JP7144683B2 - light emitting device - Google Patents

Description

The present invention relates to light emitting devices.

A backlight device has been proposed in which a plurality of light sources and a reflector having walls surrounding the light sources are arranged on a substrate (see paragraph 0032 of Patent Document 1).

WO2012/023459

A light-emitting device with high light extraction efficiency is desired.

The present invention includes the following one embodiment.

a substrate;
a plurality of light sources arranged on the substrate;
a plurality of light reflective members arranged on the substrate and provided with wall portions surrounding the plurality of light sources one by one or two or more each, the light emitting device comprising:
The light emitting device, wherein the two adjacent light reflecting members are connected by bonding the outer surfaces of the wall portions with an adhesive.

According to one embodiment of the present invention, a light emitting device with high light extraction efficiency is obtained.

1 is a schematic plan view of a light emitting device according to Embodiment 1. FIG. It is the figure which gave hatching to the side part of the wall part in FIG. 1A. It is the figure which gave hatching to the bottom face part of the wall part in FIG. 1A. It is a figure which shows the positional relationship of the through-hole (2nd opening) of a board|substrate, and a light source. FIG. 1B is a view showing a 1E-1E cross section in FIG. 1A. It is a figure explaining that four light reflecting members are connected. 3 is a schematic plan view of a light emitting device according to Embodiment 2. FIG. It is the figure which gave the hatching to the front-end|tip part of a wall part in FIG. 2A. It is the figure which gave hatching to the side part of the wall part in FIG. 2A. It is the figure which gave hatching to the bottom face part of the wall part in FIG. 2A. It is a figure which shows the positional relationship of the through-hole (2nd opening) of a board|substrate, and a light source. FIG. 2F is a diagram showing a 2F-2F cross section in FIG. 2A. 4A to 4C are schematic cross-sectional views illustrating a method for manufacturing the light emitting device according to Embodiment 1; 4A to 4C are schematic cross-sectional views illustrating a method for manufacturing the light emitting device according to Embodiment 1; 4A to 4C are schematic cross-sectional views illustrating a method for manufacturing the light emitting device according to Embodiment 1; 4A to 4C are schematic cross-sectional views illustrating a method for manufacturing the light emitting device according to Embodiment 1; 10A to 10C are schematic cross-sectional views illustrating a method for manufacturing a light emitting device according to Embodiment 2; 10A to 10C are schematic cross-sectional views illustrating a method for manufacturing a light emitting device according to Embodiment 2; 10A to 10C are schematic cross-sectional views illustrating a method for manufacturing a light emitting device according to Embodiment 2; 10A to 10C are schematic cross-sectional views illustrating a method for manufacturing a light emitting device according to Embodiment 2; FIG. 10 is a photograph showing an example of a plan view of one cell with a light source 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 Embodiment 2). FIG. 10 is a photograph showing an example of a plan view of one cell with the light source 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).

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. The following description may use terms that indicate specific directions or positions (eg, "upper", "lower" and other terms that include those terms). The terms use the relative orientations and positions in the referenced figures only for the sake of clarity. In addition, the sizes and positional relationships of components shown in the drawings may be exaggerated for the sake of clarity. It may not be reflected. Also, in order to facilitate understanding, illustration of each member may be omitted as appropriate.

[Light emitting device 1 according to Embodiment 1]
1A is a schematic plan view of a light emitting device according to Embodiment 1. FIG. FIG. 1B is a diagram in which the side surface portion 324 of the wall portion 32 is hatched in FIG. 1A. FIG. 1C is a diagram in which the bottom 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, illustration of the light reflecting member 30 and the adhesive 80 is omitted. FIG. 1E is a diagram showing a 1E-1E cross section in FIG. 1A. In FIG. 1E, members arranged above the light emitting device 1 are also illustrated. FIG. 1F is a diagram explaining that four light reflecting members are connected.

As shown in FIGS. 1A and 1F, the light-emitting device 1 according to Embodiment 1 includes a plurality of light sources 20 arranged on a substrate 10 and a plurality of light sources 20 arranged on the substrate 10, one or two. and a plurality of light reflecting members 30 each having wall portions 32 surrounding each other, wherein the outer surfaces of the wall portions 32 of the adjacent two light reflecting members 30 are adhered with an adhesive 80. It is a light-emitting device connected by bonding through. In the light-emitting device 1 according to Embodiment 1, four light-reflecting members 30a, 30b, 30c, and 30d are connected. placed respectively. One light reflecting member has nine surrounding portions X arranged in a matrix of 3 rows and 3 columns. A detailed description will be given below.

(Substrate 10)
The substrate 10 is a member for arranging the 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 bendable thin rigid substrate.

Examples of materials for the substrate 10 include resins such as ceramics, phenol resin, epoxy resin, polyimide resin, BT resin, polyphthalamide (PPA), and polyethylene terephthalate (PET). Examples of ceramics include alumina, mullite, forsterite, glass ceramics, nitrides (eg, AlN), carbides (eg, SiC), LTCC, and the like. When resin is used, glass fibers and inorganic fillers such as SiO ₂ , TiO ₂ , and Al ₂ O ₃ are mixed with resin to improve mechanical strength, reduce thermal expansion coefficient, and improve light reflectance. can also A metal substrate in which an insulating layer is formed on the surface of a metal member may be used.

The thickness of the substrate 10 can be selected appropriately.

The upper surface of the substrate 10 is preferably flat so that the light reflecting member 30 can be easily arranged. A plane includes cases 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, and circles.

(plurality of light sources 20)
A plurality of light sources 20 are arranged on the substrate 10 . Specifically, when the light emitting device 1 is viewed from above, the plurality of light sources 20 are arranged and mounted in an area where the light reflecting member 30 does not exist. A conductive member 72 is exposed in the region, and electrodes of the light source 20 are electrically connected to the conductive member 72 . This region can be called an opening in the sense that the reflecting member 70 covering the substrate 10 does not exist and the conductive member 72 is exposed. The light source 20 can be mounted, for example, by a flip-chip method, but can also be mounted by other methods such as wire bonding using wires.

The interval between the plurality of light sources 20, that is, the interval between the plurality of light sources 20 is, for example, 5 mm or more and 25 mm or less. The intervals between the plurality of light sources 20 are preferably uniform (including cases where they can be considered uniform) in the vertical direction and the horizontal direction in plan view. Adjacent light sources 20 possessed by two adjacent light reflecting members 30, for example, the light source 20 located on the leftmost side of the light reflecting member 30a and the light source located on the rightmost side of the light reflecting member 30b in plan view. The distance between the light sources 20 and 20 is the same as the distance between the light sources 20 and the distance between the other light sources 20 so that the shape of the boundary region between the two connected light reflecting members has substantially the same shape and the same reflection state as the shape of the other portion. It is preferably uniform (including cases where it can be regarded as uniform) in both directions and lateral directions.

It is preferable that the plurality of light sources 20 can be driven independently of each other, and it is particularly preferable that dimming control (for example, local dimming or high dynamic range: HDR) for each light source 20 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 semiconductor layers laminated on the substrate. Sapphire, for example, can be used for the translucent substrate. 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. The semiconductor layer includes, for example, ZnSe, a nitride-based semiconductor (In _x Al _y Ga _1-x-y N, 0≦X, 0≦Y, X+Y≦1), or GaP, GaAlAs, AlInGaP, or the like. can be used. For example, an n-side electrode is connected to the n-type semiconductor layer, and 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 . A sealing member 26 is arranged on the substrate 10 to cover the light emitting element 22 . As a material of the sealing member 26, an epoxy resin, a silicone resin, a mixed resin thereof, or a translucent material such as glass can be used. Among 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 converting material such as a phosphor that absorbs light from the light emitting element 22 and emits light with a wavelength different from that of the output light from the light emitting element 22, and a light emitting element 22. A colorant corresponding to the emission color can be included. The sealing member 26 can be formed by, for example, compression molding, injection molding, dripping, or drawing. Also, by optimizing the viscosity of the material of the sealing member 26, the shape can be controlled by the surface tension of the material itself. In the case of dripping or drawing, the sealing member 26 can be formed more easily without requiring 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-described light diffusing agent, wavelength converting agent, or coloring agent.

Each light source 20 preferably has a batwing-type light distribution characteristic. In this way, the amount of light emitted directly above each light source 20 can be suppressed, and the light distribution of each light source 20 can be widened. Therefore, the thickness of the light-emitting device 1 can be reduced particularly when the translucent optical member 54 is provided so as to face the substrate 10 . A batwing type light distribution characteristic is a light distribution characteristic in which the central portion is darker than the outer peripheral portion. As an example of the batwing 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 increases at angles where the absolute value of the light distribution angle is larger than 0°. Orientation characteristics having an emission intensity distribution in which the emission intensity becomes the strongest in the vicinity of 45° to 90°. The sealing member 26 can be provided, for example, so as to cover the light emitting element 22 and the reflective layer. By providing the sealing member 26 in this way, a batwing 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 has a wall portion 32 that surrounds the plurality of light sources 20 . The light reflecting member 30 is sometimes called a reflector. The wall portion 32 may surround the plurality of light sources 20 one by one as in the present embodiment, or may surround two or more of them. That is, the wall portion 32 has a plurality of enclosing portions X, and one light source 20 or two or more light sources 20 are arranged in each enclosing portion X. In this specification, the enclosure X is sometimes called a cell.

Two adjacent light reflecting members 30 are connected by bonding the outer surfaces of the wall portions 32 via an adhesive 80 . For example, the outer surface of the leftmost wall portion 32 of the light reflecting member 30 d is bonded to the outer surface of the rightmost wall portion 32 of the light reflecting member 30 c via an adhesive 80 . In this way, the two adjacent light reflecting members 30 are connected by bonding the outer surfaces of the wall portions via the adhesive 80, so that the two light reflecting members 30 that are connected are connected. The formation of gaps is suppressed. In addition, the shape of the boundary region between the two light reflecting members 30 that are connected has substantially the same shape and the same reflection state as the shape of the other portion. For example, although FIG. 1E shows wall portions 32 or portions thereof at three locations, right, center, and left, each wall portion 32 has substantially the same shape. Therefore, according to this embodiment, it is possible to integrate a plurality of light reflecting members while suppressing the influence on the optical characteristics of each light reflecting member 30 .

It is preferable that the outer surfaces of the wall portions 32 contact each other without an adhesive 80 interposed therebetween at the distal end portions of the wall portions 32 (see the partial enlarged view in FIG. 1E). In other words, it is preferable that the outer surfaces of the wall portions 32 are in contact with each other without forming a gap. Thereby, it is possible to suppress luminance unevenness caused by light entering the gap.

The light-reflective member 30 preferably comprises a bottom portion 322 , which is disposed on the substrate 10 . Thereby, the light reflecting member 30 can be stably arranged on the substrate 10 . The bottom surface portion 322 is preferably planar so that the light reflecting member 30 can be arranged more stably. Planar includes the case where it can be regarded as a plane. No double-sided tape is interposed between the bottom portion 322 and the substrate 10 .

The side surface of the wall portion 32 has a side portion 324 that is inclined so that the tip portion 326 of the wall portion 32 is further away from the light source 20 than the bottom portion 322 so that the light from the light source 20 is easily reflected upward. preferably. Preferably, the side portion 324 has an inclined plane, or the entire side portion 324 consists of an inclined plane so that the light from the light source 20 can be easily reflected upward. A bottom portion 322 extends from one end of the side portion 324, and a tip portion 326 of the wall portion 32 extends from the other end.

The interval between the wall portions 32, that is, the interval between adjacent wall portions 32 is, for example, 5 mm or more and 25 mm or less. It is preferable that the intervals between the wall portions 32 are uniform (including cases where they can be regarded as uniform) in the vertical direction and the horizontal direction in plan view. The adjacent wall portions 32 of the two adjacent light reflecting members 30, for example, the leftmost wall portion 32 of the light reflecting member 30a and the rightmost portion of the light reflecting member 30b in plan view. The interval between the wall portion 32 and the other wall portion 32 is such that the shape of the boundary region of the two connected light reflecting members has substantially the same shape and the same reflection state as the shape of the other portion. It is preferable that the spacing between the 2 is uniform (including the case where it can be regarded as uniform) in the vertical direction and the horizontal direction.

The light reflective member 30 includes, for example, a member molded using a resin containing a reflecting material made of metal oxide particles such as titanium oxide, aluminum oxide, and silicon oxide, and a resin that does not contain a reflecting material. A member or the like provided with a reflective material 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. It is preferable that the thickness of the light reflecting member 30 is uniform. Uniform includes the case where it can be regarded as uniform.

(Adhesive 80)
For example, a thermoplastic resin or the like can be used for the adhesive 80 .

The adhesive 80 can be a member that reflects the light emitted from the light source 20 . By doing so, the reflectance of the light reflecting member 30 can be improved. On the other hand, the adhesive 80 can also be a member that absorbs light emitted from the light source 20 . In this way, it is possible to reduce leakage light to adjacent non-lit cells during local dimming.

According to the light emitting device 1 according to Embodiment 1 described above, the light emitting device 1 with high light extraction efficiency can be obtained.

The size of each light reflecting member 30 is determined according to the equipment for manufacturing the light reflecting member 30 . Therefore, when a large-sized light-reflecting member 30 is required, such as when the light-emitting device is used for a large-sized monitor, it is necessary to connect and integrate a plurality of light-reflecting members 30 . . In this regard, if there is a gap between the combined light reflecting members 30, light enters the gap, which may cause luminance unevenness. However, in this embodiment, two adjacent light reflecting members 30 are connected by bonding the outer surfaces of the wall portions 32 via the adhesive 80 . Therefore, the formation of a gap between the two light reflecting members 30 that are connected is suppressed.

When a plurality of light-reflecting members are stuck together with double-sided tape, the thickness of the double-sided tape may cause the stuck part to have a shape different from that of other parts, resulting in a different reflection state, which may cause luminance unevenness. be. However, in this embodiment, two adjacent light reflective members 30 are connected by joining the outer surfaces of the wall portions 32 via the adhesive 80 instead of the double-sided tape. Therefore, it is possible to make the shape of the boundary region of the two connected light reflecting members 30 substantially the same shape and the same reflection state as the shape of the other portion. For example, although FIG. 1E shows wall portions 32 or portions thereof at three locations, right, center, and left, each wall portion 32 has substantially the same shape. Therefore, according to this embodiment, it is possible to integrate a plurality of light reflecting members 30 while suppressing the influence on the optical characteristics of each light reflecting member 30 . Therefore, it is possible to provide a light-emitting device in which a plurality of light-reflecting members 30 are integrated and in which luminance unevenness is suppressed.

Further description will be continued below.

The substrate 10 preferably has a through-hole Z penetrating through the substrate 10 in the vertical direction. This makes it possible to inject the adhesive 80 into the hollow portion Y of the wall portion 32 of the light reflecting member 30 through the through hole Z from the lower surface side of the substrate 10 . 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, shape, etc. of the through-hole Z are not limited as long as the adhesive 80 can be injected into the hollow portion Y. However, the second opening W2 (the outer edge of the second opening W2) is located inside the first opening W1 (the outer edge of the first opening W1). As a result, a 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 adhesive 80 is in continuous contact with the region W3 and the inner wall of the cavity portion Y. becomes possible. For example, if 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, 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 and left sides of the second opening W2 in cross-sectional view, respectively. Both have a height of 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.

Although the number of through-holes Z may be one, it is preferable that there are a plurality of through-holes Z so that the adhesive 80 can be efficiently injected into the hollow portion Y of the wall portion 32 . The through hole Z is preferably provided at the boundary between two adjacent light reflecting members 30 . For example, through holes Z1 to Z12 shown in FIG. 1D are examples of through holes provided at such boundaries. This makes it easier to inject the adhesive 80 into the hollow portion Y of the wall portion 32 in the boundary region. Therefore, it becomes easy to join the outer surfaces of the wall portions 32 of two adjacent light reflecting members 30 with the adhesive 80 .

The wall portion 32 preferably has a hollow 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 hollow portion Y of the wall portion 32 are connected, and the through hole Z of the substrate 10 can be opened from the lower surface side of the substrate 10. It becomes possible to inject the adhesive 80 into the hollow portion Y of the wall portion 32 through the hole. The inner diameter, shape, etc. of the first opening W1 are not limited as long as the adhesive 80 can be injected into the cavity Y. However, the first opening W1 (the outer edge of the first opening W1) is positioned outside the second opening W2 (the outer edge of the second opening W2). As a result, a 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 adhesive 80 is in continuous contact with the region W3 and the inner wall of the cavity portion Y. becomes possible. Note that the adhesive 80 may fill the hollow portion Y of the wall portion 32, that is, the entire space within the hollow portion Y of the wall portion 32 may be filled with the adhesive 80 (in other words, the adhesive 80 may be completely filled). may be used). However, as in the present embodiment, the adhesive 80 is preferably injected into the cavity to such an extent that it spreads from the periphery of the second opening W2 in a plane (including cases where it can be regarded as a plane) in plan view. In other words, it is not necessary to fill the entire space within the cavity Y with the adhesive 80, and the adhesive 80 is sufficient to secure the light reflecting member 30 to the substrate 10 as necessary. should be injected into

The wall portion 32 is formed, for example, by 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 protrude upward. The light reflecting member 30 has, for example, a shape in which a bottom 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 below the light reflecting member 30 by bending the light reflecting member 30 . The first opening W<b>1 of the cavity Y is the opening surface of such a recess, for example, in the same plane as the bottom 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 adhesive 80 is preferably in continuous contact with the inner wall of the cavity Y and the region W3 on the top 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 adhesive 80 adheres the inner wall of the cavity Y and the area W3 on the top surface of the substrate 10 to each other, so that the light reflecting member 30 can be fixed to the substrate 10 . Note that the adhesive 80 can also serve as an anchor that suppresses misalignment due to heat shrinkage of the light reflecting member 30 .

As described above, the wall portion 32 has the hollow portion Y having the first opening W1 on the substrate 10 side, and the substrate 10 penetrates the substrate 10 in the vertical direction and is positioned inside the first opening W1. A through hole Z having two openings W2 on the upper surface of the substrate 10, an inner wall of the hollow portion Y, and a 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. , the light-reflecting member 30 is fixed to the substrate 10 by the adhesive 80, so there is no possibility that the light is absorbed by the double-sided tape for fixing the reflecting member. . In addition, since there is no bright spot caused by the absorption of light by the double-faced tape, uneven brightness caused by this does not occur. In addition, even when the distance between the light sources 20 is narrow, sufficient mounting strength of the reflecting member to the substrate 10 can be ensured. Also. Since the double-sided tape is not used, the thickness (height) of the light-emitting device 1 can be reduced by the amount of the double-sided tape, and the thickness of the light-emitting device 1 can be reduced. Therefore, it is possible to reduce the thickness of the light emitting device 1 and improve its optical characteristics. This is particularly effective, for example, when the light emitting device 1 is used as a unit. In addition, when the member arranged above the light emitting device 1 is further supported by a support member such as a pin, and when the wall portion 32 and the support member are integrally molded, the adhesive injected into the wall portion 32 80 can improve the strength of the light reflecting member 30 .

Other configurations will be further described below.

(Conductor wiring 72, 84)
A conductor wiring 72 for supplying 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 supplies current (power) from the outside. The thickness of the conductor wiring 72 can be selected as appropriate. The material of the conductor wiring 72 can be appropriately selected according to the material used for the substrate 10, the manufacturing method, and the like. For example, when ceramics is 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. For example, tungsten and molybdenum have a high melting point. is preferably used. Furthermore, the conductor wiring 72 may be formed by coating the surface of these metals with other metal materials such as nickel, gold, and silver by plating, sputtering, vapor deposition, or the like. When 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 surface or both surfaces of the substrate 10 by a method such as vapor deposition, sputtering, or plating. A metal foil may be attached by pressing to form 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 etching. It is preferable that the thickness of the conductor wiring 72 is uniform. Uniform includes the case where it can be regarded as uniform. The light emitting device 1 may have conductor wiring 84 on the bottom surface of the substrate 10 in addition to the top surface of the substrate 10 .

(Reflection members 70, 82)
The reflecting member 70 is an insulating member that reflects light or prevents leakage or absorption of light to increase the light extraction efficiency of the light emitting device 1 . The reflective member 70 is arranged to cover the upper surface of the substrate 10 and the upper surface of the conductor wiring 72 . A member containing a white filler, for example, can be used for the reflecting member 70 . The material of the reflecting member 70 is not particularly limited as long as it is insulating, but it is particularly preferable to use a material that 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), etc. can be used as the material of the reflecting member 70 . . The thickness of the reflecting member 70 can be selected as appropriate. The thickness of the reflecting member 70 is preferably uniform. Uniform includes the case where it can be regarded as uniform. Further, the reflecting 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 .

(joining member 74)
The light emitting device 1 may have a bonding 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. A conductive member can be used as the joining member 74 when the light source 20 is flip-chip mounted. Au-containing alloy, Ag-containing alloy, Pd-containing alloy, In-containing alloy, Pb--Pd-containing alloy, Au--Ga-containing alloy, Au--Sn-containing alloy, Sn-containing alloy, Sn--Cu-containing alloy, Sn--Cu--Ag-containing Alloys, Au--Ge containing alloys, Au--Si containing alloys, Al-containing alloys, Cu--In containing alloys, mixtures of metals and fluxes, etc. are examples of the joining member 74. FIG. As the bonding member 74, for example, liquid, paste, or solid (sheet-like, block-like, powder-like, or wire-like) members can be used singly or in combination. It can be selected as appropriate. 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 not performed in one step but in separate steps, the bonding member 74 and the may also use another wire to electrically connect the light source 20 and the conductor trace 72 .

Examples of members arranged above the light emitting device will be described below.

(Light diffusion member 52)
A light diffusion member 52 may be arranged on the light incident side of the wavelength conversion member 40 above the light emitting device 1 . The light diffusion member 52 is a member that diffuses the light emitted from the plurality of light sources 20 to reduce uneven brightness. As a material for forming the light diffusing member 52, for example, a material that absorbs less visible light, such as polycarbonate resin, polystyrene resin, acrylic resin, or polyethylene resin, can be used. For the light diffusing member 52, for example, a member in which a material having a different refractive index is contained in the base material, or a member that scatters light by processing the surface shape of the base material can be used. . The thickness of the light diffusion member 52 is preferably uniform. Uniform includes the case where it can be regarded as uniform.

When the light diffusing member 52 is arranged above or on the top surface of the light reflecting member 30, regardless of whether the light diffusing member 52 is supported by a support member such as a pin, the light scattered by the light diffusing member 52 is Light (that is, returned light) hits the light reflecting member 30, and the wall portion 32 (side surface portion 324), tip portion 326, and the like of the light reflecting member 30 may become bright spots. However, according to this embodiment, two adjacent light reflective members 30 are connected by bonding the outer surfaces of the wall portions 32 via the adhesive 80 instead of the double-sided tape. Therefore, it is possible to make the shape of the tip of the wall portion 52 (preferably, in addition to this, the inclination angle of the side surface portion 324) the same (including the case where it can be regarded as the same) among the plurality of cells. . Therefore, according to the present embodiment, even when the light diffusing member 52 is arranged above or on the upper surface of the light reflecting member 30, the influence on the optical characteristics of each light reflecting member 30 is suppressed, and a plurality of of light reflecting members 30 can be integrated. Therefore, even when the light diffusing member 52 is arranged above or on the upper surface of the light reflecting member 30, a light emitting device in which a plurality of light reflecting members 30 are integrated and luminance unevenness is suppressed is provided. be able to.

(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 optical effects to the light from the light source 20 . A translucent member such as a half mirror can be used for the optical member 54 . For the half mirror, for example, a member that partially reflects and partially transmits incident light can be used. The reflectance of the half mirror is preferably set to be lower for oblique incidence than for vertical incidence. That is, the half mirror has a high light reflectance for light emitted from each light source 20 parallel to the optical axis direction, and has a high emission angle (parallel to the optical axis direction). In some cases, the radiation angle is assumed to be 0 degrees. preferable. In this way, a homogeneous luminance distribution can be easily obtained when the half mirror is observed from the light emitting side. A dielectric multilayer film, for example, can be used for the half mirror. By using a dielectric multilayer film, a reflective film with little light absorption can be obtained. In addition, the reflectance can be arbitrarily adjusted by film design, and the reflectance can be controlled by the angle. For example, if the dielectric multilayer film is designed so that the reflectance of light incident obliquely to the half mirror is lower than that of light incident perpendicular to the half mirror, It is possible to easily realize a characteristic that the reflectance for light incident on the light-extracting surface is high, and the reflectance decreases as the angle to the light extraction surface increases. The thickness of the optical member 54 is preferably uniform. Uniform includes 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 containing a phosphor is used for the wavelength conversion member 40 . Specifically, a member containing a phosphor in a base material such as polyethylene terephthalate (PET) or polycarbonate (PC), or a member obtained by sintering a phosphor can be preferably used as the wavelength conversion member 40 . Phosphors can be oxides, nitrides, sulfides, fluorides, or quantum dots. Specific examples of phosphors include cerium-activated yttrium-aluminum-garnet (YAG)-based phosphors and cerium-activated lutetium-aluminum-garnet (LAG). The phosphor is excited by the light of the first color emitted by the light source 20 and emits the light of the second color. When the color of light (first color) emitted by the light source 20 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. Further, when the color (first color) of the light emitted by the light source 20 is yellow, the phosphor is excited by the yellow light and emits green light and/or red light as light of the second color. It is preferred to use a substance that emits as . It is preferable that the thickness of the wavelength conversion member 40 is uniform. Uniform 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 exit side of the wavelength conversion member 40 . The prism sheets 56 and 58 are members for improving the front luminance by changing the direction of light incident in an oblique direction to the vertical direction. Polyethylene terephthalate or acryl can be used as the material of the prism sheets 56 and 58 . It is preferable that the prism sheets 56 and 58 have a uniform thickness. Uniform includes the case where it can be regarded as uniform.

(Polarizing sheet 60)
Furthermore, a polarizing sheet 60 can also be arranged. The polarizing sheet 60 is a sheet that changes the direction of the polarized light that has been reflected without being able to pass through the liquid crystal panel, bounces it back toward the liquid crystal panel, and converts it into polarized light that passes through the liquid crystal panel, thereby improving the luminance. .

[Light-emitting device 2 according to Embodiment 2]
2A is a schematic plan view of a light emitting device according to Embodiment 2. FIG. FIG. 2B is a diagram in which the tip of the wall portion in FIG. 2A is hatched. FIG. 2C is a diagram in which the side surface of the wall is hatched in FIG. 2A. FIG. 2D is a diagram in which the bottom surface of the wall 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, illustration of the light reflecting member 30 and the adhesive 80 is omitted. FIG. 2F is a view showing a 1F-1F section in FIG. 2A. In FIG. 2F, members arranged above the light emitting device 1 are also illustrated.

As shown in FIGS. 2A to 2F, in the light-emitting device 2 according to Embodiment 2, the distal end portion 326 of the wall portion 32 is attached to a member (specifically, the light diffusion member 52) arranged above the light-emitting device 2. It is different from the light emitting device 1 according to Embodiment 1 in that it is in contact.

According to the light-emitting device 2 according to Embodiment 2, in addition to obtaining the same effect as the light-emitting device 1 according to Embodiment 1, the space between the wall portion 32 (light-emitting device 2) and the light diffusion member 52 is reduced. can be eliminated, light leakage to adjacent cells X can be reduced. Therefore, it is possible to prevent the contrast ratio from lowering due to the leakage. For example, FIG. 5 shows an example of a plan view of one cell 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 Embodiment 2). FIG. 6 is a photograph, and FIG. 6 is an example of a plan view of one cell while the light source is turned on when the tip of the wall portion does not come into contact with the member arranged above the light emitting device (in the case of the comparative example). is a photograph showing In FIGS. 5 and 6, what looks white is light. The light in FIG. 5 has a square shape and the light in 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 a member arranged above the light emitting device 2, the shape of the light is the shape of the cell in plan view, compared to the case where the tip portion 326 is not in contact. , which indicates that the light in FIG. 5 has less leakage of light to adjacent cells than the light in FIG. According to the second embodiment, it is possible to provide a light-emitting device with good visibility in which deterioration of the contrast ratio is suppressed by reducing leakage of light to adjacent cells.

In general, the strength of the light reflecting member 30 is considered to be insufficient from the viewpoint of supporting a member located above the light reflecting member 30 with the light reflecting member 30 . For this reason, the member located above the light reflecting member 30 is supported by a separately provided supporting member such as a pin. A space is formed between the cell and the member positioned above it, and there is a risk that light may leak to an adjacent cell. However, in Embodiment 2, the adhesive 80 is injected into the hollow portion Y of the wall portion 32 of the light reflective member 30, and the adhesive 80 serves as a reinforcing material, whereby the light reflective member 30 strength can be increased. Therefore, the light reflecting member 30 can be provided with sufficient strength to support the members located above the light reflecting member 30, and the light reflecting member 30 can support the members located thereabove. Therefore, it is possible to eliminate the need to separately provide a support member such as a pin, thereby preventing the formation of a space between the light reflecting member 30 and the member positioned thereabove. As described above, according to the second embodiment, since it is possible to mount a member above the light reflecting member 30, it is possible to provide a light emitting device 2 that can realize a high contrast ratio with good visibility. can be done.

The distal end portion 326 of the wall portion 32 is preferably planar. In this way, the member located above the light emitting device 2 can be stably supported. Planar includes the case where it can be regarded as a plane. Note that the tip portion 326 of the wall portion 32 may be formed in the shape of the support member such as the pin described above.

Although the light emitting device 2 according to Embodiment 2 has been described above, the rest of the configuration is the same as that of the light emitting device 1 according to Embodiment 1, so description thereof will be omitted.

[Manufacturing Method of Light Emitting Device 1 According to Embodiment 1]
3A to 3D are schematic cross-sectional views explaining the method for manufacturing the light emitting device according to Embodiment 1. FIG. Hereinafter, a method for manufacturing the light emitting device 1 according to Embodiment 1 will be described with reference to FIGS. 3A to 3D. In FIGS. 3B and 3C, the boundary between two adjacent light reflecting members 30 is marked with a dotted line so as to facilitate understanding of how the plurality of light reflecting members 30 are connected.

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 vertically penetrates the substrate 10 and has a second opening W2 located inside the first opening W1 on the upper surface of the substrate 10 . The through hole Z may be formed in the substrate 10 after the substrate 10 is prepared, or the substrate 10 having the through hole Z formed in advance may be prepared.

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

Next, as shown in FIG. 3C, with the bottom surface of the substrate 10 facing upward, an adhesive 80 is injected from the bottom surface side of the substrate 10 through the through hole Z into the cavity Y of the wall portion 32. The adhesive 80 is brought into 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 adhesive 80 is cured (or solidified). As a result, the inner wall of the hollow portion 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 bonded with the adhesive 80, and the light reflecting member 30 is fixed to the substrate 10 .

[Manufacturing method of light-emitting device 2 according to Embodiment 2]
4A to 4D are schematic cross-sectional views illustrating the method for manufacturing the light emitting device according to Embodiment 2. FIG. Hereinafter, a method for manufacturing the light emitting device 2 according to Embodiment 2 will be described with reference to FIGS. 4A to 4D. In FIGS. 4B and 4C, the boundary between two adjacent light reflecting members 30 is marked with a dotted line to facilitate understanding of how the plurality of light reflecting members 30 are connected.

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 vertically penetrates the substrate 10 and has a second opening W2 located inside the first opening W1 on the upper surface of the substrate 10 . The through hole Z may be formed in the substrate 10 after the substrate 10 is prepared, or the substrate 10 having the through hole Z formed in advance may be prepared.

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

Next, as shown in FIG. 4C, with the lower surface of the substrate 10 facing upward, an adhesive 80 is injected from the lower surface side of the substrate 10 through the through hole Z into the hollow portion Y of the wall portion 32. The adhesive 80 is brought into 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 adhesive 80 is cured (or solidified). As a result, the inner wall of the hollow portion 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 bonded with the adhesive 80, and the light reflecting member 30 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, 30a, 30b, 30c, 30d Light reflecting member 32 Wall portion 322 Bottom portion 324 Side portion 326 Tip portion 40 Wavelength conversion member 52 Light Diffusing member 54 Optical members 56, 58 Prism sheet 60 Polarizing sheets 70, 82 Reflecting members 72, 84 Conductor wiring 74 Joining member 80 Adhesive X Surrounding portion Y Cavity portion Z Through hole W1 First opening W2 Second opening W3 Second opening A region of the upper surface of the substrate provided between the peripheral edge of the and the peripheral edge of the first opening

Claims (11)

a substrate;
a plurality of light sources arranged on the substrate;
a plurality of light reflective members arranged on the substrate and provided with wall portions surrounding the plurality of light sources one by one or two or more each, the light emitting device comprising:
The two adjacent light reflective members are connected by bonding the outer surfaces of the wall portions with an adhesive ,
The light source has a light emitting element and a sealing member arranged on the substrate so as to cover the light emitting element,
The sealing member is arranged on the substrate at a distance from the light reflecting member,
The wall portion has a hollow portion having a first opening on the substrate side,
the substrate has a through hole vertically penetrating the substrate and having a second opening in the upper surface of the substrate;
The second opening is a light emitting device located inside the first opening . a substrate;
a plurality of light sources arranged on the substrate;
a plurality of light reflective members arranged on the substrate and provided with wall portions surrounding the plurality of light sources one by one or two or more each, the light emitting device comprising:
the two adjacent light reflecting members are connected by bonding the outer surfaces of the wall portions together via an adhesive, and are bonded to the substrate by the adhesive;
The wall portion has a hollow portion having a first opening on the substrate side,
the substrate has a through hole vertically penetrating the substrate and having a second opening in the upper surface of the substrate;
The second opening is a light emitting device located inside the first opening. a substrate;
a plurality of light sources arranged on the substrate;
a plurality of light reflective members arranged on the substrate and provided with wall portions surrounding the plurality of light sources one by one or two or more each, the light emitting device comprising:
The two adjacent light reflective members are connected by bonding the outer surfaces of the wall portions with an adhesive,
The light-emitting device in which the outer surfaces of the wall portions are in contact with each other without the adhesive interposed therebetween at the distal end portion of the wall portion. 4. The light emitting device according to claim 3, wherein the two adjacent light reflecting members are adhered to the substrate with the adhesive. The light source has a light emitting element and a sealing member arranged on the substrate so as to cover the light emitting element,
5. The light emitting device according to claim 3, wherein the sealing member is arranged on the substrate apart from the light reflecting member. The wall portion has a hollow portion having a first opening on the substrate side,
6. The cavity according to any one of claims 3 to 5 , wherein in a boundary region between the two light reflecting members that are connected, the cavity is formed by joining the outer surfaces of the walls with an adhesive. A light emitting device as described. the substrate has a through hole vertically penetrating the substrate and having a second opening in the upper surface of the substrate;
7. The light emitting device according to claim 6 , wherein said second opening is positioned inside said first opening. The light reflective member has a bottom portion,
The light emitting device according to any one of claims 1 to 7, wherein the bottom portion is arranged on the substrate. The light emitting device according to any one of claims 1 to 8 , wherein the adhesive is a member that reflects light emitted from the light source. The light emitting device according to any one of claims 1 to 8 , wherein the adhesive is a member that absorbs light emitted from the light source. The light emitting device according to any one of claims 1 to 10, wherein the distance between the plurality of light sources is 5 mm or more and 25 mm or less.

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