Light-emitting device

Abstract

To provide a light-emitting device that is able to reduce a light loss and achieve narrow angled emitted light.SOLUTION: A light-emitting device includes: a light-emitting element having an element electrode surface on which a pair of element electrodes made of a cathode and an anode are formed on a lower surface and a light-emitting surface on an upper surface opposed to the element electrode surface; a plate-shaped wavelength conversion member disposed to cover the light-emitting surface of the light-emitting element as viewed from above; and an optical structure adhered, via a translucent adhesive member, on an upper surface, of the wavelength conversion member, opposed to a surface facing the light-emitting element, the optical structure having a plurality of lens portions in convex in an upper side. The optical structure has a plurality of projections which each project downward from a bottom surface of each of the plurality of lens portions, and the adhesive member is formed to cover a region including the upper surface of the wavelength conversion member and a lower end of a side surface of each of the plurality of projections of the optical structure.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a light emitting device including a light emitting element. [Background technology]

[0002] 2. Description of the Related Art Light emitting devices using light emitting elements such as light emitting diodes (LEDs) as light sources have been known.

[0003] For example, Patent Document 1 discloses a light-emitting device having a light-emitting element mounted on a substrate, a resin layer covering the substrate and the light-emitting element and having a lens portion formed in the light-emitting element region, and a reflector surrounding the outer periphery of the lens portion on the resin layer. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2005 / 029597 Summary of the Invention [Problem to be solved by the invention]

[0005] For example, when a light-emitting device using an LED as a light source is used as a light source for a display device such as a head-up display (HUD), an optical system that deflects the light emitted from the light-emitting device is built into the HUD. In this case, it is preferable that the light emitted from the light-emitting device is emitted in a narrow angle range in order to miniaturize the optical system in the subsequent stage.

[0006] However, when a light emitting device such as that disclosed in Patent Document 1 is used as a light source, the light emitted from the light emitting element may enter the resin layer covering the substrate as stray light, which may result in significant light loss.

[0007] The present invention has been made in consideration of the above-mentioned points, and an object of the present invention is to provide a light emitting device capable of reducing the loss of light and achieving a narrow angle of emitted light. [Means for solving the problem]

[0008] The light emitting device of the present invention comprises a light emitting element having an element electrode surface on which a pair of element electrodes consisting of a cathode and an anode are formed on the underside and a light emitting surface on an upper surface facing the element electrode surface, a plate-shaped wavelength conversion member arranged so as to cover the light emitting surface of the light emitting element in a top view, and an optical structure having a plurality of lens portions convex upwardly and bonded via a translucent adhesive member to the upper surface of the wavelength conversion member, which is the surface opposite to the surface facing the light emitting element, wherein the optical structure has a plurality of protrusions each protruding downward from a bottom surface of each of the plurality of lens portions, and the adhesive member is formed so as to cover an area including the upper surface of the wavelength conversion member and the lower ends of the side surfaces of each of the plurality of protrusions of the optical structure. [Brief description of the drawings]

[0009] [Figure 1] FIG. 2 is a top view of a light emitting device according to an embodiment of the present invention. [Diagram 2] 1 is a cross-sectional view of a light emitting device according to an embodiment of the present invention. [Diagram 3] 2 is an enlarged cross-sectional view of an optical structure of a light-emitting device according to an embodiment of the present invention. [Figure 4] FIG. 4 is a cross-sectional view of a light emitting device according to a comparative example of the present invention. [Diagram 5] 11 is a diagram showing the light distribution characteristics of emitted light from a light emitting device according to a comparative example of the present invention. FIG. [Figure 6] FIG. 4 is a diagram showing the light distribution characteristics of emitted light from a light emitting device according to an embodiment of the present invention. [Figure 7] 13 is an enlarged cross-sectional view of a light-collecting member and an optical structure according to a modified example of the present invention. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the following description and accompanying drawings, substantially the same or equivalent parts are designated by the same reference numerals. EXAMPLES

[0011] The configuration of a light emitting device 1 according to Example 1 will be described with reference to Fig. 1 and Fig. 2. Fig. 1 is a top view of the light emitting device 1 according to Example 1. Fig. 2 is a cross-sectional view taken along line AA of the light emitting device 1 shown in Fig. 1.

[0012] (Light emitting device) The light emitting device 1 has a substrate 10 having a cavity, a light emitting element 20 arranged in the cavity of the substrate 10, a wavelength conversion member 50 arranged on the upper surface of the light emitting element 20, and an optical structure 60 having a plurality of lens portions 61 arranged on the wavelength conversion member 50 via an adhesive member 70. The light emitting device 1 also includes a covering member 80 that fills the cavity of the substrate 10 and covers a portion of the side surface of the light emitting element 20 excluding the plurality of lens portions 61 of the optical structure 60.

[0013] (substrate) The substrate 10 is an insulating substrate having a rectangular upper surface shape and made of ceramic such as aluminum nitride (AlN). The substrate 10 has a cavity formed therein, the cavity being made up of a flat portion and a wall portion extending upward along the outer edge of the upper surface of the flat portion.

[0014] The substrate 10 may be integrally formed to have a recess that opens upward, or may be formed by joining a flat plate and a frame body having a frame shape that follows the outer edge of the flat plate. The substrate 10 may be made of an insulating material other than ceramic, such as a resin material.

[0015] 2, the substrate 10 is provided with a pair of substrate electrodes 12, 13 made of metal on the bottom surface of the cavity, which can supply power to the light emitting element 20 from outside the substrate 10. For example, the wiring electrodes are formed so as to be conductive to the outside of the substrate 10 via a through electrode or the like.

[0016] In this embodiment, a step ST is provided at the upper end of the inner wall surface of the substrate 10. The step ST prevents the covering member 80 from creeping up onto the upper surface of the optical structure 60.

[0017] Moreover, the portion extending upward from the step portion ST is a lens guard portion LG that protects the surface of the lens portion 61 of the optical structure 60 .

[0018] (Light emitting element) The light emitting element 20 is a light emitting diode (LED) having a rectangular parallelepiped shape and a gallium nitride (GaN)-based semiconductor structure layer that emits blue light. As shown in FIG. 2, the light emitting element 20 is disposed on the bottom surface of the cavity of the substrate 10 such that its side surface is spaced apart from the inner side surface of the recess of the substrate 10.

[0019] The light-emitting element 20 is a flip-chip connected LED element that includes a semiconductor structure layer (not shown) and a pair of element electrodes consisting of an anode electrode 22 and a cathode electrode 23 on the lower surface of a light-transmitting growth substrate 21, and is configured to emit light from the upper surface of the growth substrate 21. In other words, the upper surface of the light-emitting element 20 is a light emission surface that emits light.

[0020] The anode electrode 22 and the cathode electrode 23 of the light emitting element 20 are electrically connected to the substrate electrodes 12, 13 formed on the bottom surface of the cavity of the substrate 10 via an element bonding member 30 such as a gold-tin alloy (Au-Sn). That is, the light emitting element 20 is mounted on the substrate 10 in a flip chip manner, and is configured to be capable of receiving power from the outside via wiring electrodes formed on the substrate 10.

[0021] (Wavelength conversion material) The wavelength conversion member 50 has a plate-like shape, and is disposed so as to cover the light emission surface of the light emitting element 20 via a light-transmitting adhesive 40 such as silicone resin.

[0022] In this embodiment, a ceramic material made of alumina (Al2O3) containing yttrium aluminum garnet (YAG:Ce) phosphor particles using cerium (Ce) as an activator was used as the wavelength conversion member 50. The wavelength conversion member 50 converts a part of the blue light from the light emitting element 20 incident on the bottom surface, which is the light incident surface, into yellow light, and emits white light from the top surface.

[0023] The wavelength conversion member 50 may be made of a glass material containing β-sialon (β-SiAlON:Eu) phosphor particles using europium (Eu) as an activator, potassium silicofluoride (KSF, K2SiF6:Mn) using manganese (Mn) as an activator, or calcium fluoride (CaF2) material containing phosphor particles.

[0024] β-SiAlON:Eu converts blue light into green light, and K2SiF6:Mn converts blue light into red light. The content of each phosphor can be determined so as to arbitrarily set the conversion rate of blue light of the light-emitting element 20 depending on the application. Also, several wavelength conversion members 50 can be arranged in a stacked manner. Note that, when only the light emitted from the light-emitting element 20 is used, the wavelength conversion member 50 can be omitted. Dummy glass or the like can also be used.

[0025] (optical structure) As shown in Fig. 2, the optical structure 60 is integrally formed with a plurality of lens portions 61, which are convex lenses convex upward, a support portion 62 that supports the plurality of lens portions 61 while connecting them to each other, and a plurality of protrusions 63 that protrude downward from the bottom surface of each of the plurality of lens portions 61. In other words, each of the plurality of protrusions 63 is formed at a position overlapping each of the plurality of lens portions 61 when viewed from above. For example, each of the plurality of protrusions 63 is formed at a position overlapping each of the optical axes of the plurality of lens portions 61 when viewed from above. Note that in Fig. 2, the boundaries between the plurality of lens portions 61, the support portion 62, and the plurality of protrusions 63 are indicated by dashed lines.

[0026] In this embodiment, the optical structure 60 is made of a thermosetting silicone resin formed by injection molding or the like.

[0027] The optical structure 60 is an optical function section that collimates light incident from the multiple protrusions 63 on the surfaces of the multiple lens sections 61 and emits the collimated light to the outside of the light emitting device 1 .

[0028] Each of the lens portions 61 is an elliptical hemispherical convex lens with the long axis extending in the vertical direction in the figure. Each of the lens portions 61 may be an upwardly convex parabolic hemispherical shape. The shape of the lens portion 61 can be arbitrarily designed depending on the light distribution characteristics of the emitted light from the light emitting device 1, for example, the half-value angle.

[0029] The support portion 62 is formed so as to connect the lower end portions of the side surfaces of the plurality of lens portions 61 to each other.

[0030] 1, the multiple protrusions 63 are formed at the center positions of the bottom surfaces of the multiple lens portions 61. In this embodiment, the multiple protrusions 63 are each formed in a cylindrical shape. In this embodiment, the optical structure 60 is formed so that the multiple lens portions 61 and the multiple protrusions 63 are arranged in 3 rows and 3 columns.

[0031] 2, the multiple protrusions 63 are adhered to the upper surface of the wavelength conversion member 50 via a light-transmitting adhesive member 70 described below. The multiple protrusions 63 receive light that has been emitted from the upper surface of the wavelength conversion member 50 via the light-transmitting adhesive member 70, and guide the light that has entered the multiple protrusions 63 to the multiple lens portions 61 that correspond to each of them.

[0032] In this embodiment, the tip shape of the protrusion 63 is flat (the protrusion 63 is cylindrical), but the tip shape of the protrusion 63 may be hemispherical or a cone shape with a narrowed tip region.

[0033] (Adhesive material) As described above, the adhesive member 70 is a light-transmitting thermosetting resin that bonds the upper surface of the wavelength conversion member 50 and the protruding portion 63 of the optical structure 60. In this embodiment, the adhesive member 70 is made of the same thermosetting silicone resin as the optical structure 60.

[0034] The adhesive member 70 is formed on the upper surface side of the wavelength conversion member 50 so as to cover the entire upper surface of the wavelength conversion member 50 .

[0035] Moreover, the adhesive member 70 is formed so as to creep up onto a part of each side surface of the protrusions 63 of the optical structure 60 on the side opposite to the upper surface of the wavelength conversion member 50. That is, the upper surface of the adhesive member 70 has an upwardly concave surface shape between the side surfaces of the adjacent protrusions 63 of the optical structure 60.

[0036] Therefore, the light emitted from the upper surface of the wavelength conversion member 50 is guided from within the adhesive member 70 to the multiple protrusions 63 of the optical structure 60 by the covering member 80 described below. That is, the adhesive member 70 functions as a light guiding member that guides light from the upper surface of the wavelength conversion member 50 to the multiple protrusions 63 of the optical structure 60.

[0037] Each of the multiple protrusions 63 of the optical structure 60 is fixed at a position where the tip of the protrusion 63 does not contact the upper surface of the wavelength conversion member 50 due to the balance of the surface energy of the adhesive member 70 around each of the protrusions 63. This makes it possible to prevent the occurrence of scratches, etc. on the tips of the multiple protrusions 63 of the optical structure 60 and the upper surface of the wavelength conversion member 50 when the optical structure 60 is adhered.

[0038] In this embodiment, a thermosetting silicone resin having the same refractive index is used for the adhesive member 70 and the optical structure 60. This makes it possible to reduce the loss of light at the interface between the adhesive member 70 and the multiple protrusions 63 of the optical structure 60.

[0039] The upper surface of the adhesive member 70 is a continuous surface that is concavely curved toward the wavelength conversion member 50 between the side surfaces of adjacent protrusions 63 of the optical structure 60. The adhesive member 70 also covers the upper surface of the wavelength conversion member 50 so as not to expose it. In other words, the adhesive member 70 is formed in a pyramidal shape facing upward so as to surround each of the protrusions 63. By forming the adhesive member 70 in this manner, it is possible to reduce light loss.

[0040] Moreover, it is preferable that the adhesive member 70 creeps up the multiple protrusions 63 of the optical structure 60 so as not to reach the upper ends of the multiple protrusions 63, i.e., the bottom surfaces of the multiple lens portions 61. This is because when the adhesive member 70 adheres to the bottom surfaces of the multiple lens portions 61, the area of ​​light incident on the multiple lens portions 61 increases, and the amount of oblique light emitted from the light emitting device 1 at an angle to the optical axis increases.

[0041] (Detailed structure of optical structure and adhesive member) FIG. 3 is an enlarged cross-sectional view of the optical structure 60 and adhesive member 70 of the light emitting device 1, and a diagram showing light emitted from the optical structure 60. As shown in FIG.

[0042] As described above, the protrusion 63 is formed at the center position of the bottom surface of the lens portion 61. That is, in a top view, the midpoint O of the lens portion 61 (the center point of the bottom surface of the lens portion 61) and the center point of the protrusion 63 are arranged at positions that coincide with each other. In other words, the centers of the multiple protrusions 63 corresponding to each of the multiple lens portions 61 of the optical structure 60 are arranged on the optical axes of the multiple lens portions 61.

[0043] As a result, light LM1 incident on the midpoint O of the lens portion 61 from the protrusion 63 is emitted in a direction approximately perpendicular to the light emitting device 1. Light LM2 incident on the lens portion 61 from the outer end of the protrusion 63 is emitted slightly obliquely, but a light collecting effect is obtained.

[0044] It is preferable that the diameter φT of the protrusion 63 is formed relative to the diameter φL of the bottom surface of the lens portion 61 such that (1 / 4)φL<φT<(1 / 2)φL.

[0045] Specifically, in order to suppress the oblique emission angle of light LM2 incident on the lens portion 61 from the outer end of the protrusion 63, it is preferable that the diameter φT of the protrusion 63 is less than 1 / 2 the diameter φL of the bottom surface of the lens portion 61.

[0046] In order to reduce the loss of light within the adhesive member 70, it is preferable that the diameter φT of the protrusion 63 exceeds ¼ of the diameter φL of the bottom surface of the lens portion 61.

[0047] In addition, in this embodiment, the case where the adjacent lens portions 61 of the optical structure 60 do not overlap each other has been described, but the adjacent lens portions 61 may be formed to partially overlap each other. In this case, it is preferable to provide the overlapping portion within a range in which light incident on one lens portion 61 does not enter the adjacent other lens portion 61 through the overlapping portion, or light emitted from one lens portion 61 does not re-enter the adjacent other lens portion 61.

[0048] In this embodiment, a case has been described in which a thermosetting silicone resin is used for the optical structure 60. However, other materials such as thermosetting resins or thermoplastic resins, such as epoxy resin, acrylic resin, and polycarbonate resin, can also be used for the optical structure 60. Thermoplastic amorphous fluororesins, heat-softening glass-based materials, and the like can also be used.

[0049] For example, thermosetting resin can be formed by injection molding using a mold, and thermoplastic resin and glass-based materials can be formed by press molding using a mold. When fluororesin is used for the optical structure 60, the surfaces of the lens portion 61 of the optical structure 60 and the support portion 62 connected to the lens portion 61, except for the upper surface, are plasma-treated to modify the surfaces so that the adhesive member 70 and the covering member 80 can be adhered. As the adhesive member 70, it is preferable to use an adhesive member whose base material is a resin that has high affinity (adhesion) with the optical structure 60 and has a refractive index that is approximately the same (or close to the same).

[0050] In addition, as a method for adhering the optical structure 60 to the upper surface of the wavelength conversion member 50, a precursor resin having the fluidity of the adhesive member 70 (in the embodiment, resin before heat curing) is applied to the upper surface of the wavelength conversion member 50, and multiple protrusions 63 of the optical structure 60 are placed on the adhesive member 70 from above so as to be in contact with the precursor resin.

[0051] As another method, the precursor resin of the adhesive member 70 may be applied to the tip region of each of the multiple protrusions 63 of the optical structure 60, and the optical structure 60 may be placed on the upper surface of the wavelength conversion member 50. Specifically, a dip method may be used in which the optical structure 60 is immersed (dipped) from the tip of each of the multiple protrusions 63 to a predetermined height in the precursor resin of the adhesive member 70, and the tip of the protrusion 63 to which the precursor resin of the adhesive member 70 has been applied is placed on the upper surface of the wavelength conversion member 50. By using the dip method, the amount of the precursor resin of the adhesive member 70 applied to the tip of the protrusion 63 becomes constant, and the application height of the precursor resin of the adhesive member 70 from the tip of the protrusion 63 can be made constant.

[0052] (Covering material) The covering member 80 is a light-reflective covering member filled in the cavity of the substrate 10. In this embodiment, a light-transmitting medium resin material such as silicone resin containing light-scattering particles such as titanium oxide (TiO2) particles is used. As the light-scattering particles, composite ceramic particles containing two or more of alumina, zirconia, and silica can be used. Composite ceramic particles are preferable as light-scattering particles that are not affected by the refractive index of the medium resin material because the particles themselves have high reflective properties.

[0053] The covering member 80 covers an area extending from the exposed surface and side surface of the bottom surface of the light emitting element 20 to the exposed surface of the adhesive member 70 and the side surface of the protrusion 63 of the optical structure 60. This causes light emitted from the light emitting element 20, the wavelength conversion member 50, the adhesive member 70, and the side surface of the protrusion 63 to be reflected inward.

[0054] (Comparative Example) FIG. 4 is a diagram showing a cross section of a light emitting device 1A according to a comparative example of the present invention.

[0055] The light emitting device 1A of the comparative example uses the same substrate 10, light emitting element 20, wavelength conversion member 50, and respective joining members 30 and adhesive material 40 as those of the light emitting device 1 of the embodiment.

[0056] The light emitting device 1A of the comparative example is different from the light emitting device 1 of the embodiment in that the adhesive member 70 and the optical structure 60 are not provided. In the light emitting device 1A of the comparative example, the height of the wall portion of the substrate 10 is approximately the same as the height of the upper surface of the wavelength conversion member 50.

[0057] (Comparison of light distribution characteristics between the comparative example and this embodiment) Fig. 5 shows a light distribution characteristic diagram of emitted light from a light emitting device 1A according to a comparative example, and Fig. 6 shows a light distribution characteristic diagram of emitted light from a light emitting device 1 according to an example.

[0058] The vertical lines in Figures 5 and 6 indicate the optical axis direction of the light emitting devices 1 and 1A. Also, the sector-shaped ranges in Figures 5 and 6 indicate the luminous flux ratio in the range from -90° to +90° with respect to the optical axis when the maximum luminous flux at a given angle is taken as 100%.

[0059] 5, the light emitted from the light emitting device 1A according to the comparative example had light distribution characteristics almost equivalent to the Lambertian light distribution. That is, the light emitted from the light emitting device 1A according to the comparative example had an angular range in which the light was 50% or more of the maximum luminous flux, i.e., a half-value angle of about 120°.

[0060] 6, it can be seen that the light emitted from the light emitting device 1 according to the example is emitted within a narrower angle range than the light emitting device 1A according to the comparative example. Specifically, the half-value angle of the light emitted from the light emitting device 1 according to the example was about 54°.

[0061] Furthermore, the amount of luminous flux within a range of 54° from the optical axis of the emitted light of the light emitting device 1 according to the embodiment was increased by about 10% compared to the amount of luminous flux within a range of 54° from the optical axis of the emitted light of the light emitting device 1A according to the comparative example. In other words, the light emitting device 1 according to the embodiment can narrow the angle of the emitted light from the light emitting device 1 while suppressing the loss of the emitted light of the light emitting element 20 within the half-value angle range of 54°.

[0062] As described above, according to the light emitting device 1 of the embodiment, the adhesive member 70 guides the light emitted from the upper surface of the wavelength conversion member 50 to the protruding portion 63 of the optical structure 60, and the light is emitted from the protruding portion 63 to the outside of the light emitting device 1 via the elliptical hemispherical lens portion 61. This makes it possible for the light emitting device 1 of the embodiment to achieve a narrow angle of emitted light while reducing the loss of light emitted from the light emitting element 20.

[0063] (Modification) FIG. 7 is a cross-sectional view of an optical structure 90 which is a modified example of the optical structure 60 of the light emitting device 1 of the embodiment.

[0064] The configuration other than the optical structure 90 is similar to that of the light emitting device 1 of the embodiment, and therefore the description thereof will be omitted.

[0065] The optical structure 90 of the modified example differs from the optical structure 60 of the embodiment in that each of the multiple protrusions 93 has a first portion 93A and a second portion 93B integrally formed via a step portion 93ST.

[0066] Specifically, the protrusion 93 extends downward from the bottom surface of the lens portion 91 with a diameter φT1 of the first portion 93A being in the range of (1 / 4)φL<φT1<(1 / 2)φL, where φL is the diameter of the bottom surface of the lens portion 61.

[0067] Further, the protruding portion 93 has a second portion 93B extending downward via a step portion 93ST and having a diameter φT2 smaller than the diameter φT1 of the first portion 93A.

[0068] Therefore, the adhesive member 70 stops creeping up to the step ST of the protrusion 93. That is, the adhesive member 70 covers up to the outer edge of the bottom surface of the first portion 93A of the step 93ST of the protrusion 93. This makes it possible to prevent the adhesive member 70 from unintentionally creeping up excessively over the protrusion 93 and adhering to the bottom surface of the lens portion 91.

[0069] Furthermore, even if an excessive amount of adhesive member 70 is applied, the surface tension of the adhesive member 70 on the step portion 93ST causes the optical structure 90 to move up and down, thereby preventing the adhesive member 70 from dripping onto the side surface of the wavelength conversion member 50 and maintaining the surface shape of the adhesive member 70 between adjacent protrusions 93.

[0070] In this embodiment, the substrate 10 has a cavity and each component is disposed in the cavity. However, the configuration of the light emitting device 1 is not limited to this.

[0071] For example, the light emitting device may be of a chip-size package type, without using the substrate 10, in which the anode electrode 22 and the cathode electrode 23 of the light emitting element 20 are mounted electrodes that are electrically connected directly to the outside.

[0072] In this case, the side surfaces of the light emitting element 20, the side surfaces of the wavelength conversion member 50, and the surface of the adhesive member 70 may be covered with a covering member 80 having a thickness that does not cause light leakage.

[0073] The above-mentioned chip size package type light emitting device may be connected to a Zener diode built-in device substrate having a top surface shape substantially the same as that of the light emitting device.

[0074] For example, the device substrate may be made of non-doped (high resistance) silicon, and a p-type impurity region and an n-type impurity region having the opposite polarity to the light emitting element 20 may be formed between a pair of substrate electrodes inside the device substrate to form a Zener diode.

[0075] This makes it possible to mount a plurality of light emitting devices at a high mounting density even in a chip size package type light emitting device without providing an external Zener diode.

[0076] As described above, the described embodiments are not intended to limit the scope of the invention. The described embodiments can be implemented in various forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These modifications are also included in the scope and spirit of the invention, and are included in the invention and its equivalents described in the claims. [Explanation of symbols]

[0077] 1 Light emitting device 10 Substrate 20 Light emitting element 30 Element bonding material 40 Adhesive 50 Wavelength conversion material 60, 90 optical structure 61, 91 Lens body 62, 92 Support part 63, 93 protrusion 70 Adhesive Materials 80 Covering material

Claims

1. a light emitting element having a device electrode surface on a lower surface of which a pair of device electrodes consisting of a cathode and an anode are formed, and a light emitting surface on an upper surface opposite to the device electrode surface; A plate-shaped wavelength conversion member arranged so as to cover and conceal the light emission surface of the light emitting element when viewed from above; an optical structure bonded via a light-transmitting adhesive member to an upper surface of the wavelength conversion member opposite to a surface facing the light emitting element, the optical structure having a plurality of lens portions convex upward; the optical structure has a plurality of protrusions each protruding downward from a bottom surface of each of the plurality of lens portions; The light emitting device, characterized in that the adhesive member is formed so as to cover an area including an upper surface of the wavelength conversion member and lower ends of each of the side surfaces of the plurality of protrusions of the optical structure.

2. The light emitting device according to claim 1 , wherein the upper surface of the adhesive member has an upwardly concave surface shape in areas between the plurality of protrusions when viewed from above.

3. The light emitting device according to claim 1 , wherein the plurality of lens portions of the optical structure have a shape of an elliptical hemisphere or a parabolic hemisphere.

4. The light emitting device according to claim 1 , wherein the protrusion of the optical structure is formed at a position overlapping with an optical axis of the lens portion on the bottom surface of the plurality of lens portions when viewed from above.

5. The light emitting device according to claim 1 , wherein the protrusion has a cylindrical shape.

6. The light-emitting device of claim 5, characterized in that each of the protrusions of the optical structure comprises a columnar first portion extending downward from a bottom surface of the lens portion, and a second portion extending downward from a tip surface of the first portion and having a smaller diameter than the first portion.

7. 2. The light emitting device according to claim 1, further comprising a light reflective coating member that covers the side surfaces of the light emitting element, the side surfaces of the wavelength conversion member, the upper surface of the adhesive member, and the side surfaces of each of the plurality of protrusions of the optical structure.

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