Light-emitting module

Abstract

To provide a highly reliable light-emitting module using a phosphor.SOLUTION: The light-emitting module includes a light-emitting device including first light-emitting elements that emit first light having peak wavelengths in a range of 430nm to 480nm inclusive and second light-emitting elements that emit second light having peak wavelengths in a range of 500nm to 600nm inclusive, and a wavelength-converting member that absorbs light having wavelengths in at least one of the first light and the second light and emits third light having peak wavelengths in a range of 600nm to 780nm inclusive. The first light emitting element and the second light emitting element are disposed in the light emitting device, and the wavelength conversion member is disposed away from the light emitting device.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a light emitting module. [Background technology]

[0002] Technology is being developed to improve the light utilization efficiency of light-emitting modules by using phosphors. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-058586 Summary of the Invention [Problem to be solved by the invention]

[0004] On the other hand, when a phosphor that absorbs light of a specific wavelength is used, there is a problem that reliability is reduced. An embodiment of the present invention provides a highly reliable light-emitting module that uses a phosphor. [Means for solving the problem]

[0005] A light-emitting module according to one embodiment of the present disclosure includes a light-emitting device including a first light-emitting element that outputs a first light having a peak wavelength in the range of 430 nm to 480 nm and a second light-emitting element that outputs a second light having a peak wavelength in the range of 500 nm to 600 nm, and a wavelength converting member that absorbs light having a wavelength included in at least one of the first light and the second light and outputs a third light having a peak wavelength in the range of 600 nm to 780 nm. The wavelength converting member is disposed apart from the light-emitting device. [Effects of the Invention]

[0006] According to the embodiment of the present disclosure, a highly reliable light-emitting module using a phosphor can be realized. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a schematic side view illustrating a light-emitting module according to an embodiment; [Figure 2] 1 is a schematic perspective view of a light emitting device according to an embodiment. [Figure 3] 1A to 1C are schematic diagrams of a light emitting device according to an embodiment, taken from multiple viewpoints. [Figure 4] FIG. 4 is a schematic cross-sectional view showing the cross section IV-IV of FIG. 3. [Figure 5] FIG. 4 is a schematic cross-sectional view showing the VV cross section of FIG. 3. [Figure 6] FIG. 6 is a schematic cross-sectional view showing the cross section VI-VI of FIG. [Figure 7] 1 is a table showing the manufacturing conditions and measurement results of wavelength conversion members according to examples and comparative examples. [Figure 8] 1 is a table showing the manufacturing conditions and measurement results of wavelength conversion members according to examples and comparative examples. [Figure 9] 1 is a graph showing the relationship between wavelength and total light transmittance measured in Examples. [Figure 10] 10 is a graph showing the relationship between wavelength and total light transmittance measured in a comparative example. DETAILED DESCRIPTION OF THE INVENTION

[0008] A light-emitting module according to an embodiment of the present disclosure will be described below with reference to the drawings. The following embodiments are intended to exemplify a light-emitting device and a manufacturing method thereof to embody the technical concept of the present embodiment, and are not limited thereto. Furthermore, unless otherwise specified, the dimensions, materials, shapes, and relative arrangements of components described in the embodiments are merely illustrative examples and are not intended to limit the scope of the present disclosure. The size, positional relationships, etc. of components shown in each drawing may be exaggerated for clarity. In the following description, identical names and symbols indicate identical or similar components, and detailed descriptions will be omitted as appropriate. Cross-sectional views may also be shown as end views showing only the cut surface.

[0009] In the following description, terms indicating specific directions or positions (e.g., "above," "below," and other terms including these terms) may be used. However, these terms are used merely to facilitate understanding of relative directions or positions in the referenced drawings. As long as the relative direction or position relationship indicated by terms such as "above" and "below" in the referenced drawings is the same, the arrangement in drawings other than those disclosed herein, actual products, etc., does not need to be the same as in the referenced drawings. In this specification, the positional relationship expressed as "above (or below)" includes, for example, when two components are assumed to exist, a case in which the two components are in contact with each other, and a case in which the two components are not in contact with each other and one component is located above (or below) the other component. Furthermore, in this specification, unless otherwise specified, a component covering an object to be covered includes a case in which the component is in contact with the object to be covered and directly covers the object to be covered, and a case in which the component is not in contact with the object to be covered and indirectly covers the object to be covered.

[0010] <1. Embodiment> (1.1. Light Emitting Module 300) 1 is a schematic side view illustrating a light-emitting module 300 including a light-emitting device 100 according to an embodiment. As shown in FIG. 1, the light-emitting module 300 includes the light-emitting device 100, an optical plate 310 disposed adjacent to the light-emitting device 100, and a wavelength conversion member 320 disposed on the light-emitting side of the optical plate 310. The light-emitting device 100 is a light-emitting device in which a plurality of light-emitting devices 100 are linearly arranged on a substrate 185, and can be arranged along the light-incident surface of the optical plate 310. The light-emitting module 300 is, for example, an LED display.

[0011] In addition to the light emitting device 100, the optical plate 310, and the wavelength conversion member 320, the light emitting module 300 may also include one or more of a reflector 330, a prism sheet 340, a polarizing film 350, and a liquid crystal panel 360, as shown in FIG. 1, depending on the purpose.

[0012] The optical plate 310 is, for example, a light-guiding member for guiding the primary light emitted from the light-emitting device 100, and is a so-called light guide plate. The light guide plate has, for example, a substantially flat plate shape formed so that at least one surface is a light incident surface and another surface substantially perpendicular thereto is a light exit surface. The light guide plate contains a resin whose base material is mainly acrylic or polycarbonate. If necessary, the light guide plate may contain resin particles having a refractive index different from that of the base resin. Each surface of the light guide plate may have a regular or irregular grain pattern or notches.

[0013] The wavelength conversion member 320 may be, for example, a phosphor containing quantum dots (QDs) that absorbs a portion of the light emitted by the light-emitting device 100 and emits light of a different wavelength from the absorbed light. The wavelength conversion member 320 is spaced apart from the light-emitting device 100 and arranged in a planar configuration along the light-emitting direction of the light-emitting device 100. The quantum dots contained in the wavelength conversion member 320 are typically semiconductor nanocrystals with diameters of 3 nm to 12 nm. The physical diameter of the quantum dots is smaller than the bulk excitation Bohr radius, allowing the quantum confinement effect to prevail. As a result, the electronic state of the quantum dots, i.e., the band gap, depends on the composition and physical diameter of the quantum dots. In other words, the absorption and emission colors of the wavelength conversion member 320 are related to the diameter of the quantum dots.

[0014] The optical quality of quantum dots is directly related to the uniformity of their composition and physical diameter. More monodisperse quantum dots result in smaller full widths at half maximum. As quantum dots reach diameters larger than the Bohr radius, quantum confinement effects are impeded, and nonradiative pathways for exciton recombination can become dominant, in which case the quantum dots may no longer be luminescent. As an example, quantum dots are a specific subgroup of nanocrystals, defined specifically by their diameter and size distribution. The properties of quantum dots are directly related to these parameters, distinguishing them from nanocrystals. Many quantum dots absorb light at wavelengths shorter than their emission wavelength, making them desirable because they enable the use of highly efficient short-wave green LEDs, as discussed below. Among quantum dots, red InP is even more desirable because it absorbs green short-wave light well.

[0015] The wavelength conversion member 320 is, for example, a planar member containing quantum dots, but may also be a rod-shaped member containing quantum dots. When the wavelength conversion member 320 is a planar member, the wavelength conversion member 320 has a length and width that exceed its thickness. The wavelength conversion member 320 may have a length and width that are 10 times or more the thickness.

[0016] The wavelength conversion member 320 preferably absorbs the first light (hereinafter also referred to as blue light) output from the light emitting device 100, whose peak wavelength is in the range of 430 nm to 480 nm, and the second light (hereinafter also referred to as green light) whose peak wavelength is in the range of 500 nm to 600 nm, and outputs the third light (hereinafter also referred to as red light) whose peak wavelength is in the range of 600 nm to 780 nm. Generally, green-wavelength LEDs are more efficient at shorter wavelengths. However, too short a wavelength narrows the color reproduction range. When the wavelength conversion member 320 absorbs the second light, absorption is generally stronger at shorter wavelengths, shortening the wavelength of the second light, allowing the use of highly efficient short-wavelength green LEDs and increasing brightness. Let T2 be the second light transmittance, which is the transmittance of the second light through the wavelength conversion member 320, and T3 be the third light transmittance, which is the transmittance of the third light. When the second light is absorbed, T2 / T3 becomes smaller. It is preferable that T2 / T3≦0.96. It is also preferable that the second light transmittance T2 decreases as the wavelength of the second light decreases. This allows the use of a highly efficient short-wave green LED, thereby increasing brightness.

[0017] Reflector 330 is disposed on the opposite side to the direction in which light is emitted from optical plate 310. Prism sheet 340 is disposed in the direction in which light is emitted from optical plate 310. By providing reflector 330 and prism sheet 340, a backlight with excellent balance between front brightness and viewing angle can be realized. Polarizing film 350 is an optical film for increasing brightness. Liquid crystal panel 360 is a panel that controls the image of the display.

[0018] (1.2. Light-emitting device 100) The light emitting device 100 will be described in detail below. FIG. 2 is a schematic perspective view of the light emitting device 100 according to the embodiment. FIG. 3 is a schematic diagram of the light emitting device 100 according to the embodiment, viewed from multiple viewpoints. The light emitting device 100 includes a substrate 130 and a first light emitting element 121 and a second light emitting element 122 disposed on the substrate 130. The first light emitting element 121 and the second light emitting element 122 are, for example, LED (Light Emitting Diode) chips. The first light emitting element 121 has an emission peak wavelength in a first wavelength range. The second light emitting element 122 has an emission peak wavelength in a second wavelength range that is longer than the first wavelength range. The emission peak wavelength of the first light emitting element 121 is in the range of 430 nm to 480 nm, and the first light emitting element 121 is a blue LED chip that mainly emits blue light (first light). The emission peak wavelength of the second light emitting element 122 is in the range of 500 nm to 600 nm, and the second light emitting element 122 is a green LED chip that mainly emits green light (second light).

[0019] 2, the light emitting device 100 has a front surface 100a that is parallel to the XY plane in the coordinate system shown in the drawing. The front surface 100a of the light emitting device 100 has a rectangular shape that is longer in the X direction than in the Y direction. The light emitting device 100 can be used as a light source for a backlight, as a side-emitting light emitting device in which light enters a light guide plate from the side surface of the light guide plate.

[0020] The light emitting device 100 includes a substrate 130, a light-reflecting member 140, and a light-transmitting member 150. As described below, the light-transmitting member 150 may contain a wavelength conversion member such as a phosphor. The light-transmitting member 150 has a light-extraction surface 50a parallel to the XY plane. Here, the light-extraction surface 50a is a part of the front surface 100a. The light-reflecting member 140 is located around the light-extraction surface 50a.

[0021] As shown in Fig. 3, the light emitting device 100 has a bottom wiring 30R on the back surface 100b side opposite the front surface 100a. The bottom wiring 30R includes a total of four wirings, namely, a fifth wiring 35R, a sixth wiring 36R, a seventh wiring 37R, and an eighth wiring 38R. The fifth wiring 35R, the sixth wiring 36R, the seventh wiring 37R, and the eighth wiring 38R are arranged in a line along the X direction (X direction) with a gap between them. In this example, an insulating layer 180 is arranged on the back surface 100b of the light emitting device 100 to prevent short-circuiting between two adjacent terminals.

[0022] In the embodiment of the present disclosure, the first light emitting element 121 and the second light emitting element 122 are arranged in a line along the Y direction in the light emitting device 100. In the example shown in Fig. 3, the first light emitting element 121 is located on the +Y direction side relative to the second light emitting element 122 (the upper side when the light emitting device 100 is mounted on a wiring board or the like). However, the arrangement of the first light emitting element 121 and the second light emitting element 122 in the light emitting device 100 is not limited to the example shown in Fig. 3.

[0023] FIG. 4 is a schematic cross-sectional view showing a cross section taken along line IV-IV in FIG. FIG. 5 is a schematic cross-sectional view showing the VV cross section of FIG. FIG. 6 is a schematic cross-sectional view showing a cross section taken along line VI-VI in FIG. The substrate 130 has a rectangular upper surface defined by short sides extending in the Y direction and long sides extending in the X direction. The substrate 130 has an insulating base material 30, upper surface wiring, and the above-mentioned lower surface wiring 30R. The base material 30 has an upper surface 30a and a lower surface 30b located opposite the upper surface 30a. The upper surface wiring is located on the upper surface 30a of the base material 30. The upper surface of the substrate 130 includes the upper surface 30a of the base material 30 and the upper surface of the upper surface wiring. The lower surface wiring 30R is located on the lower surface 30b of the base material 30.

[0024] The upper surface wirings include four wirings, a first wiring 31T to a fourth wiring 34T. As shown in Fig. 4, the substrate 130 has the first wiring 31T and the third wiring 33T, each located on the upper surface 30a. Also, as shown in Fig. 5, the substrate 130 has the second wiring 32T and the fourth wiring 34T, each located on the upper surface 30a.

[0025] The substrate 130 further has a plurality of conductive portions inside the base material 30, each of which extends from the upper surface 30a to the lower surface 30b of the base material 30 and connects the upper surface wiring and the lower surface wiring. In this embodiment, four conductive portions, namely, a first conductive portion 31V, a second conductive portion 32V, a third conductive portion 33V, and a fourth conductive portion 34V, are arranged inside the base material 30.

[0026] 4, the first conductive portion 31V connects the first wiring 31T and the fifth wiring 35R, electrically connecting them to each other. The third conductive portion 33V connects the third wiring 33T and the seventh wiring 37R, electrically connecting them to each other. In this embodiment, of the first conductive portion 31V and the third conductive portion 33V, the third conductive portion 33V is located below the first light-emitting element 121.

[0027] 5, the second conductive portion 32V connects the second wiring 32T and the sixth wiring 36R, electrically connecting them to each other. The fourth conductive portion 34V connects the fourth wiring 34T and the eighth wiring 38R, electrically connecting them to each other. In this embodiment, of the second conductive portion 32V and the fourth conductive portion 34V, the second conductive portion 32V is located below the second light-emitting element 122.

[0028] (1.2.1. Substrate 130) The components of the light emitting device 100 will be described in detail below. The substrate 130 is a support member on which the first light emitting element 121 and the second light emitting element 122 are mounted. As described above, the first light emitting element 121 and the second light emitting element 122 are arranged in a row along the Y direction on the substrate 130. As will be described later, in the embodiment of the present disclosure, elements having a shape with a relatively large aspect ratio in the X direction to the Y direction may be used as the first light emitting element 121 and the second light emitting element 122. Correspondingly, the substrate 130 may also have a shape that is relatively long in the X direction as a whole.

[0029] The base material 30 of the substrate 130 is a generally rectangular parallelepiped insulating member having a first wiring 31T, a second wiring 32T, a third wiring 33T, and a fourth wiring 34T arranged on its upper surface 30a. The dimension of the base material 30 in the Y direction is, for example, in the range of 400 μm to 800 μm. The dimension of the base material 30 in the X direction is, for example, in the range of 1800 μm to 5000 μm. The dimension of the base material 30 in the Z direction is, for example, in the range of 200 μm to 1000 μm.

[0030] Examples of materials for the substrate 30 include resin, ceramics, and glass. Bismaleimide triazine (BT), for example, can be used as the material for the substrate 30. The substrate 30 may be formed from a composite material such as fiber-reinforced resin, and for example, a glass epoxy substrate may be used for the substrate 30. Other base materials for the substrate 30 include epoxy and polyimide. Examples of ceramics that can be used include aluminum oxide, aluminum nitride, zirconium oxide, zirconium nitride, titanium oxide, titanium nitride, and mixtures of two or more of these. It is advantageous to use a ceramic material for the substrate 30 that has a linear expansion coefficient close to that of the first light-emitting element 121 or the second light-emitting element 122.

[0031] The materials for the fifth wiring 35R, sixth wiring 36R, seventh wiring 37R, and eighth wiring 38R on the lower surface 30b of the substrate 30, and the materials for the first wiring 31T, second wiring 32T, third wiring 33T, and fourth wiring 34T on the upper surface 30a, can be copper, iron, nickel, tungsten, chromium, aluminum, silver, platinum, gold, titanium, palladium, rhodium, or alloys containing one or more of these. From the perspective of heat dissipation, it is advantageous to use copper or a copper alloy as the material for these wirings. The upper surface wiring and / or lower surface wiring may be a single-layer film or a multilayer film. It is advantageous to use silver, platinum, aluminum, rhodium, or gold, or an alloy containing one or more of these, as the outermost surfaces of these upper surface wiring and / or lower surface wiring, because this provides good solder wettability.

[0032] Each of the first to fourth conductive portions 31V to 34V may be a conductive member that fills the entire interior of a through hole provided in the base material 30, or may be a combination of a conductive film disposed on the inner surface of the through hole and an insulating filler. The conductive film that covers the inner surface of the through hole may be made of, for example, the same material as the underside wiring on the underside 30b of the base material 30. The area surrounded by the conductive film may be filled with an insulating material such as epoxy resin. In the example shown in FIGS. 4 and 5, each of the first to fourth conductive portions 31V to 34V includes a conductive film 37 that covers the inner surface of the through hole provided in the base material 30 and an insulating portion 39 located in the area surrounded by the conductive film 37.

[0033] (1.2.2. First Light-Emitting Element 121 and Second Light-Emitting Element 122) The first light-emitting element 121 and the second light-emitting element 122 may have generally the same basic configuration except for the above-mentioned emission peak wavelength. In the following, a description of the configuration of the second light-emitting element 122 that is common to the first light-emitting element 121 may be omitted.

[0034] In the embodiment of the present disclosure, the first light emitting element 121 and the second light emitting element 122 are mounted by flip-chip connection on a substrate having first to fourth wirings 31T to 34T. As shown in Fig. 4, the first light emitting element 121 is electrically connected to the first wiring 31T and the third wiring 33T on the base material 30. As shown in Fig. 5, the second light emitting element 122 is electrically connected to the second wiring 32T and the fourth wiring 34T on the base material 30.

[0035] As shown in Figures 4 and 6, the first light-emitting element 121 has an upper surface 121a and an element lower surface 121b located opposite the upper surface 121a. The first light-emitting element 121 also has a positive electrode and a negative electrode on the element lower surface 121b. As shown in Figures 5 and 6, the second light-emitting element 122 has an upper surface 122a and an element lower surface 122b located opposite the upper surface 122a. The second light-emitting element 122 also has a positive electrode and a negative electrode on the element lower surface 122b. Examples of materials for the electrodes (positive electrode and negative electrode) of the first light-emitting element 121 and the second light-emitting element 122 include gold, silver, tin, platinum, rhodium, titanium, aluminum, tungsten, palladium, nickel, or an alloy containing one or more of these.

[0036] The first light-emitting element 121 is mounted on the substrate 130 by connecting and fixing the electrodes on the element lower surface 121b side to the first wiring 31T and the third wiring 33T by a bonding member 161 such as solder. The second light-emitting element 122 is mounted on the substrate 130 by connecting and fixing the electrodes on the element lower surface 122b side to the second wiring 32T and the fourth wiring 34T by a bonding member 162 such as solder.

[0037] Each of the first light emitting element 121 and the second light emitting element 122 has a semiconductor structure. The semiconductor structure includes an n-side semiconductor layer, a p-side semiconductor layer, and an active layer sandwiched between the n-side semiconductor layer and the p-side semiconductor layer. The active layer may have a single quantum well (SQW) structure or a multiple quantum well (MQW) structure including multiple well layers. The semiconductor structure includes multiple semiconductor layers made of nitride semiconductors. The nitride semiconductors include In x Al y Ga1-x-y The term "x+y" includes all semiconductors with compositions in which the composition ratios x and y are varied within the respective ranges in a chemical formula of N (0≦x, 0≦y, x+y≦1). The first light-emitting element 121 and the second light-emitting element 122 have semiconductor structures selected such that the forward voltage Vf of the second light-emitting element 122 is lower than the forward voltage Vf of the first light-emitting element 121.

[0038] The semiconductor structure may include a plurality of light emitting sections, each including an n-side semiconductor layer, an active layer, and a p-side semiconductor layer. When the semiconductor structure includes a plurality of light emitting sections, each light emitting section may include well layers with different emission peak wavelengths, or may include well layers with the same emission peak wavelength. Note that the same emission peak wavelength includes cases where there is a variation of about several nanometers. The combination of emission peak wavelengths of the plurality of light emitting sections can be selected appropriately.

[0039] In the embodiment of the present disclosure, the first light-emitting element 121 and the second light-emitting element 122 are elements having a shape that is relatively longer in the X direction than in the Y direction. The length of the element upper surface 121a of the first light-emitting element 121 along the Y direction may be, for example, in the range of 150 μm to 300 μm, and the length along the X direction may be, for example, in the range of 400 μm to 1500 μm. The ratio of the length along the X direction to the length along the Y direction of the element upper surface 121a of the first light-emitting element 121 is, for example, in the range of 1.1 to 10. The same applies to the dimensions of the element upper surface 122a of the second light-emitting element 122. By arranging the first light-emitting element 121 and the second light-emitting element 122, which are relatively longer in the X direction, in the Y direction (i.e., arranging them in a line in the Y direction), high light extraction efficiency can be achieved while reducing the number of light-emitting elements in the X direction. Reducing warping of the substrate 130 is also advantageous for mounting such elongated elements on the substrate 130.

[0040] (1.2.3. Translucent member 150) The light-transmitting member 150 is a plate-like member that has the function of protecting the first light-emitting element 121 and the second light-emitting element 122. The upper surface of the light-transmitting member 150 forms the light extraction surface 50a of the light-emitting device 100. The light-transmitting member 150 is made of a base material such as silicone resin, and has light-transmitting properties.

[0041] The light-transmitting member 150 has, for example, a transmittance of 60% or more for light having the peak emission wavelength of the first light-emitting element 121. It can also exhibit a transmittance of 60% or more for light having the peak emission wavelength of the second light-emitting element 122. From the viewpoint of effective use of light, it is beneficial if the transmittance of the light-transmitting member 150 at the peak emission wavelength of at least one of the first light-emitting element 121 and the second light-emitting element 122 is 70% or more, and more beneficial if it is 80% or more.

[0042] In this embodiment, the light-transmitting member 150 is disposed above the first light-emitting element 121 and the second light-emitting element 122 so as to collectively cover the entire upper surface 121a of the first light-emitting element 121 and the entire upper surface 122a of the second light-emitting element 122. By covering both the first light-emitting element 121 and the second light-emitting element 122 with the single light-transmitting member 150, the light from the first light-emitting element 121 and the light from the second light-emitting element 122 can be efficiently mixed inside the light-transmitting member 150.

[0043] Examples of the base material of the light-transmitting member 150 include silicone resin, modified silicone resin, epoxy resin, modified epoxy resin, urea resin, phenol resin, polycarbonate resin, trimethylpentene resin, polynorbornene resin, acrylic resin, urethane resin, fluororesin, and resins containing two or more of these. Glass may be selected as the base material of the wavelength conversion layer 152. The base material of the light-transmitting member 150 may contain a wavelength conversion material such as a phosphor.

[0044] 6, the light-transmitting member 150 includes a protective layer 151 and a wavelength conversion layer 152. The protective layer 151 is located farther from the substrate 130 than the wavelength conversion layer 152. That is, in this example, the wavelength conversion layer 152 is located between the pair of the first light-emitting element 121 and the second light-emitting element 122 and the protective layer 151.

[0045] The wavelength conversion layer 152 is a plate-shaped member containing a wavelength conversion material, which converts the wavelength of part of the incident light and emits light of a different wavelength, for example. A known phosphor can be used as the wavelength conversion material contained in the base material of the wavelength conversion layer 152. Phosphors include yttrium-aluminum-garnet phosphors (e.g., Y3(Al,Ga)5O12:Ce), lutetium-aluminum-garnet phosphors (e.g., Lu3(Al,Ga)5O12:Ce), terbium-aluminum-garnet phosphors (e.g., Tb3(Al,Ga)5O12:Ce), CCA phosphors (e.g., Ca10(PO4)6Cl2:Eu), and SAE phosphors. Phosphors (e.g., Sr4Al14O25:Eu), chlorosilicate phosphors (e.g., Ca8MgSiO16Cl2:Eu), oxynitride phosphors, nitride phosphors, fluoride phosphors, phosphors having a perovskite structure (e.g., CsPb(F,Cl,Br,I)3), or quantum dot phosphors (e.g., CdSe, InP, AgInS2, or AgInSe2) can be used. Representative examples of oxynitride phosphors include β-sialon phosphors (e.g., (Si,Al)3(O,N)4:Eu) and α-sialon phosphors (e.g., Ca(Si,Al)12(O,N)16:Eu). Representative examples of nitride-based phosphors include SLA-based phosphors (e.g., SrLiAl3N4:Eu), CASN-based phosphors (e.g., CaAlSiN3:Eu), and SCASN-based phosphors (e.g., (Sr,Ca)AlSiN3:Eu). Representative examples of fluoride-based phosphors include KSF-based phosphors (e.g., K2SiF6:Mn), KSAF-based phosphors (e.g., K2Si0.99Al0.01F5.99:Mn), and MGF-based phosphors (e.g., 3.5MgO·0.5MgF2·GeO2:Mn).

[0046] The phosphor in the wavelength conversion layer 152 can be, in particular, a fluoride phosphor such as a KSF phosphor (e.g., K2SiF6:Mn), a KSAF phosphor (e.g., K2Si0.99Al0.01F5.99:Mn), or an MGF phosphor (e.g., 3.5MgO·0.5MgF2·GeO2:Mn), a phosphor having a perovskite structure (e.g., CsPb(F,Cl,Br,I)3), or a quantum dot phosphor (e.g., CdSe, InP, AgInS2, or AgInSe2). With this selection of light-emitting element and phosphor, the wavelength conversion layer 152 absorbs part of the light from the light-emitting element and emits light in the red wavelength range, which can be mixed with the blue and green light transmitted through the wavelength conversion layer 152 to produce white light. When a wavelength conversion layer containing a phosphor that emits red light upon excitation is disposed above a blue-emitting LED and a green-emitting LED, the wavelength conversion layer may selectively cover the blue-emitting LED, i.e., the wavelength conversion layer may not cover the green-emitting LED. However, from the viewpoint of obtaining white light with reduced color unevenness, it is preferable to dispose the wavelength conversion layer 152 so as to cover both the blue-emitting LED and the green-emitting LED.

[0047] The wavelength conversion layer 152 may contain one of the above-mentioned phosphors alone, a combination of two or more of these phosphors, or no phosphors. When the wavelength conversion layer 152 contains two or more phosphors, it is beneficial to adjust the distribution of the wavelength conversion materials in the wavelength conversion layer 152 so that the phosphor that emits light with a shorter wavelength is located closer to the light emitting element. Alternatively, the wavelength conversion layer may have two layers, each containing a different type of phosphor. In this case, it is beneficial to contain the phosphor that emits light with a shorter wavelength upon excitation in the layer closer to the light emitting element.

[0048] A material having a refractive index different from that of the base material may be dispersed in the material of the wavelength conversion layer 152 to impart a light diffusion function to the wavelength conversion layer 152. For example, the wavelength conversion layer 152 may contain a light diffusing material, which will be described later.

[0049] The protective layer 151 is a light-transmitting layer located on the outermost surface of the light-transmitting member 150 opposite to the first light-emitting element 121 and the second light-emitting element 122. The upper surface of the protective layer 151 forms the light extraction surface 50a of the light-transmitting member 150, and in the example shown in FIG.

[0050] The base material of the protective layer 151 can be the same as the base material of the wavelength conversion layer 152, such as a silicone resin or an epoxy resin. From the viewpoint of efficiently introducing light into the protective layer 151, it is beneficial if the material of the protective layer 151 has a higher refractive index than the material of the wavelength conversion layer 152. The protective layer 151 may be given a light diffusing function by dispersing a light diffusing material having a refractive index different from that of the base material in the base material.

[0051] (1.2.4. Light diffusing member 154) 6, the light emitting device 100 further includes a light diffusing member 154. The light diffusing member 154 is a plate-like member disposed between the upper surface 121a of the first light emitting element 121 and the light-transmitting member 150, and between the upper surface 122a of the second light emitting element 122 and the light-transmitting member 150.

[0052] The light diffusing member 154 contains a translucent base material and a light diffusing material dispersed in the base material. As with the protective layer 151, the base material of the light diffusing member 154 can be the same material as the base material of the wavelength conversion layer 152. The light diffusing material can be, for example, resin particles having a refractive index different from that of the base material, or particles of silicon oxide, aluminum oxide, zirconium oxide, or zinc oxide. Nanoparticles having a particle size defined by D50 of 1 nm to 100 nm can also be used as the light diffusing material dispersed in the base material. Using nanoparticles as the light diffusing material can increase light scattering in the light diffusing member 154.

[0053] (1.2.5. Light-guiding member 170) 4 to 6, the light emitting device 100 further includes a light guide member 170. In this example, by arranging the light guide member 170, the light diffusion member 154 is arranged above the upper surface 121a of the first light emitting element 121 and the upper surface 122a of the second light emitting element 122. The light guide member 170 includes at least a portion located on the element side surface 121c of the first light emitting element 121 and a portion located on the element side surface 122c of the second light emitting element 122.

[0054] The light-guiding member 170 may be made of a resin material containing a transparent resin as a base material. The base material of the light-guiding member 170 may be, for example, the same material as the base material of the light-transmissive member 150. The light-guiding member 170 may have a light-diffusing function by dispersing a light-diffusing material having a refractive index different from that of the base material. The refractive index of the light-guiding member 170 may be set to be greater than that of the light-transmissive member 150 and smaller than that of the first light-emitting element 121 and the second light-emitting element 122. The light-guiding member 170 may be made of a material having a refractive index of 1.52 or greater and 1.60 or less. When this refractive index relationship is satisfied, the refractive index gradually decreases from the first light-emitting element 121 and the second light-emitting element 122 to the light-transmissive member 150, thereby improving the efficiency with which light from the first light-emitting element 121 and the second light-emitting element 122 is emitted to the outside of the light-emitting device 100.

[0055] The light-guiding member 170 includes a portion located between the element side surface 121c of the first light-emitting element 121 and the light-reflective member 140. By providing the light-guiding member 170, a portion of the light emitted by the first light-emitting element 121 and exiting from the element side surface 121c can be made incident on the light-diffusing member 154 (or the light-transmitting member 150) by utilizing reflection at the interface between the light-guiding member 170 and the light-reflective member 140. That is, the light incident on the light-guiding member 170 is reflected toward the light-diffusing member 154 at the position of the outer surface 170c of the light-guiding member 170, and is emitted toward the outside of the light-emitting device 100 via the light-diffusing member 154 and the light-transmitting member 150. The same can be said for a portion of the light emitted by the second light-emitting element 122 and exiting from the element side surface 122c. By providing the light-guiding member 170, the light extraction efficiency of the light-emitting device 100 can be improved.

[0056] The light-guiding member 170 is formed, for example, by curing a liquid resin. Because the size of the light-emitting device 100 in the Y direction is smaller than the size in the X direction, the light-guiding member 170 is likely to be formed so as to bulge more in the short-side direction than in the long-side direction of the light-emitting element. This allows the Y-direction thickness of the lower portion of the light-guiding member 170 located on the element side surface 121c, 122c of each of the first light-emitting element 121 or the second light-emitting element 122, which is parallel to the X direction, located on the element lower surface 121b, 122b side, to be greater than the Y-direction thickness of the upper portion located on the element upper surface 121a, 122a side. This structure makes it easy to reflect light emitted from the element side surface 121c, 122c of each of the first light-emitting element 121 or the second light-emitting element 122 upward at the interface between the lower portion of the light-guiding member 170 and the light-reflective member 140, thereby improving the light extraction efficiency from the light extraction surface 50a of the light-emitting device 100.

[0057] (1.2.6. Light-Reflecting Member 140) Light-reflective member 140 surrounds the set of first light-emitting element 121 and second light-emitting element 122 and light-transmitting member 150 on substrate 130. In this specification, "light-reflective" refers to a reflectance of 60% or more at the emission peak wavelength of the light-emitting element (first light-emitting element 121 or second light-emitting element 122). It is more beneficial if the reflectance of light-reflective member 140 at the emission peak wavelength of the light-emitting element is 70% or more, and even more beneficial if it is 80% or more.

[0058] Examples of materials for the light-reflecting member 140 include resin materials in which a light-diffusing material is dispersed. Examples of materials that can be used for the base material of the light-reflecting member 140 include silicone resin, modified silicone resin, epoxy resin, urea resin, polycarbonate resin, phenolic resin, acrylic resin, urethane resin, fluororesin, or modified resins thereof, or resins containing two or more of these. Examples of light-diffusing materials include particles of inorganic or organic materials having a refractive index higher than that of the base material. Examples of light-diffusing materials include particles of titanium oxide, magnesium oxide, zirconium dioxide, potassium titanate, aluminum oxide, aluminum nitride, boron nitride, mullite, niobium oxide, barium sulfate, silicon oxide, and various rare earth oxides (e.g., yttrium oxide and gadolinium oxide). The light-reflecting member 140 can be white.

[0059] 4 to 6, the light reflective member 140 covers the structure on the upper surface 30a of the base material 30 except for the light extraction surface 50a of the light-transmitting member 150. The light reflective member 140 is in contact with the side surface 51c of the protective layer 151, the side surface 52c of the wavelength conversion layer 152, and the side surface 54c of the light diffusing member 154. At least a portion of the light reflective member 140 faces the element side surface 121c of the first light emitting element 121 and the element side surface 122c of the second light emitting element 122. In other words, at least a portion of the light reflective member 140 can be in contact with the element side surface 121c of the first light emitting element 121 and the element side surface 122c of the second light emitting element 122.

[0060] A part of light reflecting member 140 may be located between first light emitting element 121 and substrate 130, and between second light emitting element 122 and substrate 130. By arranging light reflecting member 140 on the element lower surface 121b side of first light emitting element 121 and the element lower surface 122b side of second light emitting element 122, it is possible to reduce the emission of light from the element lower surface side of the light emitting element, and the effect of improving the light utilization efficiency can be obtained.

[0061] (1.3. Example) An embodiment will be described with reference to FIGS. FIG. 7 is a table showing the manufacturing conditions and measurement results of wavelength conversion members according to examples and comparative examples.

[0062] 7, wavelength conversion members 320 in Examples 1 and 2 and wavelength conversion member C in Comparative Example 1 were produced under the resin formulation conditions shown in Fig. 7. Specifically, in Example 1, a resin composition was obtained by mixing 2.079 g of acrylic resin, 0.900 g of thiol resin, 0.272 g of scattering silicone resin powder, 0.021 g of photoinitiator, and 0.150 g of InP quantum dot concentrated solution (red InP-QDC) that absorbs at least one of blue light and green light and emits red light.

[0063] In Example 2, 2.053 g of acrylic resin, 0.684 g of thiol resin, 0.249 g of scattering silicone resin powder, 0.028 g of photoinitiator, 0.0003 g of reaction retarder, and 0.097 g of red InP-QDC were mixed to obtain a resin composition.

[0064] In Comparative Example 1, a resin composition was obtained by mixing 1.620 g of acrylic resin, 0.688 g of thiol resin, 0.230 g of scattering silicone resin powder, 0.017 g of photoinitiator, 0.197 g of InP quantum dot concentrate (green InP-QDC) that absorbs at least one of blue light and green light and emits green light, and 0.030 g of red InP-QDC.

[0065] Each of these resin compositions was formed into a sheet, and barrier films were placed above and below each of the resin composition sheets. Furthermore, each of the resin composition sheets was irradiated with UV light at room temperature to UV-cure the resin in the sheet, thereby obtaining wavelength conversion member 320 of the example and wavelength conversion member C of the comparative example. The thickness of the resin layer (sheet) not including the barrier film was 84 μm in Example 1, 70 μm in Example 2, and 69 μm in Comparative Example 1.

[0066] The luminance maintenance factor after 2000 hours was measured for Examples 1 and 2 and Comparative Example 1. The excitation output condition was adjusted so that the light source output was 50,000 nits of white light. The light sources in Examples 1 and 2 were the first light-emitting element 121 and the second light-emitting element 122. The light source in Comparative Example 1 was a single light-emitting element that output blue light. The measured luminance maintenance factors were 101% for Example 1, 103% for Example 2, and 71% for Comparative Example 1. Thus, the use of the wavelength conversion member 320 in Examples 1 and 2 resulted in improved reliability of the light-emitting module 300. Furthermore, comparing Examples 1 and 2, the reliability was improved regardless of the quantum dot concentration.

[0067] FIG. 8 is a table showing the manufacturing conditions and measurement results of wavelength conversion members according to examples and comparative examples. FIG. 9 is a graph showing the relationship between wavelength and total light transmittance measured in the examples. FIG. 10 is a graph showing the relationship between wavelength and total light transmittance measured in the comparative example.

[0068] 8, wavelength conversion members 320 in Examples 3 to 5 and wavelength conversion members C in Comparative Examples 2 to 4 were produced. Specifically, in Example 3, 2.080 g of acrylic resin, 0.900 g of thiol resin, 0.270 g of scattering silicone resin powder, 0.021 g of photoinitiator, and 0.090 g of red InP-QDC were mixed to obtain a resin composition.

[0069] In Example 4, a resin composition was obtained by mixing 2.079 g of acrylic resin, 0.900 g of thiol resin, 0.272 g of scattering silicone resin powder, 0.021 g of photoinitiator, and 0.150 g of red InP-QDC.

[0070] In Example 5, a resin composition was obtained by mixing 2.079 g of acrylic resin, 0.904 g of thiol resin, 0.270 g of scattering silicone resin powder, 0.021 g of photoinitiator, and 0.270 g of red InP-QDC.

[0071] In Comparative Example 2, a resin composition was obtained by mixing 2.970 g of acrylic resin, 0.270 g of scattering silicone resin powder, 0.030 g of photoinitiator, and 0.120 g of a complex (red complex / for example, a β-diketone europium metal complex) that absorbs at least one of blue light and green light and emits red light.

[0072] In Comparative Example 3, 2.969 g of acrylic resin, 0.272 g of scattering silicone resin powder, 0.030 g of photoinitiator, and 0.210 g of red complex were mixed to obtain a resin composition.

[0073] In Comparative Example 4, a resin composition was obtained by mixing 2.970 g of acrylic resin, 0.270 g of scattering silicone resin powder, 0.030 g of photoinitiator, and 0.330 g of red complex.

[0074] These resin compositions were each formed into a sheet, and wavelength conversion member 320 of the example and wavelength conversion member C of the comparative example were obtained by the method described above. The thickness of the resin layer (sheet) not including the barrier film was 81 μm in Example 3, 83 μm in Example 4, 82 μm in Example 5, 76 μm in Comparative Example 2, 80 μm in Comparative Example 3, and 81 μm in Comparative Example 4.

[0075] For wavelength conversion members 320 of Examples 3 to 5 and Comparative Examples 2 to 4, and wavelength conversion member C of Comparative Example, the total light transmittance was measured while the wavelength of input light was changed from 300 nm to 800 nm. The measurement results are shown in Figs. 8 to 10. In Fig. 9, P1 corresponds to the measurement result of total light transmittance for wavelength conversion member 320 of Example 3, P2 corresponds to the measurement result of total light transmittance for wavelength conversion member 320 of Example 4, and P3 corresponds to the measurement result of total light transmittance for wavelength conversion member C of Example 5. In Fig. 10, Q1 corresponds to the measurement result of total light transmittance for Comparative Example 2, Q2 corresponds to the measurement result of Comparative Example 3, and Q3 corresponds to the measurement result of total light transmittance for wavelength conversion member C of Comparative Example 4.

[0076] 8 , if the total light transmittance for green light with a wavelength of 546 nm is the second light transmittance T2 and the total light transmittance for red light with a wavelength of 700 nm is the third light transmittance T3, T2 / T3 was 0.95 in Example 3, 0.94 in Example 4, 0.92 in Example 5, 0.98 in Comparative Example 2, 0.98 in Comparative Example 3, and 0.97 in Comparative Example 4. Thus, in the examples, the second light transmittance T2 and the third light transmittance T3 of the wavelength conversion member 320 were T2 / T3≦0.96. In contrast, in Comparative Examples 2 to 4 using red complexes that do not absorb green light, T2 / T3≧0.97.

[0077] 9, in Examples 3 to 5, for green light having an input wavelength of 500 nm to 600 nm, the second light transmittance T2 tended to decrease as the wavelength of the green light became shorter, as indicated by arrow A1. In contrast, as shown in FIG. 10, in the comparative example, the second light transmittance T2 tended to remain almost constant even when the wavelength of the green light decreased from 600 nm to 500 nm. This is because the red complex does not absorb green light.

[0078] (1.4.Summary) As described above, the light-emitting module 300 according to this embodiment includes a light-emitting device 100 including a first light-emitting element 121 that outputs a first light having a peak wavelength within the range of 430 nm to 480 nm and a second light-emitting element 122 that outputs a second light having a peak wavelength within the range of 500 nm to 600 nm, and a wavelength conversion member 320 that absorbs light having wavelengths within at least one of the first light and the second light and outputs a third light having a peak wavelength within the range of 600 nm to 780 nm. The first light-emitting element 121 and the second light-emitting element 122 are disposed within the light-emitting device 100, and the wavelength conversion member 320 is disposed apart from the light-emitting device. This configuration allows the wavelength conversion member 320 to be disposed at a position away from the first light-emitting element 121 and the second light-emitting element 122, thereby reducing the optical density of the first light or the second light that excites the wavelength conversion member 320 and improving the reliability of the light-emitting module 300.

[0079] Moreover, the wavelength conversion member 320 is disposed in a plane along the light emitting direction of the light emitting device 100. With this configuration, the light emitting device 100 can be mounted as a backlight for the light emitting module 300.

[0080] Furthermore, quantum dots are included in the wavelength conversion member 320. By adopting such a configuration, it becomes possible to specifically manufacture the wavelength conversion member 320 that can realize the technical idea of ​​the present disclosure.

[0081] Furthermore, if the second light transmittance, which is the total light transmittance of the second light in the wavelength conversion member 320, is T2 and the third light transmittance, which is the total light transmittance of the third light in the wavelength conversion member, is T3, then T2 / T3≦0.96. Furthermore, the second light transmittance T2 of the wavelength conversion member 320 decreases as the wavelength of the second light becomes shorter. By configuring in this way, the optical properties of the wavelength conversion member 320 suitable for realizing the technical idea of ​​the present disclosure are specifically specified.

[0082] <2. Other embodiments> Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above. For example, in the above embodiment, the first light-emitting element 121 and the second light-emitting element 122 are disposed within the light-emitting device 100, and the wavelength conversion member 320 is disposed apart from the light-emitting device 100. However, the present disclosure is not limited to this embodiment.

[0083] Specifically, for example, the light emitting device 100 may be configured to include only one light emitting element that outputs a first light. The light emitting element and a first wavelength conversion member that absorbs light of a wavelength included in the first light and outputs a second light may be disposed inside the light emitting device 100, and a second wavelength conversion member that absorbs light of a wavelength included in at least one of the first light and the second light and outputs a third light may be disposed outside the light emitting device 100. Even with such a configuration, a highly reliable light emitting module using a phosphor can be realized, as in the above embodiment.

[0084] The present disclosure includes the following aspects. (Appendix 1) a first light-emitting element that outputs first light having a peak wavelength within a range of 430 nm to 480 nm; a light emitting device including a second light emitting element that outputs second light having a peak wavelength within a range of 500 nm to 600 nm; a wavelength converting member that absorbs light having a wavelength included in at least one of the first light and the second light and outputs third light having a peak wavelength included in the range of 600 nm to 780 nm, the first light-emitting element and the second light-emitting element are disposed within the light-emitting device; The light-emitting module, wherein the wavelength conversion member is disposed apart from the light-emitting device. (Appendix 2) 2. The light-emitting module according to claim 1, wherein the wavelength conversion member is disposed in a planar shape along the light-emitting direction of the light-emitting device. (Appendix 3) 3. The light-emitting module according to claim 1, wherein the wavelength conversion member includes quantum dots. (Appendix 4) 4. The light-emitting module according to claim 3, wherein the quantum dots contained in the wavelength conversion member include red InP. (Appendix 5) The light-emitting module described in Appendix 1 or 2, wherein T2 is a second light transmittance that is the total light transmittance of the second light in the wavelength conversion member, and T3 is a third light transmittance that is the total light transmittance of the third light in the wavelength conversion member, and T2 / T3≦0.96. (Appendix 6) 6. The light-emitting module according to claim 5, wherein the second light transmittance decreases as the wavelength of the second light decreases. (Appendix 7) a light emitting device including: a light emitting element that outputs first light having a peak wavelength within the range of 430 nm to 480 nm; and a first wavelength converting member that absorbs light of wavelengths included in the first light and outputs second light having a peak wavelength within the range of 500 nm to 600 nm; a second wavelength conversion member that absorbs light having a wavelength included in at least one of the first light and the second light and outputs third light having a peak wavelength included in the range of 600 nm to 780 nm, the light-emitting element and the first wavelength conversion member are disposed within the light-emitting device, a light-emitting module, wherein the second wavelength conversion member is disposed apart from the light-emitting device;

[0085] The embodiments of the present disclosure have been described above with reference to specific examples. However, the present disclosure is not limited to these specific examples. All forms that can be implemented by a person skilled in the art through appropriate design modifications based on the above-described embodiments of the present disclosure also fall within the scope of the present disclosure as long as they include the gist of the present disclosure. In addition, within the scope of the concept of the present disclosure, a person skilled in the art may conceive of various modifications and alterations, and these modifications and alterations also fall within the scope of the present disclosure. [Explanation of symbols]

[0086] 30: base material, 30R: bottom wiring, 30a: top surface, 30b: bottom surface, 31T: first wiring, 31V: first conductive portion, 32T: second wiring, 32V: second conductive portion, 33T: third wiring, 33V: third conductive portion, 34T: fourth wiring, 34V: fourth conductive portion, 35R: fifth wiring, 36R: sixth wiring, 37: conductive film, 37R: seventh wiring, 38R: eighth wiring, 39: insulating portion, 50a: light extraction surface, 51c: side surface, 52c: side surface, 54c: side surface, 100: light emitting device, 100a: front surface, 100b: back surface, 121: first light emitting element, 121a: element top surface, 121 b: lower surface of element, 121c: side surface of element, 122: second light-emitting element, 122a: upper surface of element, 122b: lower surface of element, 122c: side surface of element, 130: substrate, 140: light-reflective member, 150: light-transmitting member, 151: protective layer, 152: wavelength conversion layer, 154: light-diffusing member, 161: bonding member, 162: bonding member, 170: light-guiding member, 170c: outer surface, 180: insulating layer, 185: substrate, 300: light-emitting module, 310: optical plate, 320: wavelength conversion member, 330: reflector, 340: prism sheet, 350: polarizing film, 360: liquid crystal panel

Claims

1. a first light-emitting element that outputs first light having a peak wavelength within a range of 430 nm to 480 nm; a light emitting device including a second light emitting element that outputs second light having a peak wavelength within a range of 500 nm to 600 nm; a wavelength converting member that absorbs light having a wavelength included in at least one of the first light and the second light and outputs third light having a peak wavelength included in the range of 600 nm to 780 nm, The light-emitting module, wherein the wavelength conversion member is disposed apart from the light-emitting device.

2. The light-emitting module according to claim 1 , wherein the wavelength conversion member is disposed in a planar shape along the light-emitting direction of the light-emitting device.

3. The light-emitting module according to claim 1 , wherein the wavelength conversion member includes quantum dots.

4. The light emitting module according to claim 3 , wherein the quantum dots contained in the wavelength conversion member include red InP.

5. 3. The light-emitting module according to claim 1, wherein T2 is a second light transmittance that is a total light transmittance of the second light in the wavelength conversion member, and T3 is a third light transmittance that is a total light transmittance of the third light in the wavelength conversion member, and T2 / T3≦0.

96.

6. The light emitting module according to claim 5 , wherein the second light transmittance decreases as the wavelength of the second light decreases.

7. a light emitting device including: a light emitting element that outputs first light having a peak wavelength included in the range of 430 nm to 480 nm; and a first wavelength converting member that absorbs light of wavelengths included in the first light and outputs second light having a peak wavelength included in the range of 500 nm to 600 nm; a second wavelength conversion member that absorbs light having a wavelength included in at least one of the first light and the second light and outputs third light having a peak wavelength included in the range of 600 nm to 780 nm, the light-emitting element and the first wavelength converting member are disposed within the light-emitting device, The light-emitting module, wherein the second wavelength conversion member is disposed apart from the light-emitting device.

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