lens holder 320 is preferably in the same plane as the lower surface 100b of the substrate 100, or located below the lower surface 100b. In a cross-sectional view, the lens holder 320 may be positioned with a gap between it and the substrate 100.

[0100] In this example, the outer edge of the lens holder 320 is rectangular in plan view, and the size of the rectangle is, for example, 8 mm x 8 mm. The shape of the outer edge of the lens holder 320 in plan view is not particularly limited and may be circular, elliptical, polygonal, etc. Notches may be provided at least one corner of the lens holder 320 so that the orientation of the light-emitting device 500 can be determined.

[0101] Furthermore, if the light source unit 200 has a plurality of light-emitting elements 70 arranged in two dimensions, the center of the lens unit 310 may be positioned opposite the center of the substrate. Also, if a lens unit 310 including a plurality of Fresnel lenses is used, and a plurality of light-emitting elements 70 are arranged in pairs with each Fresnel lens, the center of each Fresnel lens may be positioned opposite the center of each light-emitting element 70.

[0102] (Method of manufacturing a substrate for a light-emitting element) The manufacturing method of the substrate according to this embodiment will be described below, with reference to the drawings, using the method for manufacturing the first substrate 1000 shown in Figures 4A to 4C as an example. Figures 8A and 8B are a top view and a cross-sectional view, respectively, showing a part of the metal plate used in the manufacture of the first substrate. Figure 8C is a cross-sectional view, respectively, showing a part of the prepreg used in the manufacture of the first substrate. Figures 9A to 9G are process cross-sectional views, respectively, showing the manufacturing method of the first substrate. For simplicity, Figures 9A to 9G show parts corresponding to two unit regions U in the first substrate.

[0103] The manufacturing method for a light-emitting element substrate of this embodiment includes the steps of: (I) preparing a sheet-like metal plate 120 having at least one protrusion 121 on a first surface 120a, and a prepreg having a plurality of fiber bundles and a resin; (II) bonding the first surface of the metal plate and the prepreg; (III) curing the prepreg to form a resin layer 10; (IV) forming a resist on the metal plate; (V) etching at least one protrusion on the metal plate; and (VI) removing the resist.

[0104] In this embodiment, after manufacturing a first substrate 1000 having multiple unit regions U by the method described above, the first substrate 1000 may be separated into individual pieces according to the unit regions U. This can increase productivity.

[0105] <Process (I)> • Preparation of metal plates Prepare the metal plate 120 shown in Figures 8A and 8B. Here, prepare a Cu plate with a thickness of, for example, 0.1 mm and a size of, for example, 1.2 m × 1.0 m, and form a sheet-like metal plate 120 having at least one protrusion 121 by etching (for example, wet etching) the surface of the Cu plate. The metal plate 120 has a first surface 120a and a second surface 120b located on the opposite side of the first surface 120a. Preferably, the first surface 120a is provided with multiple protrusions 121. The height of the protrusions 121 is, for example, 0.05 mm, and the thickness of the part of the metal plate 120 other than the protrusions 121 is, for example, 0.035 mm or more and 0.5 mm or less.

[0106] In this example, in a plan view, a plurality of protrusions 121 parallel to the y-axis are arranged on the first surface 120a at intervals in the x-direction. Each protrusion 121 may extend continuously from one end to the other end of the first surface 120a of the metal plate 120. The height of the protrusions 121 can be set according to the depth of the grooves 30 formed in the first substrate 1000, for example, as shown in Figure 4B. The number, arrangement, and width in the x-axis direction in a plan view of the protrusions 121 can be set according to the number, arrangement, and width in the x-axis direction of the grooves 30 formed in the first substrate 1000. The corners of each protrusion 121 may have a rounded shape. In other words, the design freedom of the grooves 30 can be increased by adjusting the shape of the protrusions 121.

[0107] • Preparing the prepreg As shown in Figure 8C, a prepreg 110 is prepared, which includes multiple fiber bundles and a thermosetting resin in a semi-cured state (stage B). The prepreg 110 has a first surface 110a and a second surface 110b located opposite the first surface 110a. A metal foil 140 is also prepared on the first surface 110a side of the prepreg 110. The metal foil 140 is, for example, a Cu foil (thickness: for example, 0.1 mm to 0.2 mm). The metal foil 140 is used to form the upper conductive layer. .

[0108] <Process (II)> Next, the first surface 120a of the metal plate 120 and the prepreg 110 are bonded together. First, as shown in Figure 9A, the second surfaces 120b of the two metal plates 120 are placed facing each other via a sheet-like support 130. In this step (II), the productivity of the first substrate 1000 can be increased by using two or more metal plates 120. As the support 130, a metal plate such as stainless steel, paper, etc., can be used.

[0109] Next, as shown in Figure 9B, the two metal plates 120 are stacked with the support 130 in between. Then, the second surface 110b of the prepreg 110 faces the first surface 120a of the metal plate 120. In this example, the second surfaces 110b of the two prepregs 110 face the first surface 120a of each of the two metal plates 120.

[0110] Next, as shown in Figure 9C, the first surface 120a of the metal plate 120 and the second surface 110b of the prepreg 110 are bonded together. At the same time, the metal foil 140 placed on the first surface 110a side of the prepreg 110 is also pressed to obtain a laminate 150. In Figure 9C, two laminates 150 are stacked on top of each other via a support 130. To further increase productivity, three or more laminates 150 may be stacked via the support 130.

[0111] <Process (III)> After this, the prepreg 110 is cured to form the resin layer 10.

[0112] When multiple laminates 150 are stacked, multiple prepregs 110 may be cured simultaneously. The curing method for the prepregs 110 is not particularly limited. Here, the laminate 150 is heated and then pressurized in the stacking direction (z-axis direction) by a press or the like. The heating temperature is, for example, 130°C to 200°C, and the pressing pressure is, for example, 20 kg / cm². 2 More than 60kg / cm 2 The following settings may be used. This causes the semi-cured resin in the prepreg 110 to be remelted and then fully cured in the laminate 150. In this way, the resin layer 10 is formed from the prepreg 110. As the prepreg 110 deforms to match the shape of the first surface 120a of the metal plate 120, a recess 30E is formed on the second surface 10b of the resin layer 10, which will become a groove 30 in the portion that contacts the convex portion 121 of the first surface 120a of the metal plate 120.

[0113] In this case, the fiber bundles within the prepreg 110 can also be deformed according to the shape of the protrusions 121 on the first surface 120a of the metal plate 120. In this embodiment, the resin layer 10 is formed such that at least one fiber bundle of the multiple fiber bundles within the prepreg 110 bends in the depth direction along at least one groove 30 in the portion that overlaps with at least one groove 30 in a plan view (see Figure 3A).

[0114] Next, multiple through-holes are formed in the resin layer 10 obtained by curing the prepreg 110 using a laser, drill, or the like. At this time, it is preferable to form through-holes in at least one of the metal plate 120 and the metal foil 140 simultaneously. After that, conductive members 50 are placed in each through-hole. Note that Cu plating may be placed as the conductive member 50 on the side wall of the through-hole. After forming the resin layer 10, the laminate 150 including the resin layer 10 is peeled off from the support 130 as shown in Figure 9D.

[0115] <Process (IV)> Next, an etching resist (hereinafter sometimes abbreviated as resist) is formed on the metal plate 120. As shown in Figure 9E, the first resist 161 and the second resist 162 are formed on the first surface 120a of the metal plate 120 and the surface 140a of the metal foil 140 of the laminate 150, respectively. The first resist 161 and the second resist 162 are formed by applying an etching resist to the first surface 120a of the metal plate 120 and the surface 140a of the metal foil 140, followed by exposure and development. In a plan view, the first resist 161 is positioned on the portion of the first surface 120a of the metal plate 120 that does not overlap with the groove 30. The first resist 161 has a pattern corresponding to the conductive layer 20 (Figure 9F), and the second resist 162 has a pattern corresponding to the upper conductive layer 40 (Figure 9F).

[0116] <Process (V)> Next, at least one protrusion 121 of the metal plate 120 is etched. As shown in Figure 9F, the metal plate 120 is etched using the first resist 161 as an etching mask, removing the portion of the metal plate 120 that includes the protrusion 121. This forms at least one groove 30 in the resin layer 10 that is opposite to at least one protrusion 121 of the metal plate 120. Since the groove 30 is formed by removing the protrusion 121 of the metal plate 120 after the prepreg 110 has hardened, the designed shape of the groove 30 can be formed accurately and easily. Furthermore, by removing the protrusion 121, the metal plate 120 can be divided into two or more parts so as to straddle the groove 30, and a conductive layer 20 can be formed.

[0117] Similarly, by using the second resist 162 as an etching mask and etching the metal foil 140, the upper conductive layer 40 can be obtained from the metal foil 140.

[0118] <Process (VI)> Next, as shown in Figure 9G, the first resist 161 and the second resist 162 are removed. In this way, the first substrate 1000 is manufactured.

[0119] After this, the first substrate 1000 manufactured by the above method is separated into individual pieces for each unit region U. This allows for the production of substrates 100 as shown in Figures 1A to 1D from each unit region U. Alternatively, one or more light sources 200 (Figure 2B) or 201 (Figure 6) may be formed on the first surface 10a of the first substrate 1000 for each unit region U before the first substrate 1000 is separated into individual pieces.

[0120] The method of fragmentation is not particularly limited. For example, the first substrate 1000 may be cut between adjacent unit regions U by methods such as blade dicing or laser dicing. In the examples shown in Figures 4A and 4B, the unit regions U are rectangular, but the planar shape of the fragmented substrate 100 may be circular, elliptical, or the like.

[0121] According to the above method, a first substrate 1000 and a substrate 100 having grooves 30 that suppress short circuits due to ion migration between conductive layers can be manufactured.

[0122] For example, if grooves are formed in the resin layer using the reference example method using a dicer or laser, as shown in Figure 21, the fiber bundles 911Y located shallower than the bottom of the groove 930 will be cut, and the cut surfaces of the fiber bundles 911Y will be exposed on the surface of the groove 930 (in other words, the surface 910b of the resin layer 910), which may reduce the strength of the substrate. In contrast, in this embodiment, grooves 30 are formed by deforming a semi-cured resin using a metal plate 120 having a protrusion 121 (Figures 8A and 8B). With this method, as shown in Figure 3A, in the resin layer 10 of this embodiment, the first fiber bundles 11Y located shallower than the bottom P of the groove 30 are arranged continuously so as to traverse the groove 30 in a plan view. That is, the first fiber bundles 11Y are not cut when the groove 30 is formed, and a portion of the first fiber bundles 11Y is located between the groove 30 and the first surface 10a of the resin layer 10. This makes it possible to suppress the reduction in the strength of the substrate 100 due to the formation of the groove 30.

[0123] The following describes modified versions of the substrate and light-emitting device of this embodiment. Some configurations similar to those of the embodiments already described have been omitted.

[0124] (Modified circuit board 1) Figures 10A and 10B are a top view and a bottom view illustrating the substrate 101 of Modification Example 1, respectively. Figure 10C is a cross-sectional view taken along the line 10C-10C shown in Figures 10A and 10B.

[0125] The substrate 101 has a plurality of conductive layers 20 including a first conductive layer 21 to an eighth conductive layer 28, and a plurality of upper conductive layers 40 including a first upper conductive layer 41 to an eighth upper conductive layer 48.

[0126] As shown in Figure 10B, the second surface 10b of the resin layer 10 is divided into eight conductive layer arrangement regions by grooves 30, including the first groove 31 to the fourth groove 34. The eight conductive layer arrangement regions are the first region R1 to the eighth region R8.

[0127] The first groove 31 to the fourth groove 34 are, in a plan view, grooves that extend in a straight line and intersect at point Qb, which is the center of the second surface 10b. In this example, the second surface 10b of the resin layer 10 is a rectangle having four corners c1 to c4 and four sides s1 to s4, similar to the example shown in Figure 1B. The first groove 31 extends from corner c1 to corner c3 of the second surface 10b. The third groove 33 extends from corner c2 to corner c4 of the second surface 10b. In other words, the first groove 31 and the third groove 33 are located on the diagonals of the second surface 10b. The second groove 32 is approximately parallel to the x-axis and divides the second surface 10b vertically (i.e., into two parts in the y-direction). Both ends of the second groove 32 may be in contact with sides s2 and s4 of the second surface 10b, respectively. The fourth groove 34 is approximately parallel to the y-axis and divides the second surface 10b into left and right halves (i.e., into two parts in the x-direction). Both ends of the fourth groove 34 may be tangent to sides s1 and s3 of the second surface 10b, respectively. In a plan view, the first region R1 to the eighth region R8 are right-angled triangular regions, respectively, enclosed by the groove 30 and the four sides of the second surface 10b of the substrate 101.

[0128] The first conductive layer 21 to the eighth conductive layer 28 are located in the first region R1 to the eighth region R8, respectively. The first conductive layer 21 to the eighth conductive layer 28 may each have a planar shape that is substantially similar to the first region R1 to the eighth region R8. In this example, the planar shape of each of the first conductive layer 21 to the eighth conductive layer 28 is a right triangle with two sides parallel to the x and y axes.

[0129] As shown in Figure 10A, the first surface 10a of the resin layer 10 includes multiple light source placement regions and a peripheral region Vb located around them. The light source placement regions are areas where light sources, including light-emitting elements, are placed. In this example, the multiple light source placement regions include four rectangular regions V1 to V4. Each side of the rectangles in regions V1 to V4 is parallel to the x-axis or y-axis, respectively. Regions V1 to V4 are arranged in pairs in the x-direction and y-direction. Here, regions V1 to V4 are located to the lower right, upper right, upper left, and lower left of point Qa. Point Qa is, for example, the center of the first surface 10a. Point Qa is the center of all regions V1 to V4 and preferably overlaps with point Qb, which is the center of the second surface 10b, in a plan view.

[0130] The first upper conductive layer 41 to the eighth upper conductive layer 48 are arranged on the first surface 10a of the resin layer 10, spaced apart from each other. The first upper conductive layer 41 to the eighth upper conductive layer 48 are each electrically connected to the first conductive layer 21 to the eighth upper conductive layer 28 via conductive members 50 in through holes formed in the resin layer 10. In this example, the plan view shape of each of the first upper conductive layer 41 to the eighth upper conductive layer 48 is a right triangle with two sides parallel to the x and y axes. The first upper conductive layer 41 and the second upper conductive layer 42 are arranged in region V1. The third upper conductive layer 43 and the fourth upper conductive layer 44 are arranged in region V2, the fifth upper conductive layer 45 and the sixth upper conductive layer 46 are arranged in region V3, and the seventh upper conductive layer 47 and the eighth upper conductive layer 48 are arranged in region V4. In plan view, two upper conductive layers are arranged in each of regions V1 to V4. The hypotenuses of the 40 right triangles are opposite each other.

[0131] The substrate 101 can also be manufactured in the same manner as described above, with reference to Figures 8A to 8C and 9A to 9G. In step (I) shown in Figures 8A and 8B, grooves 30 including the first groove 31 to the fourth groove 34 can be formed by using a metal plate 120 having a plurality of linearly extending protrusions 121 in a plan view.

[0132] Figure 11 is an enlarged bottom view showing a part of the first substrate 1001 in this embodiment. One unit region U of the first substrate 1001 is substrate 101. In the first substrate 1001, the first grooves 31 to the fourth grooves 34 in one unit region U may be connected to grooves 30 of adjacent unit regions U in the x, y, or diagonal directions.

[0133] (Modified example 1 of the light-emitting device) An example of a light-emitting device using the substrate 101 of Modification 1 will be described.

[0134] Figure 12A is a top view of the light-emitting device 401, and Figure 12B is a bottom view of the light-emitting device 401. Figure 12C is a cross-sectional view taken along the line 12C-12C shown in Figure 12A.

[0135] The light-emitting device 401 comprises a substrate 101, a light source unit 202, and a lens 300. The lens 300 has a structure similar to the lens described above, with reference to Figures 7A to 7D. The light source unit 202 of the light-emitting device 401 includes a plurality of light-emitting elements 70. The configuration of the light source unit 202 will be described in detail below.

[0136] [Light source section 202] Figure 13 is a diagram illustrating the substrate 101 and the light source unit 202, and is a cross-sectional view obtained by removing the lens 300 from the light-emitting device 401 shown in Figure 12C.

[0137] The light source unit 202 is positioned on the upper surface 101a side of the substrate 101 and has a light-emitting surface 202a located on the opposite side of the substrate 101. The light source unit 202 has a plurality of light-emitting elements 70 arranged in two dimensions. The light source unit 202 further comprises a plurality of wavelength conversion layers 90, a plurality of diffusion layers 92, and a light-reflecting member 94.

[0138] As shown in Figure 12A, each of the multiple light-emitting elements 70 is positioned in a corresponding light-emitting element placement area on the first surface 10a of the resin layer 10 of the substrate 101. In plan view, each light-emitting element 70 is rectangular, and each side of the rectangle is positioned parallel to the x-axis or y-axis. In plan view, each light-emitting element 70 is positioned to straddle the hypotenuses of two adjacent upper conductive layers from the first upper conductive layer 41 to the eighth upper conductive layer 48. The positive and negative electrodes of each light-emitting element 70 are located on the two adjacent upper conductive layers. The positive and negative electrodes of the light-emitting element 70 have a triangular (in this case, a right-angled triangle) planar shape.

[0139] In this example, the multiple light-emitting elements 70 are the first to fourth light-emitting elements 71 to 74. The first to fourth light-emitting elements 71 to 74 are each located in regions V1 to V4 on the first surface 10a of the resin layer 10. The electrodes 81 and 82 of the first light-emitting element 71 are electrically connected to the first upper conductive layer 41 and the second upper conductive layer 42 via a bonding member such as solder. Similarly, the electrodes 83 to 88 of the second to fourth light-emitting elements 72 to 74 are electrically connected to the third to eighth upper conductive layers 43 to 48, respectively.

[0140] As shown in Figure 13, multiple wavelength conversion layers 90 are each placed on the light-emitting surface 70a of the corresponding light-emitting element 70 and are separated from each other. In this example, a wavelength conversion layer 90 is provided for each light-emitting element 70, but a common wavelength conversion layer is provided for multiple light-emitting elements 70. I don't mind being kicked.

[0141] Each of the multiple diffusion layers 92 is located on the upper surface of the corresponding wavelength conversion layer 90. The multiple diffusion layers 92 are separated from each other. In this example, a diffusion layer 92 is provided for each light-emitting element 70, but a common diffusion layer 92 may be provided for multiple light-emitting elements 70.

[0142] The light-reflecting member 94 encloses and integrally holds the first to fourth light-emitting elements 71 to 74. The light-reflecting member 94 may be provided for each light-emitting element 70 and may be spaced apart from each other. By placing the light-reflecting member 94 between two adjacent light-emitting elements 70, the propagation of light between the light-emitting elements 70 can be suppressed, thereby reducing color unevenness. Furthermore, when multiple light-emitting elements 70 are driven to light up independently of each other, the contrast between the lit and unlit light-emitting elements can be improved.

[0143] (Modified circuit board 2) Figures 14A and 14B are a top view and a bottom view illustrating the substrate 102 of Modification 2, respectively. Figure 14C is a cross-sectional view taken along the line 14C-14C shown in Figures 14A and 14B.

[0144] The substrate 102 comprises a plurality of conductive layers 20 including a first conductive layer 21 to a fifth conductive layer 25, and a plurality of upper conductive layers 40 including a first upper conductive layer 41 to an eighth upper conductive layer 48.

[0145] As shown in Figure 14B, the second surface 10b of the resin layer 10 has grooves 30 and a plurality of conductive layer arrangement regions. The grooves 30 include grooves that are annular or have arc-shaped portions in plan view. In this example, the grooves 30 include first grooves 31 to fifth grooves 35, each of which is annular or has arc-shaped portions in plan view. The plurality of conductive layer arrangement regions are first region R1 to fifth region R5. In plan view, the first groove 31 is annular, the first region R1 is the region enclosed by the first groove 31, and the second region R2 to fifth region R5 are located on the opposite side of the first region R1, with the first groove 31 in between.

[0146] In plan view, the first groove 31 is annular. In plan view, the first groove 31 has an annular first edge e1 and an annular second edge e2 located outside the first edge e1 and facing the first edge e1. In this example, the first groove 31 is substantially circular in plan view. In this specification, "annular" means a ring-shaped object in plan view, such as a circle, ellipse, or polygon with rounded corners. An annular groove may include an arc-shaped portion that is part of a circle or ellipse, or a straight portion, as long as it forms a ring shape in plan view.

[0147] The second grooves 32 to the fifth grooves 35 each have a portion that intersects with the annular first groove 31 in a plan view, and are located on the second edge e2 side of the first groove 31. In other words, each of the second grooves 32 to the fifth grooves 35 and the annular first groove 31 share a portion of the groove 30. In this example, the second surface 10b is a rectangle having four corners c1 to c4 and four sides s1 to s4. In a plan view, the second groove 32 includes an arc-shaped portion that curves concavely with respect to corner c1. Similarly, in a plan view, the third grooves 33 to the fifth grooves 35 each include an arc-shaped portion that curves concavely with respect to corners c2 to c4.

[0148] The second surface 10b is divided into the first region R1 to the fifth region R5 and the outer region Rb by the first groove 31 to the fifth groove 35 described above.

[0149] The first region R1 is the region enclosed by the first groove 31. The second region R2 to the fifth region R5 are located outside the first groove 31. In the illustrated example, the second region R2 to the fifth region R5 are Each of these regions is located between the first region R1 and the four corners c1 to c4. The second region R2 is the region enclosed by the arc-shaped second groove 32 and the two sides s1 and s2 that constitute corner c1 of the resin layer 10. Similarly, the third region R3 to the fifth region R5 are the regions enclosed by the third groove 33 to the fifth groove 35 and the two sides that constitute corners c2 to c4 opposite to those grooves.

[0150] The outer region Rb is located outside the conductive layer placement region and is a region where the conductive layer 20 is not placed. The outer region Rb may be a single continuous region or may be divided into multiple regions. The outer region Rb is separated from the conductive layer placement region by a groove 30. In this example, the outer region Rb is located outside the first region R1, between two adjacent conductive layer placement regions. A groove 30 is placed between the two adjacent conductive layer placement regions and the outer region Rb located between them. In this example, the second groove 32 is located in a plan view between the second region R2 and the outer region Rb other than the second region R2, in the region on the second surface 10b of the resin layer 10 that is opposite the first region R1 across the first groove 31. Furthermore, the second groove 32 includes an arc-shaped or annular portion. Similarly, the third groove 33 is located between the third region R3 and the outer region Rb. The fourth groove 34 is located between the fourth region R4 and the outer region Rb. The fifth groove 35 is located between the fifth region R5 and the outer region Rb.

[0151] The first conductive layer 21 to the fifth conductive layer 25 are located in the first region R1 to the fifth region R5, respectively. The first conductive layer 21 is positioned inside the first edge e1 of the first groove 31, and spaced away from the first edge e1. The second conductive layer 22 to the fifth conductive layer 25 are positioned inside the edges of the arc-shaped second groove 32 to the fifth groove 35, and spaced away from each edge. In this example, the first conductive layer 21 to the fifth conductive layer 25 have a substantially circular planar shape. In plan view, the second conductive layer 22 to the fifth conductive layer 25 may have a smaller area than the first conductive layer 21.

[0152] In other words, the second surface 10b of the resin layer 10 is a rectangle having four corners c1 to c4. In plan view, the second surface 10b of the resin layer 10 further includes a third region R3, a fourth region R4, and a fifth region R5, and an outer region Rb excluding the second region R2, the third region R3, the fourth region R4, and the fifth region R5. The second region R2, the third region R3, the fourth region R4, and the fifth region R5 are located between the first groove 31 and the four corners c1 to c4, respectively. The light-emitting element substrate 100 further includes a third conductive layer 23, a fourth conductive layer 24, and a fifth conductive layer 25 located in the third region R3, the fourth region R4, and the fifth region R5, respectively. In plan view, at least one groove 30 further includes a second groove 32 located between a second region R2 and an outer region Rb, a third groove 33 located between a third region R3 and an outer region Rb, a fourth groove 34 located between a fourth region R4 and an outer region Rb, and a fifth groove 35 located between a fifth region R5 and an outer region Rb. In plan view, the second groove 32, the third groove 33, the fourth groove 34, and the fifth groove 35 each have an arc-shaped portion tangent to the first groove 31.

[0153] As shown in Figure 14A, the first surface 10a of the resin layer 10 includes multiple light source placement areas and a peripheral area Vb located around them. In this example, the multiple light source placement areas are four rectangular areas V1 to V4. Each side of the rectangles in areas V1 to V4 is parallel to the x-axis or y-axis. Here, areas V1 to V4 are located to the lower right, upper right, upper left, and lower left of point Qa. Point Qa is the center of all areas V1 to V4, for example, the center of the first surface 10a.

[0154] The first upper conductive layer 41 to the eighth upper conductive layer 48 are arranged on the first surface 10a of the resin layer 10, spaced apart from each other. In this example, each of the first upper conductive layer 41 to the eighth upper conductive layer 48 is a right triangle with two sides parallel to the x and y axes. The first upper conductive layer 41 and the second upper conductive layer 42 are arranged in region V1. The third upper conductive layer 43 and the fourth upper conductive layer 44 are in region V2, the fifth upper conductive layer 45 and the sixth upper conductive layer 46 are in region V3, and region The seventh upper conductive layer 47 and the eighth upper conductive layer 48 are located in V4, respectively. In a plan view, the two upper conductive layers 40 located in each region V are arranged so that the hypotenuses of the right triangles they form face each other. Also in a plan view, the right vertices of the right triangles of one of the upper conductive layers 40 located in each region V1 to V4 (here, the second upper conductive layer 42, the fourth upper conductive layer 44, the sixth upper conductive layer 46, and the eighth upper conductive layer 48) are located near point Qa on the first surface 10a, while the right vertices of the right triangles of the other upper conductive layer 40 (here, the first upper conductive layer 41, the third upper conductive layer 43, the fifth upper conductive layer 45, and the seventh upper conductive layer 47) are located near the four corners of the first surface 10a, respectively.

[0155] The second upper conductive layer 42, the fourth upper conductive layer 44, the sixth upper conductive layer 46, and the eighth upper conductive layer 48 are each electrically connected to the first conductive layer 21 via conductive members 50 in through holes formed in the resin layer 10. On the other hand, the first upper conductive layer 41, the third upper conductive layer 43, the fifth upper conductive layer 45, and the seventh upper conductive layer 47, located near the four corners of the first surface 10a, are each electrically connected to the second conductive layer 22 to the fifth conductive layer 25 via conductive members 50 in through holes formed in the resin layer 10.

[0156] The substrate 102 can also be manufactured in the same manner as described above, with reference to Figures 8A to 8C and 9A to 9G. In step (I) shown in Figures 8A and 8B, a metal plate 120 having a convex portion that extends in an arc or ring shape in a plan view can be used to form a groove 30 including an annular or arc-shaped portion. The first substrate in an assembled state may be manufactured using the above method and then separated into individual pieces for each unit region.

[0157] Figure 15 is an enlarged bottom view showing a part of the assembled first substrate 1002 in this embodiment. In the first substrate 1002, the arc-shaped second grooves 32 to fifth grooves 35 in one unit region U may be connected to the arc-shaped grooves of adjacent unit regions U in the x or y direction. The connection of the second grooves 32 to fifth grooves 35 of adjacent unit regions U may form an annular groove.

[0158] Figure 16 is a bottom view showing another substrate 103 of this modified example. In the example shown in Figure 16, the second surface 10b of the resin layer 10 has, in plan view, an annular first groove 31 and second grooves 32 to fifth grooves 35 located outside the first groove 31. In plan view, the second grooves 32 to fifth grooves 35 are all annular grooves and are located in the -y, +x, +y, and -x directions of the first groove 31, respectively. Each of the second grooves 32 to fifth grooves 35 may be in contact with the first groove 31.

[0159] The second surface 10b of the resin layer 10 includes the conductive layer arrangement region, regions 1 to 5, R5, and the outer region Rb, which is not the conductive layer arrangement region. Regions 1 to 5, R5, are each regions enclosed by grooves 1 to 5, R1 and R2, R1 and R5, respectively. The areas of regions 1 to 5, R1 and R5, may be approximately equal or different from each other. The outer region Rb is a region located outside regions 1 to 5, R1 and R5, and in this example, it is a single continuous region.

[0160] The first conductive layer 21 to the fifth conductive layer 25 are located in the first region R1 to the fifth region R5, respectively. The planar shapes of the first conductive layer 21 to the fifth conductive layer 25 may be similar to or different from the planar shapes of the first region R1 to the fifth region R5, respectively.

[0161] The number, shape, and arrangement of grooves 30, conductive layer placement regions, and conductive layers 20 in this modified example are not limited to the illustrated example. The substrates 102 and 103 shown in Figures 14A to 14C and Figure 16 have five conductive layer placement regions and five conductive layers 20, but the number of conductive layer placement regions and conductive layers 20 can be two or more.

[0162] (Modified circuit board 3) Below, as Modification 3, another example of the arrangement of grooves and conductive layer placement areas on the second surface of the resin layer will be described.

[0163] Figure 17A is a bottom view illustrating the substrate 104 of the modified example 3.

[0164] In the substrate 104, the planar shape of the second surface 10b of the resin layer 10 is a rectangle having four corners c1 to c4 and four sides s1 to s4, similar to the example shown in Figure 1B. The second surface 10b includes grooves 30 that extend linearly in different directions in a plan view. The second surface 10b is divided into multiple conductive layer arrangement regions by the grooves 30.

[0165] In the illustrated example, groove 30 includes a first groove 31 extending to divide the second surface 10b horizontally (in the x-direction), a second groove 32 extending to divide the region located to the right (+x side) of the first groove 31 vertically (in the y-direction), and a third groove 33 extending to divide the region located to the left (-x side) of the first groove 31 in the y-direction. The second groove 32 and the third groove 33 are linear grooves extending in directions that intersect each other. The second groove 32 is connected to the first groove 31, and its end extending in the +x direction is in contact with the periphery (side s2) of the second surface 10b. Similarly, the third groove 33 is connected to the first groove 31, and its end extending in the -x direction is in contact with the periphery (side s4) of the second surface 10b. In plan view, the first groove 31, the second groove 32, and the third groove 33 intersect at a single point Qc.

[0166] The second surface 10b is divided into a first region R1 to a fourth region R4 by the groove 30. The first conductive layer 21 to the fourth conductive layer 24 are arranged in the first region R1 to the fourth region R4, respectively.

[0167] In this modified example, at least one groove 30 may include a groove having, in plan view, a first position on the periphery of the second surface 10b of the resin layer 10, a second position inside the second surface 10b, and a linear portion extending linearly from the first position to the second position. The "first position" and "second position" of the groove may be the ends of the groove. In the illustrated example, the second groove 32 and the third groove 33 each have a first position on the periphery of the second surface 10b, a second position including point Qc inside the second surface 10b, and a linear portion extending linearly from the first position to the second position.

[0168] Referring to the method described above with reference to Figures 8A to 8C and Figures 9A to 9G, by adjusting the shape of the protrusions 121 on the metal plate 120, grooves that intersect within the second surface 10b (in this case, intersect at point Qb), such as the second groove 32 and third groove 33 shown in Figure 17A, can be formed more easily.

[0169] Figure 17B is a bottom view illustrating another substrate 105a of the modified example 3.

[0170] In substrate 105a, the groove 30 includes a linear groove parallel to the y-axis and a linear groove parallel to the x-axis. In this example, in plan view, it includes a first groove 31 extending along the y-axis to divide the second surface 10b in the x-direction, a second groove 32 and a third groove 33 dividing the area to the right (+x side) of the first groove 31 into three parts in the y-direction, and a fourth groove 34 extending to divide the area to the left (-x side) of the first groove 31 in the y-direction. The second groove 32 to the fourth groove 34 may be linear grooves parallel to the x-axis in plan view. The second groove 32 and the third groove 33 are connected to the first groove 31 in the -x direction, and their respective ends extending in the +x direction may be in contact with the periphery (side s2) of the second surface 10b. The fourth groove 34 is connected to the first groove 31 in the +x direction, and the end extending in the -x direction may be in contact with the periphery (side s4) of the second surface 10b. The second grooves 32 to the fourth grooves 34 each have a first position on the periphery of the second surface 10b, a second position inside the second surface 10b (here, a position connected to the first groove 31), and a second position from the first position. It has a straight section that extends linearly to the position.

[0171] The second surface 10b is divided into first region R1 to fifth region R5 by the groove 30. First conductive layer 21 to fifth conductive layer 25 are arranged in the first region R1 to fifth region R5, respectively.

[0172] In this modified example, the number, planar shape, and arrangement of grooves and conductive layer arrangement regions are not limited to the illustrated example. For example, as shown in Figure 19, the second surface 10b of the resin layer 10 of the substrate 105b may have first grooves 31 to fifth grooves 35 that extend radially from point Qd within the second surface 10b toward the periphery of the second surface 10b in a plan view.

[0173] (Modified circuit board 4) Other examples of groove shapes in cross-sectional view are described below. In cross-sectional view, grooves 30 of various shapes can be formed in the resin layer 10 by appropriately changing the shape of the protrusions 121 of the metal plate 120 (see Figures 8A and 8B). Therefore, the cross-sectional shape of the groove 30 can be set with a high degree of freedom. For example, the width of the groove 30 may be different in the depth direction (z direction). For example, the width w of the opening of the groove 30 may be greater than the width P of the bottom of the groove 30. Also, the depth of the groove may be different in the width direction (±x direction) of the groove. Furthermore, a single continuous groove may include multiple parts with different cross-sectional shapes and opening widths w.

[0174] The following describes a modified shape of the groove 30 provided in the resin layer 10. The groove shape of this modified shape can be applied to some or all of the grooves in the substrate of this embodiment (for example, the substrates 101 to 104, 105a and 105b described above).

[0175] Figures 19A to 19C are cross-sectional views of substrates 106 to 108 of modified example 4, respectively, showing cross-sections including grooves 30A to 30C and the first conductive layer 21 and second conductive layer 22 located on both sides thereof.

[0176] In the substrate 106 shown in Figure 19A, the cross-sectional shape of the groove 30A includes a part of the arc of a circle or ellipse. In this example, in cross-sectional view, the side surface of the groove 30A is a concave, curved arc. In cross-sectional view, the groove 30A includes a bottom P, which is the deepest point.

[0177] In the substrate 107 shown in Figure 19B, the cross-sectional shape of the groove 30B is V-shaped. In this example, the groove 30B has a bottom P which is the deepest point in cross-section, a side surface f1 located between the bottom P and the first edge e1, and a side surface f2 located between the bottom P and the second edge e2. In cross-sectional view, the angle between side surfaces f1 and f2 may be approximately 90 degrees, for example. In other words, the groove 30B may be part of a rectangle.

[0178] In the substrate 108 shown in Figure 19C, the cross-sectional shape of the groove 30C has a bottom surface f3 that is narrower than the opening. In cross-sectional view, the groove 30C has a step, comprising the bottom surface f3 which is the bottom P of the groove 30C, side surfaces f1 and ff1 located between the bottom surface f3 and the first edge e1, and side surfaces f2 and ff2 located between the bottom surface f3 and the second edge e2. The width wa of the bottom surface f3 is smaller than the width w of the opening of the groove 30C. The side surfaces f1, ff1, f2 and ff2 may each be planes inclined with respect to the second surface 10b. The step in the groove 30C allows for an even greater creepage distance between the first conductive layer 21 and the second conductive layer 22.

[0179] Figure 20 is a bottom view of another substrate 109 of the modified example 4. In the substrate 109, in plan view, the groove 30D has multiple parts with different opening widths. Specifically, the groove 30D includes a part g1 having a width w1 and a part g2 having a width w2 that is greater than the width w1. These parts g1 and g2 may be connected to each other. In this case, in plan view, the first The distance D1 between the conductive layer 21 and the second conductive layer 22 that spans portion g1 of the first groove 31 may be smaller than the distance D2 that spans portion g2 of the first groove 31. [Industrial applicability]

[0180] The light-emitting substrate and light-emitting device of this disclosure can be suitably used in a variety of applications, such as lighting, camera flashes, and automotive headlights. In particular, they are suitably used as flash light sources for small cameras mounted on smartphones and the like. [Explanation of Symbols]

[0181] 10: Resin layer 10a: First surface of the resin layer 10b: Second surface of the resin layer 10c: Side of the resin layer 11: Fiber bundle 12: Resin 13: Fiber layer 20: Conductive layer 21-28: First conductive layer to eighth conductive layer 30, 30A~30D: Groove 30E: Recess 31~38: 1st groove ~ 8th groove 40: Upper conductive layer 41-48: 1st upper conductive layer to 8th upper conductive layer 50: Conductive material 51: First conductive member 52: Second conductive member 70: Light-emitting element 71-74: 1st to 4th light-emitting elements 81~88: Electrode 100~109: Circuit board 110: Prepreg 110a: First face of the prepreg 110b: Prepreg side 2 11Y: First fiber bundle 11Yd: recess 112: Longitudinal fiber bundle 113: Transverse fiber bundle 120: Metal plate 120a: First surface of the metal plate 120b: Second side of the metal plate 121: Convex part 130:Support 13Y: First fiber layer 140: Metal foil 150: Laminate 161, 162: Resist 200, 201: Light source section 1000: First substrate R1~R8: 1st area~8th area (conductive layer arrangement area) Rb: Outer area U: Unit area V1~V4: Light source placement area c1~c4: corner e1: First edge e2: Second edge f1, ff1, f2, ff2: Side f3: Bottom p1 :1st part p2 :2nd part s1~s4: edges

Claims

1. A substrate for light-emitting elements, A light source unit is arranged on the substrate for the light-emitting element and includes at least one light-emitting element, Equipped with, The aforementioned light-emitting substrate is A sheet-like resin layer comprising a first surface and a second surface located opposite the first surface, wherein the second surface has at least one groove including a first groove, and a first region and a second region located on both sides of the first groove, and comprising at least a plurality of fiber bundles and resin, A first conductive layer disposed in the first region of the resin layer, A second conductive layer disposed in the second region of the resin layer, Equipped with, In a cross-sectional view passing through the first conductive layer, the first groove, and the second conductive layer, at least one continuous fiber bundle of the plurality of fiber bundles located at a position shallower than the bottom of the first groove is arranged in a plan view to traverse the first region, the first groove, and the second region within the resin layer. The resin layer includes, in a plan view, a first portion that overlaps the first conductive layer or the second conductive layer, and a second portion that overlaps the at least one groove. The density of the plurality of fiber bundles in the second portion is greater than the density of the plurality of fiber bundles in the first portion. The light source unit includes an electrode forming surface on which a first electrode electrically connected to the first conductive layer and a second electrode electrically connected to the second conductive layer are arranged. A light-emitting device wherein the electrode-forming surface faces the substrate for the light-emitting element.

2. The at least one fiber bundle includes two or more fiber bundles stacked in the thickness direction of the resin layer between the first and second surfaces of the resin layer. The light-emitting device according to claim 1, wherein the spacing between the stacking of the two or more fiber bundles in the second portion is smaller than the spacing between the stacking of the two or more fiber bundles in the first portion.

3. The light-emitting device according to claim 1 or 2, wherein the surface of at least one groove is disposed only of the resin.

4. The light-emitting device according to any one of claims 1 to 3, wherein, in a plan view, the first groove is annular, the first region is the region enclosed by the first groove, and the second region is located on the opposite side of the first region across the first groove.

5. The at least one groove further includes a second groove, In a plan view, the second groove is located between the second region and an outer region other than the second region in a region on the second surface of the resin layer that is opposite to the first region with respect to the first groove, and the second groove includes a portion that extends in an arc shape or annular shape, according to claim 4.

6. The second surface of the resin layer is rectangular with four corners, In plan view, the second surface of the resin layer further includes a third region, a fourth region and a fifth region, and an outer region excluding the second region, the third region, the fourth region and the fifth region, the second region, the third region, the fourth region and the fifth region being located between the first groove and the four corners, The light-emitting substrate further includes a third conductive layer, a fourth conductive layer, and a fifth conductive layer located in the third region, the fourth region, and the fifth region, respectively. In a plan view, the at least one groove further includes a second groove located between the second region and the outer region, a third groove located between the third region and the outer region, a fourth groove located between the fourth region and the outer region, and a fifth groove located between the fifth region and the outer region. The light-emitting device according to claim 4 or 5, wherein, in a plan view, the second groove, the third groove, the fourth groove, and the fifth groove each have an arc-shaped portion that is in contact with the first groove.

7. The light-emitting device according to any one of claims 1 to 3, wherein, in a plan view, the first groove is a groove that extends linearly between the first region and the second region.

8. The light-emitting device according to any one of claims 1 to 7, wherein the second surface of the resin layer is divided into a plurality of regions including the first region and the second region by at least one groove.

9. The light-emitting device according to any one of claims 1 to 3, wherein the at least one groove includes a groove having, in a plan view, a first position on the periphery of the second surface, a second position on the inside of the second surface, and a straight portion extending linearly from the first position to the second position.

10. The light-emitting device according to any one of claims 1 to 9, wherein the at least one groove includes a groove having a plurality of portions of different widths in a plan view.

11. The light-emitting device according to any one of claims 1 to 10, wherein the cross-sectional shape of the at least one groove includes a portion of a rectangle.

12. The light-emitting device according to any one of claims 1 to 10, wherein the cross-sectional shape of the at least one groove includes an arc of part of a circle or ellipse.

13. The light-emitting device according to any one of claims 1 to 12, wherein the width of the opening of at least one groove is greater than the width of the bottom of the groove.

14. The light-emitting device according to any one of claims 1 to 13, wherein, in a plan view, the first groove is arranged to intersect a line segment connecting the shortest distance between the first conductive layer and the second conductive layer.

15. The light-emitting device according to any one of claims 1 to 14, wherein the at least one fiber bundle is bent in the direction of the depth of the at least one groove along the at least one groove in a portion that overlaps the at least one groove in a plan view.

16. The first conductive layer is a first lower conductive layer, and the second conductive layer is a second lower conductive layer, and the first surface side of the resin layer comprises a first upper conductive layer and a second upper conductive layer arranged at intervals from each other. The light-emitting device according to any one of claims 1 to 15, wherein the first upper conductive layer is electrically connected to the first lower conductive layer, and the second upper conductive layer is electrically connected to the second lower conductive layer.

17. The light-emitting device according to any one of claims 1 to 16, wherein the light source is arranged to straddle the first groove in a plan view.

18. The light-emitting device according to any one of claims 1 to 17, wherein the light source is arranged to straddle the first conductive layer and the second conductive layer in a plan view.

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