JP6506899B2 - Light emitting device, integrated light emitting device and light emitting module - Google Patents

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 thereof is also increasing. In particular, electronic components are required to maintain performance for a long time even in a severe use environment. Such requirements are no exception for light emitting devices using semiconductor light emitting elements such as light emitting diodes (LEDs). That is, in the field of general illumination and in-vehicle illumination, the performance required of the light emitting device is increasing day by day, and a further increase in output (brightness) and reliability are required. Furthermore, while maintaining these high performances, it is also required for light emitting devices to supply at low cost.
With regard to backlights and general lighting fixtures used in liquid crystal TVs, it is considered important to design them, and there is a high demand for thinning.

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

JP 2008-4948 A

  According to the light emitting device of Patent Document 1, although it is possible to realize a light emitting device with a wide light distribution, a light emitting device capable of realizing a wider light distribution is required as the backlight becomes thinner.

  The embodiment according to the present invention is made in view of the above circumstances, and provides a light emitting device capable of wide-angle light distribution without using a secondary lens.

  The light emitting device according to the present embodiment includes a base having a conductor wiring, a light emitting element mounted on the base and emitting a first light, a light reflecting film provided on the upper surface of the light emitting element, and the light emitting element And a sealing member for covering 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 an embodiment of the present invention, wide light distribution is enabled 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 zone | band 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 view of the light-emitting device of this embodiment. It is a light distribution characteristic view of the light-emitting device of the comparative example which uses 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. FIG. The light emitting device No. 1 according to the present embodiment. It is a figure which shows the light distribution characteristic of 3. FIG. The light emitting device No. 1 according to the present embodiment. It is a figure which shows the light distribution characteristic of 4. FIG. The light emitting device No. 1 according to the present embodiment. It is a figure which shows the light distribution characteristic of 5. FIG. The light emitting device No. 1 according to the present embodiment. It is a figure which shows the light distribution characteristic of 6. FIG. The light emitting device No. 1 according to the present embodiment. It is a figure which shows the light distribution characteristic of 7. FIG. The light emitting device No. 1 according to the present embodiment. It is a figure which shows the light distribution characteristic of 8. FIG. The light emitting device No. 1 according to the present embodiment. It is a figure which shows the light distribution characteristic of 9. FIG. It is a sectional view showing an example of a 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 concept, and the present invention is not limited to the following ones unless there is a specific description. Further, the contents described in one embodiment and examples can be applied to the other embodiments and examples.
Further, in the following description, the same names and symbols indicate the same or the same members, and the detailed description will be appropriately omitted. Furthermore, each element constituting the present invention may be configured such that a plurality of elements are constituted by the same member and one member is used in common as a plurality of elements, or conversely, the function of one member is realized by a plurality of members It can be shared and realized.

First Embodiment
FIG. 1 is a schematic structural view showing an example of the light emitting device of the first embodiment.
As shown in FIG. 1, the present embodiment includes a base 101 having a conductor wiring 102 and a light emitting element 105 mounted on the base 101. The light emitting element 105 is flip-chip mounted via the connection member 103 so as to straddle at least a pair of conductor wires 102 provided on the surface of the base 101. A light reflection film 106 is formed on the light extraction surface side of the light emitting element 105 (upper surface of the light emitting element 105). The insulating member 104 may be provided on at least a part of the conductor wiring, and a region of the top surface of the conductor wiring 102 to be 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 on the light incident from the light emitting element 105. FIG. 2 shows the incident angle dependency characteristic of the light transmittance of the light reflecting film 106 of the present embodiment. The light reflection film 106 hardly transmits light in the vertical direction with respect to the top surface of the light emitting element 105, but the light transmission amount increases when the light reflection film 106 is angled from the vertical direction. Specifically, the transmittance is about 10% when the incident angle is in the range of -30 ° to 30 °, but the transmittance gradually increases when the incident angle is smaller than -30 °. When it becomes smaller than 50 °, the transmittance rapidly increases. Similarly, when the incident angle becomes larger than 30 °, the transmittance gradually increases, and when it becomes larger than 50 °, the transmittance rapidly increases. That is, the light transmittance of the light reflection film to the first light becomes higher as the absolute value of the incident angle becomes larger. With such a film, it is possible to realize a bat wing light distribution characteristic as shown in FIG.
Here, the bat wing light distribution characteristic has a first peak of intensity greater than the intensity when the light distribution angle is 90 ° in the first region where the light distribution angle is 90 ° or less, and the light distribution angle is 90 ° The light distribution characteristic is such that it has a second peak whose intensity is greater than the intensity when the light distribution angle is 90 ° in the second region.

  The light emitting element 105 is covered by 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 to optically control the light output from the light emitting element. The sealing member 108 is formed in a substantially dome shape, and the light emitting element 105 with the light reflection film 106, the surface of the conductor wiring 102 around the light emitting element 105, and the light emitting element 105 including the connection member 103 and the conductor wiring 102. Cover the joints. 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 not covered with the reflective film 106 is also in contact with the sealing member 108. The joint may be covered with an underfill separately from the sealing member 108. In this case, the sealing member 108 is formed to cover the top surface of the underfill and the light emitting element. In the present embodiment, the light emitting element 105 is directly covered by the sealing member 108.

The sealing member 108 is preferably formed to have a circular or oval outer shape in top view, and the height (H) of the sealing member in the optical axis direction is the diameter of the sealing member in top view It is formed at a ratio smaller than 0.5 of (width: W). In the case of the oval shape, the major axis and the minor axis exist in the length of the width, but in the present specification, the minor axis is taken as the sealing diameter (W). The surface of the sealing member 108 is formed by a convex curved surface.
With such a configuration, light emitted from the light emitting element 105 can be refracted at the interface between the sealing member 108 and the air, and light distribution can be further broadened.
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. In addition, the width (W) of the sealing member refers to the diameter as described above when the shape of the bottom of the sealing member is circular, and in the case of other shapes, the shortest length Point to

  FIG. 4 shows an example of a change in light distribution characteristics depending on the presence or absence of the sealing member 108. The light distribution characteristic of the light emitting device 100 of the first embodiment is shown by a solid line in FIG. Moreover, the light distribution characteristic of the light-emitting device produced similarly to Embodiment 1 except not forming the sealing member 108 is shown with a dotted line. 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 than in the light emitting device in which the sealing member 108 is not formed, and the light distribution angle becomes larger. The second peak moves to the point where the light distribution is wider.

  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, by forming the light reflection film 106, the brightness immediately above the light emitting element 105 can be reduced, while the sealing member 108 can be specialized for widening the light distribution of the light from the light emitting element 105. Significant miniaturization of the sealing member having a function can be realized. In other words, in the related art, it was necessary to increase the height of the sealing member because it was necessary to reduce the luminance immediately above the light emitting element and widen the light distribution by using only the sealing member. On the other hand, in the light emitting device of the present embodiment, the bat wing light distribution characteristic is realized by providing the light reflecting film 106 for reducing the brightness immediately above the light emitting element 105, and the function of the sealing member 108 is wider. The company has been able to reduce its size by specializing in As a result, as described later, it becomes possible to realize a thin backlight module (light emitting module) with improved luminance unevenness. The light distribution characteristic at the time of using a secondary lens as a comparative example in FIG. 5 is shown. According to the light emitting device of the present embodiment, it is possible to obtain light distribution characteristics equivalent to the case of using the secondary lens without using the secondary lens.

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, the height (H) of the sealing member 108 in the optical axis direction and the diameter (width: W) of the sealing member in top view were changed to create nine light emitting devices, and the light distribution characteristics were confirmed. The results are shown in FIG. As a light emitting element, a blue LED with a thickness of 150 μm is used, which is a square having a side of 600 mμ in plan view. The light reflection film 106 has an 11-layer configuration by repeating the SiO ₂ layer (82 nm) and the ZrO ₂ layer (54 nm).
Nine light emitting device Nos. 1 to No. The ratio of the height (H) of the sealing member to the diameter (width: W) of the sealing member at 9 is shown in Table 1. Light emitting device No. 1 to 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 diameter of the sealing member is small, and the ratio of the height (H) of the sealing member to the diameter (width: W) of the sealing member affects the orientation characteristics. It is thought that it gives.
And from the graph of FIG. 6, in order to obtain wider light distribution, it is more preferable to set the ratio (H / W) of the height (H) to the width (W) of the sealing member to 0.3 or less I understand that.

Hereinafter, preferable forms of the light emitting device 100 according to the present embodiment will be described.
(Substrate 101)
The base 101 is a member for mounting the light emitting element 105 thereon. The base 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), polyethylene terephthalate (PET) and the like. Among them, it is preferable to select a resin as the material in view of low cost and ease of molding. The thickness of the substrate can be selected appropriately, and it may be either 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.

  In order to obtain a light emitting device excellent in heat resistance and light resistance, it is preferable to select ceramics as the material of the base 101. Examples of the ceramic include alumina, mullite, forsterite, glass ceramics, nitrides (eg, AlN), carbides (eg, SiC), and the like. Among them, ceramics made of alumina or containing alumina as a main component are preferable.

When a resin is used as the material of the substrate 101, glass fiber or an inorganic filler such as SiO ₂ , TiO ₂ or Al ₂ O ₃ is mixed with the resin to improve mechanical strength and reduce the coefficient of thermal expansion. The light reflectance can also be improved. Further, as the substrate 101, any substrate capable of insulating and separating the pair of conductor wires 102 may be used, 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 (power) from the outside. That is, it plays a role as an electrode for supplying electricity from the outside or a part thereof. Usually, at least two of positive and negative are formed apart.

  The conductor wiring 102 is formed on at least the upper surface of the base serving as the mounting surface of the light emitting element 105. The material of the conductor wiring 102 can be appropriately selected depending on the material used as the base 101, the manufacturing method, and the like. For example, when a ceramic is used as the material of the base 101, the material of the conductor wiring 102 is preferably a material having a high melting point that can withstand the sintering temperature of the ceramic sheet, for example, a high melting point metal such as tungsten or molybdenum. It is preferred to use. Furthermore, it may be coated with another metal material such as nickel, gold, silver or the like by plating, sputtering, vapor deposition or the like.

  When a 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 an injection-molded epoxy resin is used, the material of the conductor wiring 102 is preferably a member which is easily processed by punching, etching, bending or the like and has relatively large mechanical strength. Specific examples thereof include metals such as copper, aluminum, gold, silver, tungsten, iron and nickel, or metal layers such as iron-nickel alloy, phosphor bronze, iron-containing copper and molybdenum, lead frames and the like. Also, the surface of the lead frame may be coated with another metal material different from the lead frame body. The material is not particularly limited, but may be, for example, silver alone, or an alloy of silver and copper, gold, aluminum, rhodium or the like, or a multilayer film using these, silver or each alloy. In addition to the plating method, a sputtering method, a vapor deposition method, or the like can be used as the method of coating the metal material.

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

  As the connecting member 103, liquid, paste, solid (sheet, block, powder, wire) can be used, and can be appropriately selected according to the composition, the shape of the substrate, etc. . In addition, 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 the insulating member 104 except for a portion electrically connected to the light emitting element 105 or another material. That is, as shown in each drawing, a resist for insulating coating of the conductor wiring 102 may be disposed on the base, and the insulating member 104 can function as a resist.

When the insulating member 104 is disposed, not only for the purpose of insulating the conductor wiring 102, but also by containing a white-based filler, light leakage and absorption are prevented, and the light extraction efficiency of the light emitting device 100 is increased. It can also be done.
The material of the insulating member 104 is a material with little absorption of 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 and the like can be used.

(Light-emitting element 105)
A well-known light emitting element 105 can be used as the light emitting element 105 mounted on the base. In the present embodiment, it is preferable to use a light emitting diode as the light emitting element 105.
The light emitting element 105 can select an arbitrary wavelength. For example, as a blue or green light emitting element, ZnSe or a nitride semiconductor (In _x Al _y Ga _1-x-y N, 0 ≦ x
It is possible to use one using 0 ≦ Y, X + Y ≦ 1), and GaP. A translucent sapphire substrate or the like can be used as a growth substrate. In addition, GaAlAs, AlInGaP, or the like can be used as the red light-emitting element. Furthermore, semiconductor light emitting devices made of materials other than these can also be used. The composition, emission color, size, number, and the like of the light-emitting elements to be used can be appropriately selected depending on the purpose.

  Various emission wavelengths can be selected depending on the material of the semiconductor layer and the mixed crystal ratio thereof. The light emitting element may have positive and negative electrodes on the same side so as to enable flip chip mounting, or may have positive and negative electrodes on different sides.

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

  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 as shown in FIG. 1, and a surface facing the surface on which the electrode is formed, ie, a light transmitting substrate The main surface of the light is the light extraction surface. However, in the present embodiment, since the light reflection film 106 is formed on the light extraction surface, the side surface of the light emitting element 105 is a substantial light extraction surface. That is, part of the light emitted from the light emitting element 105 and directed to the main surface side of the light emitting element 105 is returned to the inside of 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 of the element 105. Therefore, the light distribution characteristic (see the dotted line in FIG. 4) as 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 insulated and separated positively and negatively, is electrically connected by a conductive connection member 103, and is mechanically fixed. The mounting method of the light emitting element 105 can be, for example, a mounting method using a bump in addition to a mounting method using a solder paste. In addition, as the light emitting element 105, a small package product in which the light emitting element is sealed with a resin or the like can be used, and the light emitting element is not particularly limited in shape or structure.

As described later, in the case of a light emitting device provided with a wavelength conversion member, a nitride semiconductor (In _x Al _y Ga _1-x-y N) capable of emitting a short wavelength capable of efficiently exciting the wavelength conversion member 109. And 0 ≦ X, 0 ≦ Y, and X + Y ≦ 1) are preferably mentioned.

  Note that although the example of flip chip mounting has been described, the insulating substrate side of the light emitting element may be used as the mounting surface, and an electrode formed on the upper surface of the light emitting element and a wire may be connected. In this case, the upper surface of the light emitting element is on the electrode formation surface side, and the reflective film is provided on the electrode formation surface side.

(Light reflecting film 106)
The light reflection 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 is a material that reflects at least light emitted from the light emitting element 105 (first light).
Further, by using a dielectric multilayer film, it is possible to obtain a reflective film with less absorption. In addition, it is possible to arbitrarily adjust the reflectance in the film design, and also to control the reflectance by angle. In particular, the shape of the bat wing light distribution is controlled by increasing the reflectance in the direction perpendicular to the light extraction surface (also referred to as the optical axis direction) and decreasing the reflectance when the angle increases with respect to the optical axis. It will also be possible.

Particularly, as for the reflection wavelength band in the optical axis of the dielectric multilayer film, ie, in the direction perpendicular to the top surface of the light emitting element, as shown in FIG. It is useful to widen the reflection wavelength band of
This is because, when the angle is shifted from the optical axis, in other words, as the angle from the optical axis of the incident light increases, the reflection wavelength band of the dielectric multilayer film shifts to the short wavelength side, and light emission By widening the reflection wavelength band on the long wavelength side with respect to the wavelength, it is possible to maintain the reflectance even for light incident at a large angle with respect to the optical axis up to the wide angle side.
As a material of 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 also be used, and the material is not particularly limited.

(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 the light from the light emitting element 105 and emits light of a wavelength different from the emission wavelength of the light emitting element. Alternatively, a coloring agent can be contained in accordance with the emission color of the light-emitting element.
When the sealing member 108 is made to contain these members, it is preferable to use one which does not affect the light distribution characteristic as much as possible. For example, if the particle diameter of the member to be contained is 0.2 μm or less, it is preferable because the effect on the light distribution characteristic is small. In the present specification, the particle size refers to the average particle size, and the value of the average particle size is determined by the air permeation method using an air permeation method. 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 also possible to optimize the viscosity of the material of the sealing member 108, drop or draw it on the light emitting element 105, and control the shape by the surface tension of the material itself.

  In the case of the latter formation method, the sealing member can be formed by a simpler method without requiring a mold. Moreover, as a means to adjust the viscosity of the material of the sealing member by such a formation method, in addition to the inherent viscosity of the material, the desired viscosity using the light diffusing material, the wavelength conversion member and the coloring agent as described above It can also be adjusted to

Second Embodiment
FIG. 7 is a cross-sectional view of a light emitting module 300 including the light emitting device 200 according to the second embodiment.
In this embodiment, a plurality of light emitting elements 105 are mounted on the base 101 at predetermined intervals, and the light emitting elements 105 emit light at a small angle with respect to the upper surface of the light emitting element (upper surface of the base 101). The light reflecting member 110 is disposed to reflect the light. That is, the light emitting device 200 is an integrated light emitting device including a plurality of the light emitting devices 100 of the first embodiment, and the light reflecting member 110 is disposed between the light emitting devices 100. Further, 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. A wavelength conversion layer 112 is disposed in substantially parallel to the light diffusion plate 111 to convert part of the light emitted from the light emitting element 105 into light of another wavelength.

Generally, as the distance between the base 101 and the light diffusion plate 111 (hereinafter, also referred to as optical distance: OD) / light emitting element interval (hereinafter, also referred to as pitch) decreases, the light amount between the light emitting elements 105 on the surface of the light diffusion plate 111 Decreases and dark areas occur.
However, by disposing the light reflecting member 110 in this manner, the light amount between the light emitting elements is compensated by the reflected light from the light reflecting member 110, and the smaller OD / Pitch region on the surface of the light diffusing plate 111. Inconsistencies in brightness are 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 diffusing plate 111 in consideration of the light distribution characteristic of each light emitting device 100. It is set so that the uneven brightness above is reduced. Moreover, speaking of the light distribution characteristics of the plurality of light emitting devices 100, in order to suppress the uneven brightness on the surface of the light diffusion plate 111 and to realize the thin light emitting device 200, the light emitting device 100 has a light distribution angle. It is preferable to have a light distribution characteristic such that the amount of light at a region where the light distribution angle is close to ± 90 ° is large.

  For example, when the OD / Pitch decreases to 0.2 or less, light incident on the light reflecting member 110 with respect to the light emitting surface of the light emitting element 105 has an elevation angle of less than 22 °. Therefore, when the low OD / Pitch is 0.2 or less, the light distribution characteristic of the light emitting device 100 is, for example, less than 20.degree. It is preferable that the light quantity is increased. Specifically, it is preferable that the first and second peaks of the light emission intensity be located in the range of an elevation angle of less than 20 °. Here, the elevation angle of 20 ° corresponds to the light distribution angle of 20 ° and 160 ° in FIG. 4. That is, as shown in FIG. 4, it is preferable that the first peak of the light emission intensity be located in a range less than the light distribution angle 20 ° and the second peak be located in the range larger than the light distribution angle 160 °. In addition, it is preferable that the light amount with an elevation angle of less than 20 ° be 30% or more of the total light amount, and more preferably 40% or more.

(Light reflecting member 110)
The light reflecting member 110 is disposed 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.
In addition, by using a dielectric multilayer film as the reflecting surface of the light reflecting member, it is possible to obtain a reflecting surface with less absorption. In addition, it is possible to arbitrarily adjust the reflectance in the film design, and also to control the reflectance by 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 base 101 may take any value, and the reflecting surface may be flat or curved. It is possible to make the optimum inclination angle θ and the shape of the reflecting surface so as to obtain desired light distribution characteristics. The height of the light reflecting member 110 is preferably 0.3 times or less, more preferably 0.2 times or less, the distance between the light emitting elements, thereby making the light emitting module 300 thin and having reduced luminance unevenness. Can be provided.

  In the light emitting device 200 used in an environment where the operating temperature largely changes, 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 largely different, the light emitting device 200 may warp due to temperature change, or the positional relationship between the constituent members, in particular, between the light emitting device 100 and the light reflecting member 110 may be deviated. It is because desired optical characteristics can not be obtained. However, the fact is that the linear expansion coefficient does not have many options because it is a physical property value. Therefore, it is preferable to form the light reflecting member 110 of a film molded product capable of elastic deformation so that the light emitting device 200 does not warp even if the linear expansion coefficients are largely different. If the light reflecting member 110 is made of a material (non-cress material) having a small elastic deformation, it expands while maintaining its shape, but if it is a film, it is possible to deform at an appropriate place and absorb the expansion.

  Moreover, it is preferable that the light reflection member 110 has a plurality of light reflection members 110 connected in a plate shape, 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. FIG. 8 (a) is a top view, and FIG. 8 (b) is a cross-sectional view taken along the line AA of FIG. 8 (a). Such a light reflection plate 110 'can be formed by molding, vacuum forming, pressure forming, press forming or the like. The light reflection plate 110 ′ is disposed on the base 101. Further, the light reflecting member 110 may be formed by a method such as drawing a light reflecting resin directly on the substrate 101. The height of the light reflecting member 110 is preferably 0.3 times or less the distance between light emitting elements, and more preferably 0.2 times or less the distance between light emitting elements, for example.

Example 1
In this embodiment, as shown in FIG. 1, a glass epoxy base material is used as the base 101, and a 35 μm Cu material is used as the conductor wiring.
As the light emitting element 105, a nitride-based blue LED of 150 μm in thickness and having a square shape with one side of 600 μm in plan view is used, and for the insulating member 104, an epoxy-based white solder resist is used.
The light reflecting film 106 formed on the main surface of the light emitting element 105 has an 11-layer structure by repeating the SiO ₂ layer (82 nm) and the ZrO ₂ layer (54 nm).
The transmittance of the light reflecting film 106 at this time is as shown in FIG. 2, the transmittance is low in the direction perpendicular to the main surface side (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. The sealing member 108 is made of silicone resin 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 air interface with the sealing member 108, and the light distribution angle further spreads. The light distribution characteristic of the light emitting device 100 at this time is shown by a solid line in FIG. The light distribution characteristic when the sealing member 108 is not formed is shown by a dotted line in FIG. 4. Thus, by using the sealing member 108 together with the light reflection film 106, it is possible to realize 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, is a polypropylene sheet (0.2 mm thick) containing TiO ₂ filler, has a reflection angle θ (elevation angle) of 55 °, and a height of It shape | molds using a vacuum forming method so that it may be set to 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 diffusion plate 111 and a wavelength conversion layer 112 are disposed thereon to form a liquid crystal back light (light emitting module). FIG. 9 shows the result of comparing the presence or absence of the light reflecting member 110 by the uneven brightness on the surface of the light diffusing plate 111 in such a configuration. FIG. 9A does not arrange the light reflection member, and FIG. 9B arranges the light reflection member. As shown in FIG. 9, in the case where the light reflection member is not disposed, there is a point that the relative brightness drops to about 0.6 to 0.7 in the region (250 pixels to 720 pixels) where the relative brightness is high, It can be seen that, in the case where is arranged, the relative luminance does not fall below 0.8 in the region (250 pixels to 720 pixels) where the relative luminance is high. That is, by arranging the light reflecting member, it is possible to confirm the effect of improving the uneven brightness.

  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.

100, 200 Light emitting device 300 Light emitting module 101 Base 102 Conductor wiring 103 Connecting member 104 Insulating member 105 Light emitting element 106 Light reflecting film 108 Sealing member 110 Light reflecting member 110 'Light reflecting plate 111 Light diffusing plate 112 Wavelength conversion layer 113 Through hole

Claims (14)

A substrate having a conductor wiring,
A light emitting element mounted on the base and emitting a first light;
A light reflecting film provided on an upper surface which is a surface on the light extraction side of the light emitting element;
And a sealing member covering the light emitting element and the light reflecting film,
The sealing member is substantially dome-shaped,
A light emitting device in which the ratio (H / W) of the height (H) to the width (W) of the sealing member is smaller than 0.5. The light emitting device according to claim 1 , wherein the light transmittance of the light reflecting film to the first light has an incident angle dependency. The light emitting device according to claim 1 or 2 , wherein the light transmittance of the light reflecting film to the first light becomes higher as the absolute value of the incident angle becomes larger. The light emitting device according to any one of claims 1 to 3 , wherein the light reflecting film is formed of a dielectric multilayer film. Reflection wavelength band for light which is perpendicularly incident of the light reflecting layer, the comprises an emission peak wavelength of the light emitting element, and one said longer wavelength side than the emission peak wavelength of claims 1-4 which is wider than the shorter wavelength side The light-emitting device according to claim 1. The light emitting device according to any one of claims 1 to 5 , wherein 30% or more of the total light amount of the light emitted from the light emitting device is emitted in the direction of 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 5 , wherein 40% or more of the total light amount of the light emitted from the light emitting device is emitted in the direction of 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 7 , 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 any one of claims 1 to 8 , wherein the light emitting element is flip chip mounted. A substrate having a conductor wiring,
A plurality of light emitting elements each mounted on the substrate and emitting a first light;
A plurality of light reflecting films respectively provided on an upper surface which is a surface on the light extraction side of the light emitting element;
A plurality of sealing members respectively covering the light emitting element and the light reflecting film;
A light reflecting member provided between the sealing members ;
Equipped with
Each of the sealing members is formed in a substantially dome shape, and the ratio (H / W) of the height (H) to the width (W) of the sealing members is smaller than 0.5 . 11. The integrated light emitting device according to claim 10, wherein the height of the light reflecting member is 0.3 times or less the distance between the sealing members . The integrated light emitting device according to claim 10, wherein the height of the light reflecting member is 0.2 times or less of the distance between the sealing members . A light emitting device according to any one of claims 1 to 9 , and a light of a wavelength different from the light emitting wavelength of the light emitting element by partially absorbing the light of the light emitting element on the light extraction surface side of the light emitting device. Light emitting module comprising a wavelength conversion member for converting into And integrated light-emitting device according to any one of claims 1 0 to 1 2, the light extraction surface side of the integrated light-emitting device, by absorbing a portion of light of said light emitting element, light emission of the light emitting element A light emitting module comprising a wavelength conversion member for converting light of a wavelength different from the wavelength.
that's all

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