JP2017073549A - Light-emitting device, integrated light-emitting device, and light-emitting module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light-emitting device that enables wide light distribution without using a secondary lens.SOLUTION: A light-emitting device includes: a base 101 including a conductive wiring 102; a light-emitting element 105 mounted on the base 101 and having a light reflective film 106 on an upper surface of the light-emitting element; and a sealing member 108 covering the light-emitting element 105. A ratio (H/W) of a height (H) of the sealing member 108 to a width (W) thereof is less than 0.5.SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to a light emitting device, an integrated light emitting device, and a light emitting module.

In recent years, various electronic components have been proposed and put into practical use, and the performance required for them has been increased. In particular, electronic components are required to maintain long-term performance even under severe usage environments. Such a requirement is no exception for a light emitting device using a semiconductor light emitting element such as a light emitting diode (LED). That is, in the general lighting field and the in-vehicle lighting field, the performance required for the light emitting device is increasing day by day, and further higher output (high luminance) and higher reliability are required. Furthermore, the light emitting device is also required to be supplied at a low price while maintaining these high performances.
For backlights and general lighting fixtures used in liquid crystal televisions, the importance of design is important, and there is a strong demand for thinning.

  For example, Patent Document 1 discloses a light-emitting device that realizes a thinner backlight by providing a reflector on the upper surface of a light-emitting element flip-chip mounted on a submount.

JP 2008-4948 A

  According to the light emitting device of Patent Document 1, although a light emitting device with a wide light distribution can be realized, a light emitting device capable of realizing a wider light distribution has been demanded as the backlight is made thinner.

  Embodiments according to the present invention have been made in view of such circumstances, and provide a light emitting device capable of wide light distribution without using a secondary lens.

  The light-emitting device according to the present embodiment includes a base body having conductor wiring, a light-emitting element that is mounted on the base body and emits first light, a light reflection film provided on an upper surface of the light-emitting element, and the light-emitting element And a sealing member that covers the light reflecting film, and the ratio (H / W) of the height (H) to the width (W) of the sealing member is smaller than 0.5.

  According to the embodiment of the present invention, wide light distribution is possible without using a secondary lens.

It is sectional drawing which shows an example of the light-emitting device of this embodiment. It is a figure which shows the angle dependence characteristic of the light transmittance of the light reflection film of this embodiment. It is a figure which shows the relationship between the wavelength range of the light reflection film of the light-emitting device of this embodiment, and the light emission wavelength of a light emitting element. It is a light distribution characteristic figure of the light-emitting device of this embodiment. It is a light distribution characteristic view of the light-emitting device of the comparative example using a secondary lens. The light emitting device No. 1 according to the present embodiment. It is a figure which shows the light distribution characteristic of 1. FIG. The light emitting device No. 1 according to the present embodiment. It is a figure which shows the light distribution characteristic of 2. The light emitting device No. 1 according to the present embodiment. FIG. The light emitting device No. 1 according to the present embodiment. FIG. The light emitting device No. 1 according to the present embodiment. 5 is a diagram illustrating a light distribution characteristic of No. 5. FIG. The light emitting device No. 1 according to the present embodiment. 6 is a diagram illustrating light distribution characteristics of FIG. The light emitting device No. 1 according to the present embodiment. 7 is a diagram showing the light distribution characteristics of FIG. The light emitting device No. 1 according to the present embodiment. 8 is a diagram illustrating light distribution characteristics of FIG. The light emitting device No. 1 according to the present embodiment. FIG. It is sectional drawing which shows an example of the light emitting module of this embodiment. It is a figure which shows an example of a light reflection board. It is a figure which shows the luminance distribution characteristic of the light emitting module which has not arrange | positioned the light reflection member. It is a figure which shows the luminance distribution characteristic of the light emitting module of Example 2 which has arrange | positioned the light reflection member.

Hereinafter, embodiments of the present invention will be described with reference to the drawings as appropriate. However, the light-emitting device described below is for embodying the technical idea, and the present invention is not limited to the following unless otherwise specified. In addition, the contents described in one embodiment and example can be applied to other embodiments and examples.
Further, in the following description, the same name and reference sign indicate the same or the same members, and detailed description will be omitted as appropriate. Furthermore, each element constituting the present invention may be configured such that a plurality of elements are constituted by the same member and the plurality of elements are shared by one member, and conversely, the function of one member is constituted by a plurality of members. It can also be realized by sharing.

[First Embodiment]
FIG. 1 is a schematic structural diagram illustrating an example of a light emitting device according to the first embodiment.
As shown in FIG. 1, the present embodiment includes a base body 101 having a conductor wiring 102 and a light emitting element 105 placed on the base body 101. The light emitting element 105 is flip-chip mounted via a connection member 103 so as to straddle at least a pair of conductor wirings 102 provided on the surface of the base 101. A light reflecting film 106 is formed on the light extraction surface side of the light emitting element 105 (the upper surface of the light emitting element 105). An insulating member 104 may be provided on at least a part of the conductor wiring, and a region of the upper surface of the conductor wiring 102 that is electrically connected to the light emitting element 105 is exposed from the insulating member 104.

The light transmittance of the light reflecting film 106 has an incident angle dependency with respect to the light incident from the light emitting element 105. FIG. 2 shows the incident angle dependence characteristics of the light transmittance of the light reflecting film 106 of the present embodiment. The light reflecting film 106 hardly transmits light in the vertical direction with respect to the upper surface of the light emitting element 105, but the amount of transmitted light increases as the angle increases from the vertical direction. Specifically, the transmittance is about 10% when the incident angle is within a range of −30 ° to 30 °, whereas the transmittance gradually increases when the incident angle is smaller than −30 ° − When the angle is smaller than 50 °, the transmittance is rapidly increased. Similarly, when the incident angle is larger than 30 °, the transmittance is gradually increased. When the incident angle is larger than 50 °, the transmittance is rapidly increased. That is, the light transmittance of the light reflecting film with respect to the first light increases as the absolute value of the incident angle increases. By using such a film, a batwing light distribution characteristic as shown in FIG. 4 can be realized.
Here, the batwing light distribution characteristic means that the first region having a light distribution angle of 90 ° or less has a first peak with an intensity greater than the intensity when the light distribution angle is 90 °, and the light distribution angle is 90 °. The light distribution characteristic is such that the second region has a second peak with an intensity greater than the intensity when the light distribution angle is 90 °.

  The light emitting element 105 is covered with a translucent sealing member 108. The sealing member 108 is a member disposed on the base so as to cover the light emitting element 105 in order to protect the light emitting element 105 from the external environment and optically control light output from the light emitting element. The sealing member 108 is formed in a substantially dome shape, and includes the light emitting element 105 with the light reflecting film 106, the surface of the conductor wiring 102 around the light emitting element 105, and the light emitting element 105 and the conductor wiring 102 including the connection member 103. Cover the joint. That is, the upper surface and the side surface of the reflective film 106 are in contact with the sealing member 108, and the side surface of the light emitting element 105 that is not covered with the reflective film 106 is also in contact with the sealing member 108. Note that this joint may be covered with an underfill separately from the sealing member 108. In this case, the sealing member 108 is formed so as to cover the upper surface of the underfill and the light emitting element. In the present embodiment, the light emitting element 105 is directly covered with the sealing member 108.

The sealing member 108 is preferably formed so that its outer shape is circular or elliptical when viewed from above, and the height (H) of the sealing member in the optical axis direction is the diameter of the sealing member when viewed from above. It is formed with a ratio smaller than 0.5 of (width: W). In the case of an ellipse, a major axis and a minor axis exist in the width, but in this specification, the minor axis is defined as a sealing diameter (W). The surface of the sealing member 108 is formed with a convex curved surface.
With such a structure, light emitted from the light-emitting element 105 is refracted at the interface between the sealing member 108 and the air, so that a wider light distribution can be achieved.
Here, the height (H) of the sealing member refers to the height from the mounting surface of the light emitting element 105 as shown in FIG. The width (W) of the sealing member refers to the diameter as described above when the shape of the bottom surface of the sealing member is circular, and in the case of other shapes, the width is the shortest. Shall be pointed to.

  FIG. 4 shows an example of changes in light distribution characteristics depending on the presence or absence of the sealing member 108. The light distribution characteristics of the light-emitting device 100 of Embodiment 1 are indicated by solid lines in FIG. Further, the light distribution characteristics of the light-emitting device produced in the same manner as in Embodiment 1 except that the sealing member 108 is not formed are indicated by dotted lines. As shown in FIG. 4, in the light emitting device of the first embodiment, the first peak moves in the direction in which the light distribution angle becomes smaller and the light distribution angle becomes larger than in the light emitting device in which the sealing member 108 is not formed. The second peak moves to a wider light distribution.

  As described above, by using both the light reflecting film 106 and the sealing member 108, desired light distribution characteristics can be obtained without using a secondary lens. That is, while the light reflection film 106 is formed to reduce the luminance directly above the light emitting element 105, the sealing member 108 can specialize in widening the light distribution from the light emitting element 105. A significant reduction in size of the sealing member having a function can be realized. In other words, conventionally, since it has been necessary to reduce the luminance directly above the light emitting element and widen the light distribution with only the sealing member, it has been necessary to increase the height of the sealing member. On the other hand, in the light emitting device of the present embodiment, the batwing light distribution characteristic is realized by providing the light reflecting film 106 that reduces the luminance directly above the light emitting element 105, and the function of the sealing member 108 is more widely distributed. Because of its specialization in miniaturization, it was possible to reduce the size. Thereby, as will be described later, a thin backlight module (light emitting module) with improved luminance unevenness can be realized. FIG. 5 shows a light distribution characteristic when a secondary lens is used as a comparative example. According to the light emitting device of the present embodiment, even if a secondary lens is not used, it is possible to obtain light distribution characteristics equivalent to the case where a secondary lens is used.

これらの実験結果より、封止部材の径の違いによる配光特性の差は小さく、封止部材の高さ（Ｈ）と封止部材の径（幅：Ｗ）の比率が配向特性に影響を与えるものと考えられる。
そして、図６のグラフから、より広配光とするためには、封止部材の幅（Ｗ）に対する高さ（Ｈ）の比（Ｈ／Ｗ）を０．３以下とすることがより好ましいことがわかる。 Here, nine light emitting devices were created by changing the height (H) in the optical axis direction of the sealing member 108 and the diameter (width: W) of the sealing member in a top view, and the light distribution characteristics were confirmed. The results are shown in FIG. The light emitting element is a blue LED having a square shape with a side of 600 mμm in a plan view and a thickness of 150 μm. Further, the light reflecting film 106 has an 11-layer structure by repeating a SiO ₂ layer (82 nm) and a ZrO ₂ layer (54 nm).
Nine light emitting devices No. 1-No. Table 1 shows the ratio between the height (H) of the sealing member and the diameter (width: W) of the sealing member in FIG. Light-emitting device No. 1-No. The light distribution characteristics of 9 are shown in FIGS. 6A to 6I.

From these experimental results, the difference in light distribution characteristics due to the difference in the diameter of the sealing member is small, and the ratio between the height (H) of the sealing member and the diameter (width: W) of the sealing member has an influence on the orientation characteristics. It is thought to give.
From the graph of FIG. 6, in order to obtain a wider light distribution, the ratio (H / W) of the height (H) to the width (W) of the sealing member is more preferably 0.3 or less. I understand that.

Hereinafter, the preferable form of the light-emitting device 100 which concerns on this Embodiment is demonstrated.
(Substrate 101)
The base 101 is a member on which the light emitting element 105 is placed. The substrate 101 has a conductor wiring 102 for supplying power to the light emitting element 105 on the surface thereof.
Examples of the material of the substrate 101 include resins such as ceramics, phenol resin, epoxy resin, polyimide resin, BT resin, polyphthalamide (PPA), and polyethylene terephthalate (PET). Among these, it is preferable to select a resin as a material from the viewpoint of low cost and ease of molding. The thickness of the substrate can be selected as appropriate, and may be a flexible substrate or a rigid substrate that can be manufactured by a roll-to-roll method. The rigid substrate may be a thin rigid substrate that can be bent.

  In order to obtain a light emitting device having excellent heat resistance and light resistance, it is preferable to select ceramics as the material of the substrate 101. Examples of ceramics include alumina, mullite, forsterite, glass ceramics, nitrides (for example, AlN), carbides (for example, SiC), and the like. Among these, ceramics made of alumina or mainly composed of alumina is preferable.

In the case of using a resin material constituting the substrate 101, and a glass _fiber, an inorganic filler such as _{SiO 2, TiO 2, Al 2} O 3 were mixed in a resin, the improvement of mechanical strength, reduction in coefficient of thermal expansion In addition, the light reflectance can be improved. The substrate 101 may be any substrate as long as the pair of conductor wirings 102 can be insulated and separated, and a so-called metal substrate in which an insulating layer is formed on a metal member may be used.

(Conductor wiring 102)
The conductor wiring 102 is a member that is electrically connected to the electrode of the light emitting element 105 and supplies a current (electric power) from the outside. That is, it plays a role as an electrode for energizing from the outside or a part thereof. Usually, it is formed to be separated into at least two of positive and negative.

  The conductor wiring 102 is formed on at least the upper surface of the base body on which the light emitting element 105 is placed. The material of the conductor wiring 102 can be appropriately selected depending on the material used for the substrate 101, the manufacturing method, and the like. For example, when ceramic is used as the material of the substrate 101, the material of the conductor wiring 102 is preferably a material having a high melting point that can withstand the firing temperature of the ceramic sheet. For example, a high melting point metal such as tungsten or molybdenum is used. It is preferable to use it. Furthermore, you may coat | cover with other metal materials, such as nickel, gold | metal | money, and silver, by plating, sputtering, vapor deposition, etc. on it.

  Further, when glass epoxy resin is used as the material of the base 101, the material of the conductor wiring 102 is preferably a material that can be easily processed. When using an injection-molded epoxy resin, the material of the conductor wiring 102 is preferably a member that can be easily processed by stamping, etching, bending, and has a relatively large mechanical strength. Specific examples include metals such as copper, aluminum, gold, silver, tungsten, iron, and nickel, or metal layers such as iron-nickel alloys, phosphor bronze, iron-containing copper, and molybdenum, lead frames, and the like. Further, the surface of the lead frame may be covered with another metal material different from the lead frame main body. Although this material is not specifically limited, For example, it can be set as the multilayer film using only silver, the alloy of silver, copper, gold | metal | money, aluminum, rhodium, etc., or these, silver, or each alloy. As a method for coating the metal material, a sputtering method, a vapor deposition method, or the like can be used in addition to the plating method.

(Connection member 103)
The connection member 103 is a member for fixing the light emitting element 105 to the base body 101 or the conductor wiring 102. In the case of flip chip mounting as in this embodiment, a conductive member is used. Specifically, 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 alloy, Au-Ge containing alloy, Au-Si containing alloy, Al containing alloy, Cu-In containing alloy, the mixture of a metal and a flux, etc. can be mentioned.

  As the connection member 103, a liquid, paste, or solid (sheet, block, powder, wire) can be used, and can be appropriately selected depending on the composition, the shape of the substrate, and the like. . Further, these connection members 103 may be formed as a single member or may be used in combination of several kinds.

(Insulating member 104)
The conductor wiring 102 is preferably covered with an insulating member 104 except for portions that are electrically connected to the light emitting element 105 and other materials. That is, as shown in each drawing, a resist for insulatingly covering the conductor wiring 102 may be disposed on the base, and the insulating member 104 can function as a resist.

In the case where the insulating member 104 is arranged, not only the purpose of insulating the conductor wiring 102 but also the inclusion of a white filler prevents leakage and absorption of light and increases the light extraction efficiency of the light emitting device 100. You can also
The material of the insulating member 104 is a material that absorbs less light from the light emitting element and is not particularly limited as long as it is insulating. For example, epoxy, silicone, modified silicone, urethane resin, oxetane resin, acrylic, polycarbonate, polyimide, or the like can be used.

(Light emitting element 105)
As the light emitting element 105 mounted on the substrate, a known element can be used. In the present embodiment, it is preferable to use a light emitting diode as the light emitting element 105.
A light emitting element 105 having an arbitrary wavelength can be selected. For example, blue and green light-emitting elements include ZnSe and nitride-based semiconductors (In _x Al _y Ga _1-xy N, 0 ≦ X
, 0 ≦ Y, X + Y ≦ 1), and those using GaP can be used. A light-transmitting sapphire substrate or the like can be used as the growth substrate. As the red light emitting element, GaAlAs, AlInGaP, or the like can be used. Furthermore, a semiconductor light emitting element made of a material other than this can also be used. The composition, emission color, size, number, and the like of the light emitting element to be used can be appropriately selected according to the purpose.

  Various emission wavelengths can be selected depending on the material of the semiconductor layer and the degree of mixed crystal. The light emitting element may have positive and negative electrodes on the same surface side so that flip chip mounting is possible, or may have positive and negative electrodes on different surfaces.

  The light-emitting element 105 of this embodiment includes a light-transmitting substrate and a semiconductor layer stacked over the substrate. In this semiconductor layer, an n-type semiconductor layer, an active layer, and a p-type semiconductor layer are formed in this order, an n-type electrode is formed on the n-type semiconductor layer, and a p-type electrode is formed on the p-type semiconductor layer. ing.

  As shown in FIG. 1, the light emitting element 105 is flip-chip mounted on the conductor wiring 102 on the surface of the base 101 via the connection member 103, and is a surface facing the surface on which the electrode is formed, that is, a translucent substrate. The main surface is a light extraction surface. However, in this embodiment, since the light reflecting film 106 is formed on this light extraction surface, the side surface of the light emitting element 105 becomes a substantial light extraction surface. That is, part of the light emitted from the light emitting element 105 and directed toward the main surface side of the light emitting element 105 is returned into the light emitting element 105 by the light reflecting film 106 and repeatedly reflected inside the light emitting element 105 to emit light. The light is emitted from the side surface side of the element 105. Therefore, the light distribution characteristic (see the dotted line in FIG. 4) of the light emitting device 100 is a combination of the light transmitted through the light reflecting film 106 and the light emitted from the side surface of the light emitting element 105.

  The light emitting element 105 is disposed so as to straddle two conductor wirings 102 that are positively and negatively insulated and separated, and is electrically connected by a conductive connecting member 103 and mechanically fixed. The mounting method of the light emitting element 105 can be, for example, a mounting method using bumps in addition to a mounting method using solder paste. Further, as the light emitting element 105, a small package product in which the light emitting element is sealed with resin or the like can be used, and the shape and structure are not particularly limited.

As will be described later, when a light emitting device including a wavelength conversion member is used, a nitride semiconductor (In _x Al _y Ga _1-xy N capable of emitting a short wavelength capable of efficiently exciting the wavelength conversion member 109 can be used. , 0 ≦ X, 0 ≦ Y, X + Y ≦ 1).

  In addition, although demonstrated in the example of flip chip mounting, it is good also as a mounting form which uses the insulating substrate side of a light emitting element as a mounting surface, and connects the electrode and wire which were formed in the upper surface of a light emitting element. In this case, the upper surface of the light emitting element is on the electrode forming surface side, and the reflective film is provided on the electrode forming surface side.

(Light reflecting film 106)
The light reflecting film 106 is formed on the light extraction surface side which is the main surface of the light emitting element 105.
The material may be a metal or a white filler-containing resin, and the material is not particularly defined as long as it reflects at least light (first light) emitted from the light emitting element 105.
Moreover, a reflection film with little absorption can be obtained by using a dielectric multilayer film. In addition, the reflectance can be arbitrarily adjusted by designing the film, and the reflectance can be controlled by the angle. In particular, the shape of the batwing light distribution is controlled by increasing the reflectivity in the direction perpendicular to the light extraction surface (also called the optical axis direction) and decreasing the reflectivity when the angle increases with respect to the optical axis, that is, increasing the transmittance. It is also possible to do.

In particular, the reflection wavelength band at the optical axis of the dielectric multilayer film, that is, in the direction perpendicular to the upper surface of the light emitting element, is longer than the emission peak wavelength of the light emitting element 105 as shown in FIG. It is useful to widen the reflection wavelength band.
This is because if the angle is shifted from the optical axis, in other words, the reflection wavelength band of the dielectric multilayer film shifts to the short wavelength side as the angle of the incident light from the optical axis increases. By widening the reflection wavelength band on the long wavelength side with respect to the wavelength, it becomes possible to maintain the reflectivity even for the light incident on the wide angle side, that is, at a large angle with respect to the optical axis.
As a material for the dielectric multilayer film, a metal oxide film material, a metal nitride film, an oxynitride film, or the like can be used. In addition, organic materials such as silicone resin and fluorine resin can be used, and the material is not particularly specified.

(Sealing member 108)
As a material of the sealing member 108, an epoxy resin, a silicone resin, a resin obtained by mixing them, 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.

In addition to the light diffusing material, the sealing member 108 is a wavelength conversion member such as a phosphor or a quantum dot that partially absorbs light from the light emitting element 105 and emits light having a wavelength different from the emission wavelength from the light emitting element. Alternatively, a colorant can be contained in accordance with the emission color of the light emitting element.
When these members are contained in the sealing member 108, it is preferable to use one that does not affect the light distribution characteristics as much as possible. For example, if the particle diameter of the member to be included is 0.2 μm or less, it is preferable because the influence on the light distribution characteristics is small. In the present specification, the particle diameter means an average particle diameter, and the value of the average particle diameter is F.F. S. S. S. No (Fisher-SubSieve-Sizers-No.).

  The sealing member 108 can be formed by compression molding or injection molding so as to cover the light emitting element 105. In addition, it is possible to optimize the viscosity of the material of the sealing member 108, drop or draw on the light emitting element 105, and control the shape by the surface tension of the material itself.

  When the latter forming method is used, the sealing member can be formed by a simpler method without requiring a mold. Further, as a means for adjusting the viscosity of the material of the sealing member by such a forming method, in addition to the inherent viscosity of the material, a desired viscosity using the light diffusing material, the wavelength conversion member, and the colorant as described above. It can also be adjusted.

[Second Embodiment]
FIG. 7 is a cross-sectional view of a light emitting module 300 including the light emitting device 200 of the second embodiment.
In the present embodiment, a plurality of light emitting elements 105 are mounted on the base body 101 at a predetermined interval, and light is emitted between the light emitting elements 105 at a small angle with respect to the upper surface of the light emitting element (the upper surface of the base body 101). A light reflecting member 110 that reflects the light to be emitted is disposed. That is, the light emitting device 200 is an integrated light emitting device including a plurality of the light emitting devices 100 of Embodiment 1 and the light reflecting member 110 disposed between the light emitting devices 100. A light diffusion plate 111 for diffusing light from the light emitting element 105 is disposed above the light emitting device 100 and the light reflecting member 110 so as to be substantially parallel to the upper surface of the light emitting element. In addition, a wavelength conversion layer 112 for converting a part of the light emitted from the light emitting element 105 into light of another wavelength is disposed substantially parallel to the light diffusion plate 111.

In general, as the distance between the substrate 101 and the light diffusing plate 111 (hereinafter also referred to as optical distance: OD) / light emitting element interval (hereinafter also referred to as Pitch) becomes smaller, the light quantity between the light emitting elements 105 on the surface of the light diffusing plate 111. Decreases and dark areas occur.
However, with the configuration in which the light reflecting member 110 is arranged in this way, the amount of light between the light emitting elements is compensated by the reflected light from the light reflecting member 110, so that even on a smaller OD / Pitch region, the light diffusing plate 111 can be on the surface. The brightness unevenness at is reduced.
Specifically, in the light emitting device 200 of the second embodiment, the inclination angle θ of the light reflecting surface of the light reflecting member 110 with respect to the base 101 is the surface of the light diffusion plate 111 in consideration of the light distribution characteristics of each light emitting device 100. It is set so that the luminance unevenness at the top is reduced. Further, regarding the light distribution characteristics of a plurality of light emitting devices 100, in order to suppress the luminance unevenness on the surface of the light diffusion plate 111 and realize a thin light emitting device 200, the light emitting device 100 has a light distribution angle. It is preferable that the light distribution characteristics be such that the amount of light increases in a large area, that is, where the light distribution angle is close to ± 90 °.

  For example, when OD / Pitch is reduced to 0.2 or less, the light incident on the light reflecting member 110 when the light emitting surface of the light emitting element 105 is used as a reference is less than 22 ° in elevation. Accordingly, when the low OD / Pitch is 0.2 or less, in order to increase the light reflection efficiency by the light reflecting member 110, the light distribution characteristic of the light emitting device 100 is, for example, less than 20 ° in elevation with respect to the upper surface of the substrate. It is preferable that the amount of light is increased. Specifically, it is preferable that the first and second peaks of the emission intensity are located in a range where the elevation angle is less than 20 °. Here, the elevation angle of 20 ° corresponds to the light distribution angles of 20 ° and 160 ° in FIG. That is, as shown in FIG. 4, it is preferable that the first peak of the emission intensity is located in a range where the light distribution angle is less than 20 ° and the second peak is located in a range where the light distribution angle is larger than 160 °. Further, the amount of light with an elevation angle of less than 20 ° is preferably 30% or more of the total amount of light, more preferably 40% or more.

(Light reflecting member 110)
The light reflecting member 110 is installed between the plurality of light emitting elements 105.
The material is not particularly limited as long as the material reflects at least the emission wavelength of the light-emitting element 105. For example, a metal plate or a white filler-containing resin can be suitably used.
Further, by using a dielectric multilayer film as the reflecting surface of the light reflecting member, a reflecting surface with little absorption can be obtained. In addition, the reflectance can be arbitrarily adjusted by designing the film, and the reflectance can be controlled by the angle.

  The height of the light reflecting member 110 and the inclination angle θ of the light reflecting surface with respect to the surface of the substrate 101 can take any value, and the reflecting surface may be flat or curved. Thus, the optimum inclination angle θ and the shape of the reflecting surface can be obtained so as to obtain desired light distribution characteristics. The height of the light reflecting member 110 is preferably not more than 0.3 times, more preferably not more than 0.2 times the distance between the light emitting elements, whereby the light emitting module 300 which is thin and has reduced luminance unevenness. Can be provided.

  In the light emitting device 200 used in an environment where the use temperature changes greatly, the linear expansion coefficients of the light reflecting member 110 and the base 101 need to be close to each other. When the linear expansion coefficient between the light reflecting member 110 and the base 101 is greatly different, the light emitting device 200 is warped due to a temperature change, or the positional relationship between the constituent members, particularly between the light emitting device 100 and the light reflecting member 110 is shifted. This is because desired optical characteristics cannot be obtained. However, the fact is that there are not many options for the linear expansion coefficient because of its physical properties. Therefore, it is preferable to form the light reflecting member 110 with a film molded product that can be elastically deformed so that the light emitting device 200 does not warp even if the linear expansion coefficients are greatly different. This is because if the light reflecting member 110 is made of a material having a small elastic deformation (solid material), the light reflecting member 110 expands while maintaining its shape, but if it is a film, it can be deformed at an appropriate place to absorb the expansion.

  The light reflecting member 110 is preferably formed in a plate shape by connecting a plurality of light reflecting members 110 and has a through hole 113 in which the light emitting device 200 is disposed. Such a plate-like light reflecting plate 110 'is shown in FIG. 8A is a top view, and FIG. 8B is a cross-sectional view taken along the line AA in FIG. 8A. Such a light reflecting plate 110 'can be formed by mold forming, vacuum forming, pressure forming, press forming or the like. The light reflecting plate 110 ′ is disposed on the base 101. The light reflecting member 110 may be formed by a method such as drawing light reflecting resin directly on the base 101. The height of the light reflecting member 110 is preferably 0.3 times or less of the distance between the light emitting elements, and more preferably 0.2 times or less of the distance between the light emitting elements.

[Example 1]
In this embodiment, as shown in FIG. 1, a glass epoxy substrate is used as the substrate 101, and a 35 μm Cu material is used as the conductor wiring.
As the light emitting element 105, a nitride blue LED having a square of 600 μm on a side and a thickness of 150 μm in plan view is used, and an epoxy white solder resist is used for the insulating member 104.
The light reflecting film 106 formed on the main surface of the light-emitting element 105 has an 11-layer structure in which an SiO ₂ layer (82 nm) and a ZrO ₂ layer (54 nm) are repeated.
The transmittance of the light reflecting film 106 at this time is as shown in FIG. 2, and the transmittance is low in the main surface side vertical direction (optical axis direction) of the light emitting element, and the transmittance increases when the angle deviates from the optical axis. .
The light emitting element 105 is covered with a sealing member 108. A silicone resin is used for the sealing member 108 and has a height (H) of 1.0 mm and a body diameter (W) of 3.0 mm.
With such a configuration, light emitted from the light emitting element 105 is refracted at the interface between the sealing member 108 and the air, and the light distribution angle is further widened. The light distribution characteristic of the light emitting device 100 at this time is shown by a solid line in FIG. In addition, the light distribution characteristic when not forming the sealing member 108 is shown by the dotted line of FIG. In this way, by using the sealing member 108 together with the light reflecting film 106, it is possible to realize a lower OD / Pitch.

[Example 2]
In the second embodiment, a plurality of light emitting elements 105 of the first embodiment are mounted on the base 101, and the light reflecting member 110 is disposed therebetween. The pitch is 12.5 mm.
The light reflecting member 110 is a plate-like light reflecting plate, and is a polypropylene sheet (thickness (t) is 0.2 mm) containing a TiO ₂ filler, the reflection angle θ (elevation angle) is 55 °, and the height is It shape | molds using a vacuum forming method so that it may become 2.4 mm. The light reflecting member 110 is a plate-like light reflecting plate as shown in FIG. 8 and is disposed on the insulating member 104.
A milky white light diffusing plate 111 and a wavelength conversion layer 112 are arranged thereon to form a liquid crystal backlight (light emitting module). FIG. 9 shows a result of comparing the presence / absence of the light reflecting member 110 with the luminance unevenness on the surface of the light diffusing plate 111 in such a configuration. FIG. 9A shows a case where no light reflecting member is arranged, and FIG. 9B shows a case where a light reflecting member is arranged. As shown in FIG. 9, in the case where the light reflecting member is not disposed, the relative luminance decreases to about 0.6 to 0.7 in the region where the relative luminance is high (250 pixels to 720 pixels), whereas the light reflecting member It can be seen that the relative luminance does not fall below 0.8 in the region where the relative luminance is high (250 pixels to 720 pixels). That is, the effect of improving luminance unevenness can be confirmed by arranging the light reflecting member.

  The light emitting device and the light emitting module of the present invention can be used for a backlight light source of a liquid crystal display, various lighting fixtures, and the like.

DESCRIPTION OF SYMBOLS 100,200 Light-emitting device 300 Light-emitting module 101 Base body 102 Conductor wiring 103 Connection member 104 Insulating member 105 Light-emitting element 106 Light reflection film 108 Sealing member 110 Light reflection member 110 'Light reflection plate 111 Light diffusion plate 112 Wavelength conversion layer 113 Through hole

Claims (15)

A substrate having conductor wiring;
A light emitting element mounted on the substrate and emitting a first light;
A light reflecting film provided on an upper surface of the light emitting element;
A sealing member that covers the light emitting element and the light reflecting film,
A light emitting device having a ratio (H / W) of height (H) to width (W) of the sealing member of less than 0.5.   The light emitting device according to claim 1, wherein a surface of the sealing member is formed with a convex curved surface.   The light-emitting device according to claim 1, wherein a light transmittance of the light reflecting film with respect to the first light has an incident angle dependency.   The light-emitting device according to claim 1, wherein the light transmittance of the light reflecting film with respect to the first light increases as the absolute value of the incident angle increases.   The light emitting device according to claim 1, wherein the light reflecting film is formed of a dielectric multilayer film.   6. The reflection wavelength band for light incident perpendicularly on the light reflecting film includes an emission peak wavelength of the light emitting element, and a longer wavelength side than the emission peak wavelength is wider than a shorter wavelength side. The light emitting device according to claim 1.   The light emitting device according to any one of claims 1 to 6, wherein 30% or more of the total amount of light emitted from the light emitting device is emitted in a direction with an elevation angle of less than 20 ° with respect to the upper surface of the substrate.   7. The light emitting device according to claim 1, wherein 40% or more of the total amount of light emitted by the light emitting device is emitted in a direction with an elevation angle of less than 20 ° with respect to the upper surface of the base.   The light emitting device according to any one of claims 1 to 8, wherein a ratio (H / W) of a height (H) to a width (W) of the sealing member is 0.3 or less.   The light emitting device according to claim 1, wherein the light emitting element is flip-chip mounted.   An integrated light emitting device comprising a plurality of light emitting device elements according to claim 1, wherein a light reflecting member is disposed between the light emitting devices.   The integrated light emitting device according to claim 11, wherein a height of the light reflecting member is 0.3 times or less a distance between the light emitting devices.   The integrated light emitting device according to claim 11, wherein a height of the light reflecting member is 0.2 times or less of a distance between the light emitting devices.   The light emitting device according to any one of claims 1 to 10, and light having a wavelength different from an emission wavelength of the light emitting device by partially absorbing light of the light emitting device on a light extraction surface side of the light emitting device. A light emitting module comprising a wavelength conversion member that converts the light into a wavelength.   The integrated light emitting device according to any one of claims 10 to 13, and a light extraction surface side of the integrated light emitting device, wherein a part of light of the light emitting element is absorbed, and an emission wavelength of the light emitting element is obtained. A light emitting module comprising a wavelength conversion member that converts light of different wavelengths.

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