JP7104350B2 - Luminescent device - Google Patents

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, a display, and lighting of a liquid crystal display. For example, Patent Documents 1 and 2 disclose a semiconductor light emitting device. In order to obtain planar light emission with such a semiconductor light emitting device, a configuration in which a plurality of LEDs are arranged in a matrix on the back surface side of the light guide plate is known.

Japanese Unexamined Patent Publication No. 2013-115088 Japanese Unexamined Patent Publication No. 2014-45194

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

In order to achieve the above object, according to the light emitting device according to one embodiment of the present invention, the upper surface, the lower surface having a pair of electrodes, the light emitting element having the side surface, and the upper surface and the side surface are continuously covered. A wavelength conversion member that converts the wavelength of light emitted by the light emitting element to emit light of a different wavelength, and a light-reflecting material arranged on the lower surface and below the wavelength conversion member so that the electrode is exposed. It is possible to provide a light-reflecting layer made of a resin containing the above, and a light-shielding layer having a light-shielding property, which is arranged above the wavelength conversion member.

According to the light emitting device according to one embodiment of the present invention, a thin and wide light distribution device can be provided by blocking the light having the highest brightness emitted from the upper surface of the light emitting element with a light shielding layer.

It is a schematic cross-sectional view which shows the light emitting device which concerns on Embodiment 1. FIG. FIG. 5 is a horizontal cross-sectional view taken along the line II-II of FIG. It is a schematic cross-sectional view which shows the light emitting device which concerns on Embodiment 2. It is a horizontal sectional view of the light emitting device which concerns on Embodiment 3. It is a horizontal sectional view of the light emitting device which concerns on Embodiment 4. FIG. It is a horizontal sectional view of the light emitting device which concerns on Embodiment 5. It is a schematic plan view which shows the planar light emitting body using the light emitting device which concerns on Embodiment 1. FIG. It is a schematic cross-sectional view which shows one state of the manufacturing process of the light emitting device which concerns on Embodiment 1. FIG. It is a schematic cross-sectional view which shows one state of the manufacturing process of the light emitting device which concerns on Embodiment 1. FIG. It is a schematic cross-sectional view which shows one state of the manufacturing process of the light emitting device which concerns on Embodiment 1. FIG. It is a schematic cross-sectional view which shows one state of the manufacturing process of the light emitting device which concerns on Embodiment 1. FIG. It is a schematic cross-sectional view which shows one state of the manufacturing process of the light emitting device which concerns on Embodiment 1. FIG. It is a schematic cross-sectional view which shows one state of the manufacturing process of the light emitting device which concerns on Embodiment 1. FIG. It is a schematic cross-sectional view which shows one state of the manufacturing process of the light emitting device which concerns on Embodiment 1. FIG. It is a schematic cross-sectional view which shows one state of the manufacturing process of the light emitting device which concerns on Embodiment 1. FIG. It is a schematic cross-sectional view which shows one state of the manufacturing process of the light emitting device which concerns on Embodiment 1. FIG. It is a schematic cross-sectional view which shows one state of the manufacturing process of the light emitting device which concerns on Embodiment 1. FIG. It is a schematic cross-sectional view which shows one state of the manufacturing process of the light emitting device which concerns on Embodiment 1. FIG. It is a schematic cross-sectional view which shows one state of the manufacturing process of the light emitting device which concerns on Embodiment 1. FIG. It is a schematic cross-sectional view which shows one state of the manufacturing process of the light emitting device which concerns on Embodiment 1. FIG. It is a schematic cross-sectional view which shows one state of the manufacturing process of the light emitting device which concerns on 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 the use of these terms is used. This is for facilitating the understanding of the invention with reference to the drawings, and the meaning of these terms does not limit the technical scope of the present invention. Further, the parts having the same reference numerals appearing in a plurality of drawings indicate the same or equivalent parts or members.

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

The light emitting device according to the first embodiment of the present invention is shown in a schematic cross-sectional view of FIG. 1 and a horizontal cross-sectional view of FIG. The light emitting device 100 shown in these figures includes a light emitting element 10, a wavelength conversion member 20, a light diffusing layer 30, a light shielding layer 40, and a light reflecting 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. Further, 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, a side surface thereof is also referred to as an element side surface, and a lower surface thereof is also referred to as an element electrode forming surface.

As the light emitting element 10, an element that emits light having an arbitrary wavelength can be selected. For example, as an element that emits blue or green light, a nitride semiconductor (In _x Aly Ga _{1-xy N} , 0 ≦ X, 0 ≦ Y, X + Y ≦ 1) or a light emitting device using GaP is used. be able to. Further, as an element that emits red light, a light emitting element containing a semiconductor such as AlGaAs or AlInGaP can be used. Further, a semiconductor light emitting device 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 the mixed crystalliteity thereof. The composition, emission color, size, number, etc. of the light emitting element to be 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 the light emitted by the light emitting element 10 to emit light having a different wavelength. 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 contains a wavelength conversion substance that is excited by the light from the light emitting element 10 and emits light having a different wavelength. Of the light emitted by the light emitting element 10 in this way, the component transmitted through the wavelength conversion member 20 and the component wavelength-converted by the wavelength conversion member 20 are mixed in color, and mixed color light is emitted.

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

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

As the material constituting the first resin serving as the 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 having high hardness after curing and excellent processability. From the viewpoint of light resistance and moldability of the wavelength conversion member 20, it is beneficial 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 constituting the light guide plate 70 described later. This has the advantage of being easy to process by grinding or the like.

A fluorescent substance can be preferably used as the wavelength conversion substance contained in the wavelength conversion member 20. Examples thereof include fluoride-based phosphors such as YAG phosphors, β-sialone phosphors, KSF-based phosphors or MGF-based phosphors, and nitride-based phosphors. 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 above 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 Group 4 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 above general formula (II), Ma is at least one selected from Ca, Sr, Ba, Zn, and Mb is at least one selected from Sc, La, Lu, and Mc Is at least one selected from Ca, Sr, Ba, Zn, X is at least one selected from F, Cl, and Md is at least one selected from Ti, Sn, Zr. Me is at least one selected from B, Al, Ga, and In. 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)

Max _{MbyAl 3} N _z : Eu ... (III)
(However, in the above 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 half width 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 Ti or Si (composition formula). Then, K ₂ (Si, Ti, Ge) F ₆ : Mn is expressed), and a part of K constituting the composition of KSF phosphor K ₂ SiF ₆ : Mn ⁴⁺ is changed to another alkali metal. Substitution may be performed, a part of Si may be replaced with Al or the like of a trivalent element, 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 fluorescent substance such as a KSF phosphor that emits red light. can. As a result, the color reproduction range of the light emitting device can be expanded. In this case, the light emitting device is a nitride semiconductor (In _x Ally Ga _{1-xy N} , 0 ≦ X, 0 ≦ Y, X + Y) capable of emitting short wavelength light capable of efficiently exciting the wavelength conversion member. It is preferable to provide ≦ 1). Further, for example, when a light emitting element 10 that emits blue light is used and it is desired to obtain red light as a light emitting device, 60% by weight of a KSF phosphor (red phosphor) is added to the wavelength conversion member. As described above, preferably 90% by weight or more may be contained. That is, a wavelength conversion substance that emits light of a specific color may be contained in the wavelength conversion member to emit light of a specific color. Moreover, the wavelength conversion substance may be a quantum dot. The wavelength conversion substance may be arranged in any way in the wavelength conversion member. For example, it may be distributed substantially uniformly, or may be unevenly distributed in a part. Further, a plurality of layers each containing a wavelength conversion member may be laminated and provided. Further, the wavelength conversion member may be provided with a member that diffuses and reflects light. For example, a light diffusing 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. It is preferably within the above range in order to reduce the thickness of the light emitting module and exert the effects of various wavelength conversions.
(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 cross-sectional view of FIG. 2, the entire outer circumference of the wavelength conversion member 20 formed in a rectangular shape in a plan view is covered with the light diffusion layer 30. The light diffusion layer 30 serves as a light emitting region for radiating light from the light emitting device 100 to the outside. The light diffusing layer 30 further diffuses the light emitted by the light emitting element 10 and the light whose wavelength has been converted by the wavelength conversion member 20, and promotes color mixing thereof. 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 ratio of 50% or more. Further, a plurality of light diffusion layers are laminated in the outer peripheral direction to form a light diffusion region.

The light diffusing layer 30 can be formed by adding a diffusing material to the base material. For example, a second resin containing white inorganic fine particles such as SiO ₂ and TiO ₂ as a diffusing material can be used as the light diffusing layer 30. As the resin material of the second resin serving as the base 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. Preferably, a phenyl resin having high hardness and excellent processability after curing is used. By using the same resin as the wavelength conversion member 20 for the base material of the light diffusion layer 30, it has excellent adhesiveness, and at the junction interface between the wavelength conversion member 20 and light diffusion due to resin shrinkage during curing and deformation during expansion. It is possible to prevent stress from being generated and causing peeling.

Further, as the diffusing material, a material obtained by processing a white resin or metal, which is a light-reflecting member, into fine particles can also be used. These diffusing materials are irregularly contained inside the base material, so that the light passing through the inside of the light diffusing layer 30 is irregularly and repeatedly reflected to diffuse the transmitted light in multiple directions. Therefore, the irradiation light is suppressed from being locally concentrated to prevent uneven brightness.

In addition, by arranging 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 a phosphor that may be adversely affected by moisture from the outside is used, 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 and the wavelength conversion member 20 increases the brightness of the upper surface of the light-emitting element 10. Suppress. The light-shielding layer 40 preferably has a light transmittance of 50% or less. As described above, the light-shielding layer 40 does not necessarily require to have a complete light-shielding property, and even if it is incomplete, it is sufficient if the light-shielding layer 40 exhibits the light-shielding property. As used herein, the term "light-shielding property" does not mean a transmittance of 0%.

The light-shielding layer 40 is configured by dispersing a light-reflecting material in a third resin 41 which is a base material. As the resin material of the third resin 41 serving as the base material, a phenyl resin, a dimethyl resin, an epoxy resin, a silicone resin, a resin in which these are mixed, or a translucent material such as glass can be used. Preferably, a phenyl resin is used. As a result, the hardness is high after the resin is cured, and effects such as easy processing can be obtained. 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-shielding layer 40, the adhesiveness is excellent, and stress is generated at the bonding interface due to resin shrinkage during curing and 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 difference in refractive index at the interface between them. It is possible to reduce the amount of light entering. As the light-reflecting material, TiO ₂ , SiO ₂ , Al ₂ O ₃ or a glass filler can be used. The refractive index can be selected by using a glass filler. Here, the transmittance can be adjusted by adjusting the content of the filler. The light diffusing layer 30 preferably has a transmittance of 50% or more, and the light-shielding layer 40 preferably has a transmittance of 50% or less.

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

Further, a light reflecting layer 50 is arranged on the lower surface of the light emitting element 10, below the wavelength conversion member 20, and below the light diffusing layer 30. The light-reflecting layer 50 reflects the light emitted by the light emitting element 10 and the light wavelength-converted by the wavelength conversion member 20 to prevent 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 which is the base material. As the resin material of the fourth resin 52 as the base 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. Preferably, a phenyl resin is used. As a result, the hardness is high after the resin is cured, and effects such as easy processing can be obtained. 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 and deformation during expansion. It can be suppressed that it occurs and causes peeling. Further, as the light-reflecting material, TiO ₂ , SiO ₂ , Al ₂ O ₃ , glass filler and the like can be used.
(Metal film 60)

Further, the end surface of the electrode 12 of the light emitting element 10 exposed from the light reflecting layer 50 is covered with a 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 face of the electrode 12 of the light emitting element 10, the light emitting device 100 can be easily electrically connected to the outside. Using this metal film 60, the light emitting device 100 can be mounted on a mounting substrate, wire bonded, or otherwise electrically connected to an external wiring to supply power to the light emitting element 10. The metal film 60 can be formed of, for example, a single layer film or a laminated film of a metal such as Au, Pt, Pd, Rh, Ni, W, Mo, Cr, Ti or an alloy thereof. Specifically, Ti / Rh / Au, W / Pt / Au, Rh / Pt / Au, W / Pt / Au, Ni / Pt / Au, Ti / Rh, etc. were laminated from the light emitting element 10 side. Laminated membranes are available. In particular, by protecting Cu, which is easily oxidized, with a stable metal such as Au, the reliability of the electrical connection is enhanced.
[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 have a partially convex shape. 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. As a result, the adhesion between the light reflecting layer 50 and the wavelength conversion member 20 is strengthened. In particular, it can exert an anchor effect.
[Embodiments 3 and 4]

In the above example, the outer shape of the light emitting device is rectangular in a plan view. In the example shown in FIG. 2, it 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 as in the light emitting device 400 according to the fourth embodiment shown in FIG. Or circular.
[Embodiment 5]

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 is shown in a plan view, but the present invention is not limited to this configuration, and a part around the wavelength conversion member is covered with the light diffusion layer. It may be covered with, and other parts around it may be covered 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 (left and right of the wavelength conversion member 20 in FIG. 6) is covered with the light diffusion layer 30 and the side surface is covered. The other (above and below the wavelength conversion member 20 in FIG. 6) may be covered with the second light-shielding layer 42. In this configuration, the portion of the side surface of the light emitting device 500 covered with the light diffusion layer 30 is designated as a light emitting region, and the surface covered with the second light shielding layer 42 is designated as a non-light emitting region, and extra light emission is performed by limiting the light emitting region. Can be regulated. Further, by concentrating the light emitting region, the brightness can be improved. Furthermore, it is suitable for applications where the top and bottom of the light emitting element are shielded and the light is anisotropy by mainly obtaining the emitted light in the left-right direction among the four lateral surfaces, and the brightness is required only in the left-right direction. Become.
(Light guide plate 70)

The light emitting devices of the first to fifth embodiments as described above can be used as a light source for emitting light in a planar manner such as lighting and a backride for a liquid crystal display. As an example, FIG. 7 shows an example in which the light emitting device is applied to a planar light emitting body. In this example, a 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 arranging such a light emitting device, it is 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. The materials constituting the light guide plate 70 include thermoplastic resins such as acrylic, polycarbonate, cyclic polyolefin, polyethylene terephthalate and polyester, resin materials such as thermosetting resins such as epoxy and silicone, and optically transparent glass and the like. Materials can be used. In particular, a thermoplastic resin material is preferable because it can be efficiently produced by injection molding. Of these, polycarbonate, which has high transparency and is inexpensive, is preferable. Further, the light guide plate 70 may be formed of a single layer, or may be formed by laminating a plurality of translucent layers. When a plurality of translucent layers are laminated, it is preferable to provide layers having different refractive indexes, for example, an air layer, between arbitrary layers. As a result, it becomes easier to diffuse the light, and it is possible to obtain a planar illuminant with reduced brightness unevenness.
(Manufacturing method of light emitting device)

Next, a method of manufacturing the light emitting device according to the first embodiment will be described with reference to the schematic cross-sectional views of FIGS. 8 to 21. First, as shown in FIG. 8, the light reflecting 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 heat-resistant member can be preferably used for the base sheet 80, and for example, a heat-resistant tape having an adhesive layer can be used. A white resin is applied onto the base sheet 80 as a fourth resin 52 in which a light-reflecting material is dispersed. The white resin has TiO ₂ dispersed in a phenyl resin. Here, a heat-resistant tape having an adhesive layer is attached and held on the ring RG, but if the base sheet can be held, a support plate or the like can be used as appropriate.

Next, as shown in FIG. 9, the light emitting element 10 is mounted on the white resin in an uncured state. Here, a plurality of light emitting elements 10 are arranged on the upper surface of the white resin so as to be separated from each other. The light emitting element 10 is a light emitting diode in which a GaN-based semiconductor layer is grown on a sapphire substrate. The light emitting diode projects a pair of electrodes 12 from the element electrode forming 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-reflecting layer 50.

Next, as shown in FIG. 10, the upper surface of the light reflecting layer 50 on which the light emitting element 10 is mounted is covered with the wavelength conversion member 20. Here, the phenyl resin, which is the first resin 22 in which the YAG phosphor is dispersed as the wavelength conversion material, is compression-molded so as to cover the periphery and the upper surface of the light-reflecting 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 with a grinder or the like. If the thickness can be controlled by adjusting the amount of the first resin 22 at the time of forming the wavelength conversion member 20, the mechanical grinding step can be omitted.

Further, in the example shown in FIG. 11, the molded product is transferred from the base sheet 80 to the UV tape 90. The UV tape 90 is an adhesive tape having a sufficient adhesive strength and having a property of weakening the adhesive strength by irradiating with UV light (ultraviolet rays). By using the UV tape 90, the wafer is firmly fixed with a strong adhesive force during the grinding and cutting processing of the wavelength conversion member 20, and after the processing is completed, UV light is irradiated to weaken the adhesive force, and the tape can be peeled off. Facilitates die pickup. 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 individualized. Here, the wavelength conversion layer is cut out for each light emitting element 10 by using a die or the like. Each individualized wavelength conversion layer is arranged on the second base sheet 82. For example, as in FIG. 8, as shown in FIG. 13, a new light-reflecting layer 50 is newly prepared on the second base sheet 82, and each piece is separated and rearranged. In addition, the same process as in FIG. 8 is performed before FIG. 13, the light reflecting layer 50 is prepared again, 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 diffusing material is dispersed is applied so as to cover each piece arranged on the second base sheet 82. Here, a phenyl resin, which is a second resin 32 in which SiO ₂ is dispersed as a light diffusing material, is compression-molded 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 diffusion layer 30 is ground to form a predetermined thickness. In the example shown in FIG. 15, the upper surface of the light diffusion layer 30 is mechanically ground with a grinder or the like. If the thickness can be controlled by adjusting the amount of the second resin 32 at the time of forming the light diffusion layer 30, the mechanical grinding step can be omitted.

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

Further transfer and backside 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 reflecting layer 50 (fourth resin 52) side is the upper surface.

Furthermore, it protects the surface of the exposed electrode 12. 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 protective film 14.

Further, a metal film 60 for protecting the terminals is formed. Here, after separating each light emitting element as shown in FIG. 19, as shown in FIG. 20, 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 reflecting layer 50. The metal coating 62 is formed so as to be electrically connected to the electrode 12. The metal coating 62 is subjected to sputtering, vapor deposition, atomic layer deposition (ALD) method, metallic organic chemical vapor deposition (MOCVD) method, plasma CVD (Plasma-Enhanced Chemical Vapor Deposition); It can be formed by a PECVD) method, an atmospheric pressure plasma deposition method, or the like.

For the metal coating 62, for example, it is preferable that the outermost layer is a metal of a platinum group element such as Au or Pt. Further, Au having good solderability can be used on the outermost surface. The metal film may be composed of only one layer of a single material, or may be composed of layers of different materials laminated. 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 layer, it is possible to reduce the diffusion of Sn contained in the solder to the electrode 12 and the layer close to the electrode 12. It can be an anti-diffusion layer that can be used. Examples of the laminated structure provided with such a diffusion prevention layer include Ni / Ru / Au, Ti / Pt / Au and the like. The thickness of the diffusion prevention layer (for example, Ru) is preferably about 10 Å to 1000 Å.

The thickness of the metal coating 62 can be variously selected. The degree to which laser ablation occurs selectively can be set to, for example, 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, the thickness of the metal coating film 62 means the total thickness of the plurality of layers when the metal film is formed by laminating a plurality of layers.

Then, a part of the metal coating 62 is removed. Here, as shown in FIG. 21, the metal film 62 is irradiated with laser light to provide an inter-electrode slit without the metal film as the insulating region 10. The laser beam irradiates 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 extending direction thereof to divide the metal coating 62.

The insulating region 10 of the inter-electrode slit has a width substantially the same as the width between the electrodes 12 of the light emitting element 10. For example, the width of the insulating region 10 is slightly wider than the width of the electrode 12. The metal film 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 in a slit shape between the pair of electrodes 12 of the light emitting element 10.

The laser beam can irradiate the metal film 62 by continuously or sequentially moving the irradiation spot on the member. The laser beam may be continuously irradiated or may be pulsed. The intensity of the laser beam, the diameter of the irradiation spot, and the moving speed of the irradiation spot are determined 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 thermal conductivity between them. 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 for the laser in the red region (for example, 640 nm). As a result, ablation can be efficiently generated and mass productivity can be improved.

The molded product thus obtained can be individualized into a predetermined size to obtain a light emitting device 100.

The light emitting device according to the present disclosure can be suitably used as a backlight for 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, or the like. It can also be used as a light source for lighting, and can also be used for emergency lights, line lighting, various illuminations, and in-vehicle installations.

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-reflecting 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 (10)

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 and converts the wavelength of light emitted by the light emitting element to emit light of different wavelengths.
A light-reflecting layer made of a resin containing a light-reflective material, which is arranged on the lower surface and below the wavelength conversion member so that the electrodes are exposed.
A light-shielding layer having a light-shielding property, which is arranged above the wavelength conversion member,
With
The light reflecting layer is a light emitting device having a convex shape on the outer periphery of the wavelength conversion member . The light emitting device according to claim 1, further
A light emitting device that covers an end face of the electrode exposed from the light-reflecting layer and includes a metal film larger than the end face of the electrode. The light emitting device according to claim 1 or 2.
A light emitting device in which the light-reflecting material is TiO ₂ , SiO ₂ , Al ₂ O ₃ , or a glass filler. The light emitting device according to claim 3.
A light emitting device in which the resin of the light reflecting layer is made of a phenyl resin. The light emitting device according to any one of claims 1 to 4.
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 5.
A light emitting device in which the resin of the light-shielding layer is made of a phenyl-based resin. The light emitting device according to claim 5.
A light emitting device in which the resin of the light-shielding layer is made of a dimethyl resin. The light emitting device according to any one of claims 1 to 7.
A light emitting device in which the wavelength conversion member includes at least one of a YAG phosphor, a β-sialone phosphor, a KSF-based phosphor, and an MGF-based phosphor. The light emitting device according to claim 8.
A light emitting device in which the wavelength conversion member is made of a phenyl resin. The light emitting device according to any one of claims 1 to 9.
A light emitting device having a thickness of a region located above the light reflecting layer of the wavelength conversion member of 0.02 mm to 0.40 mm.

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