JP2021057504A - Light-emitting device - Google Patents

Abstract

To fix a light-reflecting member to a substrate by a resin member.SOLUTION: A light-emitting device includes a substrate, a plurality of light sources arranged on the substrate, and a light-reflecting member arranged on the substrate and having a wall portion surrounding the plurality of light sources one by one or two or more of them; the wall portion has a cavity portion having a first opening on the substrate side; the substrate has a penetrating hole that penetrates the substrate in the vertical direction and has a second opening located inside the first opening on the upper surface of the substrate; and a resin member is continuously in contact with the inner wall of the cavity portion and a region on the upper surface of the substrate provided between the peripheral edge of the second opening and the peripheral edge of the first opening.SELECTED DRAWING: Figure 1E

Description

The present invention relates to a light emitting device.

A backlight device has been proposed in which a plurality of light sources and a reflecting member provided with a wall portion surrounding the light sources are arranged on a substrate (see paragraph 0032 of Patent Document 1).

International Publication No. 2012/023459

A light emitting device having excellent light extraction efficiency is desired.

The present invention includes the following embodiment.

With the board
With a plurality of light sources arranged on the substrate,
A light emitting device including a light-reflecting member arranged on the substrate and having a wall portion surrounding the plurality of light sources one by one or two or more.
The wall portion has a hollow portion having a first opening on the substrate side.
The substrate has a through hole that penetrates the substrate in the vertical direction and has a second opening located inside the first opening on the upper surface of the substrate.
A light emitting device in which a resin member is continuously in contact with an inner wall of the cavity and a region on the upper surface of the substrate provided between the peripheral edge of the second opening and the peripheral edge of the first opening.

According to one embodiment of the present invention, a light emitting device having excellent light extraction efficiency can be obtained.

It is a schematic plan view of the light emitting device which concerns on Embodiment 1. FIG. FIG. 1A is a view in which a side surface portion of a wall portion is hatched. FIG. 1A is a view in which the bottom surface of the wall portion is hatched. It is a figure which shows the positional relationship between the through hole (second opening) of a substrate, and a light source. It is a figure which shows the cross section of 1E-1E in FIG. 1A. It is a schematic plan view of the light emitting device which concerns on Embodiment 2. FIG. FIG. 2A is a view in which the tip portion of the wall portion is hatched. FIG. 2A is a view in which the side surface portion of the wall portion is hatched. FIG. 2A is a view in which the bottom surface of the wall portion is hatched. It is a figure which shows the positional relationship between the through hole (second opening) of a substrate, and a light source. It is a figure which shows the 2F-2F cross section in FIG. 2A. It is a schematic cross-sectional view explaining the manufacturing method of the light emitting device which concerns on Embodiment 1. FIG. It is a schematic cross-sectional view explaining the manufacturing method of the light emitting device which concerns on Embodiment 1. FIG. It is a schematic cross-sectional view explaining the manufacturing method of the light emitting device which concerns on Embodiment 1. FIG. It is a schematic cross-sectional view explaining the manufacturing method of the light emitting device which concerns on Embodiment 1. FIG. It is a schematic cross-sectional view explaining the manufacturing method of the light emitting device which concerns on Embodiment 2. FIG. It is a schematic cross-sectional view explaining the manufacturing method of the light emitting device which concerns on Embodiment 2. FIG. It is a schematic cross-sectional view explaining the manufacturing method of the light emitting device which concerns on Embodiment 2. FIG. It is a schematic cross-sectional view explaining the manufacturing method of the light emitting device which concerns on Embodiment 2. FIG. It is a photograph which shows an example of the case where one cell is viewed in a plan view while lighting a light source when the tip end portion of a wall portion is in contact with a member arranged above the light emitting device (in the case of the second embodiment). It is a photograph which shows an example of the case where one cell is viewed in a plan view while lighting a light source when the tip end portion of a wall portion does not come into contact with a member arranged above the light emitting device (in the case of a comparative example).

Hereinafter, the light emitting device of the present disclosure will be described in detail with reference to the drawings. The light emitting device of the present disclosure is an example, and is not limited to the light emitting device described below. In the following description, terms indicating a specific direction or position (for example, "top", "bottom" and other terms including those terms) may be used. These terms use relative orientation and position in the referenced drawings for clarity only. In addition, the size and positional relationship of the components shown in the drawings may be exaggerated for the sake of clarity, and the size in the actual light emitting device or the size relationship between the components in the actual light emitting device may be exaggerated. It may not be reflected. Further, in order to facilitate understanding, the illustration of each member may be omitted as appropriate.

[Light emitting device 1 according to the first embodiment]
FIG. 1A is a schematic plan view of the light emitting device according to the first embodiment. FIG. 1B is a view in which the side surface portion 324 of the wall portion 32 is hatched in FIG. 1A. FIG. 1C is a view in which the bottom surface portion 322 of the wall portion 32 is hatched in FIG. 1A. FIG. 1D is a diagram showing the positional relationship between the through hole (second opening) of the substrate and the light source. In FIG. 1D, the light reflecting member 30 and the adhesive 80 are not shown. FIG. 1E is a diagram showing a cross section of 1E-1E in FIG. 1A. In FIG. 1E, a member arranged above the light emitting device 1 is also shown.

As shown in FIGS. 1A to 1E, the light emitting device 1 according to the first embodiment includes a substrate 10, a plurality of light sources 20 arranged on the substrate 10, and a plurality of light sources 20 arranged on the substrate 10. A light source including a light-reflecting member 30 having wall portions 32 surrounding one by one or two or more, and the wall portion 32 has a cavity portion Y having a first opening W1 on the substrate 10 side. The substrate 10 has a through hole Z that penetrates the substrate 10 in the vertical direction and has a second opening W2 located inside the first opening W1 on the upper surface of the substrate 10. This is a light emitting device in which the resin member 80 is continuously in contact with the region W3 on the upper surface of the substrate 10 provided between the peripheral edge of the two openings W2 and the peripheral edge of the first opening W1. Hereinafter, a detailed description will be given.

(Board 10)
The substrate 10 is a member for arranging a plurality of light sources 20.

The substrate 10 may be, for example, a flexible substrate that can be manufactured by a roll-to-roll method, or a rigid substrate. The rigid substrate may be a curvable thin rigid substrate.

Examples of the material of the substrate 10 include resins such as ceramics, phenol resin, epoxy resin, polyimide resin, BT resin, polyphthalamide (PPA), and polyethylene terephthalate (PET). Examples of the ceramics include alumina, mullite, forsterite, glass ceramics, nitride-based (for example, AlN), carbide-based (for example, SiC), and LTCC. When using a resin, glass fiber or _{an inorganic filler such as SiO 2} , TiO ₂ , Al ₂ O ₃ is mixed with the resin to improve mechanical strength, reduce the coefficient of thermal expansion, improve the light reflectance, etc. You can also do it. A metal substrate having an insulating layer formed on the surface of the metal member may be used.

The thickness of the substrate 10 can be appropriately selected.

The upper surface of the substrate 10 is preferably flat so that the light reflecting member 30 can be easily arranged. The plane includes the case where it can be regarded as a plane. The plan view shape of the substrate 10 includes a square, a rectangle, a circle, and the like. These squares, rectangles, or circles include cases that can be regarded as squares, rectangles, or circles.

The substrate 10 has a through hole Z that penetrates the substrate 10 in the vertical direction. As a result, the resin member 80 can be injected into the cavity Y of the wall portion 32 of the light reflecting member 30 from the lower surface side of the substrate 10 through the through hole Z. The through hole Z has a second opening W2 on the upper surface of the substrate 10, and is connected to the hollow portion Y of the wall portion 32 of the light reflecting member 30 through the second opening W2. The inner diameter and shape of the through hole Z are not limited as long as the resin member 80 can be injected into the cavity Y. However, the second opening W2 (outer edge of the second opening W2) is located inside the first opening W1 (outer edge of the first opening W1). As a result, the region W3 on the upper surface of the substrate 10 is secured between the peripheral edge of the second opening W2 and the peripheral edge of the first opening W1, and the resin member 80 is continuously in contact with the region W3 and the inner wall of the cavity portion Y. Is possible. For example, assuming that the thickness of the substrate 10 is 0.5 mm and the diameter of the first opening W1 is 3 mm, the diameter of the second opening W2 is 1 mm. In this case, the regions W3 on the upper surface of the substrate 10 formed between the peripheral edge of the second opening W2 and the peripheral edge of the first opening W1 are provided on the right side and the left side of the second opening W2 in the cross-sectional view, respectively, and their lengths thereof. Both are 1 mm. That is, for example, in a cross-sectional view, (the length of the region W3 on the upper surface of the substrate 10 formed between the peripheral edge of the second opening W2 and the peripheral edge of the first opening W1) + the diameter of the second opening W2 + (the second). The length of the region W3 on the upper surface of the substrate 10 formed between the peripheral edge of the opening W2 and the peripheral edge of the first opening W1) = the diameter of the first opening W1.

The number of through holes Z may be one, but it is preferable that the number of through holes Z is a plurality so that the resin member 80 can be efficiently injected into the cavity Y of the wall portion 32.

(Multiple light sources 20)
The plurality of light sources 20 are arranged on the substrate 10. Specifically, the plurality of light sources 20 are arranged and mounted in a region where the light reflecting member 30 does not exist when the light emitting device 1 is viewed in a plan view. A conductive member 72, which will be described later, is exposed in the region, and the electrode of the light source 20 is electrically connected to the conductive member 72. The area can be called an opening or the like. The light source 20 can be mounted by, for example, a flip chip method, but can also be mounted by other methods such as wire bonding using wires.

The distance between the plurality of light sources 20, that is, the distance between the plurality of light sources 20 adjacent to each other is, for example, 5 mm or more and 25 mm or less, but is uniform (including the case where it can be regarded as uniform) in the vertical and horizontal directions in a plan view. It is preferable to have.

It is preferable that the plurality of light sources 20 can be driven independently of each other, and in particular, it is preferable that dimming control for each light source 20 (for example, local dimming or high dynamic range: HDR) is possible.

Each of the plurality of light sources 20 emits blue light, for example. However, in addition to blue, it may be yellow, green, or red.

Each light source 20 may have a light emitting element 22 such as a light emitting diode. The light emitting element 22 has, for example, a translucent substrate and a semiconductor layer laminated on the substrate. For the translucent substrate, for example, sapphire can be used. The semiconductor layer has, for example, an n-type semiconductor layer, an active layer, and a P-type semiconductor layer in this order from the substrate side. Examples of the semiconductor layer include ZnSe, nitride-based semiconductors (In _x Al _y Ga _1-x-y N, 0 ≦ X, 0 ≦ Y, X + Y ≦ 1), GaP, and the like, as well as GaAlAs and AlInGaP. Can be used. For example, an n-side electrode is connected to the n-type semiconductor layer, and for example, a P-side electrode is connected to the P-type semiconductor layer. Each light source 20 may have a reflective layer on the upper surface of the light emitting element 22 (the surface opposite to the surface close to the substrate on which the light emitting element is arranged). The reflective layer may be a metal film or a dielectric multilayer film.

Each light source 20 may have a sealing member 26. The sealing member 26 is a member that protects the light emitting element 22 from the external environment and optically controls the light output from the light emitting element 22. The sealing member 26 is arranged on the substrate 10 so as to cover the light emitting element 22. As the material of the sealing member 26, an epoxy resin, a silicone resin, a resin in which they are mixed, or a translucent material such as glass can be used. Of these, it is preferable to select a silicone resin in consideration of light resistance and ease of molding. The sealing member 26 includes a light diffusing material, a wavelength conversion material such as a phosphor that absorbs light from the light emitting element 22 and emits light having a wavelength different from the output light from the light emitting element 22, and the light emitting element 22. A colorant corresponding to the emission color can be contained. The sealing member 26 can be formed by, for example, compression molding or injection molding, as well as dropping or drawing. Further, by optimizing the viscosity of the material of the sealing member 26, it is possible to control the shape by the surface tension of the material itself. In the case of dropping or drawing, the sealing member 26 can be formed more easily without the need for a mold. The viscosity may be adjusted by using a material having a desired viscosity as the material of the sealing member 26, or may be adjusted by using the above-mentioned light diffusing material, wavelength converting material, or colorant.

It is preferable that each light source 20 has a butt wing type light distribution characteristic. In this way, the amount of light emitted in the direction directly above each light source 20 can be suppressed, and the light distribution of each light source 20 can be expanded. Therefore, the thickness of the light emitting device 1 can be reduced, especially when the translucent optical member 54 is provided so as to face the substrate 10. The butt-wing type light distribution characteristic refers to a light distribution characteristic in which the central portion becomes darker than the outer peripheral portion. As an example of the butt-wing type light distribution characteristic, when the optical axis L is 0 °, the light distribution has a light emission intensity distribution in which the light emission intensity becomes stronger at an angle where the absolute value of the light distribution angle is larger than 0 °. Examples thereof include characteristics and orientation characteristics having an emission intensity distribution in which the emission intensity is strongest in the vicinity of 45 ° to 90 °. The sealing member 26 can be provided so as to cover, for example, the light emitting element 22 and the reflective layer. If the sealing member 26 is provided in this way, the butt wing type light distribution characteristic can be easily realized.

(Light reflective member 30)
The light reflective member 30 is a member that is arranged on the substrate 10 and includes a wall portion 32 that surrounds a plurality of light sources 20. The light reflecting member 30 is sometimes called a reflector. The wall portion 32 may surround a plurality of light sources 20 one by one as in the present embodiment, or may surround two or more light sources 20 at a time. That is, the wall portion 32 has a plurality of surrounding portions X, and one light source 20 or two or more light sources 20 are arranged in each surrounding portion X. In this specification, the surrounding portion X may be referred to as a cell.

The wall portion 32 has a cavity portion Y having a first opening W1 on the substrate 10 side. Since the first opening W1 and the second opening W2 of the substrate 10 overlap each other, the through hole Z of the substrate 10 and the cavity Y of the wall portion 32 are connected, and the through hole Z of the substrate 10 is formed from the lower surface side of the substrate 10. Through this, the resin member 80 can be injected into the hollow portion Y of the wall portion 32. The inner diameter and shape of the first opening W1 are not limited as long as the resin member 80 can be injected into the cavity Y. However, the first opening W1 (outer edge of the first opening W1) is located outside the second opening W2 (outer edge of the second opening W2). As a result, the region W3 on the upper surface of the substrate 10 is secured between the peripheral edge of the second opening W2 and the peripheral edge of the first opening W1, and the resin member 80 is continuously in contact with the region W3 and the inner wall of the cavity portion Y. Is possible. The resin member 80 may be filled in the hollow portion Y of the wall portion 32, that is, all the spaces in the hollow portion Y of the wall portion 32 may be filled with the resin member 80 (in other words, the resin member 80 is completely filled). May be). However, it is preferable that the resin member 80 is injected into the cavity to the extent that it spreads in a planar shape (including a case where it can be regarded as a surface) from the peripheral edge of the second opening W2 in a plan view as in the present embodiment. In other words, it is not necessary to fill all the spaces in the cavity Y with the resin member 80, and the resin member 80 is provided in the cavity Y to the extent that the light reflecting member 30 is required and sufficiently fixed to the substrate 10. It may be injected into.

It is preferable that the light reflecting member 30 includes a bottom surface portion 322, and the bottom surface portion 322 is arranged on the substrate 10. As a result, the light reflective member 30 can be stably arranged on the substrate 10. The bottom surface portion 322 is preferably flat so that the light reflecting member 30 can be arranged more stably. No double-sided tape is interposed between the bottom surface portion 322 and the substrate 10.

The wall portion 32 is formed by, for example, bending the light reflecting member 30 so as to open outward. In other words, the wall portion 32 is formed by, for example, bending the light reflecting member 30 so as to be convex upward. The light-reflecting member 30 has a shape in which, for example, a bottom surface portion 322 and such a wall portion 32 are repeated. The hollow portion Y of the wall portion 32 is, for example, a recess formed on the lower side of the light reflecting member 30 by bending the light reflecting member 30. The first opening W1 of the cavity portion Y is an opening surface of such a recess, and is, for example, on the same plane as the lower surface of the bottom surface portion 322. That is, the opening surface of the first opening W1 and the lower surface of the bottom surface portion 322 have the same height with respect to the upper surface of the substrate 10.

The side surface of the wall portion 32 has a side surface portion 324 in which the tip portion 326 of the wall portion 32 is inclined so as to be farther from the light source 20 than the bottom surface portion 322 so that the light from the light source 20 is easily reflected upward. Is preferable. It is preferable that the side surface portion 324 has an inclined plane, or all of the side surface portions 324 are formed of the inclined plane so that the light from the light source 20 is easily reflected upward. The bottom surface portion 322 extends from one end of the side surface portion 324, and the tip portion 326 of the wall portion 32 extends from the other end.

The distance between the wall portions 32, that is, the distance between the wall portions 32 adjacent to each other is, for example, 5 mm or more and 25 or less, but is uniform (including the case where it can be regarded as uniform) in the vertical direction and the horizontal direction in a plan view. Is preferable.

The light-reflecting member 30 may be formed on a member formed by using a resin containing a reflective material made of metal oxide particles such as titanium oxide, aluminum oxide, or silicon oxide, or on the surface of a resin containing no reflective material. A member provided with a reflective material or the like can be used.

The thickness of the light reflecting member 30 (height from the upper surface of the substrate 10 to the upper end of the wall portion 32) is, for example, 100 to 300 μm. The thickness of the light reflecting member 30 is preferably uniform. Uniformity includes the case where it can be regarded as uniform.

(Resin member 80)
The resin member 80 is continuously in contact with the inner wall of the cavity Y and the region W3 on the upper surface of the substrate 10 provided between the peripheral edge of the second opening W2 and the peripheral edge of the first opening W1. In this way, the resin member 80 can fix the light reflective member 30 to the substrate 10 by adhering the inner wall of the cavity Y and the region W3 on the upper surface of the substrate 10 to each other. The resin member 80 can also serve as an anchor that suppresses the positional deviation due to heat shrinkage of the light reflecting member 30.

The resin member 80 can be a member that reflects the light emitted from the light source 20. In this way, the reflectance of the light reflective member 30 can be improved. On the other hand, the resin member 80 can also be a member that absorbs the light emitted from the light source 20. In this way, it is possible to reduce the light leakage to the adjacent non-lighting cell during local dimming.

For the resin member 80, for example, a thermoplastic resin or the like can be used.

According to the light emitting device 1 according to the first embodiment described above, a light emitting device having excellent light extraction efficiency can be obtained.

When the light-reflecting member is fixed to the substrate with the double-sided tape, the light emitted from the light source may be incident on the double-sided tape and absorbed. However, when the light-reflecting member 30 is fixed to the substrate 10 by the resin member 80 instead of using the double-sided tape, there is no possibility that the light is absorbed by the double-sided tape fixing the light-reflecting member 30. Therefore, a light emitting device having excellent light extraction efficiency can be obtained.

When fixing the light-reflecting member to the substrate with double-sided tape, if the distance between the light sources is narrow, the contact area between the light-reflecting member and the substrate becomes small, so the area to which the double-sided tape is attached is insufficient, and light reflection occurs. There is a risk that sufficient mounting strength of the sex member to the substrate cannot be secured. However, when the light-reflecting member 30 is fixed to the substrate 10 by the resin member 80 instead of using double-sided tape, the attachment strength of the light-reflecting member 30 to the substrate 10 even when the distance between the light sources is narrow. Can be sufficiently secured.

When the light-reflecting member 30 is fixed to the substrate 10 by the resin member 80 instead of using the double-sided tape, the thickness (height) of the light emitting device 1 is lost by the amount of the double-sided tape, and the light emitting device 1 is used. It can be made thinner. Therefore, it is possible to reduce the thickness of the light emitting device 1 and improve the optical characteristics. This is particularly effective when, for example, the light emitting device 1 is made into a unit.

When the member arranged above the light emitting device 1 is further supported by a support member such as a pin, and the wall portion 32 and the support member are integrally molded, the resin member 80 injected into the wall portion 32 is used. The strength of the light reflective member 30 can be improved.

Other configurations will be described below.

(Conductor wiring 72, 84)
A conductor wiring 72 for supplying electric power to the light source 20 can be arranged on at least the upper surface of the substrate 10. The conductor wiring 72 is a member that is electrically connected to the electrodes of the light source 20 and is for supplying an electric current (electric power) from the outside. The thickness of the conductor wiring 72 can be appropriately selected. The material of the conductor wiring 72 can be appropriately selected depending on the material used as the substrate 10, the manufacturing method, and the like. For example, when ceramics are used as the material of the substrate 10, it is preferable to use a material having a high melting point that can withstand the firing temperature of the ceramic sheet as the material of the conductor wiring 72, and for example, a material having a high melting point such as tungsten or molybdenum is used. It is preferable to use the metal of. Further, a conductor wiring 72 in which the surface of these metals is coated with another metal material such as nickel, gold, or silver by plating, sputtering, vapor deposition, or the like can also be used. When a glass epoxy resin is used as the material of the substrate 10, it is preferable to use a material that is easy to process as the material of the conductor wiring 72. The conductor wiring 72 can be formed on one side or both sides of the substrate 10 by a method such as thin film deposition, sputtering, or plating. A metal foil may be attached by pressing and used as the conductor wiring 72. The conductor wiring 72 can be patterned into a predetermined shape by masking using a printing method, photolithography, or the like and performing an etching process. The thickness of the conductor wiring 72 is preferably uniform. Including the case where it can be regarded as uniform. The light emitting device 1 may have a conductor wiring 84 on the lower surface of the substrate 10 in addition to the upper surface of the substrate 10.

(Reflective members 70, 82)
The reflective member 70 is an insulating member that reflects light or prevents light leakage or absorption to improve the light extraction efficiency of the light emitting device 1. The reflective member 70 is arranged so as to cover the upper surface of the substrate 10 and the upper surface of the conductor wiring 72. As the reflective member 70, for example, a member containing a white filler can be used. The material of the reflective member 70 is not particularly limited as long as it is insulating, but it is particularly preferable that the material absorbs less light from the light emitting element 22. Specifically, for example, epoxy, silicone, modified silicone, urethane resin, oxetane resin, acrylic, polycarbonate, polyimide, polyethylene terephthalate (PET), polyethylene naphthalate (PEN) and the like can be used as the material of the reflective member 70. .. The thickness of the reflective member 70 can be appropriately selected. The thickness of the reflective member 70 is preferably uniform. Including the case where it can be regarded as uniform. Further, the reflective member 82 may be arranged on the lower surface side of the substrate 10 so as to cover the lower surface of the conductor wiring 84.

(Joint member 74)
The light emitting device 1 may have a joining member 74. The joining member 74 is a member for fixing the light source 20 to the substrate 10 and / or the conductor wiring 72. Examples of the joining member 74 include an insulating resin and a conductive member. When the light source 20 is flip-chip mounted, a conductive member can be used as the joining member 74. Au-containing alloys, Ag-containing alloys, Pd-containing alloys, In-containing alloys, Pb-Pd-containing alloys, Au-Ga-containing alloys, Au-Sn-containing alloys, Sn-containing alloys, Sn-Cu-containing alloys, Sn-Cu-Ag-containing Alloys, Au-Ge-containing alloys, Au-Si-containing alloys, Al-containing alloys, Cu-In-containing alloys, mixtures of metals and flux, and the like are examples of the joining member 74. As the joining member 74, for example, a liquid, paste-like, or solid-like (sheet-like, block-like, powder-like, or wire-like) member can be used alone or in combination, and the composition, the shape of the substrate 10, and the like can be adjusted. Depending on the situation, it can be appropriately selected. When the step of electrically connecting the light source 20 to the conductor wiring 72 and the step of placing or fixing the light source 20 on the substrate 10 are divided into different steps instead of one step, the joining member 74 is used. May also use another wire to electrically connect the light source 20 and the conductor wiring 72.

Hereinafter, an example of a member arranged above the light emitting device will be described.

(Light diffusing member 52)
A light diffusing member 52 may be arranged above the light emitting device 1 on the light incident side of the wavelength conversion member 40. The light diffusing member 52 is a member that reduces luminance unevenness by diffusing the light radiated from a plurality of light sources 20. As the material for forming the light diffusing member 52, for example, a material having little light absorption with respect to visible light, such as a polycarbonate resin, a polystyrene resin, an acrylic resin, and a polyethylene resin, can be used. As the light diffusing member 52, for example, a member in which a material having a different refractive index is contained in a material used as a base material, or a member in which the surface shape of the material used as a base material is processed to scatter light can be used. .. The thickness of the light diffusing member 52 is preferably uniform. Including the case where it can be regarded as uniform.

(Optical member 54)
The optical member 54 can be arranged on the light incident side of the wavelength conversion member 40. The optical member 54 is a member that applies an optical action to the light from the light source 20. As the optical member 54, a translucent member such as a half mirror can be used. For the half mirror, for example, a member that reflects a part of the incident light and transmits a part of the incident light can be used. It is preferable that the reflectance of the half mirror is set to be lower in the oblique incident than in the vertical incident. That is, the half mirror has a high light reflectance for the light emitted parallel to the optical axis direction among the light emitted from each light source 20, and the radiation angle (parallel to the optical axis direction). In some cases, the radiation angle is assumed to be 0 degrees), and as the light reflectance increases, the light reflectance decreases (in other words, the amount of light transmitted through the half mirror increases). preferable. In this way, a homogeneous luminance distribution can be easily obtained when the half mirror is observed from the light emitting side. For example, a dielectric multilayer film can be used for the half mirror. By using a dielectric multilayer film, a reflective film with low light absorption can be obtained. In addition, the reflectance can be arbitrarily adjusted by the design of the film, and the reflectance can be controlled by the angle. For example, if the dielectric multilayer film is designed so that the reflectance is lower for light incident perpendicularly to the half mirror and light incident obliquely than this, it is perpendicular to the light extraction surface. It is possible to easily realize the characteristic that the reflectance with respect to the light incident on the light is high and the reflectance is lowered as the angle with respect to the light extraction surface is increased. The thickness of the optical member 54 is preferably uniform. Including the case where it can be regarded as uniform.

(Wavelength conversion member 40)
The wavelength conversion member 40 can be arranged so as to face the substrate 10 with the plurality of light sources 20 interposed therebetween. A member having a phosphor is used as the wavelength conversion member 40. Specifically, a member containing a phosphor in a base material such as polyethylene terephthalate (PET) or polycarbonate (PC), a member obtained by sintering a phosphor, or the like can be preferably used as the wavelength conversion member 40. Oxides, nitrides, sulfides, fluorides, or quantum dots can be used as the phosphor. Specific examples of the phosphor include yttrium aluminum garnet (YAG) -based phosphor activated with cerium, lutetium aluminum garnet (LAG) activated with cerium, and the like. The phosphor is excited by the light of the first color emitted by the light source 20 to emit the light of the second color. When the color of the light emitted by the light source 20 (first color) is blue, a substance that is excited by the blue light and emits yellow light as the second color light can be used as the phosphor. preferable. When the color of the light emitted by the light source 20 (first color) is yellow, the phosphor is excited by the yellow light to emit green light and / or red light as the second color light. It is preferable to use a substance that emits light. The thickness of the wavelength conversion member 40 is preferably uniform. Uniformity includes the case where it can be regarded as uniform.

(Prism sheets 56, 58)
Prism sheets 56 and 58 can be arranged on the light emitting side of the wavelength conversion member 40. The prism sheets 56 and 58 are members that improve the front luminance by changing the direction of the light incident in the oblique direction in the vertical direction. Polyethylene terephthalate or acrylic can be used as the material of the prism sheets 56 and 58. The thicknesses of the prism sheets 56 and 58 are preferably uniform. Including the case where it can be regarded as uniform.

(Polarizing sheet 60)
Further, the polarizing sheet 60 can be arranged. The polarizing sheet 60 is a sheet that changes the direction of the deflected light that cannot be transmitted through the liquid crystal panel and is reflected, and then rebounds toward the liquid crystal panel to make the polarized light transmitted through the liquid crystal panel, and the brightness can be improved. ..

[Light emitting device 2 according to the second embodiment]
FIG. 2A is a schematic plan view of the light emitting device according to the second embodiment. FIG. 2B is a view in which the tip end portion of the wall portion is hatched in FIG. 2A. FIG. 2C is a view in which the side surface portion of the wall portion is hatched in FIG. 2A. FIG. 2D is a view in which the bottom surface of the wall portion is hatched in FIG. 2A. FIG. 2E is a diagram showing the positional relationship between the through hole (second opening) of the substrate and the light source. In FIG. 2E, the light reflecting member 30 and the adhesive 80 are not shown. FIG. 2F is a diagram showing a cross section of 1F-1F in FIG. 2A. In FIG. 2F, a member arranged above the light emitting device 1 is also shown.

As shown in FIGS. 2A to 2F, the light emitting device 2 according to the second embodiment is a light emitting device according to the first embodiment in that the tip portion 326 of the wall portion 32 contacts a member arranged above the light emitting device. Different from 1.

According to the light emitting device 2 according to the second embodiment, in addition to obtaining the same effect as the light emitting device 1 according to the first embodiment, the space between the wall portion 32 (light emitting device 2) and the light diffusing member is provided. Since it can be eliminated, it is possible to reduce the leakage of light to the adjacent cell. Therefore, it is possible to prevent the contrast ratio from being lowered due to the leakage. For example, FIG. 5 shows an example in which one cell is viewed in a plan view while the light source is turned on when the tip of the wall portion is in contact with a member arranged above the light emitting device (in the case of the second embodiment). It is a photograph, and FIG. 6 shows an example in which one cell is viewed in a plan view while the light source is turned on when the tip of the wall portion does not contact the member arranged above the light emitting device (in the case of the comparative example). It is a photograph showing. In FIGS. 5 and 6, what appears white is light. The light of FIG. 5 has a quadrangular shape, and the light of FIG. 6 has a circular shape. As shown in FIGS. 5 and 6, when the tip portion 326 of the wall portion is in contact with the member arranged above the light emitting device 2, the shape of the light is the plan view shape of the cell as compared with the case where it is not in contact with the member. This indicates that the light of FIG. 5 has a smaller leakage of light to the adjacent cell than the light of FIG. According to the second embodiment, it is possible to provide a light emitting device having a good visibility by reducing leakage of light to adjacent cells and suppressing a decrease in contrast ratio.

Generally, it is said that the strength of the light-reflecting member 30 is insufficient from the viewpoint of supporting the member located above the light-reflecting member 30 with the light-reflecting member 30. Therefore, the member located above the light-reflecting member 30 is supported by separately providing a support member such as a pin. However, if such a support member is provided, the light-reflecting member 30 is provided. A space is formed between the surface and the member located above the space, and there is a risk that light leaks to the adjacent cell. However, in the second embodiment, the resin member 80 is injected into the cavity Y of the wall portion 32 of the light-reflecting member 30, and the resin member 80 serves as a reinforcing material, so that the light-reflecting member The strength of 30 can be increased. Therefore, the light-reflective member 30 can be provided with sufficient strength to support the member located above the light-reflective member 30, and the member 30 above the light-reflective member 30 can support the member. Therefore, it is not necessary to separately provide a support member such as a pin, and it is possible to prevent a space from being formed between the light-reflecting member 30 and the member located above the light-reflecting member 30. As described above, according to the second embodiment, since the member above the light reflecting member 30 can be mounted on the light reflecting member 30, it is possible to provide a light emitting device capable of achieving a high contrast ratio with good visibility. it can.

The tip portion 326 of the wall portion 32 is preferably flat. In this way, the member located above the light emitting device can be stably supported. The plane includes the case where it can be regarded as a plane. The tip portion 326 of the wall portion 32 may be formed in the shape of a support member such as the pin described above.

The light emitting device 2 according to the second embodiment has been described above, but since the other configurations are the same as those of the light emitting device 1 according to the first embodiment, the description thereof will be omitted.

[Manufacturing method of light emitting device 1 according to the first embodiment]
3A to 3D are schematic cross-sectional views illustrating a method of manufacturing the light emitting device according to the first embodiment. Hereinafter, the method for manufacturing the light emitting device 1 according to the first embodiment will be described with reference to FIGS. 3A to 3D.

First, as shown in FIG. 3A, a substrate 10 on which a plurality of light sources 20 are arranged is prepared. Here, the substrate 10 has a through hole Z that penetrates the substrate 10 in the vertical direction and has a second opening W2 located inside the first opening W1 on the upper surface of the substrate 10. A through hole Z may be formed in the substrate 10 after the substrate 10 is prepared, or a substrate 10 in which the through hole Z is formed in advance may be prepared.

Next, as shown in FIG. 3B, a light-reflecting member 30 having a wall portion 32 that surrounds one or two or more of the plurality of light sources 20 is arranged on the substrate 10. Here, the wall portion 32 has, for example, a hollow portion Y having a first opening W1 on the substrate 10 side in advance.

Next, as shown in FIG. 3C, the resin member 80 is injected into the hollow portion Y of the wall portion 32 from the lower surface side of the substrate 10 through the through hole Z with the lower surface of the substrate 10 facing upward, and the hollow portion Y is formed. The resin member 80 is in continuous contact with the inner wall and the region W3 on the upper surface of the substrate 10 provided between the peripheral edge of the second opening W2 and the peripheral edge of the first opening W1.

Next, as shown in FIG. 3D, the resin member 80 is cured (or solidified). As a result, the inner wall of the cavity Y and the region W3 on the upper surface of the substrate 10 provided between the peripheral edge of the second opening W2 and the peripheral edge of the first opening W1 are adhered by the resin member 80, and the light reflective member 30 is bonded. Is fixed to the substrate 10.

[Manufacturing method of light emitting device 2 according to the second embodiment]
4A to 4D are schematic cross-sectional views illustrating a method of manufacturing the light emitting device according to the second embodiment. Hereinafter, a method for manufacturing the light emitting device 2 according to the second embodiment will be described with reference to FIGS. 4A to 4D.

First, as shown in FIG. 4A, a substrate 10 on which a plurality of light sources 20 are arranged is prepared. Here, the substrate 10 has a through hole Z that penetrates the substrate 10 in the vertical direction and has a second opening W2 located inside the first opening W1 on the upper surface of the substrate 10. A through hole Z may be formed in the substrate 10 after the substrate 10 is prepared, or a substrate 10 in which the through hole Z is formed in advance may be prepared.

Next, as shown in FIG. 4B, a light-reflecting member 30 having a wall portion 32 that surrounds one or two or more of the plurality of light sources 20 is arranged on the substrate 10. Here, the wall portion 32 has, for example, a hollow portion Y having a first opening W1 on the substrate 10 side in advance.

Next, as shown in FIG. 4C, the resin member 80 is injected into the hollow portion Y of the wall portion 32 from the lower surface side of the substrate 10 through the through hole Z with the lower surface of the substrate 10 facing upward, and the hollow portion Y is formed. The resin member 80 is in continuous contact with the inner wall and the region W3 on the upper surface of the substrate 10 provided between the peripheral edge of the second opening W2 and the peripheral edge of the first opening W1.

Next, as shown in FIG. 4D, the resin member 80 is cured (or solidified). As a result, the inner wall of the cavity Y and the region W3 on the upper surface of the substrate 10 provided between the peripheral edge of the second opening W2 and the peripheral edge of the first opening W1 are adhered by the resin member 80, and the light reflective member 30 is bonded. Is fixed to the substrate 10.

The light emitting device according to the present disclosure can be preferably used as a direct type backlight device, particularly as a direct type backlight device used for applications such as TVs and monitors.

1, 2 Light emitting device 10 Substrate 20 Light source 22 Light emitting element 26 Sealing member 28 Reflective layer 30 Light reflective member 32 Wall part 322 Bottom part 324 Side part 326 Tip part 40 Wavelength conversion member 52 Light diffusion member 54 Optical members 56, 58 Prism sheet 60 Polarizing sheet 70, 82 Reflecting member 72, 84 Conductor wiring 74 Joining member 80 Resin member X Surrounding part Y Cavity part Z Through hole W1 First opening W2 Second opening W3 Periphery of second opening and peripheral edge of first opening Area on the upper surface of the substrate provided between

Claims (9)

With the board
With a plurality of light sources arranged on the substrate,
A light emitting device including a light-reflecting member arranged on the substrate and having a wall portion surrounding the plurality of light sources one by one or two or more.
The wall portion has a hollow portion having a first opening on the substrate side.
The substrate has a through hole that penetrates the substrate in the vertical direction and has a second opening located inside the first opening on the upper surface of the substrate.
A light emitting device in which a resin member is continuously in contact with an inner wall of the cavity and a region on the upper surface of the substrate provided between the peripheral edge of the second opening and the peripheral edge of the first opening. The light emitting device according to claim 1, wherein each of the through holes is connected to the cavity. The light emitting device according to claim 1 or 2, wherein the resin member extends in the plane direction from the peripheral edge of the second opening in a plan view. The light-reflecting member has a bottom surface and has a bottom surface.
The light emitting device according to any one of claims 1 to 3, wherein the bottom surface portion is arranged on the substrate. The light emitting device according to any one of claims 1 to 4, wherein the resin member is a member that reflects light emitted from the light source. The light emitting device according to any one of claims 1 to 4, wherein the resin member is a member that absorbs light emitted from the light source. The light emitting device according to any one of claims 1 to 6, wherein the tip end portion of the wall portion is in contact with a member arranged above the light emitting device. The light emitting device according to any one of claims 1 to 7, wherein the distance between the plurality of light sources is 5 mm or more and 25 mm or less. The light emitting device according to any one of claims 1 to 8, wherein the distance between the wall portions is 5 mm or more and 25 mm.

Images