JP7260828B2 - light emitting device - Google Patents

Description

The present disclosure relates to a method for manufacturing a light emitting device and a light emitting device.

Light-emitting devices having semiconductor light-emitting elements typified by LEDs are widely used. In such a light-emitting device, it is common to seal a chip such as an LED with translucent resin. For example, Patent Document 1 below discloses a light-emitting device in which a semiconductor light-emitting element is sealed with a light-transmitting member such as a transparent resin, and a phosphor layer is arranged on the light-transmitting member.

Patent Document 1 proposes providing a plurality of concave portions and/or convex portions on the upper surface of the phosphor layer, which is located on the side opposite to the light emitting element. In the technique described in Patent Literature 1, the light from the light emitting element is made incident on the side surfaces that define these recesses or protrusions, thereby avoiding light confinement due to total reflection and improving the light extraction efficiency. These recesses and protrusions are formed, for example, by filling a molding die with a liquid resin material containing a phosphor and then thermally curing the resin material (paragraph 0027). A phosphor layer having recesses and/or protrusions formed on its surface is fixed above the light emitting element via a translucent member such as a transparent resin.

JP 2006-237264 A

In the field of light-emitting devices, there is a demand for improved luminance.

A method for manufacturing a light-emitting device according to an embodiment of the present disclosure is a step of preparing a light-emitting body including a light-emitting element and a light-transmitting member covering the light-emitting element and having an upper surface, wherein the light-transmitting member is made of silicone. step (A) containing a resin, and the plurality of first protrusions of a mold having a plurality of first protrusions are opposed to the upper surface of the light-transmitting member, and the light-transmitting member in a heated state is formed. A step (B) of forming a plurality of first recesses each having a bottom surface on the upper surface by pressing the mold against the upper surface; a step (C) of forming at least the bottom surface of the plurality of first recesses in a region other than the plurality of first recesses on the upper surface of the translucent member; and a step (D) of irradiating the translucent member with ultraviolet rays.

A method for manufacturing a light-emitting device according to another embodiment of the present disclosure is a step of preparing a light-emitting body including a light-emitting element and a light-transmitting member covering the light-emitting element and having an upper surface, wherein the light-transmitting member is , the step (A) containing a silicone resin, and the plurality of first projections of a mold having a plurality of first projections and a plurality of second projections finer than the first projections A step (B) of forming a plurality of recesses in the light-transmitting member by making the second convex portion face the upper surface of the light-transmitting member and pressing the mold against the upper surface of the light-transmitting member in a heated state; ), and a step (C) of irradiating the light-transmitting member with ultraviolet rays from the upper surface side after the step (B), wherein the plurality of recesses include a plurality of first recesses each having a bottom surface; and a plurality of second recesses that are finer than the plurality of first recesses. It is formed in areas other than the provided area and on the bottom surfaces of the plurality of first recesses.

A light-emitting device according to still another embodiment of the present disclosure includes a light-emitting element and a light-transmitting member having a top surface and covering the light-emitting element, wherein the top surface of the light-transmitting member includes a bottom surface and one or more each of the first recesses has a plurality of second recesses that are finer than the first recesses on the bottom surface and the one or more side surfaces.

According to an embodiment of the present disclosure, a light emitting device with improved light extraction efficiency is provided.

1 is a schematic perspective view showing an example of the appearance of a light-emitting device according to an embodiment of the present disclosure; FIG. FIG. 2 is a diagram schematically showing a cross section of the light emitting device 100A shown in FIG. 1; 2 is a schematic perspective view schematically showing an upper surface 100a of the light emitting device 100A; FIG. It is a typical sectional view which expands and shows a part of upper surface 140a vicinity among 140 A of translucent members. 4A and 4B are diagrams schematically showing an example of a shape of a second concave portion 142; FIG. 4 is a flow chart outlining a method for manufacturing a light emitting device according to an embodiment of the present disclosure; 1A-1D are schematic cross-sectional views for explaining an exemplary method of manufacturing a light-emitting device according to an embodiment of the present disclosure; FIG. 3 is a schematic perspective view showing an example of a mold 200 having a plurality of first protrusions 210 on one main surface 200b. 1A-1D are schematic cross-sectional views for explaining an exemplary method of manufacturing a light-emitting device according to an embodiment of the present disclosure; FIG. 10 is a schematic cross-sectional view showing the light emitter 100U after the mold 200 is pulled out from the translucent member 140U. It is a schematic diagram for demonstrating the process of formation of several 2nd recessed parts by irradiation of a laser beam. 1A-1D are schematic cross-sectional views for explaining an exemplary method of manufacturing a light-emitting device according to an embodiment of the present disclosure; FIG. 10 is a schematic diagram for explaining a method of forming a plurality of second recesses 142q by exposing the upper surface 140a of the translucent member 140U to the treatment liquid 450; FIG. 4A is a schematic cross-sectional view showing a modification of a light-emitting device according to an embodiment of the present disclosure; 5 is a flow chart outlining a method for manufacturing a light emitting device according to another embodiment of the present disclosure; FIG. 3 is a schematic perspective view showing an example of a mold 200A having a plurality of first projections 210 and a plurality of second projections 220 finer than the first projections 210 on one main surface 200b. 17 is a schematic perspective view showing an enlarged first convex portion 210 of the mold 200A shown in FIG. 16 and its surroundings. FIG. FIG. 4A is a schematic cross-sectional view for explaining an exemplary method of manufacturing a light emitting device according to another embodiment of the present disclosure; FIG. 4A is a schematic cross-sectional view for explaining an exemplary method of manufacturing a light emitter; FIG. 4A is a schematic cross-sectional view for explaining an exemplary method of manufacturing a light emitter; FIG. 4A is a schematic cross-sectional view for explaining an exemplary method of manufacturing a light emitter; FIG. 4A is a schematic cross-sectional view for explaining an exemplary method of manufacturing a light emitter; FIG. 4A is a schematic cross-sectional view for explaining an exemplary method of manufacturing a light emitter; FIG. 10 is a schematic cross-sectional view for explaining another exemplary method of manufacturing a light emitter; FIG. 10 is a schematic cross-sectional view for explaining another exemplary method of manufacturing a light emitter; FIG. 10 is a schematic cross-sectional view for explaining another exemplary method of manufacturing a light emitter; FIG. 10 is a schematic cross-sectional view for explaining another exemplary method of manufacturing a light emitter; FIG. 11 is a schematic cross-sectional view showing another example of a light emitter having a light emitting element 110A and a translucent member 140U; FIG. 10 is a schematic cross-sectional view showing another modification of the light emitting device according to an embodiment of the present disclosure; FIG. 10 is a schematic cross-sectional view showing still another modification of the light emitting device according to an embodiment of the present disclosure; FIG. 11 is a schematic perspective view showing still another modification of the light emitting device according to an embodiment of the present disclosure; FIG. 32 is a diagram schematically showing a cross section of the light-emitting device 100E shown in FIG. 31 cut parallel to the YZ plane in FIG. 31 at a position near the center of the light-emitting device 100E; 4 is a plan view showing an example of the appearance of a composite substrate 400A having a first conductive portion 411A and a second conductive portion 412A viewed from the side of an upper surface 400a; FIG. FIG. 33 is a schematic cross-sectional view for explaining an exemplary manufacturing method of the light emitting device 100E shown in FIGS. 31 and 32; FIG. FIG. 33 is a schematic cross-sectional view for explaining an exemplary manufacturing method of the light emitting device 100E shown in FIGS. 31 and 32; FIG. FIG. 33 is a schematic cross-sectional view for explaining an exemplary manufacturing method of the light emitting device 100E shown in FIGS. 31 and 32; FIG. FIG. 4A is a schematic cross-sectional view for explaining another exemplary method of manufacturing a light-emitting device according to an embodiment of the present disclosure; FIG. 10 is a schematic cross-sectional view showing still another modification of the light emitting device according to an embodiment of the present disclosure; FIG. 10 is a schematic plan view showing still another example of a light emitter having a light emitting element and a translucent member; FIG. 4 is a schematic plan view showing an example of a composite substrate having a lead frame and a resin portion integrally formed with the lead frame; FIG. 10 is a diagram schematically showing a cross section of the light emitting structure 100Y cut parallel to the ZX plane in the figure near the center of the light emitting structure 100Y. FIG. 4A is a schematic cross-sectional view for explaining still another exemplary method of manufacturing a light-emitting device according to an embodiment of the present disclosure; FIG. 4A is a schematic cross-sectional view for explaining still another exemplary method of manufacturing a light-emitting device according to an embodiment of the present disclosure; FIG. 10 is a schematic cross-sectional view showing still another modification of the light emitting device according to an embodiment of the present disclosure; FIG. 4A is a schematic cross-sectional view for explaining still another exemplary method of manufacturing a light-emitting device according to an embodiment of the present disclosure; FIG. 10 is a schematic cross-sectional view showing still another modification of the light emitting device according to an embodiment of the present disclosure;

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The following embodiments are examples, and the method for manufacturing a light-emitting device and the light-emitting device according to the present disclosure are not limited to the following embodiments. For example, numerical values, shapes, materials, steps, order of steps, and the like shown in the following embodiments are merely examples, and various modifications are possible as long as there is no technical contradiction.

The dimensions, shapes, etc. of components shown in the drawings may be exaggerated for clarity, and may not reflect the dimensions, shapes, and size relationships between components in the actual light-emitting device and manufacturing equipment. There is Also, some elements may be omitted to avoid over-complicating the drawing.

In the following description, constituent elements having substantially the same functions are denoted by common reference numerals, and their description may be omitted. The following description may use terms (eg, "upper", "lower", "right", "left" and other terms that include those terms) that indicate particular directions or positions. However, these terms are used only for clarity of relative orientation or position in the referenced drawings. If the relative direction or positional relationship of terms such as “upper” and “lower” in the referenced drawings is the same, drawings other than the present disclosure, actual products, manufacturing equipment, etc. are the same as the referenced drawings. It does not have to be placement. In the present disclosure, “parallel” includes cases where two straight lines, sides, planes, etc. are in the range of about 0° to ±5°, unless otherwise specified. In the present disclosure, "perpendicular" or "perpendicular" includes cases where two straight lines, sides, planes, etc. are in the range of about 90° to ±5° unless otherwise specified.

(Embodiment of Light Emitting Device)
FIG. 1 shows an example of the appearance of a light emitting device according to an embodiment of the present disclosure. A light emitting device 100A illustrated in FIG. 1 has a substantially rectangular parallelepiped outer shape, and has an upper surface 100a and a lower surface 100b. For convenience of explanation, FIG. 1 also shows arrows indicating the X, Y, and Z directions that are orthogonal to each other. Arrows indicating these directions may also be illustrated in other drawings of the present disclosure. In the example shown in FIG. 1, the sides defining the rectangular shape of the upper surface 100a of the light emitting device 100A are aligned with the X direction or the Y direction in the drawing.

As shown in FIG. 1, the light emitting device 100A schematically includes a light emitting element 110A, a translucent member 140A covering the light emitting element 110A, and a reflective member 150A surrounding the light emitting element 110A and the translucent member 140A. . The translucent member 140A has an upper surface 140a. The upper surface 140a of the translucent member 140A forms part of the upper surface 100a of the light emitting device 100A.

As will be described in detail later, a plurality of first concave portions are formed in the upper surface 140a of the translucent member 140A. Furthermore, inside each first recess, a plurality of second recesses that are finer than the first recess are provided. The plurality of first recesses is a set of cylindrical or prismatic recesses each having a depth of about 50 μm, for example. These first concave portions are arranged two-dimensionally on the upper surface 140a at a pitch of, for example, 2 μm or more and 20 μm or less. By forming a plurality of first recesses each including a plurality of finer second recesses on the surface of the translucent member covering the light emitting element, it is possible to obtain the effect of improving the light extraction efficiency.

FIG. 2 shows a cross section of the light emitting device 100A shown in FIG. FIG. 2 schematically shows a cross section of the light emitting device 100A cut perpendicularly to the upper surface 100a near the center of the light emitting device 100A. In the configuration illustrated in FIG. 2, the light emitting device 100A has a wavelength converting member 120A and a light guiding member 130A in addition to the above-described light emitting element 110A, light transmitting member 140A and reflective member 150A. Hereinafter, each component of the light emitting device 100A will be described in more detail with reference to the drawings.

[Light emitting element 110A]
In the illustrated example, the light-emitting element 110A has an element body 111 having an upper surface 111a, and a positive electrode 112A and a negative electrode 114A located on the opposite side of the element body 111 from the upper surface 111a. The light emitting element 110A is, for example, an LED, and here, an LED that emits blue light is exemplified as the light emitting element 110A.

The element body 111 includes, for example, a support substrate such as sapphire or gallium nitride, and a semiconductor lamination structure on the support substrate. The semiconductor laminate structure includes an n-type semiconductor layer, a p-type semiconductor layer, and an active layer sandwiched between these layers. The semiconductor laminated structure may include a nitride semiconductor (In _x Al _y Ga _1-xy N, 0≦x, 0≦y, x+y≦1) capable of emitting light in the ultraviolet to visible region. In this example, the upper surface 111a of the element body 111 constitutes the upper surface of the light emitting element 110A.

The positive electrode 112A and the negative electrode 114A function as terminals that form an electrical connection with a wiring board or the like, and supply a predetermined current to the semiconductor laminated structure. As illustrated, the positive electrode 112A and the negative electrode 114A are partially exposed to the outside on the lower surface 100b side of the light emitting device 100A by exposing the respective lower surfaces from the reflective member 150A.

[Wavelength conversion member 120A]
120 A of wavelength conversion members are located above the upper surface of 110 A of light emitting elements, and have a substantially plate shape. The wavelength conversion member 120A is typically a member in which particles such as phosphor are dispersed in a base material such as resin, and absorbs at least part of the incident light to convert the wavelength of the incident light to Emit different wavelengths of light. For example, the wavelength conversion member 120A emits yellow light by wavelength-converting part of the blue light from the light emitting element 110A. According to such a configuration, white light is obtained by mixing the blue light that has passed through the wavelength conversion member 120A and the yellow light emitted from the wavelength conversion member 120A.

As a base material for dispersing particles such as phosphors, silicone resin, modified silicone resin, epoxy resin, modified epoxy resin, urea resin, phenol resin, acrylic resin, urethane resin, fluorine resin, or two of these resins can be used. A resin material including the above can be used. A light diffusion function may be imparted to the wavelength conversion member 120A by dispersing a material having a refractive index different from that of the base material in the material of the wavelength conversion member 120A. For example, particles of titanium dioxide, silicon oxide, or the like may be dispersed in the base material of the wavelength conversion member 120A.

A known material can be applied to the phosphor. Examples of phosphors include fluoride-based phosphors such as KSF-based phosphors, nitride-based phosphors such as CASN, YAG-based phosphors, and β-sialon phosphors. YAG phosphors are examples of wavelength conversion substances that convert blue light into yellow light, KSF phosphors and CASN are examples of wavelength conversion substances that convert blue light into red light, and β-SiAlON phosphors are examples of wavelength conversion substances that convert blue light into red light. is an example of a wavelength converting material that converts blue light to green light. The phosphor may be a quantum dot phosphor.

[Light guide member 130A]
In the configuration illustrated in FIG. 2, the light emitting element 110A is joined to the lower surface 120b of the wavelength conversion member 120A by the translucent light guide member 130A. As illustrated, the light guide member 130A covers at least a portion of the side surface 111c of the element body 111 of the light emitting element 110A and has an outer surface 130c which is an interface with the reflective member 150A.

By covering the side surface of the light emitting element 110A with the light guide member 130A, part of the light emitted from the light emitting element 110A and emitted from the side surface 111c of the element body 111 can enter the light guide member 130A. The light incident on the light guide member 130A is reflected upward from the light emitting element 110A at the position of the outer surface 130c, and is extracted to the outside of the light emitting device 100A via the wavelength conversion member 120A. Therefore, the light extraction efficiency can be improved by providing the light guide member 130A. 130 A of light guide members may cover the whole from the lower end of the side surface 111c of the element main body 111 to the upper end. It is beneficial if the light guide member 130A covers more area of the side surface of the light emitting element 110A because it can guide more light above the light emitting element 110A. 130 A of light guide members may contain the part located between the lower surface 120b of 120 A of wavelength conversion members, and the upper surface of 110 A of light emitting elements.

As a material of the light guide member 130A, a resin material containing a transparent resin or the like as a base material can be used. A typical example of the base material of the light guide member 130A is thermosetting resin such as epoxy resin and silicone resin. As the base material of the light guide member 130A, a silicone resin, a modified silicone resin, an epoxy resin, a phenol resin, a polycarbonate resin, an acrylic resin, a polymethylpentene resin, a polynorbornene resin, or a material containing two or more of these is used. good too.

The light guide member 130A has a transmittance of, for example, 60% or more with respect to light having an emission peak wavelength of the light emitting element 110A. From the viewpoint of effective use of light, it is beneficial that the transmittance of the light guide member 130A at the emission peak wavelength of the light emitting element 110A is 70% or more, and more beneficial if it is 80% or more. The terms “translucent” and “translucent” in this specification are interpreted to include the ability to diffuse incident light, and are not limited to being “transparent”. For example, the light guide member 130A may have a light diffusion function by dispersing a material having a refractive index different from that of the base material.

The shape of the outer surface 130c of the light guide member 130A in a cross-sectional view is not limited to a linear shape as shown in FIG. The shape of the outer surface 130c in a cross-sectional view may be a polygonal shape, a curvilinear shape convex in a direction toward the light emitting element 110A, a curvilinear shape convex in a direction away from the light emitting element 110A, or the like.

[Reflective member 150A]
The reflective member 150A is made of a light reflective material such as a resin in which a light reflective filler is dispersed, and is covered by the outer surface 130c of the light guide member 130A and the side surface of the light emitting element 110A by the light guide member 130A. cover the uncovered area. In the example shown in FIG. 2, the reflective member 150A also covers the side surface 120c of the wavelength converting member 120A and the side surface 140c of the translucent member 140A.

By arranging the reflective member 150A around the light emitting element 110A, the light emitted from the side surface of the light emitting element 110A is reflected at the interface between the outer surface 130c of the light guide member 130A and the reflective member 150A to form a wavelength converting member. 120A. Therefore, the light extraction efficiency is improved. In this example, the reflective member 150A also covers the area of the surface opposite to the top surface 110a of the light emitting element 110A, other than the area where the electrodes (that is, the positive electrode 112A and the negative electrode 114A) are arranged. By covering the surface opposite to the upper surface of the light emitting element 110A with the reflective member 150A except for the lower surface of the positive electrode 112A and the lower surface of the negative electrode 114A, leakage of light to the side opposite to the upper surface of the light emitting element 110A is suppressed. Therefore, the light extraction efficiency can be improved.

Silicone resin, phenol resin, epoxy resin, BT resin, polyphthalamide (PPA), or the like can be used as the base material of the reflective member 150A. As the light-reflecting filler, metal particles or inorganic or organic material particles having a higher refractive index than the base material can be used. Examples of light-reflecting fillers are particles of titanium dioxide, silicon oxide, zirconium dioxide, potassium titanate, aluminum oxide, aluminum nitride, boron nitride, mullite, niobium oxide, barium sulfate, or particles such as yttrium oxide and gadolinium oxide. Examples include particles of various rare earth oxides. In this specification, the term "light reflectivity" or "reflectivity" refers to a reflectance of 60% or more at the emission peak wavelength of the light emitting element. It is more beneficial if the reflectance of the reflective member 150A at the emission peak wavelength of the light emitting element 110A is 70% or more, and even more beneficial if it is 80% or more.

[Translucent member 140A]
In the configuration illustrated in FIG. 2, the translucent member 140A has a substantially plate-like shape like the wavelength conversion member 120A, and is arranged on the upper surface 120a of the wavelength conversion member 120A. The light-transmitting member 140A is a light-transmitting member made of a resin material containing silicone resin, and typically has a transmittance of 60% or more for light having an emission peak wavelength of the light-emitting element 110A. have. From the viewpoint of effective use of light, it is beneficial that the transmittance of the light transmitting member 140A at the emission peak wavelength of the light emitting element 110A is 70% or more, and more beneficial if it is 80% or more.

The silicone resin in the translucent member 140A contains organic polysiloxane having at least one phenyl group in its molecule. Alternatively, the silicone resin in the translucent member 140A contains organic polysiloxane having a D unit in which two methyl groups are bonded to silicon atoms. The translucent member 140A may contain both of these two organic polysiloxanes. The silicone resin in the translucent member 140A may contain, for example, an organic polysiloxane having a phenyl group and a D unit. The silicone resin composition that constitutes the translucent member 140A may contain modified silicone into which a group other than a methyl group and a phenyl group has been introduced. The base material forming the translucent member 140A may contain a resin other than silicone resin.

The translucent member 140A is not limited to a member substantially made of silicone resin, and may be a composite member containing a material other than silicone resin. For example, the translucent member 140A may be a member or the like in which a resin material containing silicone resin is used as a base material and a light-reflecting filler is dispersed. As the light-reflective filler, metal particles, inorganic material or organic material particles having a higher refractive index than the base material, or the like can be used as in the case of the reflective member 150A. The translucent member 140A may include a wavelength converting member such as phosphor particles.

As shown in FIG. 2, the upper surface 140a of the translucent member 140A has a plurality of first recesses 141. As shown in FIG. FIG. 3 schematically shows the top surface 100a of the light emitting device 100A. Here, the plurality of first recesses 141 are arranged two-dimensionally on the upper surface 140a. In addition, in FIG. 3, the 1st recessed part 141 is exaggerated and drawn large for convenience of explanation. Also in other drawings of the present disclosure, the first concave portion 141 may be exaggerated and drawn large for convenience of explanation.

As described above, each first recess 141 has a cylindrical or prismatic shape with a bottom surface. Here, the shape of the opening of each first concave portion 141 located on the upper surface 140a of the translucent member 140A is circular. That is, in the configuration illustrated in FIG. 3, each of the plurality of first recesses 141 is a cylindrical recess. In the example shown in FIG. 3, the plurality of first concave portions 141 are formed on the upper surface 140a of the translucent member 140A such that the respective centers are located on the lattice points of the square lattice. The arrangement pitch of the first recesses 141, that is, the center-to-center distance between the two closest first recesses 141 is, for example, in the range of 2 μm or more and 20 μm or less. Of course, the arrangement of the first recesses 141 and the shape of each of the first recesses 141 are not limited to the example shown in FIG. Arbitrary arrangement and shape can be adopted as the arrangement of the first recesses 141 and the shape of each of the first recesses 141 . For example, the plurality of first recesses 141 may be formed on the upper surface 140a of the translucent member 140A such that the respective centers are located on the lattice points of the triangular lattice. In addition, the outline of the opening of the first recess 141 is not limited to a smooth curve as illustrated, and may be zigzag.

FIG. 4 schematically shows an enlarged portion of the translucent member 140A near the upper surface 140a. As schematically shown in FIG. 4, each of the plurality of first recesses 141 has a plurality of finer second recesses 142 therein. In addition, in FIG. 4, the 2nd recessed part 142 is exaggerated and drawn large for clarity. Also in other drawings of the present disclosure, for convenience of explanation, the second
The concave portion 142 may be exaggerated and drawn large.

In the configuration illustrated in FIG. 4, the plurality of second recesses 142 are formed on the bottom surface 141b of each first recess 141 and the top surface 140a of the translucent member 140A. Here, the bottom surface 141b of the first recess 141 refers to the position of the opening of the second recess 142 formed inside the first recess 141, which is indicated by the dashed line in FIG. In this example, a plurality of second recesses 142 are not formed on the side surface 141c of each first recess 141, but as described later, a plurality of second recesses 142 are formed on both the side surface 141c and the bottom surface 141b that define the first recesses 141. of second recesses 142 may be formed.

The arrangement pitch of the second recesses 142, that is, the center-to-center distance between two adjacent second recesses 142 (indicated by a double-headed arrow Pt in FIG. 4) is typically in the range of 0.1 μm or more and 1 μm or less. . The depth of the second concave portion 142 (indicated by a double-headed arrow Dp in FIG. 4) is about 0.02 μm or more and 1 μm or less. In the illustrated example, the upper surface 140a of the translucent member 140A is a portion where the opening of the second recess 142 formed in a region other than the inside of the first recess 141 among the plurality of second recesses 142 is located.

FIG. 5 schematically shows an example of the shape of the second recess 142. As shown in FIG. As schematically shown in FIG. 5, the second recess 142 may be a recess having a generally pyramidal shape. Here, the conical shape is interpreted to include a conical shape and a pyramidal shape, and therefore the shape of the opening of the second recess 142 is not limited to a circle or a regular polygon, but an ellipse, a polygon, or an irregular shape. It may be a fixed form or the like. The size of the second recess 142 can be represented by the diameter of a circle (indicated by a dashed line in FIG. 5) that encompasses the opening of the second recess 142, as indicated by a double arrow Dm in FIG. The diameter of the circle that encompasses the opening of the second concave portion 142 is, for example, in the range of 0.05 μm or more and 0.5 μm or less.

(Exemplary manufacturing method of light-emitting device)
FIG. 6 outlines a method of manufacturing a light emitting device according to certain embodiments of the present disclosure. The method for manufacturing the light-emitting device illustrated in FIG. 6 generally includes a step of preparing a light-emitting body including a light-emitting element and a light-transmitting member covering the light-emitting element (step S11); A step of forming a plurality of first recesses on the upper surface of the light-transmitting member by pressing a mold against (step S12), and a step of forming a plurality of finer second recesses after forming the plurality of first recesses (step S13 ), and a step of irradiating the translucent member with ultraviolet rays from the upper surface side after the formation of the plurality of second recesses (step S14). Here, a translucent member containing a silicone resin is used as an object to which the mold is pressed. Details of an exemplary method of manufacturing a light emitting device will be described below with reference to the drawings.

First, a light emitter including the light emitting element 110A and a translucent member covering the light emitting element 110A is prepared (step S11 in FIG. 6). FIG. 7 shows an example in which a plurality of light emitters 100U each including a light emitting element 110A and a translucent member 140U are temporarily fixed on a support layer 50 such as a substrate or a heat-resistant adhesive sheet. Here, for the sake of simplicity, three light emitters 100U arranged along the left-right direction of the paper surface are shown, but a plurality of light emitters 100U may of course be arranged two-dimensionally on the support layer 50. .

A light emitter 100U shown in FIG. 7 has substantially the same configuration as the light emitting device 100A described with reference to FIG. The light emitter 100U may be prepared by purchase, or may be produced by a method that will be exemplified later.

The upper surface 140a of the translucent member 140U located above the light emitting element 110A is typically a flat surface aligned with the upper surface of the reflective member 150A of the light emitter 100U. In the illustrated example, the light-transmitting member 140U of the light-emitting body 100U is a plate-like member containing silicone resin, and the silicone resin in the light-transmitting member 140U has already been cured. The silicone resin in translucent member 140U typically contains organic polysiloxane having at least one phenyl group in the molecule or organic polysiloxane having a D unit.

Next, a mold having an uneven surface is prepared. Here, as shown in FIG. 8, a mold 200 having a plurality of first projections 210 on one main surface 200b is used. The material of the mold 200 is not particularly limited, and general materials such as hardened steel, aluminum, and beryllium copper alloy can be used, for example.

In the configuration illustrated in FIG. 8, each of the plurality of first projections 210 is a cylindrical projection that protrudes from one main surface 200b of the mold 200 and has a top surface 210a and side surfaces 210c. Here, the top surface 210a has a circular shape when viewed from above. However, the shape of the top surface 210a when viewed from above is not limited to a perfect circle, and may be an ellipse, a distorted circle, or the like. That is, the first protrusion 210 may have a shape such as an elliptical cylinder. Alternatively, the shape of each first protrusion 210 is not limited to a cylindrical shape, and may be a prismatic shape. In this case, it goes without saying that the shape of the top surface 210a when viewed from above is not limited to a regular polygonal shape. When the first protrusion 210 has a prismatic shape, the number of side surfaces 210c of the first protrusion 210 is three or more.

The height of the first convex portion 210, in other words, the distance from the main surface 200b to the top surface 210a can range, for example, from 0.5 μm to 20 μm. The diameter of the top surface 210a when the first convex portion 210 has a columnar shape, or the diameter of the circumscribed circle of the polygon defining the outer shape of the top surface 210a when the first convex portion 210 has a prismatic shape is typically Practically, it is 1 μm or more and 20 μm or less. In FIG. 8, the first convex portion 210 is exaggerated and drawn large for ease of understanding. Also in other drawings of the present disclosure, the first convex portion 210 may be exaggerated and drawn large for convenience of explanation.

In the configuration illustrated in FIG. 8, the first protrusions 210 are two-dimensionally arranged on the main surface 200b of the mold 200 so that the respective centers are located on the lattice points of the square lattice. The arrangement pitch of the first protrusions 210, that is, the center-to-center distance between the closest first protrusions 210 is, for example, in the range of 2 μm or more and 20 μm or less. Of course, the arrangement of the first protrusions 210 and the shape of each of the first protrusions 210 are not limited to the example shown in FIG. For example, the first protrusions 210 may be two-dimensionally arranged on the main surface 200b of the mold 200 so that the respective centers are located on the lattice points of the triangular lattice.

Next, the mold 200 is pressed against the heated translucent member 140U to form a plurality of first concave portions in the upper surface 140a of the translucent member 140U (step S12 in FIG. 6). Here, the plurality of light emitters 100U supported by the support layer 50 are placed together with the support layer 50 on a support having sufficient rigidity, and the mold 200 is placed with the first protrusions 210 facing the upper surface 140a of the translucent member 140U. It faces the translucent member 140U. Furthermore, as schematically indicated by a thick arrow PS in FIG. 9, the mold 200 is pressed against the upper surface 140a of the translucent member 140U.

At this time, by pressing the mold 200 against the light-transmitting member 140U heated to about 70° C. to 300° C. with a pressure of about 50 kPa to 50 MPa, the plurality of first surfaces of the mold 200 are pressed against the upper surface 140a of the light-transmitting member 140U. A plurality of first recesses 141q corresponding to one protrusion 210 can be formed. Heating of the translucent member 140U may be performed by increasing the temperature around the translucent member 140U, or may be performed by increasing the temperature of the mold 200 and/or the support.

Since the arrangement pitch of the first protrusions 210 is in the range of 2 μm or more and 20 μm or less, the mold 20
The plurality of first recesses 141q formed on the upper surface 140a of the translucent member 140U by pressing 0 also has an arrangement pitch in the range of about 2 μm or more and 20 μm or less. In the example shown in FIG. 9, a single mold 200 is used to collectively form a plurality of first concave portions 141q for the translucent members 140U of the plurality of light emitters 100U. However, the method of forming the first recesses 141q by pressing the mold 200 is not limited to this example. A plurality of first recesses 141q may be formed.

FIG. 10 schematically shows the luminous body 100U after the mold 200 is pulled out from the translucent member 140U. As schematically shown in FIG. 10, each of the first concave portions 141q formed in the translucent member 140U has one bottom surface 141b and one side 141c. As can be understood from this, each first concave portion 141q has a shape corresponding to the shape of the first convex portion 210 provided on the mold 200 . When the first protrusion 210 has, for example, a prismatic shape, each first recess 141q has a shape defined by one bottom surface and a plurality of side surfaces.

Here, since the top surface 210a of the cylindrical first projection 210 has a diameter in the range of 1 μm or more and 20 μm or less, the diameter of the circle encompassing the opening of the first recess 141q is generally in the range of 1 μm or more and 20 μm or less. be. The same applies to the diameter of the circle that encompasses the opening of the first concave portion 141q when the first convex portion 210 has a prismatic shape.

After forming the plurality of first concave portions 141q, the mold 200 is separated from the translucent member 140U. In this embodiment, unlike a general thermal imprint method using an uncured resin material, the mold 200 is pressed against the translucent member 140U containing the silicone resin in a cured state. Separation of the mold 200 from the translucent member 140U is relatively easy.

After forming the plurality of first recesses 141q, a plurality of finer second recesses are formed (step S13 in FIG. 6). A method for forming the plurality of second recesses is not limited to a specific method. For example, as described below, it is possible to form a plurality of second recesses inside each of the first recesses 141q using laser light irradiation.

FIG. 11 schematically shows formation of a plurality of second concave portions by laser light irradiation. A known laser ablation device can be applied to the laser light irradiation. The example shown in FIG. 11 schematically shows an example in which a laser ablation device 40 including a laser light source 430 and a galvanomirror 440 is applied. The number of galvanometer mirrors in laser ablation device 40 can be two or more. Examples of laser light sources 430 are Nd:YAG lasers, Yb:KGB lasers, Ti:sapphire lasers, _CO2 lasers, excimer lasers, and the like.

By scanning the laser light beam L from the upper surface 140a side of the translucent member 140U, a part of the translucent member 140U on the upper surface 140a side can be removed, and as a result, as schematically shown in FIG. It is possible to form a plurality of second recesses 142q in a region of the upper surface 140a of the translucent member 140U other than the region overlapping the first recesses 141q and at least on the bottom surface 141b of the first recesses 141q. The second recess 142q may be, for example, a circular dimple-shaped depression. For scanning the beam L, a galvanomirror may be used as in the example of FIG. 11, or the light emitter 100U is placed on a stage made of quartz glass or the like together with the support layer 50, and the stage is moved within the XY plane. Laser light irradiation may be performed while

An example of processing conditions for forming a fine structure pattern by irradiating laser light from the upper surface 140a side of the translucent member 140U is shown below.
Peak wavelength of laser light: 1030 nm
Laser power: 30mW
Pulse width: 260 femtoseconds Frequency: 200 kHz
Feeding speed: 0.5mm/s
Defocus from upper surface 140a of translucent member 140U: 0.1 μm
Spot diameter at the position of the upper surface 140a of the translucent member 140U: 0.5 μm

After forming the plurality of second recesses 142q, the translucent member 140U is irradiated with ultraviolet rays from the upper surface 140a side (step S14 in FIG. 6). Here, as schematically shown in FIG. 12, an ultraviolet irradiation device 500 irradiates the upper surface 140a of the translucent member 140U with ultraviolet rays. The irradiation amount of the ultraviolet rays at this time is, for example, 20 J/cm ² or more. The wavelength of the ultraviolet rays to be irradiated is not particularly limited, and for example, an ultraviolet irradiation device that emits ultraviolet rays having a spectrum over the wavelength range of UVA (400-315 nm) to UVC (280-140 nm) can be used. Here, a light source with a main peak wavelength of light emission of 365 nm is used.

In the embodiment of the present disclosure, after the first concave portion 141q and the second concave portion 142q are formed in the transparent member 140U, the ultraviolet rays are applied to the transparent member 140U. At first glance, this UV irradiation step seems to be unnecessary. However, according to the study of the present inventor, the light-emitting body 100U in which the first concave portion 141q and the second concave portion 142q are formed in the translucent member 140U and the ultraviolet rays are not intentionally irradiated is heated to a temperature of about 300°C. Under the environment, the irregular shape formed on the upper surface 140a of the translucent member 140U, especially the shape of the first concave portion 141q, may collapse.

A light-emitting device having an electrode on the bottom side like the light-emitting body 100U can be mounted on a wiring substrate or the like by reflow, for example. Therefore, if a light-emitting device that has not been intentionally irradiated with ultraviolet rays is exposed to high temperatures in a process such as reflow, the shape of the first recess 141q formed by the pressing of the mold 200 may collapse. In an extreme case, the upper surface 140a of the translucent member 140U returns to a shape close to a flat surface. In other words, if the step of irradiating ultraviolet rays is omitted, the desired shape may not be obtained.

In contrast, in the embodiment of the present disclosure, the upper surface 140a of the translucent member 140U is irradiated with ultraviolet rays after the formation of the plurality of second recesses 142q. By executing the UV irradiation step, even when the translucent member 140U is exposed to a high-temperature environment of about 300° C., it is possible to maintain the uneven shape formed on the upper surface 140a. That is, according to the embodiment of the present disclosure, the translucent member 140A having the plurality of first recesses 141 and the plurality of second recesses 142 with the shapes of the plurality of first recesses 141q and the plurality of second recesses 142q fixed. can be obtained from the translucent member 140U. In addition, even when exposed to a high-temperature environment of about 300° C., the shapes of the plurality of first recesses 141 and the plurality of second recesses 142 are unlikely to change significantly. It is advantageous for the application of processes involving high temperatures such as.

Through the above steps, the light emitting device 100A shown in FIG. 2 is obtained. The method of forming the plurality of second recesses 142q is not limited to laser surface texturing (LST), and the plurality of second recesses 142q may be formed by, for example, spraying. Alternatively, the plurality of second recesses 142q may be formed by exposing the upper surface 140a of the translucent member 140U in which the plurality of first recesses 141q are formed to the treatment liquid.

For example, as schematically shown in FIG. 13, the treatment liquid 450 is applied or dropped onto the upper surface 140a of the translucent member 140U in which the plurality of first concave portions 141q are formed. The treatment liquid 450 includes hydrofluoric acid, a mixture of hydrofluoric acid and hydrogen peroxide, a mixture of hydrofluoric acid and nitric acid, buffered hydrofluoric acid, and buffered hydrofluoric acid. One selected from the group consisting of a mixed solution of hydrogen peroxide and a mixed solution of buffered hydrofluoric acid and nitric acid can be used. Here, buffered hydrofluoric acid refers to a mixed solution of hydrofluoric acid and ammonium fluoride (NH ₄ F) as a buffer.

By treating the surface of the light-transmitting member 140U with hydrofluoric acid or the like, a region of the upper surface 140a of the light-transmitting member 140U that overlaps the first recess 141q can be removed, as in the case of applying laser light irradiation or spraying. It is possible to form a plurality of finer second recesses 142q in regions other than the above and inside the first recesses 141q. Note that when the plurality of second recesses 142q are formed by exposing the surface of the light-transmitting member 140U to the treatment liquid 450, as schematically shown in FIG. It can be formed not only on the bottom surface 141b of the recess 141q but also on the side surface 141c. After forming the plurality of second recesses 142q, the treatment liquid 450 is removed from the surface of the translucent member 140U using pure water.

After that, the upper surface 140a of the translucent member 140U is irradiated with ultraviolet rays in the same manner as in the example described with reference to FIG. Through the steps described above, the light-transmitting member 140B having a plurality of first recesses 141 and a plurality of second recesses 142 is formed from the light-transmitting member 140U, thereby obtaining the light emitting device 100B shown in FIG. Compared with the above-described light emitting device 100A (see FIG. 2, etc.), the light emitting device 100B has a light transmitting member 140B instead of the light transmitting member 140A. As schematically shown in an enlarged view in FIG. 14, in this example, the plurality of second recesses 142 are composed of a region of the upper surface 140a of the translucent member 140B other than the region overlapping the first recesses 141, and the first recesses. It is also formed on the side surface 141c of the first recess 141 in addition to the bottom surface 141b of the first recess 141 .

(Another exemplary method for manufacturing a light-emitting device)
FIG. 15 outlines a method of manufacturing a light emitting device according to another embodiment of the present disclosure. The method for manufacturing the light-emitting device illustrated in FIG. 15 generally includes a step of preparing a light-emitting body including a light-emitting element and a light-transmitting member covering the light-emitting element (step S21); a step of pressing a mold having a plurality of first protrusions and a plurality of second protrusions to form a plurality of recesses in the translucent member (step S22); and a step of irradiating the member with ultraviolet rays (step S23). Details of other exemplary methods of manufacturing light emitting devices are described below.

First, the light emitter 100U including the light emitting element 110A and the translucent member covering the light emitting element 110A is prepared (step S21 in FIG. 15). This step is the same as step S11 described with reference to FIG. The point that the translucent member 140U of the light emitter 100U contains the silicone resin is also the same as the example described with reference to FIGS. Therefore, detailed description of the process of preparing the light emitter 100U is omitted here.

Next, a mold having an uneven surface is prepared in the same manner as in the above example. However, here, as illustrated in FIG. 16, a mold 200A having a plurality of first protrusions 210 and a plurality of second protrusions 220 finer than the first protrusions 210 on one main surface 200b. Use

Similar to the mold 200 shown in FIG. 8, each of the plurality of first projections 210 provided on the mold 200A is, for example, a cylindrical projection having a top surface 210a and side surfaces 210c. The point that the shape of the first convex portion 210 may be a prismatic shape is the same as the example described with reference to FIG. 8 .

In the configuration illustrated in FIG. 16, the plurality of first protrusions 210 are two-dimensionally arranged in a region Rp of the main surface 200b of the mold 200A. In this example, the plurality of first protrusions 210 are arranged such that their respective centers are located on lattice points of the square lattice inside the region Rp. As in the example described with reference to FIG. 8, it goes without saying that the arrangement of the first projections 210 is not limited to a square lattice.

FIG. 17 shows an enlarged view of the first convex portion 210 of the mold 200A shown in FIG. 16 and its periphery. As shown in FIG. 17, here, the top surface 210a of the first protrusion 210 has a plurality of second protrusions 220 protruding from the top surface 210a. Each of the plurality of second protrusions 220 has a cone shape such as a cone shape or a pyramid shape. In addition, in FIG. 17, the 2nd convex part 220 is exaggerated and drawn large for clarity. Also in other drawings of the present disclosure, the second protrusion 220 may be exaggerated and drawn large for convenience of explanation. The height of the cone shape of the second protrusion 220 (the distance from the bottom surface to the top of the cone shape indicated by the double arrow Ht in FIG. 17) is, for example, about 0.02 μm or more and 1 μm or less. The diameter of the circle that encompasses the bottom surface of the second protrusion 220 is, for example, in the range of 0.05 μm or more and 0.5 μm or less.

As shown in FIG. 17 , in this example, the second protrusions 220 are also arranged around the first protrusions 210 . The arrangement pitch of the second protrusions 220, that is, the center-to-center distance between two adjacent second protrusions 220 (indicated by a double-headed arrow Pu in FIG. 17) is typically in the range of 0.1 μm or more and 1 μm or less. is. The arrangement of the second protrusions 220 is arbitrary, and the plurality of second protrusions 220 are regularly arranged in the region Rp of the main surface 200b of the mold 200A and the top surface 210a of the first protrusions 210. , or they may be arranged irregularly.

After preparing the mold 200A, the plurality of first convex portions 210 and the plurality of second convex portions 220 of the mold 200A are made to face the upper surface 140a of the translucent member 140U of the light emitter 100U. Furthermore, by pressing the mold 200A against the heated translucent member 140U, a plurality of recesses are formed in the translucent member (step S22 in FIG. 15). Here, similarly to the example described with reference to FIG. 9, the upper surface 140a of the translucent member 140U is heated to about 70° C. to 300° C., as schematically indicated by the thick arrow PS in FIG. The mold 200A is pressed against the mold 200A with a pressure of about 50 kPa to 50 MPa.

By pressing the mold 200A, as schematically shown enlarged in FIG. A plurality of recesses including two recesses 142q can be collectively formed in the upper surface 140a of the translucent member 140U. In this example, each of the plurality of first recesses 141q is a columnar recess having a bottom surface corresponding to the first protrusion 210 of the mold 200A having a cylindrical shape including the top surface 210a. It is formed on the upper surface 140a of the member 140U. Also, in this example, the second concave portion 142q has a generally conical shape corresponding to the conical shape of the second convex portion 220 of the mold 200A. The second recess 142q is a recess that is finer than the first recess 141q.

As described with reference to FIG. 17, here, a plurality of second protrusions 220 are provided on the top surface 210a of the first protrusions 210 of the mold 200A. Therefore, by pressing the mold 200A against the upper surface 140a of the translucent member 140U, the second recesses 142q are formed at the bottom surfaces of the first recesses 141q. Further, here, in addition to the top surface 210a of the first protrusion 210, a plurality of second protrusions 220 are also provided in the area surrounding the first protrusion 210 on the main surface 200b of the mold 200A. Therefore, by pressing the mold 200A so that the plurality of second protrusions 220 reach the upper surface 140a of the light-transmitting member 140U, the light-transmitting member 140U is enlarged as schematically shown in FIG. It is possible to form a plurality of second protrusions 220 in areas other than the area in which the first recesses 141q are formed on the upper surface 140a of 140U. For example, a plurality of second recesses 142q can be formed on the upper surface 140a of the translucent member 140U in regions around the first recesses 141q.

After forming a plurality of recesses including the first recess 141q and the second recess 142q, the mold 200A is separated from the light emitter 100U. In the embodiment of the present disclosure, unlike a general thermal imprint method using an uncured resin material, the mold is pressed against the translucent member 140U containing the silicone resin in a cured state. , separation of the mold from the translucent member 140U is relatively easy.

After that, the translucent member 140U is irradiated with ultraviolet rays from the upper surface 140a side (step S23 in FIG. 15). Irradiation of ultraviolet rays to the translucent member 140U can be performed using, for example, an ultraviolet irradiation device 500, as in the example described with reference to FIG. When the mold 200A is made of a material that transmits ultraviolet rays, the ultraviolet rays may be irradiated through the mold 200A without separating the mold 200A from the light emitter 100U.

By irradiating ultraviolet rays, the translucent member 140A having a plurality of first recesses 141 and a plurality of second recesses 142 can be formed from the translucent member 140U. As can be easily understood from FIG. 18, in this example, the second recess 142q is not formed on the side surface 141c that defines the shape of the first recess 141q. Through the above steps, the light emitting device 100A shown in FIG. 2 is obtained. Thus, by using a mold having a plurality of first protrusions 210 and a plurality of second protrusions 220, a plurality of first recesses 141 and a plurality of second recesses finer than the first recesses 141 can be obtained. 142 can be collectively formed.

According to the embodiment of the present disclosure, the upper surface 140a of the translucent member 140U can be given a fine uneven shape, which can improve the light extraction efficiency, for example. Moreover, according to the embodiment of the present disclosure, the upper surface 140a of the light-transmitting member 140U, which is the light-emitting surface of the light-emitting body 100U that can function as a light-emitting device as it is, can be given an uneven shape afterward. is.

2. Description of the Related Art As a technique for forming fine irregularities, an imprint method is conventionally known in which the surface profile of a mold having fine irregularities is transferred to a layer of a resin material. However, the object to which the shape is transferred by the imprint method is limited to a thermoplastic resin or an ultraviolet curable resin. It is difficult to give the surface of the resin body a fine uneven shape afterward. The concept of pressing the mold against the cured resin body instead of the uncured state is an unprecedented idea.

Further, in the embodiment of the present disclosure, the ultraviolet irradiation is performed after the depression is formed by pressing the mold. By irradiating with ultraviolet rays, it is possible to fix the shape formed by pressing the mold. The point of further irradiating the thermosetting resin with ultraviolet rays is also an unprecedented idea.

Even when the translucent member 140U is exposed to a high-temperature environment of about 300° C., the UV irradiation makes it possible to maintain the uneven shape formed on the upper surface 140a. The morphology is advantageous for process applications involving high temperatures, such as reflow. For example, when the light emitting device 100A is heated at a temperature of 300° C. for 40 minutes, the change in the depth of the first concave portion 141 before and after the heating can be within a range of 25% or less. Here, the change in the depth of the first recesses 141 is defined by Dq being the average value of the depths of the first recesses 141 at arbitrary 10 locations before heating, It can be defined by |Dr−Dq|/Dq, where Dr is the average value of the depth of one recess 141 .

In the example described above, the first concave portion 141 and the second concave portion 142 are selectively formed in the upper surface 140a of the translucent member 140A or 140B in the upper surface 100a of the light emitting device. However, the first concave portion 141 and/or the second concave portion 142 may be formed in a region other than the upper surface 140a of the upper surface 100a of the light emitting device. For example, when the base material of the reflective member 150A contains silicone resin, by arranging the first convex portion 210 and the second convex portion 220 of the mold at positions facing the upper surface of the reflective member 150A, A first recess 141 and a second recess 142 may be formed in the upper surface of the reflective member 150A.

An exemplary method for manufacturing the light emitter 100U will be described below with reference to the drawings. First, a light-emitting element 110A having an upper surface and a positive electrode 112A and a negative electrode 114A on the lower surface opposite to the upper surface is prepared. The light emitting element 110A may be prepared by purchase.

Next, as shown in FIG. 19, a support 60 such as a substrate or a heat-resistant adhesive sheet is prepared, and the light emitting element 110A is placed on the support 60 with the positive electrode 112A and the negative electrode 114A facing the upper surface 60a of the support 60. Deploy. Next, as shown in FIG. 20, a first resin material 130r containing a transparent resin or the like as a base material is applied to the upper surface 111a of the light emitting element 110A using a dispenser or the like.

Next, as schematically shown in FIG. 21, the wavelength converting member 120A and the translucent member 140U are arranged on the first resin material 130r, and the first resin material 130r is cured. In this example, a lamination sheet LB including the wavelength converting member 120A and the translucent member 140U is prepared, and the wavelength converting member 120A and the translucent member 140U are collectively arranged on the first resin material 130r. For the lamination sheet LB, for example, a phosphor sheet in which the resin in the resin material in which phosphor particles are dispersed is in a B-stage state, and a translucent resin sheet formed from a silicone resin raw material are prepared. It can be prepared by bonding these together with heat and obtaining a cut piece of a predetermined size with an ultrasonic cutter or the like. By curing the first resin material 130r after the lamination sheet LB is arranged, the light guide member 130A can be formed from the first resin material 130r.

Next, as shown in FIG. 22, the structure on the support 60 is covered with a light reflecting resin layer 150T. The light-reflective resin layer 150T can be formed, for example, by applying a second resin material in which a light-reflective filler is dispersed, to the upper surface 60a of the support 60, and then curing the second resin material. Transfer molding, for example, can be applied to the formation of the light-reflective resin layer 150T. In the state shown in FIG. 22, the upper surface 140a and the side surface 140c of the translucent member 140U are covered with the light reflecting resin layer 150T.

Next, a part of the light-reflective resin layer 150T is removed from the upper surface side of the light-reflective resin layer 150T by grinding or the like, thereby exposing the upper surface 140a of the translucent member 140U from the ground surface. Further, the structure on the support 60 is cut into a desired shape by a dicing machine or the like. For example, the ground light-reflective resin layer 150T is cut at the positions of the two light-emitting elements 110A adjacent to each other. Through the process of grinding and cutting the light reflective resin layer 150T, the reflective member 150A is formed from the light reflective resin layer 150T, and the light emitter 100U is obtained on the support 60 as shown in FIG.

Conventionally, in a manufacturing method in which a light-transmitting member is embedded inside a light-reflecting resin layer, it has been difficult to subsequently provide an uneven pattern on the upper surface of the light-transmitting member that appears on the ground surface. In contrast, according to the embodiment of the present disclosure, it is possible to shape the surface of the light-transmitting member 140U after curing. Therefore, after obtaining a light-emitting body that can be used as a product, it becomes possible to give a shape to a member positioned in front of the light-emitting element, such as the light-transmitting member 140U, after the fact, so that light can be extracted from the light-emitting device. The effect of improving efficiency can be expected.

The method for manufacturing the light emitter is not limited to the examples described with reference to FIGS. 19 to 23, and for example, the following manufacturing method can also be applied. First, as shown in FIG. 24, a first resin layer 170 having a translucent portion 172 is prepared. The resin layer 170 can have two or more translucent portions 172 . In the configuration illustrated in FIG. 24 , the resin layer 170 has light-reflective resin portions 174 , and the light-transmitting portions 172 are separated from each other by the light-reflective resin portions 174 . In this example, each translucent portion 172 includes a translucent layer 140L and a wavelength conversion layer 120L.

The resin layer 170 can be obtained, for example, as follows. First, a light-reflective resin sheet is prepared. The light-reflective resin sheet may be a resin sheet in which approximately 60% by weight of particles of titanium dioxide and silicon oxide are dispersed in a silicone resin. Compression molding, transfer molding, injection molding, or molding using a printing method or a spray method can be used to form the light-reflective resin sheet.

Next, through holes are provided in the resin sheet by punching or the like. The shape of the through-hole in top view is, for example, a rectangular shape. After forming the through-holes, the inside of the through-holes is filled with a third resin material containing silicone resin as a base material and phosphor particles dispersed in the base material by a potting method, a printing method, a spraying method, or the like. At this time, phosphor particles are allowed to settle in the third resin material filled in the through-holes, and the third resin material is cured to form a translucent portion having a difference in phosphor concentration in the thickness direction. It is possible to For example, it is possible to form a translucent portion in which many phosphor particles are distributed on the lower surface side. Alternatively, after a transparent resin material is placed inside the through-holes and cured, a third resin material may be applied onto the transparent resin material to fill the through-holes with these materials.

If the phosphor particles are allowed to settle and the resin layer 170 is turned upside down after the third resin material is cured, a resin layer 170 having a light reflecting resin portion 174 and a plurality of translucent portions 172 as shown in FIG. 24 can be obtained. . In the configuration illustrated in FIG. 24 , the light-transmitting layer 140L is a layer having a relatively low concentration of phosphor particles in the light-transmitting portion 172 . In FIG. 24, the layers are illustrated as if there is a boundary between the wavelength conversion layer 120L and the light-transmitting layer 140L, but the boundary between these layers cannot be clearly recognized. There is also

Next, the first resin material 130r is applied by a dispenser or the like onto the region of the resin layer 170 where the translucent portion 172 is arranged. Further, as shown in FIG. 25, the light emitting element 110A is placed on the first resin material 130r with the positive electrode 112A and the negative electrode 114A facing away from the resin layer 170. As shown in FIG. By curing the first resin material 130r, the light guide member 130A covering at least a portion of the side surface 111c of the element body 111 can be formed from the first resin material 130r.

Next, as shown in FIG. 26, a light reflecting resin layer 150T is formed as a second resin layer covering the structure on the resin layer 170. Next, as shown in FIG. The second resin material described above can be used as the material of the light-reflective resin layer. Transfer molding, for example, can be applied to the formation of the light-reflective resin layer 150T.

Next, a part of the light-reflective resin layer 150T is removed from the upper surface side of the light-reflective resin layer 150T by grinding or the like, thereby exposing the positive electrode 112A and the negative electrode 114A of each light-emitting element 110A from the ground surface. . Furthermore, the resin layer 170 and the light-reflective resin layer 150T are cut by a dicing device or the like at the positions of the two adjacent light emitting elements 110A. By cutting the resin layer 170 and the light reflective resin layer 150T, the reflective member 150A is formed from the light reflective resin part 174 and the light reflective resin layer 150T, and as shown in FIG. luminous body 100U can be obtained. In this example, the translucent layer 140L and the wavelength conversion layer 120L of the translucent portion 172 of the resin layer 170 respectively correspond to the translucent member 140U and the wavelength conversion member 120A of the light emitter 100U.

In the step of singulating a plurality of structures each having a light-emitting element 110A, the light-reflective resin layer 150T and the resin layer 170 may be cut at positions overlapping the translucent portions 172 . Alternatively, instead of the resin layer 170 shown in FIG. 24, a plurality of light-emitting elements 110A are arranged in a laminated sheet including the wavelength converting member 120A and the translucent member 140U, and the steps described with reference to FIGS. 26 and 27 are performed. may be executed. In these cases, as schematically shown in FIG. 28, a luminous body 100T is obtained in which the side surface 140c of the translucent member 140U and the side surface 120c of the wavelength conversion member 120A are exposed from the reflective member 150A.

If steps S12 to S14 in FIG. 6 or steps S22 and S23 in FIG. 15 are applied to the light emitter 100T instead of the light emitter 100U described above, for example, the light emitting device 100C shown in FIG. 29 can be obtained. . Comparing the light emitting device 100C shown in FIG. 29 with the light emitting device 100A shown in FIG. 2, in the light emitting device 100C, the side surface 140c of the translucent member 140A and the side surface 120c of the wavelength conversion member 120A are exposed from the reflective member 150A. there is As described with reference to FIGS. 8 to 13, a plurality of first concave portions 141q are formed in the upper surface 140a of the transparent member 140U by pressing the mold 200 against the heated transparent member 140U, and A plurality of second recesses 142q that are finer than the first recesses 141q may be formed by exposing the upper surface 140a of the translucent member 140U to the treatment liquid. In this case as well, it is the same as the above-described examples in that the light-transmitting member 140U is irradiated with ultraviolet rays from the upper surface 140a side after the formation of the plurality of first concave portions 141q. By adopting such steps, the light emitting device 100D shown in FIG. 30 is obtained. Light-emitting device 100D has substantially the same configuration as light-emitting device 100B shown in FIG. 14, except that side surface 140c of translucent member 140B and side surface 120c of wavelength conversion member 120A are exposed from reflective member 150A.

FIG. 31 shows another example of the appearance of the light emitting device. A light-emitting device 100E shown in FIG. 31 includes a light-emitting element (not shown in FIG. 31), a light-transmitting member 140C arranged in front of the light-emitting element, a reflective member 150B covering the side surface of the light-transmitting member 140C, and a composite substrate. 400B. The composite substrate 400B includes a substrate 410B, a first conductive portion 411B, and a second conductive portion 412B. In the configuration illustrated in FIG. 31, the reflective member 150B reaches the composite substrate 400B and covers part of the first conductive part 411B and part of the second conductive part 412B.

FIG. 32 schematically shows a cross section of the light-emitting device 100E cut parallel to the YZ plane in FIG. 31 at a position near the center of the light-emitting device 100E. As shown in FIG. 32, the first conductive portion 411B and the second conductive portion 412B are electrically connected to the positive electrode 112A and the negative electrode 114A of the light emitting element 110A by the joining member 420, respectively. In the configurations illustrated in FIGS. 31 and 32, the light emitting device 100E has a shape longer in the Y direction than the X direction in the drawing, and is used as a so-called side-view type light emitting device.

The translucent member 140C of the light emitting device 100E has a plurality of first recesses 141 on its upper surface 140a, like the translucent members 140A and 140B described above. Each first recess 141 has a bottom surface 141b and one or more side surfaces 141c, and as shown enlarged in FIG. 32, has a plurality of second recesses 142 at least on the bottom surface 141b. The light-transmitting member 140C of the light-emitting device 100E has substantially the same configuration as the light-transmitting member 140A of the light-emitting device 100A described above, except that it has an elongated planar shape that is longer in the Y direction than in the X direction in the figure. have. As with the translucent member 140B described above, a plurality of second recesses 142 may be formed on the side surface 141c of each first recess 141 of the translucent member 140C.

For example, the light emitting device 100E can be efficiently manufactured by using a composite substrate 400A as illustrated in FIG. can be manufactured. FIG. 33 shows an example of the appearance of the composite substrate 400A when viewed from its upper surface 400a side. As shown in FIG. 33, the composite substrate 400A has a substrate 410A and a first conductive portion 411A and a second conductive portion 412A provided on the substrate 410A. The substrate 410A has through holes 414 . Although not shown in FIG. 33, a portion of the first conductive portion 411A and a portion of the second conductive portion 412A extend through the through hole 414 to the lower surface on the side opposite to the upper surface 400a.

When using the composite substrate 400A, instead of temporarily fixing the plurality of light emitting elements 110A to the support 60 (see FIG. 19), for example, the plurality of light emitting elements 110A are flip-chip connected to the upper surface 400a side of the composite substrate 400A. fixed to At this time, the positive electrode 112A and the negative electrode 114A of each light emitting element 110A are connected to the first conductive portion 411A and the second conductive portion 412A of the composite substrate 400A by a joining member such as solder. A rectangle drawn with a thin dashed line in FIG. 33 indicates a position where the light emitting element 110A is arranged.

After the formation of the light guide member 130A and the arrangement of the wavelength conversion member 120A and the light transmission member 140U, the structure on the upper surface 400a of the composite substrate 400A is coated with a light reflective resin in the same manner as the steps described with reference to FIG. It is covered by layer 150T. After forming the light-reflective resin layer 150T, the upper surface 140a of the translucent member 140U is exposed from the light-reflective resin layer 150T by grinding or the like. Through the above steps, a light-emitting body having a plurality of light-emitting elements 110A, light-transmitting members 140U, and a composite substrate 400A is obtained.

Furthermore, in the same manner as the example described with reference to FIG. 9, for example, as shown in FIG. A plurality of first recesses 141q are formed in the upper surface 140a. In order to avoid overcomplicating the drawing, FIG. 34 schematically shows a cross section of three units each including the light emitting element 110A.

After the mold 200 is separated from the translucent member 140U, a plurality of finer second recesses are formed. For example, as schematically shown in FIG. 35, in the same manner as in the example described with reference to FIG. A plurality of second recesses 142q are formed in regions other than the region overlapping with the first recesses 141q. Instead of laser light irradiation, a plurality of first recesses 141q and a plurality of second recesses are formed using a mold 200A (see FIGS. 16 and 17) having a plurality of first protrusions 210 and a plurality of second protrusions 220. 142q may be collectively formed.

Further, as schematically shown in FIG. 36, the translucent member 140U is irradiated with ultraviolet rays from the upper surface 140a side of the translucent member 140U in the same manner as the example described with reference to FIG. A light-transmitting member 140C having a plurality of first recesses 141 and a plurality of second recesses 142 can be obtained from the light-transmitting member 140U by irradiation with ultraviolet rays. Thereafter, the composite substrate 400A and, if necessary, the light-reflective resin layer 150T are collectively cut by a dicing machine or the like at positions indicated by the thick broken lines CT in FIG. 33, thereby forming the composite substrate 400B shown in FIG. A light-emitting device 100E including a part can be obtained. The substrate 410B, first conductive portion 411B and second conductive portion 412B shown in FIGS. 31 and 32 are parts of the substrate 410A, first conductive portion 411A and second conductive portion 412A shown in FIG. 33, respectively.

Instead of irradiating the laser beam, as schematically shown in FIG. 37, the upper surface 140a of the translucent member 140U in which the plurality of first recesses 141q are formed is exposed to the treatment liquid 450, thereby forming the plurality of second recesses 142q. may be formed. After the formation of the plurality of second recesses 142q, the translucent member 140U is irradiated with ultraviolet rays from the upper surface 140a side of the translucent member 140U, as in the above examples. According to such a process, as shown in FIG. 38, the translucent member 140D has a plurality of second recesses 142 formed not only on the bottom surface 141b of each first recess 141 but also on the side surface 141c, and A light-emitting device 100F having a composite substrate 400B is obtained.

FIG. 39 shows still another example of a light-emitting body having light-emitting elements and translucent members. Steps S12 to S14 shown in FIG. 6 or steps S22 and S23 shown in FIG. 15 may be applied to the light emitter 100S shown in FIG. 39 instead of the light emitter 100U or the light emitter 100T described above.

In the configuration illustrated in FIG. 39, the light emitter 100S has a two-dimensional repeating structure in which light emitting structures 100Y each including a light emitting element 110B and a translucent member 340Z are used as units. The translucent member 340Z contains silicone resin, like the translucent members 140A to 140D described above. That is, the silicone resin in the translucent member 340Z is typically an organic polysiloxane having at least one phenyl group in the molecule and/or an organic polysiloxane having a D unit in which two methyl groups are bonded to silicon atoms. Contains polysiloxane. In addition, in FIG. 39, four of the plurality of light emitting structures 100Y are extracted and shown.

Each light emitting structure 100Y further has a resin portion 350F provided with a recess 350e and a pair of conductive leads 361 and 362. As shown in FIG. The light emitting element 110B is positioned inside the recess 350e of each light emitting structure 100Y, and the translucent member 340Z covers the light emitting element 110B inside the recess 350e. The top surface of the conductive lead 361, the top surface of the conductive lead 362, and the partial surface of the resin portion 350F that spatially and electrically separates them form the bottom surface of the recess 350e. In this example, the light emitting element 110B is fixed on the upper surface of the conductive lead 361 of the conductive leads 361 and 362 . As schematically shown in FIG. 39, the light emitting element 110B has a positive electrode 112B and a negative electrode 114B on its upper surface side, where the positive electrode 112B is electrically connected to a conductive lead 362 by a conductive wire 372. , and negative electrode 114 B is electrically connected to conductive lead 361 by conductive wire 371 .

The light emitter 100S can be manufactured, for example, as follows. First, a composite substrate including a conductive lead frame and a resin portion 350F provided with a plurality of recesses 350e is prepared. A composite substrate 300F illustrated in FIG. 40 has a plurality of sets of conductive leads 361 and 362, and a plurality of connecting portions 363 arranged between sets adjacent to each other and connecting these sets to each other. Includes lead frame 360F. The leadframe 360F may have a base material formed of Cu and a metal layer covering the base material, for example. The metal layer covering the substrate is, for example, a plated layer containing Ag, Al, Ni, Pd, Rh, Au, Cu, or alloys thereof.

As shown, a portion of the conductive lead 361 and a portion of the conductive lead 362 are exposed at the bottom of each recess 350e of the resin portion 350F. Each pair of conductive leads 361 and 362 facing each other in recess 350e has a gap Gp formed by spatially separating conductive leads 361 and 362 from each other. The gap Gp is filled with the material forming the resin portion 350F. The composite substrate 300F can be obtained by integrally forming the resin portion 350F on the lead frame 360F by transfer molding or the like. For example, the lead frame 360F can be obtained by placing the lead frame 360F in a mold cavity, filling the cavity with a resin material in which a light-reflecting filler is dispersed, and curing the resin material. . As the material of the resin portion 350F, the same material as that of the above-described reflective members 150A and 150B can be applied.

After obtaining the composite substrate 300F, the light emitting element 110B is bonded onto the conductive lead 361 using an insulating material such as a resin material such as epoxy resin or silicone resin, or a conductive material such as Ag paste. Furthermore, the conductive wire 372 electrically connects the positive electrode 112B of the light emitting element 110B and the conductive lead 362, and the conductive wire 371 electrically connects the negative electrode 114B and the conductive lead 361. FIG.

After arranging the light emitting element 110B in the concave portion 350e of the resin portion 350F, each concave portion 350e is filled with a silicone resin material containing an uncured silicone resin, and the silicone resin material is cured to cover the light emitting element 110B. Form member 340Z. As a material for the translucent member 340Z, a resin material similar to the material for forming the above-described translucent members 140A to 140D can be applied. Through the steps described above, the light emitter 100S shown in FIG. 39 is obtained.

Here, furthermore, a plurality of first recesses and a plurality of second recesses that are finer than the first recesses are formed on the upper surface of the translucent member 340Z. The formation of the plurality of first recesses and the plurality of second recesses may be roughly performed according to steps S12 to S14 shown in FIG. 6 or steps S22 and S23 shown in FIG. .

For example, the main surface 200b of the mold 200 provided with the first convex portion 210 is opposed to the upper surface 340a of the translucent member 340Z, and the mold 200 is pressed against the translucent member 340Z while the translucent member 340Z is heated. FIG. 41 schematically shows a cross section of one of the light emitting structures 100Y forming the light emitter 100S. In this example, the top surface 340a of the translucent member 340Z is aligned with the top surface 350a of the resin portion 350F, and the top surface 340a of the translucent member 340Z constitutes the top surface of the light emitting structure 100Y together with the top surface 350a of the resin portion 350F. there is

By pressing the mold 200, as schematically shown in FIG. 41, it is possible to form a plurality of first concave portions 341q on the upper surface 340a of the translucent member 340Z. Here, although the plurality of first concave portions 341q are selectively formed in the upper surface 340a of the translucent member 340Z, the plurality of first concave portions 341q are formed over the entire upper surface of the light emitting structure 100Y including the upper surface 350a of the resin portion 350F. A recess 341q may be formed.

After the mold 200 is separated, as schematically shown in FIG. 42, the bottom surface 341b of each first concave portion 341q and the upper surface 340a of the translucent member 340Z other than the region overlapping the first concave portion 341q are removed by, for example, laser light irradiation. A plurality of finer second recesses 342q are formed in the region. Needless to say, the plurality of first recesses 341q and the plurality of second recesses 342q may be collectively formed using the mold 200A or the like instead of laser light irradiation.

Next, as schematically shown in FIG. 43, the translucent member 340Z is irradiated with ultraviolet rays from the upper surface 340a side of the translucent member 340Z in the same manner as in the example described with reference to FIG. By irradiating ultraviolet rays, it is possible to fix the shape of the plurality of first recesses 341q and the shape of the plurality of second recesses 342q. Thereby, the translucent member 340E having the plurality of first recesses 341 and the plurality of second recesses 342 can be formed from the translucent member 340Z. After that, by singulating the light emitting body 100S in units of the light emitting structure 100Y using a dicing device or the like, the light emitting device 100G shown in FIG. 44 is obtained.

The light emitting device 100G has a reflective member 350 having a recess 350e. The reflective member 350 is formed by cutting the resin portion 350F described above in the step of separating into individual pieces. It should be noted that most of the connecting portion 363 (see FIG. 40) of the lead frame 360F is removed by the singulation process. In this example, the side surface 341 c of each first recess 341 basically does not have the second recess 342 .

Instead of irradiating the laser beam, as schematically shown in FIG. 45, the upper surface 340a of the translucent member 340Z in which the plurality of first recesses 341q are formed is exposed to the treatment liquid 450, thereby forming the plurality of second recesses 342q. may be formed. After forming the plurality of second recesses 342q, the translucent member 340Z is irradiated with ultraviolet rays from the upper surface 340a side of the translucent member 340Z in the same manner as in the example described with reference to FIG. According to such a process, the light emitting device 100H shown in FIG. 46 is obtained.

The main difference between the light-emitting device 100H shown in FIG. 46 and the light-emitting device 100G shown in FIG. 44 is that the light-emitting device 100H has a light-transmitting member 340F instead of the light-transmitting member 340E. As schematically shown enlarged in FIG. 46, each first recess 341 provided in the translucent member 340F has a plurality of second recesses 342 not only on the bottom surface 341b but also on the side surface 341c.

The light-transmitting member 340E of the light-emitting device 100G and the light-transmitting member 340F of the light-emitting device 100H may have a light diffusion function by dispersing particles of titanium dioxide, silicon oxide, or the like in a base material. Further, the light-transmitting member 340E of the light-emitting device 100G and the light-transmitting member 340F of the light-emitting device 100H may contain particles such as phosphor. Particles such as phosphors may be dispersed generally uniformly in the base material of the translucent member, or may have a biased concentration in the Z direction in the drawing, for example.

According to the embodiments of the present disclosure, it is possible to form an uneven pattern on the surface of the cured thermosetting resin, which is advantageous for improving light extraction efficiency. Light-emitting devices according to embodiments of the present disclosure can be widely used as light sources for various lighting devices, strobe light sources for cameras and the like, light sources for backlight units of liquid crystal display devices, and the like.

40 laser ablation device 100A to 100H light emitting device 100S to 100U light emitter 100Y light emitting structure 110A, 100B light emitting element 120A wavelength conversion member 130A light guide member 140, 140A to 140D, 140U translucent member 140a upper surface of translucent member 141 translucent member First concave portion 142 Second concave portion of translucent member 150A, 150B Reflective member 200, 200A Type 210 Type 1st convex portion 220 Type 2nd convex portion 300F Composite substrate 340Z, 340E, 340F Translucent member 340a Translucent member Upper surface of member 341 First concave portion of translucent member 342 Second concave portion of translucent member 350 Reflective member 350F Resin portion of composite substrate 360F Lead frame of composite substrate 361, 362 Conductive leads 400A, 400B Composite substrate 410A, 410B Substrate 411A, 411B first conductive portion 412A, 412B second conductive portion 450 treatment liquid 500 ultraviolet irradiation device

Claims (7)

a light emitting element;
a translucent member having an upper surface and covering the light emitting element;
The translucent member contains a silicone resin,
the top surface of the translucent member has a plurality of first recesses each having a bottom surface and one or more side surfaces;
Each first recess has a plurality of second recesses that are finer than the first recess on the bottom surface.
the plurality of first recesses have a cylindrical or prismatic shape including the bottom surface and one or more side surfaces that define the first recesses;
The light-emitting device , wherein the second recess has a cone shape . 2. The light-emitting device according to claim 1 , wherein the diameter of a circle surrounding the opening of said first recess is 1 [mu]m or more and 20 [mu]m or less. 3. The light-emitting device according to claim 1, wherein the arrangement pitch of said first concave portions is 2 [mu]m or more and 20 [mu]m or less. The second recess has a depth of 0.02 μm or more and 1 μm or less,
The light-emitting device according to any one of claims 1 to 3 , wherein a diameter of a circle encompassing the opening of said second recess is 0.05 µm or more and 0.5 µm or less. The light emitting device according to any one of claims 1 to 4 , wherein the arrangement pitch of said second concave portions is 0.1 µm or more and 1 µm or less. 6. The light-emitting device according to claim 1 , wherein said silicone resin contains organic polysiloxane having at least one phenyl group in its molecule. 7. The light-emitting device according to any one of claims 1 to 6 , wherein the silicone resin contains an organopolysiloxane having a D unit in which two methyl groups are bonded to silicon atoms.

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