JP2020107865A - Light-emitting device - Google Patents

Abstract

To provide a thin light-emitting device having a wide light distribution.SOLUTION: A light-emitting device 100 includes: a light-emitting element 10 having a top surface, a lower surface having an electrode, and a side surface; a wavelength conversion member 20, covering the top and side surfaces continuously, for converting a wavelength of light emitted by the light-emitting element 10 to emit light of a different wavelength; a light diffusing layer 30, covering an outer surface of the wavelength conversion member 20, for diffusing light emitted by the light-emitting element 10 and light wavelength-converted by the wavelength conversion member 20; and a light-shielding layer 40, having a light-shielding property, disposed above the wavelength conversion member 20 and above the light diffusion layer 30.SELECTED DRAWING: Figure 1

Description

The present invention relates to a light emitting device using a light emitting element.

A light emitting device using a light emitting element such as a light emitting diode (LED) is widely used as various light sources such as a backlight of a liquid crystal display, a display, and illumination. For example, Patent Documents 1 and 2 disclose semiconductor light emitting devices. In order to obtain planar light emission with such a semiconductor light emitting device, a configuration is known in which a plurality of LEDs are arranged in a matrix on the back surface side of the light guide plate.

JP, 2013-115088, A JP, 2014-45194, A

An object of the present invention is to provide a thin light emitting device with a wide light distribution.

In order to achieve the above object, according to the light emitting device of one embodiment of the present invention, a light emitting element having an upper surface, a lower surface having a pair of electrodes, and a side surface, and continuously covering the upper surface and the side surface, The wavelength conversion member that converts the wavelength of the light emitted by the light emitting element to emit light of a different wavelength, covers the outer surface of the wavelength conversion member and the wavelength conversion member, and the wavelength emitted by the light emission element is converted by the wavelength conversion member. A light diffusing layer for diffusing light and a light blocking layer having a light blocking property, which is disposed above the wavelength conversion member and above the light diffusing layer, can be provided.

According to the light emitting device of one embodiment of the present invention, the light emitting device emits light from the upper surface of the light emitting element in the lateral direction through the diffusion layer while blocking the light with the highest brightness by the light shielding layer, thereby reducing the thickness. Thus, it is possible to provide a light emitting device having a wide light distribution.

3 is a schematic cross-sectional view showing the light emitting device according to Embodiment 1. FIG. FIG. 2 is a horizontal sectional view taken along line II-II of FIG. 1. 6 is a schematic cross-sectional view showing a light emitting device according to Embodiment 2. FIG. FIG. 6 is a horizontal cross-sectional view of a light emitting device according to a third embodiment. FIG. 9 is a horizontal sectional view of a light emitting device according to a fourth embodiment. FIG. 9 is a horizontal sectional view of a light emitting device according to a fifth embodiment. FIG. 3 is a schematic plan view showing a planar light emitting body using the light emitting device according to the first embodiment. 3 is a schematic cross-sectional view showing a state of the manufacturing process of the light-emitting device according to Embodiment 1. FIG. 3 is a schematic cross-sectional view showing a state of the manufacturing process of the light-emitting device according to Embodiment 1. FIG. 3 is a schematic cross-sectional view showing a state of the manufacturing process of the light-emitting device according to Embodiment 1. FIG. 3 is a schematic cross-sectional view showing a state of the manufacturing process of the light-emitting device according to Embodiment 1. FIG. 3 is a schematic cross-sectional view showing a state of the manufacturing process of the light-emitting device according to Embodiment 1. FIG. 3 is a schematic cross-sectional view showing a state of the manufacturing process of the light-emitting device according to Embodiment 1. FIG. 3 is a schematic cross-sectional view showing a state of the manufacturing process of the light-emitting device according to Embodiment 1. FIG. 3 is a schematic cross-sectional view showing a state of the manufacturing process of the light-emitting device according to Embodiment 1. FIG. 3 is a schematic cross-sectional view showing a state of the manufacturing process of the light-emitting device according to Embodiment 1. FIG. 3 is a schematic cross-sectional view showing a state of the manufacturing process of the light-emitting device according to Embodiment 1. FIG. 3 is a schematic cross-sectional view showing a state of the manufacturing process of the light-emitting device according to Embodiment 1. FIG. 3 is a schematic cross-sectional view showing a state of the manufacturing process of the light-emitting device according to Embodiment 1. FIG. 3 is a schematic cross-sectional view showing a state of the manufacturing process of the light-emitting device according to Embodiment 1. FIG. 3 is a schematic cross-sectional view showing a state of the manufacturing process of the light-emitting device according to Embodiment 1. FIG.

Hereinafter, the present invention will be described in detail with reference to the drawings. In the following description, terms indicating a specific direction or position (for example, “upper”, “lower”, and other terms including those terms) are used as necessary, but use of those terms is not allowed. This is for facilitating the understanding of the invention with reference to the drawings, and the technical scope of the present invention is not limited by the meanings of the terms. Further, the same reference numerals appearing in a plurality of drawings indicate the same or equivalent parts or members.

Furthermore, the embodiments described below are examples for embodying the technical idea of the present invention, and the present invention is not limited to the following. Further, the dimensions, materials, shapes, relative arrangements, and the like of the components described below are not intended to limit the scope of the present invention thereto, unless specifically stated, and are merely exemplified. It was intended. Further, the contents described in one embodiment and example can be applied to other embodiments and examples. In addition, the size and positional relationship of members shown in the drawings may be exaggerated in order to clarify the explanation.
[Embodiment 1]

A light emitting device according to Embodiment 1 of the present invention is shown in a schematic sectional view of FIG. 1 and a horizontal sectional view of FIG. A light emitting device 100 shown in these drawings includes a light emitting element 10, a wavelength conversion member 20, a light diffusion layer 30, a light shielding layer 40, and a light reflective layer 50.
(Light emitting element 10)

As the light emitting element 10, a semiconductor light emitting element such as a light emitting diode can be preferably used. The light emitting element 10 has an upper surface, a lower surface having a pair of electrodes 12, and a side surface. Hereinafter, the upper surface of the light emitting element 10 is also referred to as an element main surface, the side surface is referred to as an element side surface, and the lower surface is referred to as an element electrode formation surface.

As the light emitting element 10, an element that emits light having an arbitrary wavelength can be selected. For example, blue, as the device that emits green light, using the light emitting device using nitride semiconductor _{(In x Al y Ga 1-} xy N, 0 ≦ X, 0 ≦ Y, X + Y ≦ 1) or GaP be able to. A light emitting element including a semiconductor such as AlGaAs or AlInGaP can be used as the element that emits red light. Furthermore, a semiconductor light emitting element made of a material other than these can also be used. The emission wavelength can be changed by changing the material of the semiconductor layer and its mixed crystallinity. The composition, emission color, size, number, etc. of the light emitting element used can be appropriately selected according to the purpose. In the example of FIG. 1, only one light emitting element 10 is used, but two or more light emitting elements may be included in the light emitting device.
(Wavelength conversion member 20)

The wavelength conversion member 20 is a member that converts the wavelength of light emitted by the light emitting element 10 and emits light of different wavelengths. The wavelength conversion member 20 continuously covers the element main surface and the element side surface of the light emitting element 10. The wavelength conversion member 20 receives the light emitted from the main surface of the element, converts the wavelength of the light, and emits the light from the side surface.

The wavelength conversion member 20 includes a wavelength conversion substance that is excited by light from the light emitting element 10 to emit light of different wavelengths. In this way, of the light emitted from the light emitting element 10, the component that transmits the wavelength conversion member 20 and the component that has been wavelength-converted by the wavelength conversion member 20 are mixed, and mixed-color light is emitted.

As described above, by continuously covering not only the periphery of the light emitting element 10 but also the upper surface thereof with the wavelength converting member 20, the light emitted by the light emitting element 10 is wavelength-converted by the wavelength converting member 20 over a wide area, and the light emitting element is It is possible to efficiently mix colors with the original light emission. Therefore, in a limited space, the light of the element main surface, which is the upper surface of the light emitting element, and the light of the side surface of the element can be efficiently used together, and high efficiency is achieved even in a light-emitting device that is small and thin. It will be a configuration that contributes to.

The wavelength conversion member 20 may be one in which a wavelength conversion substance is dispersed in a first resin 22 that is a base material. Further, the wavelength conversion member 20 may be composed of a plurality of layers.

As a material forming the first resin as a base material, for example, a phenyl resin, an epoxy resin, a silicone resin, a resin in which these are mixed, or a translucent material such as glass can be used. Above all, it is preferable to use a phenyl resin that has high hardness after curing and excellent processability. From the viewpoint of light resistance of the wavelength conversion member 20 and ease of molding, it is useful to select a silicone resin as the first resin. Further, the first resin is preferably a material having a higher refractive index than the material forming the light guide plate 70 described later. As a result, the advantage of easy processing such as grinding is obtained.

As the wavelength conversion substance contained in the wavelength conversion member 20, a phosphor can be preferably used. For example, YAG phosphor, β-sialon phosphor, fluoride phosphor such as KSF phosphor or MGF phosphor, nitride phosphor and the like can be mentioned. Specific examples of the composition formula include the following general formulas (I), (II), and (III).

A ₂ [M _1-a Mn ⁴⁺ _a F ₆ ]...(I)
(However, in the general formula (I), A is at least one selected from the group consisting of K ⁺ , Li ⁺ , Na ⁺ , Rb ⁺ , Cs ^+, and NH ^{4 +,} and M is a group 4 group. It is at least one element selected from the group consisting of elements and Group 14 elements, and a satisfies 0<a<0.2.)

(X-a) MgO · a (Ma) O · b / 2 (Mb) 2 O 3 · yMgF 2 · c (Mc) X 2 · (1-d-e) GeO 2 · d (Md) O 2 · e(Me) ₂ O ₃ :Mn...(II)
(However, in the general formula (II), Ma is at least one selected from Ca, Sr, Ba and Zn, Mb is at least one selected from Sc, La and Lu, and Mc Is at least one selected from Ca, Sr, Ba and Zn, X is at least one selected from F and Cl, and Md is at least one selected from Ti, Sn and Zr. And Me is at least one selected from B, Al, Ga and In. Further, for x, y, a, b, c, d and e, 2≦x≦4, 0<y≦ 2, 0≦a≦1.5, 0≦b<1, 0≦c≦2, 0≦d≦0.5, 0≦e<1)

_{Ma x MbyAl 3 N z: Eu} ··· (III)
(However, in the general formula (III), Ma is at least one element selected from the group consisting of Ca, Sr, and Ba, and Mb is at least selected from the group consisting of Li, Na, and K. It is one kind of element, and x, y, and z satisfy 0.5≦x≦1.5, 0.5≦y≦1.2, and 3.5≦z≦4.5, respectively.

The full width at half maximum of the KSF phosphor represented by the general formula (I) can be 10 nm or less. The full width at half maximum of the MGF phosphor represented by the general formula (II) can be 15 nm or more and 35 nm or less. As shown in the above general formula (I), a part of Si constituting the composition K ₂ SiF ₆ :Mn ⁴⁺ of the KSF phosphor is replaced with another tetravalent element such as Ti or Si (compositional formula). Then, K ₂ (Si,Ti,Ge)F ₆ :Mn is represented, or a part of K constituting the composition K ₂ SiF ₆ :Mn ⁴⁺ of the KSF phosphor is changed to another alkali metal. Substitution may be performed, a part of Si may be substituted with a trivalent element such as Al, or substitution of a plurality of elements may be combined.

The wavelength conversion member 20 may contain one wavelength conversion substance, or may contain a plurality of wavelength conversion substances. When a plurality of wavelength conversion substances are contained, for example, the wavelength conversion member may include a β-sialon phosphor that emits green light and a fluoride phosphor such as a KSF phosphor that emits red light. it can. As a result, the color reproduction range of the light emitting device can be expanded. In this case, the light emitting device, capable of a nitride semiconductor that emits light of short wavelength that can efficiently excite the wavelength converting member _{(In x Al y Ga 1-} xy N, 0 ≦ X, 0 ≦ Y, X + Y It is preferable to have ≦1). Further, for example, when using the light emitting element 10 that emits blue light, when it is desired to obtain red light as a light emitting device, 60 wt% of KSF phosphor (red phosphor) is used as the wavelength conversion member. The above may be contained, preferably 90% by weight or more. That is, the wavelength conversion material may emit a light of a specific color so that the light of a specific color may be emitted. Further, the wavelength conversion substance may be a quantum dot. The wavelength conversion material may be arranged in any manner within the wavelength conversion member. For example, it may be distributed substantially uniformly, or may be partially distributed. Further, a plurality of layers each containing a wavelength conversion member may be provided in a laminated manner. Further, the wavelength conversion member may be added with a member that diffuses and reflects light. For example, a light diffusion member may be mixed inside the wavelength conversion member.

The thickness of the wavelength conversion member 20 is preferably 0.02 mm to 0.40 mm. In order to achieve the effect of making the light emitting module thin and various wavelength conversion, it is preferable to set it within the above range.
(Light diffusion layer 30)

The outer surface of the wavelength conversion member 20 is covered with the light diffusion layer 30. In the example of the horizontal sectional view of FIG. 2, the outer periphery of the wavelength conversion member 20 formed in a rectangular shape in plan view is entirely covered with the light diffusion layer 30. The light diffusion layer 30 serves as a light emitting region that emits light from the light emitting device 100 to the outside. The light diffusion layer 30 further diffuses the light emitted from the light emitting element 10 and the light whose wavelength has been converted by the wavelength conversion member 20, thereby promoting color mixing of these. By providing such a light diffusion layer 30, the light emitted from the light emitting device 100 can be made more uniform. The light diffusion layer 30 preferably has a light diffusion layer excess rate of 50% or more. Moreover, a plurality of light diffusion layers are laminated in the outer peripheral direction to form a light diffusion region.

The light diffusion layer 30 can be configured by adding a diffusion material to the base material. For example, it is possible to use, as the light diffusion layer 30, a second resin as a base material and white inorganic fine particles such as SiO ₂ or TiO ₂ contained therein as a diffusion material. A phenyl resin, an epoxy resin, a silicone resin, a resin in which these are mixed, or a translucent material such as glass can be used as the resin material of the second resin as the base material. It is preferable to use a phenyl resin that has high hardness after curing and is excellent in workability. By using the same resin as the wavelength conversion member 20 for the base material of the light diffusion layer 30, the adhesiveness is excellent, and at the bonding interface between the wavelength conversion member 20 and the light diffusion due to resin shrinkage during curing or deformation during expansion. It is possible to suppress the occurrence of stress and the cause of peeling.

Further, as the diffusing material, it is possible to use a light-reflecting member such as white resin or metal processed into fine particles. Since these diffusing materials are irregularly contained in the base material, the light passing through the light diffusing layer 30 is irregularly and repeatedly reflected to diffuse the transmitted light in multiple directions. Thus, it is possible to prevent the irradiation light from being locally concentrated and prevent uneven brightness.

In addition, by disposing the light diffusion layer 30 and the light shielding layer 40 described later so as to cover the wavelength conversion member 20, the wavelength conversion member 20 can be protected from moisture and the like. Therefore, even when using a phosphor that may be adversely affected by moisture from the outside, the light emitting device can be easily manufactured.
(Shading layer 40)

A light shielding layer 40 is provided above the wavelength conversion member 20 and above the light diffusion layer 30. The light shielding layer 40 is a member having a light shielding property, and by covering the upper surface of the light emitting device 100 with the light shielding layer 40, the light from the light emitting element 10 or the wavelength conversion member 20 increases the brightness of the upper surface of the light emitting element 10. Suppress. The light blocking layer 40 preferably has a light transmittance of 50% or less. As described above, the light-shielding layer 40 does not necessarily need to have a complete light-shielding property, and even if the light-shielding layer 40 is incomplete, the light-shielding property is sufficient. In the present specification, “light-shielding property” does not mean 0% transmittance.

The light-shielding layer 40 is configured by dispersing a light-reflecting material in a third resin 41 that is a base material. As the resin material of the third resin 41, which is the base material, a light-transmitting material such as phenyl resin, dimethyl resin, epoxy resin, silicone resin, a mixture thereof, or glass can be used. Preferably, a phenyl resin is used. As a result, it is possible to obtain effects such as high hardness after resin curing and easy processing. Particularly, by using the same resin as the wavelength conversion member 20 and the light diffusion layer 30 for the base material of the light shielding layer 40, the adhesiveness is excellent, and stress is generated at the bonding interface due to resin shrinkage during curing or deformation during expansion. It is possible to suppress the cause of peeling. When a dimethyl-based resin is used for the light-shielding layer 40, if the wavelength conversion member 20 and the light diffusion layer 30 are phenyl-based resins, the light-shielding layer 40 is provided with a refractive index difference at the interface between them. It is possible to reduce the light entering. As the light-reflecting material, TiO ₂ , SiO ₂ , Al ₂ O ₃ or glass filler can be used. The refractive index can be selected by using the glass filler. Here, the transmittance can be adjusted by adjusting the content of the filler. It is preferable that the light diffusion layer 30 has a transmittance of 50% or more and the light shielding layer 40 has a transmittance of 50% or less.

By adopting such a configuration, the light emitting device 100 described above can suppress uneven brightness and realize wide light distribution. That is, the light having the highest brightness emitted from the light emitting surface of the upper surface of the light emitting element 10 is shielded by the light shielding layer 40, and the light is emitted from the side surface direction through the diffusion layer. Can be optically coupled to to obtain uniform emission.
(Light reflective layer 50)

Further, a light reflective layer 50 is arranged on the lower surface of the light emitting element 10, below the wavelength conversion member 20, and below the light diffusion layer 30. The light reflective layer 50 reflects the light emitted from the light emitting element 10 or the light wavelength-converted by the wavelength conversion member 20, and prevents the light from leaking from the lower surface of the light emitting device 100. Further, the electrode 12 of the light emitting element 10 is exposed from the light reflecting layer 50.

Like the light-shielding layer 40, the light-reflecting layer 50 is also formed by dispersing the light-reflecting material in the fourth resin 52 that is the base material. As the resin material of the fourth resin 52, which is a base material, a light-transmitting material such as phenyl resin, epoxy resin, silicone resin, a mixture thereof, or glass can be used. Preferably, a phenyl resin is used. As a result, it is possible to obtain effects such as high hardness after resin curing and easy processing. In particular, by using the same resin as the wavelength conversion member 20 and the light diffusion layer 30 for the base material of the light reflective layer 50, the adhesiveness is excellent, and stress is applied to the bonding interface due to resin shrinkage during curing or deformation during expansion. It is possible to suppress the occurrence of peeling and causing peeling. Further, as the light-reflecting material, TiO ₂ , SiO ₂ , Al ₂ O ₃ , glass filler or the like can be used.
(Metal film 60)

The end surface of the electrode 12 of the light emitting element 10 exposed from the light reflective layer 50 is covered with the metal film 60. The metal film 60 functions as an external electrode of the light emitting device 100. By making the metal film 60 larger than the end surface of the electrode 12 of the light emitting element 10, the light emitting device 100 can be easily electrically connected to the outside. By using the metal film 60, the light emitting device 100 is mounted on a mounting substrate or is wire-bonded to be electrically connected to an external wiring, so that the light emitting element 10 can be supplied with power. The metal film 60 can be formed by a single layer film or a laminated film of a metal such as Au, Pt, Pd, Rh, Ni, W, Mo, Cr, or Ti, or an alloy thereof. Specifically, they are laminated in the order of Ti/Rh/Au, W/Pt/Au, Rh/Pt/Au, W/Pt/Au, Ni/Pt/Au, Ti/Rh, etc. from the light emitting element 10 side. A laminated film can be used. In particular, by protecting Cu, which is easily oxidized, with a stable metal such as Au, the reliability of electrical connection can be improved.
[Embodiment 2]

The light-reflecting layer 50 may be formed in a flat plate shape as shown in the schematic cross-sectional view of FIG. 1, or may be partially convex. Such an example is shown in the schematic cross-sectional view of FIG. 3 as a light emitting device according to the second embodiment. The light emitting device 200 shown in this figure is formed in a flat plate shape below the wavelength conversion member 20, and is formed in a convex shape 51 on the outer periphery of the wavelength conversion member 20. This strengthens the adhesion between the light reflective layer 50 and the wavelength conversion member 20. Especially, the anchor effect can be exhibited.
[Embodiments 3 and 4]

In the above example, the outer shape of the light emitting device is rectangular in plan view. The example shown in FIG. 2 has a horizontally long rectangular shape, but it may have a square shape like the light emitting device 300 according to the third embodiment shown in FIG. Further, the shape is not limited to a rectangular shape, and a polygonal shape such as a hexagonal shape with some corners cut off or an octagonal shape with four corners cut off like a light emitting device 400 according to Embodiment 4 shown in FIG. It can also be circular.
[Fifth Embodiment]

Further, in the above example, the configuration in which the entire circumference of the wavelength conversion member 20 is covered with the light diffusion layer 30 in a plan view has been shown, but the present invention is not limited to this configuration, and the light diffusion layer covers a part of the periphery of the wavelength conversion member. It is also possible to cover with other parts and to cover other surrounding parts with another member. For example, as in the light emitting device 500 according to the fifth embodiment shown in FIG. 6, one of the facing side surfaces of the wavelength conversion member 20 (right and left of the wavelength conversion member 20 in FIG. 6) is covered with the light diffusion layer 30, and The other (upper and lower sides of the wavelength conversion member 20 in FIG. 6) may be covered with the second light shielding layer 42. In this configuration, of the side surface of the light emitting device 500, a portion covered with the light diffusion layer 30 is a light emitting area, and a surface covered with the second light shielding layer 42 is a non-light emitting area. Can be regulated. Further, by concentrating the light emitting region, the brightness can be improved. Furthermore, it is suitable for applications where light is given anisotropy by shielding the upper and lower sides of the light emitting element and obtaining emitted light mainly in the left and right direction among the four side surfaces, and which requires brightness only in the left and right direction. Become.
(Light guide plate 70)

The light emitting device of Embodiments 1 to 5 as described above can be used as a light source for planar light emission such as illumination or a liquid crystal backlight. As an example, FIG. 7 shows an example in which the light emitting device is applied to a planar light emitter. In this example, the plurality of light emitting devices 100 are arranged on the back surface of the light guide plate 70 so as to be separated from each other. Each light emitting device 100 is optically connected to the light guide plate 70. By disposing such a light emitting device, it becomes possible to reduce the thickness of the planar light emitting body.

The light guide plate 70 is preferably formed in a rectangular shape such as a rectangle or a square. As a material for forming the light guide plate 70, a thermoplastic resin such as acrylic, polycarbonate, cyclic polyolefin, polyethylene terephthalate or polyester, a resin material such as thermosetting resin such as epoxy or silicone, or an optically transparent material such as glass. Materials can be used. In particular, a thermoplastic resin material is preferable because it can be efficiently manufactured by injection molding. Of these, polycarbonate, which has high transparency and is inexpensive, is preferable. Further, the light guide plate 70 may be formed as a single layer or may be formed by stacking a plurality of translucent layers. When a plurality of translucent layers are laminated, it is preferable to provide a layer having a different refractive index, such as an air layer, between arbitrary layers. As a result, it becomes easier to diffuse light, and a planar light-emitting body with reduced uneven brightness can be obtained.
(Method of manufacturing light emitting device)

Next, a method for manufacturing the light emitting device according to the first embodiment will be described based on the schematic cross-sectional views of FIGS. First, as shown in FIG. 8, the light reflective layer 50 is prepared. Here, the fourth resin 52 in which the light reflecting material is dispersed is formed on the base sheet 80. A member having heat resistance can be suitably used for the base sheet 80, and for example, a heat resistant tape having an adhesive layer can be used. On this base sheet 80, white resin is applied as the fourth resin 52 in which the light reflecting material is dispersed. The white resin is phenyl resin in which TiO ₂ is dispersed. Here, the heat-resistant tape having an adhesive layer is attached and held to the ring RG, but if the base sheet can be held, a supporting plate or the like can be appropriately used.

Next, as shown in FIG. 9, the light emitting element 10 is mounted on the uncured white resin. Here, a plurality of light emitting elements 10 are arranged apart from each other on the upper surface of the white resin. The light emitting element 10 is a light emitting diode in which a GaN-based semiconductor layer is grown on a sapphire substrate. In the light emitting diode, a pair of electrodes 12 is projected from the element electrode formation surface. The element electrode forming surface is pressed so that the electrode 12 penetrates from the white resin. In this state, the white resin is cured to form the light reflective layer 50.

Next, as shown in FIG. 10, the upper surface of the light reflective layer 50 on which the light emitting element 10 is mounted is covered with the wavelength conversion member 20. Here, a phenyl resin, which is the first resin 22 in which the YAG phosphor is dispersed, is compression-molded as a wavelength conversion material so as to cover the periphery and the upper surface of the light reflective layer 50. In this state, the first resin 22 is cured to form the wavelength conversion member 20.

Further, if necessary, the upper surface of the formed body including the cured wavelength conversion member 20 is ground to form a predetermined thickness. In the example shown in FIG. 11, the upper surface of the cured wavelength conversion member 20 is mechanically ground by a grinder or the like. If the thickness can be controlled by adjusting the amount of the first resin 22 when forming the wavelength conversion member 20, the mechanical grinding process can be omitted.

Further, in the example shown in FIG. 11, the molded body is transferred from the base sheet 80 to the UV tape 90. The UV tape 90 is an adhesive tape having a sufficient adhesive force and a property of weakening the adhesive force by irradiating UV light (ultraviolet ray). By using the UV tape 90, the wafer is securely fixed with a strong adhesive force during the grinding or cutting process of the wavelength conversion member 20, but after the process is finished, UV light is irradiated to weaken the adhesive force, and the tape peeling or Makes die pick-up easy. This makes it possible to improve the quality of semiconductor device manufacturing and reduce costs.

Further, as shown in FIG. 12, the light emitting device is divided into individual pieces. Here, the wavelength conversion layer is cut and cut for each light emitting element 10 using a dicer or the like. The individual wavelength conversion layers are arranged on the second base sheet 82. For example, as in FIG. 8, as shown in FIG. 13, a light reflecting layer 50 is newly prepared on the second base sheet 82, and the individual pieces are separated and rearranged. Note that the light-reflecting layer 50 is prepared again by performing the same steps as those in FIG. 8 before FIG. 13 and the cut-out light-emitting elements are rearranged.

Further, the light diffusion layer 30 is formed. For example, as shown in FIG. 14, the second resin 32 in which the light diffusion material is dispersed is applied so as to cover the individual pieces arranged on the second base sheet 82. Here, a phenyl resin, which is the second resin 32 in which SiO ₂ is dispersed, is compression-molded as a light diffusion material so as to cover the periphery and the upper surface of each piece. In this state, the second resin 32 is cured to form the light diffusion layer 30.

If necessary, the upper surface of the cured light diffusing layer 30 is ground to have a predetermined thickness. In the example shown in FIG. 15, the upper surface of the light diffusion layer 30 is mechanically ground by a grinder or the like. If the thickness can be controlled by adjusting the amount of the second resin 32 when forming the light diffusion layer 30, the mechanical grinding process can be omitted.

Further, the light shielding layer 40 is formed on the wavelength conversion member 20. For example, as shown in FIG. 16, the third resin 41 in which the light-reflecting material is dispersed is applied to the upper surface and the side surface of the formed body including the wavelength conversion member 20 provided with the light diffusion layer 30. Here, a phenyl resin, which is the third resin 41 in which TiO ₂ is dispersed, is compression-molded around the formed body as a light-reflecting material. In this state, the third resin 41 is cured to form the light shielding layer 40.

Further, transfer and back surface grinding are performed. For example, as shown in FIG. 17, the formed body is peeled off from the second base sheet 82 and transferred onto the second UV tape 92 in a posture in which the light reflective layer 50 (fourth resin 52) side is the upper surface.

Furthermore, the surface of the exposed electrode 12 is protected. Here, as shown in FIG. 18, the terminal protection film 14 is formed by sputtering or the like. Au or the like can be used for the terminal protection film 14.

Further, a metal film 60 for terminal protection is formed. Here, after separating each light emitting element as shown in FIG. 19, a metal coating 62 is formed on the upper surface of the formed body in which the end surface of the electrode 12 is exposed from the light reflective layer 50, as shown in FIG. The metal coating 62 is formed so as to be electrically connected to the electrode 12. The metal coating 62 is formed by sputtering, vapor deposition, atomic layer deposition (ALD), metal organic chemical vapor deposition (MOCVD), plasma CVD (Plasma-Enhanced Chemical Vapor Deposition). It can be formed by a PECVD method, an atmospheric pressure plasma film forming method, or the like.

For the metal coating 62, for example, the outermost layer is preferably made of a platinum group metal such as Au or Pt. Further, Au having good solderability can be used on the outermost surface. Note that the metal film may be formed of only one layer of a single material, or may be formed by stacking layers of different materials. In particular, it is preferable to use a metal film having a high melting point, and examples thereof include Ru, Mo and Ta. Further, by providing these high melting point metals between the electrode 12 of the light emitting element 10 and the outermost surface layer, it is possible to reduce diffusion of Sn contained in the solder into the electrode 12 or a layer near the electrode 12. Can be used as a diffusion prevention layer. Examples of a laminated structure including such a diffusion prevention layer include Ni/Ru/Au, Ti/Pt/Au, and the like. Further, the thickness of the diffusion prevention layer (for example, Ru) is preferably about 10Å to 1000Å.

Various thicknesses of the metal coating 62 can be selected. The degree of laser ablation can be selectively generated. For example, it is preferably 1 μm or less, and more preferably 1000 Å or less. Further, it is preferable that the thickness is such that the corrosion of the electrode 12 can be reduced, for example, 5 nm or more. Here, when the metal film is formed by laminating a plurality of layers, the thickness of the metal coating 62 means the total thickness of the plurality of layers.

Then, a part of the metal coating 62 is removed. Here, as shown in FIG. 21, the metal coating 62 is irradiated with laser light to provide an inter-electrode slit having no metal film as the insulating region 10. The laser light is applied to the insulating region 10 provided between the pair of electrodes 12 of the light emitting element 10. The insulating region 10 extends not only between the pair of electrodes 12 of the light emitting element 10 but also on the surface of the covering member 3 in the extension direction thereof to divide the metal coating 62.

The insulating region 10 of the inter-electrode slit has substantially the same width as the width between the electrodes 12 of the light emitting element 10. For example, the width of the insulating region 10 is made slightly wider than the width of the electrode 12. The metal coating 62 is removed from the insulating region 10 by laser ablation. The metal coating 62 is removed in the insulating region 10, and the covering member 3 is exposed between the pair of electrodes 12 of the light emitting element 10 in a slit shape.

The laser light can be applied to the metal coating 62 by continuously or sequentially moving the irradiation spot on the member. The laser light may be continuously emitted or pulsed. The intensity of the laser beam, the diameter of the irradiation spot, and the moving speed of the irradiation spot are set on the metal coating 62 on the coating member 3 in consideration of the thermal conductivity of the coating member 3 and the metal coating 62 and the difference in their thermal conductivity. It can be set so that laser ablation occurs.

As the wavelength of the laser light, it is preferable to select a wavelength having a low reflectance with respect to the metal film 60, for example, a wavelength having a reflectance of 90% or less. For example, when the outermost surface of the metal film 60 is Au, it is preferable to use a laser having an emission wavelength shorter than that in the green region (for example, 550 nm) than that in the red region (for example, 640 nm). Thereby, ablation can be efficiently generated and mass productivity can be improved.

The light-emitting device 100 can be obtained by dividing the molded body thus obtained into individual pieces of a predetermined size.

INDUSTRIAL APPLICABILITY The light emitting device according to the present disclosure can be suitably used as a backlight of a television, a tablet, a liquid crystal display device, a television, a tablet, a smartphone, a smart watch, a head-up display, a digital signage, a bulletin board, and the like. It can also be used as a light source for lighting, and can also be used for emergency lights, line lighting, various types of illumination, and installation for vehicles.

100, 200, 300, 400, 500... Light emitting device 10... Light emitting element 12... Electrode 14... Terminal protective film 20... Wavelength conversion member 22... First resin 30... Light diffusion layer 32... Second resin 40... Light shielding layer 41... Third resin 42... Second light shielding layer 50... Light reflective layer 51... Convex 52... Fourth resin 60... Metal film 62... Metal coating 70... Light guide plate 80... Base sheet 82... Second base sheet 90... UV tape 92... Second UV tape RG... Ring

Claims (13)

A light emitting element having an upper surface, a lower surface having a pair of electrodes, and a side surface;
A wavelength conversion member that continuously covers the upper surface and the side surface, converts the wavelength of light emitted by the light emitting element, and emits light of different wavelengths,
A light diffusing layer which covers the outer surface of the wavelength conversion member and diffuses the light emitted by the light emitting element and the light wavelength-converted by the wavelength conversion member;
A light-shielding layer having a light-shielding property, which is disposed above the wavelength conversion member and above the light diffusion layer,
A light emitting device comprising. The light emitting device according to claim 1, further comprising:
The lower surface, below the wavelength conversion member, and provided with a light reflective layer disposed below the light diffusion layer,
A light emitting device in which the electrode is exposed from the light reflective layer. The light emitting device according to claim 2, further comprising:
A light emitting device, comprising a metal film which covers an end surface of the electrode exposed from the light reflecting layer and is larger than an end surface of the electrode. The light emitting device according to claim 2 or 3, wherein
The light reflecting layer has a convex shape on the outer periphery of the wavelength conversion member. It is a light-emitting device as described in any one of Claims 2-4, Comprising:
A light-emitting device, wherein the light-reflecting layer is made of a resin containing TiO ₂ , SiO ₂ , Al ₂ O ₃ or a glass filler. The light emitting device according to claim 5, wherein
A light emitting device in which the resin of the light reflective layer is composed of a phenyl resin. It is a light-emitting device as described in any one of Claims 1-6, Comprising:
A light emitting device in which the light shielding layer is made of a resin containing TiO ₂ , SiO ₂ , Al ₂ O ₃ or a glass filler. The light emitting device according to claim 7,
A light emitting device in which the resin of the light shielding layer is composed of a phenyl resin. The light emitting device according to claim 7,
A light emitting device in which the resin of the light shielding layer is composed of a dimethyl resin. It is a light-emitting device as described in any one of Claims 1-9,
A light emitting device in which the light diffusion layer is made of a resin containing SiO ₂ or a glass filler. The light emitting device according to claim 10, wherein
A light emitting device in which the light diffusion layer is made of a phenyl resin. It is a light-emitting device as described in any one of Claims 1-11,
A light-emitting device in which the wavelength conversion member includes at least one of a YAG phosphor, a β-sialon phosphor, a KSF-based phosphor, and an MGF-based phosphor. The light emitting device according to claim 12,
A light emitting device in which the wavelength conversion member is made of a phenyl resin.

Images