JP5701502B2 - Light emitting device - Google Patents

Description

  The present invention relates to a light emitting device, and more particularly to a light emitting device including a light transmission member that controls light distribution of light emitted from a light source.

  2. Description of the Related Art In recent years, light-emitting devices equipped with semiconductor light-emitting elements such as light-emitting diodes (LEDs) and laser diodes (LDs) as light sources have been used for various lighting and display devices. In addition, by combining a semiconductor light emitting element and a wavelength conversion member that emits secondary light having a hue different from that of the primary light by being excited by the primary light emitted from the light emitting element, various combinations can be made based on the principle of light color mixing. Light emitting devices capable of emitting light of various colors have been developed. In particular, since semiconductor light emitting devices have low power consumption and long life, they are attracting attention as illumination light sources that can replace fluorescent lamps. Further, light emitting devices equipped with these semiconductor light emitting devices have further improved light output and light emission efficiency. There is a need for improvement and light distribution with uniform emission color and brightness.

  For example, a semiconductor light emitting device described in Patent Document 1 includes a light emitting unit configured by flip-chip connecting a semiconductor chip on an intermediate substrate via a protruding electrode, and a sealing unit provided on the semiconductor chip. The sealing portion is made of a transparent thermosetting resin having a refractive index of 1.6 to 1.8. As a result, the ratio of the light traveling from the semiconductor chip side to the sealing portion side causing total reflection at the interface between the semiconductor chip and the sealing portion is reduced to improve the light extraction efficiency.

  Further, for example, the LED package described in Patent Document 2 includes a light emitting element and a lens portion fixed so as to surround the light emitting element, and the lens portion is perpendicular to the central axis of the light emitting element. There are provided a first optical unit that condenses the light in various directions and a second optical unit that condenses the light in the direction of the central axis of the light emitting element. As a result, the radiation direction is appropriately controlled according to the light distribution of the light-emitting elements, preventing light that cannot be controlled by the optical system from being emitted, and it is thin and compact, has excellent light collecting properties, and efficiently emits light to the outside. It is said that it can be made.

JP 2007-273964 A JP 2004-281605 A JP 2005-294786 A JP 2007-142178 A JP 2005-109289 A

  However, although the light emitting devices described in the cited documents 1 and 2 are arranged with a light source including a light emitting element at the focal point of the lens to suppress reflection on the lens surface and increase the extraction efficiency, Therefore, there is a problem that color unevenness occurs due to the light emitting element and the wavelength conversion member. On the other hand, by increasing the thickness of the wavelength conversion member or the coating member containing it and the scattering agent, or increasing the phosphor or scattering agent to increase the scattering effect, the color unevenness of the light emitted from the member can be improved. However, the light confinement effect in the member is increased, and the light extraction efficiency and the light emission efficiency are greatly reduced. That is, in the configuration of the light emitting device described in the cited documents 1 and 2, it is not possible to diffuse light while suppressing color unevenness and maintaining high luminance and light emission efficiency, and has these good optical characteristics. Does not become a light emitting device. Since the lens disclosed in the patent document forms a rotationally symmetric body with respect to the optical axis, the above-described color unevenness around the optical axis cannot be improved and light is emitted as it is.

  This is because in a light-emitting device having a light-emitting element covered with a wavelength conversion member, the primary light has a high front luminance at the output surface of the element, and as the angle from the front of the output surface increases, Since the optical path length of the primary light becomes longer, the conversion rate to the secondary light becomes higher and the orientation is lowered in luminance. On the other hand, the secondary light (wavelength converted light) emitted from the phosphor particles in the wavelength conversion member has a uniform orientation compared to the primary light due to omnidirectional light emission based on the particles and the scattering action by the particles. . For this reason, the light distribution of the primary light and the secondary light of the light source section is different, and the primary light flux is the secondary light especially in the overlapping area of the upper surface and the side surface, which is the main emission surface of the element, in the high angle region. Compared to the above, the color of the secondary light becomes strong and color unevenness occurs depending on the observation direction of light emission. The occurrence of such color unevenness is conspicuous when the wavelength conversion member is provided relatively thin and the light extraction efficiency of the light source is increased, and can be reduced by increasing the thickness of the wavelength conversion member or separately providing a reflecting mirror or a diffusion plate. However, in that case, the light extraction efficiency is lowered, and as a result, the light emission efficiency of the light emitting device is lowered.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a light-emitting device that has less color unevenness and can emit light with high efficiency.

The light emitting device according to the present invention can solve the above-described problems by the following means (1) to (14).
(1) A light source unit comprising: a light emitting element that is mounted on a mounting surface and emits primary light; and a wavelength conversion member that covers the light emitting element and emits secondary light having a wavelength different from the wavelength of the primary light; A light transmissive member that covers the light source part and has a light emitting surface that emits the primary light and the secondary light to the outside, and a plurality of convex portions are provided on the light emitting surface, The convex portions protrude in the direction of the central axis, the central axes are inclined with respect to each other through the light source unit, and the central axes of the convex portions are inclined with respect to the optical axis of the light emitting element or the light source unit. Light emitting device.
(2) A light emitting surface of the light emitting element or the light source unit is provided with a first main surface substantially perpendicular to the optical axis, a plurality of light emitting surfaces inclined to the first main surface, and provided around the first main surface. The light emitting device according to (1), wherein the light emitting surface has a surface region facing the first main surface and the plurality of second main surfaces.
(3) The above (1) or (2), wherein the light transmissive member includes a light diffusion region surrounding the light source portion with a certain distance from the light source portion, and a light collection region in which the convex portion is provided outside the light diffusion region. ).
(4) In the above (1) to (3), the light source unit is mounted on a mounting substrate, and the light diffusion region is provided to extend outside the mounting substrate so as to surround the mounting substrate. The light emitting device according to any one of the above.
(5) The light-emitting device according to any one of (1) to (3), wherein the light source unit is mounted on a mounting substrate, and the light diffusion region is disposed on the mounting substrate.
(6) The light emitting device according to any one of (1) to (5), wherein the convex portion of the condensing region is provided above the upper surface of the mounting substrate.
(7) The light source unit is disposed on the mounting substrate, the light transmitting member is extended outward from the mounting substrate with respect to the upper surface of the mounting substrate, and the light emitting surface is formed from the mounting substrate. The light emitting device according to any one of (1) to (6), wherein the light emitting device is provided outside and the convex portion is inclined with respect to the optical axis toward the upper side of the light source unit. .
(8) The light emitting device according to (7), wherein the extending portion of the light transmitting member has a bottom surface substantially parallel to the top surface of the mounting substrate.
(9) The light emitting device according to any one of (1) to (8), wherein the convex portion has an inclination angle with respect to the optical axis of 45 ° or more and 90 ° or less.
(10) The light transmitting member includes any one of the above (1) to (9), in which the convex portion has at least one pair of convex portions whose inclination angles with the optical axis are substantially the same. The light-emitting device described in one.
(11) The light emitting device according to any one of (1) to (10), wherein the convex portion has a convex curved surface of a rotating body having the central axis as a rotation central axis.
(12) The convex portion may have any one of the above (1) to (11) in which the central axis is disposed at substantially the same angle in the rotational direction with the optical axis as the rotational central axis. The light emitting device described.
(13) In any of the above (1) to (12), in the light transmitting member, the convex portion has rotational symmetry with the optical axis as a rotational symmetry axis, and the rotational symmetry is 3 times or more. The light-emitting device as described in any one.
(14) The optical axis is substantially perpendicular to the mounting surface, and the light transmitting member has a second convex portion that protrudes in the central axis direction with the optical axis as a central axis. The light emitting device according to any one of (13).

  According to the present invention, a plurality of convex portions are provided on the light exit surface of the light source unit including the light emitting element and the wavelength conversion member that respectively emit the primary light having different light distribution and the secondary light of the wavelength converted light. The light transmitting member is provided so as to cover the light source part, and the central axes of the convex parts are inclined with respect to each other and are inclined with respect to the optical axis. In a high angle region of the optical axis where unevenness is likely to occur, it is possible to provide a light-emitting device with a light distribution in which color unevenness is reduced by a condensing and reflecting function by a convex portion, that is, an optical lens function.

It is the schematic top view (b) of the light-emitting device which concerns on one embodiment of this invention, and the schematic sectional drawing (a) in the AA cross section. They are the orientation characteristic view (a) of the conventional light-emitting device, the schematic top view (c) explaining the light-emitting device, and the schematic sectional drawing (b) in the AA cross section. They are a schematic top view (b) explaining the orientation of (a) and (b) of FIG. 1, and a schematic sectional view (a). It is the schematic top view (b) of the light-emitting device which concerns on one embodiment of this invention, and the schematic sectional drawing (a) in the AA cross section. It is the schematic top view (b) of the light-emitting device which concerns on one embodiment of this invention, and the schematic sectional drawing (a) in the AA cross section. FIG. 6 is a schematic top view illustrating a mounting substrate and a wiring structure of the light emitting device according to FIG. 5. It is the schematic top view (b) of the light-emitting device which concerns on one embodiment of this invention, and the schematic sectional drawing (a) in the AA cross section. It is the schematic top view (b) of the light-emitting device which concerns on one embodiment of this invention, and the schematic sectional drawing (a) in the AA cross section. It is the schematic top view (b) of the light-emitting device which concerns on one embodiment of this invention, and the schematic sectional drawing (a) in the AA cross section.

  Hereinafter, embodiments of the invention will be described with reference to the drawings as appropriate. However, the light-emitting device described below is for embodying the technical idea of the present invention, and the present invention is not limited to the following. In particular, the dimensions, materials, shapes, relative arrangements, and the like of the components described below are not intended to limit the scope of the present invention only to specific examples unless otherwise specified. Only. Note that the size, positional relationship, and the like of the members shown in each drawing may be exaggerated for clarity of explanation. 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. Similarly, the embodiments described below can be applied by appropriately combining the components and the like unless otherwise specified. In the present invention, the term “inclination” includes vertical unless otherwise specified.

<Embodiment 1>
FIG. 1B is a schematic top view of the light-emitting device according to Embodiment 1 of the present invention, and FIG. 1A is a schematic cross-sectional view taken along line AA of FIG. The light emitting device 100 of the example shown in FIG. 1 mainly includes a light source unit 30 having a light emitting element 10 and a wavelength conversion member 20 mounted on a mounting surface on an upper surface of a mounting substrate 50, and a light transmitting member 40 covering the light source unit. And is composed of. Hereinafter, as shown in the figure, the plane parallel to the mounting surface is the xy plane, the direction perpendicular to the mounting surface is the z direction (z axis), the horizontal direction in FIG. 1B is the x direction (x axis), and the vertical direction. The direction will be described as the y direction (y axis). The viewpoint from the z direction on the xy plane is the top view of the apparatus. The arrows in the figure explain the progress of light, and the arrows with black triangles indicate that the large triangles emit light from the light exit surface, and the small triangles indicate the propagation of light in the light transmission member and to the outside. The black arrow and the white arrow indicate strong light emission of primary light and secondary light, respectively. The same applies to other figures.

  The mounting substrate 50 is a mounting substrate having positive and negative electrode wirings 55 formed on the upper surface thereof. On the wiring 55, the light-emitting element 10 having a plate-like shape having a substantially square shape when viewed from above is used as the positive and negative electrodes of the element. One piece is flip-mounted through a conductive adhesive 60 provided. The periphery of the light emitting element 10, more specifically, the upper surface and the side surface (end face) of the light emitting element 10 are covered with the wavelength conversion member 20. In the figure, the wavelength conversion member 20 is also provided between the mounting surface and the element. However, in the present invention, the wavelength conversion member 20 may not be provided in any region other than the light emission direction. A substantially entire upper surface of the mounting substrate 50 is covered with an insulating film 58, and the wiring 55 provided on the upper surface side is electrically connected to the bottom surface side, and is electrically connected to the outside of the apparatus by the wiring 56 on the bottom surface side. When power is supplied to the light source unit 30 from the wiring 56, the light emitting element 10 emits primary light, and the wavelength conversion member 20 is excited by the primary light emitted from the light emitting element 10 and has a wavelength different from the wavelength of the primary light. Emits secondary light. Further, a part of the primary light is transmitted through the wavelength conversion member 20 without being wavelength-converted. Therefore, the primary light and the secondary light are emitted from the light source unit, and the primary light and the secondary light transmitted through the light transmission member are superimposed. Mixed light is observed.

The light transmitting member 40 includes and seals the light source unit 30 and is provided on the upper surface of the mounting substrate 50. Light that emits primary light and secondary light emitted from the light source unit 30 to the outside of the surface of the light transmitting member 40. An exit surface 41 is provided. The light emitting surface 41 has five convex portions in total: four on the side of the light source unit 30 (convex portion 45) and one above the light source unit 30 (second convex portion 44). Is provided. The central axes C ₁ , C ₂ , C ₃ , and C ₄ of the _four convex portions 45 provided on the side of the light source unit 30 are in the xy plane, and the light source unit 30 is centered on the periphery at 90 ° intervals. Are roughly evenly distributed. Further, the central axis B of the second convex portion 44 is the z-axis. Each of the convex portions 44 and 45 has a convex curved surface with the central axis of the convex portion as an optical axis. That is, the central axis of each lateral projection 45 is arranged at substantially the same angle in the rotation direction with the z axis of the optical axis as the rotation center axis, while each lateral projection 45 is substantially identical. Since the z-axis is a rotationally symmetric axis, the four convex portions 45 have rotational symmetry and are configured with fourfold rotational symmetry. Similarly to the side convex portions 45, the upper convex portion 44 is also a rotationally symmetric body with the central axis as the rotation center, and the side convex portion 45 is a part thereof, that is, below the mounting surface. The shape is a part cut away. That is, each convex portion 45 is disposed as a light emission surface facing the side surface (second main surface) of the light emitting element 10 and the side surfaces of the wavelength conversion member 20 and the light source unit 30 facing each other. Light is emitted from the surface area of the end of the convex curved surface of the part. The central axis of each convex portion is an axis passing through the light source unit 30 and the light emitting element 10 as a reference, and is opposed to the main surface (upper surface) and four side surfaces of the light emitting element. Includes a substantially parallel light conversion member 20 and a surface (upper surface and side surface) of the light source unit 30, that is, a light emitting surface of the light source unit, and a central axis of each convex portion in a direction substantially perpendicular to each surface. The light transmitting member 40 is provided in the mounting surface, and its bottom surface constitutes a reflecting surface joined to the mounting surface. In the convex portion 45, the bottom surface constitutes a part of the convex portion.

  Here, FIG. 2A shows the light distribution of the primary light (thick solid line) and the secondary light (dashed line) of the conventional light emitting device 150 (the angle dependence of the emission intensity) and the color of the mixed light (thin line). It is the schematic explaining the tendency of the characteristic about the radiation angle distribution of temperature, and FIG.2 (c) and (b) are the schematic top views and its AA cross section which concern on an example of the conventional light-emitting device, respectively. It is a schematic sectional drawing. FIGS. 3A and 3B are diagrams corresponding to FIGS. 1A and 1B for explaining the propagation and emission of light. In these drawings, the direction in which the intensity of each light is high is indicated by an arrow I as primary light and an arrow II as secondary light. In this structure, the light source unit 30 is the same as that of the first embodiment. The light source unit 30 is arranged at a substantially focal point in the sealing member 40 of the hemispherical lens, and is emitted from the light source unit 30 as shown by a thin line arrow. The incident light is incident on the surface substantially perpendicularly, thereby suppressing reflection and exiting from the exit surface 41 as it is. Accordingly, the primary light (arrow I) is relatively strong in the front direction (optical axis direction) of the upper surface (main surface) of the light emitting element 10 and the front direction (x axis, y axis direction) of the four side surfaces. The light emission of each surface is superposed in the high angle region of the axis, and the secondary light (arrow II) becomes relatively strong in the angle region of the intermediate region at the inclination angle of each axis, here substantially vertical. This is because each light emitting surface of the light emitting element has a different distance and optical path length until the primary light reaches the light emitting surface of the light source unit in the front direction and the oblique direction, that is, the axial direction of each axis and the high angle region. by. At this time, since the distance becomes longer in the high angle region, the rate of wavelength conversion becomes higher. Therefore, in the region, the primary light is relatively weak and the secondary light is strong. In the conventional light emitting device shown in the figure, since the light emitted from the light source part reaches the surface 41 and is an optical lens that emits the light as it is while suppressing surface reflection, the primary and secondary light emitted from the light source part are aligned. The color unevenness is emitted as it is, and has the same tendency as shown by the light emission characteristics of the device, the thin line in FIG. Here, the hemispherical lens is illustrated, but the sealing member of a rotationally symmetric body with respect to the optical axis, for example, a rotating body as seen in the cross section of FIG. In the rotating body having the cross section seen in 3 (b), the alignment light around the optical axis, that is, the light emitted from the side surface of the light emitting element is taken out as it is, and the alignment does not change, and color unevenness occurs.

  Regarding the orientation of the primary / secondary light described above, the angle range is specifically a low tilt angle θ with respect to the central axis of the projection, that is, the z-axis which is the optical axis of the device, and the x-axis and y-axis. Primary light is emitted strongly in the angle range (near 0 ° to ± 45 °) (arrow I), and secondary light is emitted strongly in the high angle region (near -90 ° to -45 °, + 45 ° to + 90 °). (Arrow II). Therefore, in the light emitting device of the present embodiment described above, as shown in FIGS. 1 and 3, the light transmitting member is provided in the direction in which the primary light is strong in addition to the optical axis direction as well as the convex portion around the optical axis. By providing the convex portion 45 and the second convex portion 44 in the optical axis direction on the light emitting surface, the primary light and the secondary light emitted from the light source portion are guided into each convex portion inside the light transmitting member 40. The light is emitted and emitted from the surface of each convex portion to the outside of the apparatus in different central axis directions. Specifically, as shown by a thin arrow, in a region of a certain distance from the light source unit 30 to the convex portions 44 and 45, specifically, a distance from the concave portion between the convex portions, as in the conventional light emitting device. In the light transmission member 40 surrounding the light source unit 30, it functions as a light diffusion region, and in the region outside it, it functions as a light collection region by the above-mentioned convex portions. In this condensing region, the color is dispersed by the concave portions between the convex portions, reflected and condensed in the convex end direction by the convex curved surface of the convex portions, and the color described above by the light guide function and optical lens function of each convex portion. The unevenness is improved, and the light is emitted mainly from the surface of the convex curved surface of each convex portion, that is, from the curved surface. Further, since the four convex portions 45 facing the second main surface are rotating bodies on the mounting surface by rotation about a half circumference, the substantially flat surface of the bottom surface is the same as the conventional light emitting device, light Similar to the diffusion region, it functions as a reflecting surface, and the above-described light condensing function and optical lens function are provided by the convex surface on the upper surface side. Therefore, as shown in FIG. 3B, a plurality of such convex portions are provided on the light emitting surface of the light transmitting member, and the central axes of the convex portions are inclined to each other, so that the surface of each convex portion is As the emission surface, the primary light and the secondary light emitted therefrom are superimposed on each other to reduce color unevenness. Also, the optical axis direction is substantially the same as shown in FIG. 3A, but as described above, the side projection 45 is constituted by a part of the rotating body, a half-rotating rotating body, and the other side. The second convex portion 44 is a rotating body around the entire circumference and is a convex portion facing the main light emission main surface of the light emitting element 10 and the light source unit 30, so that the light emission in the optical axis direction is the second Main light emission is extracted from the convex portions 44, and auxiliary light emission is performed from the four adjacent convex portions 45. As described above, the light emitting device according to the present invention is similar to the conventional light emitting device in that the light emitting surface facing the light source unit is provided and light is extracted, so that the light extraction efficiency is maintained and the conventional light emitting device is maintained. This is a structure in which the difference in the orientation of primary light and secondary light, and the color unevenness, which are the above problems, are improved.

  In particular, in the light emitting device of the present embodiment, the light emitting surface 41 of the light transmitting member is provided with a plurality of convex portions 45 protruding toward the outside of the device, and the central axis of this convex portion 45 is the other axis. In the present embodiment, a convex portion having adjacent central axes that are inclined with respect to the central axis of at least one convex portion 45 is provided. Thereby, in the high angle region of the optical axis, that is, on the side of the light source unit 30, the light emitted from one convex part and the light emitted from the other convex part are emitted in each central axis direction and superimposed. Thus, the color unevenness can be reduced. In the light emitting device 100 of the example shown in FIG. 1, five convex portions (44, 45) are provided on the light emitting surface 41 of the light transmitting member, and the central axes of the adjacent convex portions are at an angle of 90 ° with each other. It is arranged to make. In addition, since the convex portions adjacent to each other are dispersed in the concave portions between the convex portions as described above, and are guided to each convex portion, and the light emitted from the convex curved surface of the convex portions is superimposed on each other, When the inclination angle of the central axis is increased, color unevenness is caused thereby. Therefore, in order to efficiently overlap the light emission of each convex portion, the angle formed by the central axes of both convex portions is 45 ° or more in one section. It is preferably 90 ° or less.

  In the light emitting device according to the present invention, as described above, the light distribution of the device, that is, the distribution of luminance and chromaticity is controlled by the combination of the positions and directions of the plurality of convex portions 44 and 45. Therefore, in the case of two convex portions provided around the optical axis around the light source unit, the direction of both convex portions and the inclination angle of the central axis thereof become large. When the effect of superimposing the emitted light is weak and small, it is biased to one side around the optical axis, and on the other side, the direction and inclination angle of the convex portion are similarly increased. Therefore, three or more convex portions 45 are provided on the xy plane. As described above, it is more preferable that the inclination angles are 45 ° or more and 90 ° or less as described above. The central axes of the three or more convex portions 45 are substantially equally arranged around the light source portion 30 around the light source portion 30 in the xy plane, that is, the convex portions 45 are arranged around the optical axis as a center. The angles formed by the central axes are preferably substantially the same as in the present embodiment. As a result, it is possible to reduce color unevenness balanced with respect to each direction around the optical axis (z-axis) of the apparatus, and light emission with excellent orientation is achieved.

  Furthermore, the light-emitting device of the present invention has a structure in which the light transmitting member 40 is mainly provided on the mounting surface and emits light upward from the mounting surface, that is, an angle of 0 ° to 90 ° with respect to the optical axis. In addition to the orientation around the optical axis as seen in the top views of FIGS. 1 (b) and 3 (b), the light transmitting member 40 is provided in the range and is emitted from the light emitting surface of the surface. 1A and 3A are also required to be oriented in an angular range extending from the mounting surface as seen in the cross-sectional views and centering on the optical axis. Here, the light emitting device of the present invention may emit light from the side of the light source 30, the lower side, and the lower side of the mounting surface. In other embodiments, the light emitting device is outside the side of the mounting surface. The embodiment has been described in which a light transmitting member is provided on the lower side and a light emitting surface is provided in that region. In this way, in order to maintain the light emitted upward from the mounting surface, the light beam emitted in the direction of the optical axis of the apparatus, and the luminance, the second convex portion 44 having the optical axis as the central axis as in the present embodiment. And the central axis of at least one of the plurality of projections 45 provided around the optical axis is above the light source unit 30 with respect to the upper surface of the mounting substrate 50 on which the light source unit 30 is provided. In other words, a configuration in which a convex portion having a central axis that is inclined at an angle of less than 90 ° with respect to the optical axis is provided. It can be. In the present embodiment, the second convex portion 44 having the z axis as the central axis B is provided immediately above the light source unit 30, and the light emitted in the optical axis direction of the apparatus is the second convex portion. And is emitted from the other convex part 45 arranged in a high angle range with respect to the optical axis while improving color unevenness and improving light extraction efficiency. By superimposing with light, it is possible to reduce color unevenness in the device, its high angle region, and the intermediate region between the convex portions, and to achieve good orientation.

In addition, it is preferable that the central axis of each convex portion 45 has substantially the same angle with the z-axis. Thereby, color unevenness can be reduced substantially evenly around the optical axis of the light source unit 30, that is, the z-axis that is the main light emitting direction. In particular, the angle formed by the central axis of the convex portion 45 and the z-axis is preferably 45 ° or more. Usually, the angle range in which the primary light is weak and the secondary light is strong depends on the structure of the light source unit, but as shown in FIG. 2 (a), as shown in FIG. For example, it is provided near 60 °. This depends on the difference in light distribution between the light emitting element 10 and the wavelength conversion member 20, the difference in the light emission surface, and the wavelength conversion member 20 depending on the thickness of the wavelength conversion member 20 and the incident angle of the primary light as described above. This is because, for example, the optical path length of the primary light propagating through the light beam differs, and the wavelength conversion amount varies depending on the radiation angle of the light. Further, if the angle formed by the central axis of the convex portion 45 and the z-axis is 90 ° or less, the light can be efficiently superimposed on the z-axis serving as the optical axis of the device and its low angle region. The color unevenness in the optical axis direction can be reduced. In particular, in the light emitting device 100 of the example illustrated in FIG. 1, the central axes C ₁ , C ₂ , C ₃ , and C ₄ of the _four convex portions 45 provided on the side of the light source unit 30 are provided in the xy plane. The angles formed by the central axes C _{1 to} C ₄ and the z axis are 90 ° and are equal to each other. In addition, the central axis of one of the convex portions is substantially perpendicular to the upper surface of the mounting substrate 50 on which the light source unit 30 is provided, that is, the z axis, and the central axis of the remaining convex portions is the light source unit on the xy plane. The light source unit 30 is substantially equally distributed around the light source unit 30 and is substantially parallel to the upper surface of the mounting substrate 50 on which the light source unit 30 is provided, that is, in the xy plane. In such a form, the convex portion 45 can be disposed so as to correspond to the side surface of the second main surface of the light emitting element 10 and the side surface of the light source unit 30 facing the second main surface, respectively, in the present embodiment. Since the convex portions 45 corresponding to the distributions of the primary light and the secondary light can be obtained, the function of each convex portion can be efficiently assigned, the light emission of the light source portion can be efficiently superimposed and emitted, and the light Similarly, color unevenness around the optical axis can be reduced even in a low angle region with respect to the axial direction and the optical axis.

  The convex portions 44 and 45 of the present invention are provided on the light emitting surface 41 of the light transmitting member as a portion protruding in the central axis direction toward the outside of the device as compared with the above-described conventional light emitting device. Although the shape of the surface which comprises the convex parts 44 and 45 is not specifically limited, It is preferable that each convex part has a convex curved surface which makes the central axis the optical axis. As a result, the light emitted from the light source unit 30 can be condensed in the direction of the central axis of each convex portion and can be efficiently emitted to the outside of the device, and the primary light and the secondary light can be superimposed inside and outside the device. Can be promoted. Further, the convex portions 44 and 45 can adjust the orientation of light emission from the light emitting surface 41 depending on the shape and the protruding amount, and are short in the central axis direction. For example, as in the present embodiment, the half width of the cross-sectional width If the shaft length at the rotation axis of the rotating body of the convex part is shorter than the width of the original plane of the rotating body, the directivity to each convex part is weakened, and the effect of reducing color unevenness and brightness unevenness is reduced. The directivity of the convex portion is weakened, and light emission with relatively uniform intensity can be obtained at all radiation angles. On the other hand, as in the other embodiments, the length of the central axis is longer than half of the width of the cross section with respect to the axis of the convex portion, thereby increasing the directivity to each convex portion, and from the convex portion. The emitted light can greatly reduce luminance unevenness and color unevenness. Such light with strong convexity directivity is adjusted to the shape of the light exit surface of the convex part to have a wide orientation distribution, or reflected or collected by an external reflector, an optical lens such as a lighting fixture. It can be used as a light-emitting device combining an optical structure. It is preferable that the surface of the convex part has a convex curved surface at least in part in the light condensing, dispersion, and radiation of the light emitting surface in the above-described member, and the convex part side surface and the end face of the convex part are respectively provided. It is preferable that the entire shape is formed as an integral curved surface such as a spherical surface or a rotating body. On the other hand, each reflection unit, light guide unit, so as to be light collection and reflection inside the member and light emission of a desired radiation characteristic so as to better match the orientation of the primary and secondary light of the light source unit The light emitting portion can have different surfaces and convex curved surfaces. For example, as seen in other embodiments, the end portion, the tip end region, and the vicinity thereof, and the region between these regions and the diffusion region, a different surface, curved surface, convexity for each of these regions. Can be curved. In addition, the connecting portion that connects the convex portions on the light emitting surface 41 of the light transmitting member to each other is not particularly limited in shape, and is a portion that connects adjacent convex portions, and is convex as the light emitting surface 41. What is necessary is just to be shape | molded integrally with the part. The connecting part can diffuse the primary light and the secondary light incident on the connecting part to the outside of the apparatus and emit the light, or reflect the primary light and the secondary light on the inner surface to collect the light on the convex part.

The light emitted from the light source unit 30 is collected in the central axis direction of the convex curved surface at the convex portions 44 and 45 of the light emitting surface 41, diffused at the connecting portion between the other convex portions, and emitted outside the apparatus. Is done. Therefore, it is possible to control the light distribution of the apparatus by utilizing the light condensing / diffusing action according to the surface shape and arrangement of the convex portions 44 and 45 and the connecting portion. For example, in the light emitting device 100 of the present embodiment, the light condensing action in the directions of the central axes C _{1 to} C ₄ works by the convex curved surfaces of the four convex portions 45 in the xy plane, and the light is in the directions of the central axes. By condensing the light, it is possible to promote the superimposition of the primary light and the secondary light outside the apparatus. Similarly, the convex portion 44 having the z axis in the xz plane and the yz plane as the central axis B has a condensing action in the central axis direction, and can increase the luminance in the optical axis direction of the apparatus.

  In the light emitting device according to the present embodiment in which the light transmitting member 40 is formed on a part of the upper surface of the mounting substrate 50, the light emitting surface 41 of the light transmitting member and the upper surface of the mounting substrate 50 as shown in FIG. Is located on the outermost side of the light transmissive member 40, the light transmissive member 40 can be easily formed by compression molding or the like, and is more productive than other embodiments described later. Is good.

  Next, each component of the light emitting device of the present invention will be described in detail below.

(Light emitting element)
The light-emitting element 10 can be a known element, specifically a semiconductor light-emitting element, and is particularly preferably a GaN-based compound semiconductor because it can emit visible light and ultraviolet light having a short wavelength that can excite a fluorescent substance efficiently. . A specific emission peak wavelength is 240 nm or more and 560 nm or less, preferably 380 nm or more and 470 nm or less. In addition, a light emitting element of ZnSe, InGaAs, or AlInGaP semiconductor may be used. The light-emitting element structure using a semiconductor layer is preferably composed of at least a first conductivity type (n-type) layer and a second conductivity type (p-type) layer, and further having an active layer therebetween. Further, the electrode structure is preferably the same surface side electrode structure in which both electrodes of the first conductivity type (negative) and the second conductivity type (positive) are provided on one main surface side, but facing each main surface of the semiconductor layer. Thus, a counter electrode structure in which electrodes are provided may be used. As for the mounting form of the light emitting element 10, for example, in the same-surface electrode structure described above, the flip chip mounting in which the electrode forming surface is the mounting surface and the substrate side facing it is the main emitting surface, the emitting surface, the wavelength conversion member, It is preferable in terms of optical connection. In addition, the electrode forming surface side is a main emission surface, the wavelength conversion member 20 is mounted on the surface, the face-up mounting is performed, and the light transmitting member having a wiring structure is flip-chip mounted. The transmissive member can be connected to the mounting substrate, and preferably the embodiment in which the light emitting element 10 and the wavelength conversion member 20 are not provided with wiring and electrodes is preferable. The growth substrate of the semiconductor layer may be removed when the light emitting element structure is not formed, and a support substrate such as a conductive substrate or another light transmissive member / substrate may be added to the semiconductor layer from which the growth substrate has been removed. It can also be set as the structure which adhered. In addition, an element having a structure in which a semiconductor layer is bonded and covered with a light transmission member such as glass or resin may be supported. The removal of the growth substrate can be performed by peeling, polishing, or LLO (Laser Lift Off) by mounting or holding the growth substrate on a support, device, or submount, for example. In addition, the light emitting element 10 can have a light reflecting structure. Specifically, of the two main surfaces of the semiconductor layer facing each other, the other main surface facing the light extraction side (outgoing surface side) is irradiated with light. A light reflection structure can be provided in the semiconductor layer on the light reflection side or on the electrode, etc., on the reflection side (lower side in FIG. 1). As an example of the light reflecting structure, a structure in which a multilayer reflective layer is provided in the semiconductor layer, or an electrode having a highly light reflective metal film such as Ag or Al or a dielectric multilayer film, or a reflective layer is provided on the semiconductor layer. There is a structure.

(Nitride semiconductor light emitting device)
As an example of the light-emitting element 10, in a nitride semiconductor light-emitting element, an n-type semiconductor layer that is a first nitride semiconductor layer, a light-emitting layer that is an active layer, a second layer on a C-plane sapphire substrate that is a growth substrate. A p-type semiconductor layer which is a nitride semiconductor layer is epitaxially grown in order. Then, a part of the n-type layer is exposed to form an n-type pad electrode which is a first electrode, a light-transmitting conductive layer such as ITO, and a p-type which is a second electrode over almost the entire surface of the p-type layer. A pad electrode is formed. Further, a protective film is provided to expose the surface of the n-type and p-type pad electrodes and cover the semiconductor layer. Note that the n-type pad electrode may be formed through a light-transmitting conductive layer as in the p-type. In addition to C-plane sapphire, the growth substrate is an R-plane and A-plane, an insulating substrate such as spinel (MgAl ₂ O ₄ ), silicon carbide (6H, 4H, 3C), Si, ZnS, ZnO, GaAs, There are semiconductor conductive substrates such as GaN and AlN. Examples of the nitride semiconductor, the general formula _{In x Al y Ga 1-xy} N (0 ≦ x, 0 ≦ y, x + y ≦ 1) of the other, B and P, may be mixed with As. The n-type and p-type semiconductor layers are not particularly limited to a single layer or a multilayer, and the active layer is preferably a single (SQW) or multiple quantum well structure (MQW). As an example of a blue light emitting device structure, an n-type semiconductor layer such as Si-doped GaN is formed on a sapphire substrate via a nitride semiconductor underlayer such as a buffer layer, for example, a low-temperature growth thin film GaN and a GaN layer. An n-type contact layer and an n-type multilayer film layer of GaN / InGaN are stacked, followed by an InGaN / GaN MQW active layer, and a p-type semiconductor layer, for example, an Mg-doped InGaN / AlGaN p-type multilayer film layer There is a structure in which p-type contact layers of Mg-doped GaN are stacked.

(Wavelength conversion member)
The wavelength conversion member 20 contains a phosphor that is excited by the primary light emitted from the light emitting element 10 and emits secondary light of the wavelength converted light, and has a desired hue due to color mixing of the primary light and the secondary light. It is a member constituting a composite light source capable of realizing emitted light. The wavelength conversion member 20 is preferably configured to have a structure in which a translucent member is used as a base material and a phosphor as a light conversion material is mixed in the translucent member. Can be coated. As a material of the translucent member that is a base material of the wavelength conversion member 20, for example, resin, glass, or an inorganic substance can be used. Further, the following phosphor molded body and crystal body may be used. More specific examples of the wavelength conversion member 20 include phosphor-containing glass, phosphor crystals or single crystals having a phase thereof, polycrystals, amorphous bodies, ceramic bodies, and the like. In addition, sintered bodies, aggregates, and porous bodies of phosphor particles and an appropriately added translucent material, and further, a translucent member such as a translucent resin mixed and impregnated, or fluorescent It is comprised from the translucent member containing a body particle, for example, the molded object etc. of translucent resin. The coating form of the wavelength conversion member 20 is not particularly limited. As described above, a translucent resin or molten glass containing phosphor particles may be provided around the light emitting element 10 by potting or screen printing, or a plate shape. Alternatively, a sintered body or a glass plate may be attached to the light-emitting element 10 with a translucent adhesive. Since the wavelength conversion member 20 is formed to have a substantially constant thickness, the ratio of color mixing can be stabilized and the occurrence of color unevenness on the surface of the light source unit 30 can be suppressed. In addition, the thickness of the wavelength conversion member 20 is preferably 10 μm or more and 500 μm or less, and more preferably 50 μm or more and 300 μm or less in terms of luminous efficiency and chromaticity adjustment. In addition, the number of light emitting elements 10 covered by one wavelength conversion member 20 is not particularly limited. If a plurality of light emitting elements 10 are used, the luminous flux can be increased and the luminance of the light emitted from the light source unit 30 can be increased. When a plurality of light emitting elements 10 are used, they are arranged in a line, for example, and arranged at lattice positions at equal intervals. As described above, even when a plurality of light emitting elements 10 are provided, the thickness of the wavelength conversion member 20 is substantially constant, so that unevenness in luminance and chromaticity on the surface of the light source unit 30 due to the arrangement of the individual light emitting elements 10 is obtained. Can be reduced.

The wavelength conversion member 20 is preferably one that can emit white light in combination with a blue light emitting element. Typical phosphors used in such a wavelength conversion member 20 include YAG phosphors (yttrium, aluminum, garnet) and LAG phosphors (lutetium, aluminum, garnet) that are attached with cerium having a garnet structure. . particularly, in a high luminance mode and prolonged use _{(Re 1-x Sm x)} 3 (Al 1-y Ga y) 5 O 12: Ce (0 ≦ x <1,0 ≦ y ≦ 1 However, Re is at least one element selected from the group consisting of Y, Gd, La, and Lu. Further, a phosphor containing at least one selected from the group consisting of YAG, LAG, BAM, BAM: Mn, (Zn, Cd) Zn: Cu, CCA, SCA, SCESN, SESN, CESN, CASBN, and CaAlSiN ₃ : Eu. Can be used. It is also possible to increase the reddish component using a nitride-based phosphor having yellow to red light emission, and to realize illumination with high average color rendering index Ra, light bulb color LED, and the like. Specifically, by adjusting the amount of phosphors having different chromaticity points on the CIE chromaticity diagram according to the emission wavelength of the light emitting element 10, the phosphors are connected to each other by the light emitting element 10. Any point on the chromaticity diagram can be illuminated. In addition, nitride phosphors, oxynitride phosphors, and silicate phosphors that convert near-ultraviolet to visible light into a yellow to red region can be used. For example, L ₂ SiO ₄ : Eu (L is an alkaline earth metal), particularly (Sr _x Mae _1-x ) ₂ SiO ₄ : Eu (Mae is an alkaline earth metal such as Ca and Ba) and the like. Examples of nitride phosphors and oxynitride (oxynitride) phosphors include Sr—Ca—Si—N: Eu, Ca—Si—N: Eu, Sr—Si—N: Eu, and Sr—Ca—Si. —O—N: Eu, Ca—Si—O—N: Eu, Sr—Si—O—N: Eu, and the like. As the alkaline earth silicon nitride phosphor, the general formula LSi ₂ O ₂ N ₂ : Eu , general formula _{L x Si y N (2 /} 3x + 4 / 3y): Eu or _{L x Si y O z N (} 2 / 3x + 4 / 3y-2 / 3z): Eu (L is, Sr, Ca, One of Sr and Ca).

(Light transmission member)
The light transmitting member 40 may be provided apart from the light source unit 30 as long as it covers the light source unit 30, but by being bonded to the light source unit 30, particularly the surface of the wavelength conversion member 20, The light extraction efficiency can be improved. The light transmitting member 40 can be formed using a resin material such as an epoxy resin, a silicone resin, a modified silicone resin, a urea resin, a urethane resin, an acrylic resin, a polycarbonate resin, or a polyimide resin. In addition, since the light transmissive member 40 also serves as a sealing material for protecting the light emitting element 10 and the wavelength conversion member 20, a material excellent in weather resistance, heat resistance, and hardness is preferable. An epoxy resin or a hard silicone resin is preferable. Is preferred. Further, glass may be used. Furthermore, the phosphor as described above and / or light scattering particles such as TiO ₂ and / or fillers such as quartz glass, and other pigments are appropriately added to the light transmitting member 40 to obtain desired light emission characteristics. be able to. Further, the light transmitting member 40 can be formed into a desired size and a desired shape by compression molding, transfer molding, or the like.

(Mounting substrate)
As the mounting substrate 50 on which the light emitting element 10 is mounted, a mounting substrate on which a wiring 55 having at least a surface connected to the electrode of the element can be used, and an external connection wiring 56 (Embodiments 2 and 3 described later). 4 may be provided on the lower surface of the mounting substrate 50 and connected to the wiring 55 on the upper surface through a through hole. The material of the substrate 50 is composed of aluminum nitride (AlN) as an example, and is a single crystal, polycrystal, sintered substrate, ceramics such as alumina as other materials, glass, semi-metal or metal substrate such as Si, and those materials Laminates and composites can be used, and metallic and ceramics are preferred because of their high heat dissipation. The substrate 50 may have no wiring. For example, the substrate 50 may be mounted on the growth substrate side and the electrode of the element may be wire-connected to the electrode of the device. The mounting substrate 50 preferably has at least a surface made of a highly reflective material, and a reflective layer (59) such as an insulating film 58 (or a dielectric multilayer film) covering the wiring 55 to prevent a short circuit. May be provided. In addition to this, the mounting substrate 50 may be a pair of lead frames, and the mounting portion of the light emitting element 10 may be provided with a recess (cup, cavity). Can also emit light, for example, light can be emitted in a spherical shape except under the light source unit 10 and the mounting substrate 50. The light emitting element 10 is bonded on the wiring 55 by the conductive adhesive 60 and is electrically connected to the outside. As the conductive adhesive 60, solder, Ag paste, Au bump, or the like can be used.

<Embodiment 2>
4B is a schematic top view of the light-emitting device according to Embodiment 2 of the present invention, and FIG. 4A is a schematic cross-sectional view taken along line AA in FIG. 4B. In the light emitting device 200 of the example shown in FIG. 4, the same reference numerals are given to substantially the same configurations as those of the first embodiment described above, and description thereof will be omitted as appropriate.

In the light emitting device 200 of the example shown in FIG. 4, the light source unit 30 is substantially the same as in the first embodiment, and differs in that a phosphor is disposed in a region between the mounting surface and the light emitting element 10. The transmissive member 40 has a width larger than the width of the mounting substrate 50, and is provided so as to protrude and extend laterally from the side surface of the mounting substrate 50. The light emitting surface 41 of the light transmitting member is provided with four convex portions 45 each having a convex curved surface. The central axes D ₁ , D ₂ , D ₃ , and D ₄ of the convex portions 45 form an angle of 60 ° with respect to the z axis (H axis), and the light source is on the xy plane as in the first embodiment. The portions 30 are arranged approximately equally at intervals of 90 ° with the center as the center. Thus, when the central axis of all the convex parts 45 is comprised by axes other than az axis, it is preferable that the central axis of each convex part 45 is inclined in the z-axis direction on the xz plane and the yz plane. . Thereby, while increasing the luminance of the light emitted in the optical axis direction of the apparatus, the superimposition of the primary light and the secondary light emitted in the optical axis direction is promoted, and color unevenness can be reduced. The H axis in the figure represents the optical axis, which is the same as the B axis in the first embodiment, and the same applies to FIG.

  Further, in the light emitting device 200, the light transmitting member 40 is coupled to the side surface of the mounting substrate 50, and thus the light transmitting member 40 covers at least part of the side surface of the mounting substrate 50 and seals the light source unit 30. It may be stopped. As a result, a light emitting surface 41 is also provided below the upper surface of the mounting substrate 50 of the light transmitting member 40 in the extending portion, and primary light and secondary light are also emitted from the light emitting surface 41 below the light source portion 30. In other words, it has a bottom surface that can emit light outside the mounting substrate. On the other hand, the superimposition of the primary light and the secondary light can be further promoted by condensing the convex part 45 by reflection on the inner surface of the light transmitting member 40 below the light source part 30. With such reflection at the interface between the light transmitting member 40 and air, the light can be reflected without being affected by light absorption (light loss) by the mounting substrate surface, the wiring 55, or the like, and the light source unit 30. Thus, light can be efficiently extracted outside the apparatus. Further, the light emitted from the bottom surface can be a light emitting device in which the emission angle is adjusted by combining optical functions such as a reflector and an optical lens outside the device.

  In the light emitting device 200 according to the second embodiment, since the angle formed by the central axis of each convex portion 45 and the z axis is in the high angle range of the optical axis, the primary light and the secondary light are in the direction of the central axis. The primary light and the secondary light that are collected and emitted on the z-axis by the connecting part directly above the light source part 30 are diffused and emitted. As a result, compared to other embodiments, primary light and secondary light can be diffused widely around the optical axis of the device and emitted to the outside of the device, resulting in a wide light distribution with less color unevenness. Can be obtained. On the other hand, since the central axis of the convex portion, that is, the direction is inclined to the optical axis side and the upper side, the emitted light in the optical axis direction is also inferior to the form having the second convex portion 44, It is preferably taken out.

  The direction of the central axis of the convex portion 45 with respect to the constituent surface of the light emitting element 10 in the xy plane (the surface constituting the outline of the light emitting region formed by the light emitting elements 10 when a plurality of light emitting elements 10 are arranged) There is no particular limitation. In the xy plane, when the light emitting element / region is substantially square, the primary light emitted from the side surface of the light emitting element 10 has higher luminance with respect to the side of each side surface than the diagonal direction of the substantially square element. Tend. Therefore, as in Embodiments 1 and 2, the convex portion 45 is provided to face each side surface of the light emitting element 10, and the connecting portion of the convex portion 45 is provided to face each corner portion of the light emitting element 10. Thus, primary light emitted from the side surface of the light emitting element 10 can be efficiently extracted, and light emission with high luminance can be realized. On the other hand, in the xy plane, the convex portion 45 may be provided so as to face each corner of the light emitting element 10 or the light emitting region. Preferably, the central axis of the convex portion 45 is a diagonal line of the light emitting element 10 in the xy plane. By being provided so as to substantially match, the luminance of the primary light in the diagonal direction of the element can be compensated to reduce color unevenness. Further, the light source 30 and the component surface of the wavelength conversion member 20 in the xy plane, that is, the side surface on the light emitting side are the same when the side surface is opposite to the side surface that is the second main surface of the light emitting element 10. In the case of having different surfaces, the light extraction efficiency in the light emission of the light source part tends to decrease. Examples of different surface forms include a side face different from the side face of the light emitting element 10, for example, a form rotated around the optical axis, a form having a different number of side faces, and a curved surface, a spherical surface, and the like. The problem of the conventional light emitting device described above tends to be reduced. However, for further improvement, since the degree of dependence on the orientation of the light emitting element is high, it is preferable to correspond to the side surface of the light emitting element. However, in the case of a light source unit having a plurality of light emitting elements, there is a higher tendency to depend on the side surface when the side surfaces are substantially parallel to each other, and on the side surface of the light source unit when different.

<Embodiment 3>
5 (b) is a schematic top view of the light emitting device according to Embodiment 3 of the present invention, FIG. 5 (a) is a schematic cross-sectional view along AA in FIG. 5 (b), and FIG. It is a schematic top view explaining the mounting base | substrate of this light-emitting device, and its wiring structure. In the light emitting device 300 of the example shown in FIGS. 5 and 6, components substantially similar to those of the first embodiment described above are denoted by the same reference numerals and description thereof is omitted as appropriate.

  In the light emitting device 300 of the example shown in FIGS. 5 and 6, on the mounting substrate 50, approximately four plate-shaped light emitting elements 10 having a substantially square shape in a top view are formed so as to form a substantially rectangular light emitting region. The light source section 30 is configured by covering the light emitting area, that is, the upper surface and the side surface of each light emitting element 10 with the wavelength conversion member 20. Here, as shown in FIG. 5, the light emitting elements 10 are connected in series with each other and flip chip mounted by wirings 55a, 55b, and 55c provided on the mounting substrate 50. As described above, when the light source unit 30 includes a plurality of light emitting elements 10, color unevenness due to the arrangement of the light emitting elements 10 and the thickness of the wavelength conversion member 20 is likely to occur. Such a color unevenness can be reduced by superimposing the primary light and the secondary light inside and outside the apparatus by the plurality of convex portions 45 provided on the light emitting surface 41 of the transmission member. Light emission with a small amount of high luminous flux is possible.

  In addition to the form shown in FIG. 5, the light source unit 30 has a form in which the light emitting elements 10 are each covered with another wavelength conversion member 20, for example, the light emitting elements 10 previously covered with the wavelength conversion member 20 are separated from each other. May be arranged. Even in such a form, the primary light and the secondary light respectively emitted from the light emitting element 10 covered with the wavelength conversion member 20 have the function of the convex portion, and the arrangement of the light emitting elements 10 and the thickness of the wavelength conversion member 20 Color unevenness due to the color can be reduced. Further, the arrangement of the protrusions relative to the arrangement of the plurality of light emitting elements 10 in the light source unit 30 and the direction of the central axis thereof are not particularly limited. However, as shown in FIG. 5, in the light source unit 30, when the plurality of light emitting elements 10 are arranged symmetrically with respect to the center of the light source unit, the convex portion 45 and the center axis thereof are the xy plane. In FIG. 5, the light source unit 30 is provided in a uniform arrangement around the light source unit 30, so that it is possible to reduce color unevenness balanced around the optical axis of the apparatus. On the other hand, when the plurality of light emitting elements 10 are arranged asymmetrically with respect to the center of the light source unit 30 in the light source unit 30, for example, the formation density of convex portions on the side where the light emitting elements 10 are few is increased. Corresponding to the arrangement of the projections, the projections and the central axis thereof may be offset.

  As shown in FIG. 6, in the mounting substrate 50 such as ceramic or glass epoxy, in order to prevent light from the light source unit 30 from passing through the substrate 50 and leaking to the lower side of the apparatus, A reflective layer 59 may be provided around the light source unit 30 and at the coupling portion of the light transmitting member 40. As such a reflective layer 59, a wiring layer having the same configuration as the wiring 55, or a highly reflective metal layer such as an Ag or Al layer formed thereon, and a dielectric multilayer film formed thereon are further formed. And the like.

The light transmissive member 40 according to the third embodiment has a width larger than the width of the mounting substrate 50, and is provided to project and extend from the side surface of the mounting substrate 50 to the side. The light emitting surface 41 of the light transmitting member is provided with three convex portions 45 each having a convex curved surface. The central axes E ₁ , E ₂ , E ₃ of the convex portions 45 form an angle of 45 ° with respect to the z-axis and are substantially equally spaced at 120 ° intervals around the light source unit 30 on the xy plane. Further, the light transmission member 40 is coupled to the side surface of the mounting substrate 50 and has a bottom portion that forms a bottom portion substantially the same as the mounting surface in the extending portion, and the bottom portion is a flat surface. As a result, compared to the convex curved surface of the second embodiment, the components of the primary light and the secondary light that are emitted from the light source unit 30 to the lower side of the upper surface of the mounting substrate 50 are totally reflected at the bottom, and the upper part of the device is increased. It is possible to further efficiently superimpose the primary light and the secondary light by collecting the light on the convex portion and thereby collecting the light efficiently. Further, if the connecting portion is a concave curved surface like the light transmitting member 40, the light emitting surface 41 can be easily formed, and in particular, in order to maintain the light distribution in the optical axis direction of the apparatus in a good state, the light source portion 30. It is preferable that the connecting portion located immediately above is formed in a concave curved surface.

  In the light emitting device 300 of the third embodiment, the inclination angle of the central axis of each convex portion 45 with respect to the z axis is smaller than that of the second embodiment, and the convex portions 45 are densely arranged in the optical axis direction of the device. It is arranged, has a relatively strong light condensing action in the optical axis direction of the device, has higher brightness in the optical axis direction (z-axis) of the device than other embodiments, and obtains a high luminous flux emission light Can do.

<Embodiment 4>
FIG.7 (c) is a schematic top view of the light-emitting device concerning Embodiment 4 of this invention, Fig.7 (a) is AA schematic sectional drawing of FIG.7 (b). In the light emitting device 400 of the example shown in FIG. 7, components substantially similar to those of the above-described first embodiment are denoted by the same reference numerals and description thereof is omitted as appropriate.

In the light emitting device 400 of the example shown in FIG. 7, the light source unit 30 is the same as that of the first embodiment, and the light transmission member 40 has a width larger than the width of the mounting substrate 50 and is on the side of the side surface of the mounting substrate 50. Projecting and extending in the direction. The light emitting surface 41 of the light transmitting member includes one second convex portion 44 having the z axis as the central axis B, and four convex portions 45 having substantially the same angle between the z axis and the central axis. Two convex portion groups 46 and 47 are provided. As shown in FIG. 7A, the central axes F ₁ , F ₂ , F ₃ , and F ₄ of the respective convex portions 45 of the first convex portion group 46 are in the xy plane (the angle formed with the z axis). On the other hand, as shown in FIG. 7B, the angle formed between the central axes G ₁ , G ₂ , G ₃ , G _{4 of the} convex portions 45 of the second convex portion group 47 and the z axis is Each is 45 °. Further, as shown in FIG. 7B, in the xy plane, the central axes of the convex portions 45 in the convex portion groups 46 and 47 are substantially equally spaced at 90 ° intervals with the light source portion 30 as the center. The central axis (F _{1 to} F ₄ ) of the convex portion 45 of the first convex portion group 46 and the central axis (G _{1 to} G ₄ ) of the convex portion 45 of the second convex portion group 47 are rotated by 45 °. Is provided. Further, in the xy plane, the central axes (F _{1 to} F ₄ ) of the convex portions 45 of the first convex portion group 46 are provided so as to substantially coincide with the diagonal lines of the light emitting element 10, respectively, and the second convex portion group 47. The central axis (G _{1 to} G ₄ ) of the convex portion 45 is provided so as to be a substantially vertical bisector of the side surface of the light emitting element 10. Each convex portion 45 has a convex curved surface with the central axis as the optical axis.

  As described above, the light emitting surface 41 of the light transmitting member is provided with a plurality of convex portions including a plurality of convex portions 45 whose angles formed with the central axis and the z axis are substantially equal to each other, with the angles formed with the z axis being changed. Therefore, the effect of reducing color unevenness around the optical axis (z-axis) of the device can be further enhanced. Even in such a form, it is preferable that the convex portions 45 provided in one convex portion group are substantially equally arranged around the light source portion 30 in the xy plane as described above. In addition, the number of such convex portion groups is not particularly limited. For example, if the number is two as in the fourth embodiment, the interval (formation density) between the convex portions 45 is appropriately maintained and light is efficiently superimposed. In addition, the light emitting surface 41 can be formed relatively easily. Furthermore, as in the present embodiment, if the convex portion 45 of another convex portion group is disposed above or below the connecting portion (concave portion) of the convex portion 45 in one convex portion group, The diffusion of light by the connecting portion of one convex portion group is compensated by condensing light by the convex portion 45 of another adjacent convex portion group to reduce luminance unevenness in addition to color unevenness around the optical axis of the device. be able to. The second convex portion 44 having the z axis as the central axis may be omitted.

<Embodiment 5>
FIG. 8B is a schematic top view of the light-emitting device according to Embodiment 5 of the present invention, and FIG. 8A is a schematic cross-sectional view taken along the line AA in FIG. In the light emitting device 500 of the example shown in FIG. 8, components substantially similar to those of the first embodiment described above are denoted with the same reference numerals, and description thereof is omitted as appropriate.

  In the light emitting device 500 of the example shown in FIG. 8, the light emitting surface 41 of the light transmitting member has the projecting portions 44 and 45 of the light emitting device 100 according to Embodiment 1 formed in a cannonball shape. Thus, one convex part 44 and 45 may be comprised by the combination of a convex curved surface and a cylindrical surface (henceforth a cylindrical surface). In this case, the reflection on the inner surface of the cylindrical surface can promote the superimposition of the primary light and the secondary light inside the light transmitting member 40, and direct the primary light and secondary light emitted from the convex portion in the direction of the central axis. And light collecting properties can be improved.

  Further, in the light emitting device 500, the light source unit 30 is configured such that the light emitting region by the plurality of light emitting elements 10 connected in series with each other is covered with the wavelength conversion member 20, as in the third embodiment. Covered and sealed by a sealing member 70. The sealing member 70 can be formed of a resin material or the like, similar to the light transmitting member 40 and the wavelength converting member described above, and the light emitting side surface is preferably formed in a hemispherical shape. It is possible to efficiently extract light while suppressing reflection on the inner surface of the member. Further, in the sealing member, a diffusing agent is added, the orientation of the light source part is relaxed in the first stage in the member 70, and the light is transmitted further on the outer side through the light transmitting member to be condensed in the second stage. A multistage relaxation structure for emitting light can also be formed. Further, a refractive index difference can be provided between the light transmitting member and the refractive index can be relaxed in multiple stages. Thus, the sealing member 70 can function as a light diffusion region provided at a constant distance from the light source unit described above.

  Further, the light transmitting member 40 is a molded body that is pre-molded with resin, glass or the like so as to have the light emitting surface 41 as described above, and the molded body is mounted on a mounting substrate 50 having the light source unit 30. Yes. On the surface opposite to the light emitting surface 41 of the light transmitting member, that is, the surface on the mounting side of the light transmitting member 40, a recess is provided at the substantially central portion so that the light source unit 30 is disposed. ing. As shown in the figure, such a recess is provided in a hemispherical shape, similar to the surface shape of the sealing member 70, thereby suppressing light reflection on the surface of the recess and transmitting light from the light source unit 30. The transmission member 40 can be efficiently coupled.

  When such a light transmitting member 40 is provided in contact with the light source unit 30 or the sealing member 70 covering the light source unit 30, it is preferable that the light transmitting member 40 be joined by a light transmitting adhesive (not shown) such as a resin. Further, the light transmitting member 40 and the sealing member 70, and further, the adhesive for bonding both members preferably have refractive indexes close to each other, more preferably the same kind of material in order to guide light efficiently. It is good to comprise. Alternatively, the refractive index of the light transmitting member 40 and the sealing member 70 are intentionally made different, for example, by making the refractive index of the light transmitting member 40 smaller than the refractive index of the sealing member 70, and the light transmitting member 40 and the sealing member 70. Color unevenness may be reduced by superimposing primary light and secondary light using refraction and reflection of light due to the difference in refractive index. Further, for example, a plurality of convex portions may be provided on the surface of the sealing member 70 as viewed from above, like the light emitting surface 41 of the light transmitting member. The superposition action of the primary light and the secondary light may be further enhanced by using the index interface. In addition to the adhesive, the light transmitting member 40 may be fixed to the sealing member 70 by locking or fitting. In such a case, the light transmitting member 40 may be provided apart from the mounting substrate 50. Good.

  On the other hand, when the light transmissive member 40 is provided apart from the light source unit 30 or the sealing member 70, the light transmissive member 40 is not limited to the light transmissive adhesive, and may be bonded to the mounting substrate 50 by a light reflective material such as metal. Alternatively, it may be fixed to the mounting substrate 50 or another substrate by locking or fitting. In the light emitting device 500 as well, a reflective layer 59 is provided on the upper surface of the mounting substrate 50 to which the convex portions 45 of the light transmitting member 40 are coupled, thereby preventing light from leaking downward from the device.

  In the case of the light emitting device 500 of Embodiment 5 in which the light transmitting members 40 individually molded in this way are bonded, the shape of the light transmitting member 40 is not limited by the mounting substrate surface or the like, and more convexes are formed. The light emitting surface 41 having a relatively complicated shape including the portion 45 can also be molded, and it is easy to control the color unevenness due to the convex portion 45 and the light distribution of the apparatus.

  Further, in the light emitting device of the example shown in FIG. 8, the light transmitting member 40 does not necessarily have to be formed in advance, and may be directly formed thereon after the sealing member 70 is provided. For example, the sealing member 70 may be formed of glass, and the light transmitting member 40 having the convex portions 45 thereon may be formed of resin. If it is such a form, while light emission by which the color unevenness was reduced by the convex part 45 of a light transmission member will be realized, light source part 30 will be sealed by glass with heat conductivity higher than a resin material, and light emission will be carried out. The heat dissipation of the element 10 and the wavelength conversion member 20 can be improved, and the reliability of the apparatus can be improved.

<Modification>
In the light emitting device of the present invention, as shown in FIG. 9, each of the convex portions 44 and 45 provided on the light emitting surface 41 of the light transmitting member does not have a convex curved surface, and is constituted by, for example, a polyhedron including a plurality of flat surfaces. The light emitting device 550 may be used. When the surface constituting the convex portions 44 and 45, particularly the constituent surface having the central axis of the convex portion as the optical axis, is a flat surface, the internal reflection is compared with a form having a convex curved surface having the central axis as the optical axis. By increasing the light, the superposition of the light inside the light transmitting member 40 is promoted, and the color unevenness of the light emitted from the light emitting surface 41 can be reduced. In addition, when the constituent surface having the central axis of the convex portions 44 and 45 as the optical axis in this way is a flat surface, light is diffused from the flat surface and emitted to the outside. By diffusing light, particularly primary light, in a direction orthogonal to the direction, it is possible to promote superimposition of primary light and secondary light outside the apparatus. Further, the constituent surface with the central axis of the convex portion as the optical axis may be further diffused as a concave curved surface, or the corner of the convex portion of the polyhedron is rounded, for example, the corner portion as a convex curved surface, You may heighten the condensing effect | action of a corner | angular part. Furthermore, the convex portion can be formed in a weight shape, for example, a polygonal pyramid shape or a conical shape.

Further, as in the embodiment described above, the convex portions of the light emitting surface 41 of the light transmitting member are arranged in the same shape, so that substantially uniform optical action is achieved in the direction of each central axis. On the other hand, the shape of each convex portion of the light transmitting member may be individually changed according to the light distribution of the primary light and the secondary light that the light source unit 30 has. For example, in the light emitting device 500 shown in FIG. 8, the second convex portion 44 having the z axis as the central axis (B) is formed by a convex curved surface, for example, a spherical surface, and the central axes (C _{1 to} C ₄ ) are xy. Four bullet-shaped convex portions 45 that are in a plane and are substantially equally spaced at 90 ° intervals with the light source portion 30 as the center are extended in the direction of the central axis, for example, the length of the cylindrical surface in the direction of the central axis Each is configured larger than that of the convex curved surface. With the light emission surface 41 having such a configuration, the primary light strongly emitted from the light source unit 30 on the z-axis is efficiently extracted by the convex curved surface directly above the light source unit 30 while being drawn from the extended cylindrical surface. The secondary light can be easily extracted, and the superimposition of the primary light and the secondary light in the optical axis direction of the apparatus can be promoted.

  In the present invention, in addition to the case where the central axis of the convex part is a rotationally symmetric axis of the convex part shape, in the case of the form not having the symmetrical axis and the optical axis as the light exit surface of the convex part, The main light exit surface of the convex part, for example, the end part of the convex part, the axis passing through the center and passing through the light source part, or the axis parallel to the protruding direction of the convex part becomes the central axis. In each embodiment, only the mode in which the central axis passes through the light source unit has been described. However, even if the axis is spaced from the light source unit, the effect can be obtained as long as the axis passes through the light diffusion region. In the light emitting device of the present invention, the light transmitting member includes a light diffusion region surrounding the periphery at a certain distance from the light source unit, and a light condensing region reaching each convex portion through the light diffusion region.

  Furthermore, the light emitting device of the present invention has a light transmitting member in which the mounting base is a pair of lead frames, a light source part is provided on the mounting part of one lead, and a convex part is provided on the light emitting surface. In such a device, a convex portion can also be provided on the light emitting surface on the lower side of the device, and light with a small color unevenness is obtained except for the lower portion of the light source portion and the lead frame. It is possible to emit light.

  Examples according to the present invention will be described in detail below. Needless to say, the present invention is not limited to the following examples.

<Example 1>
In Example 1, a light emitting device having a structure as shown in FIG. 1 is manufactured by the following method. A positive electrode and negative electrode wiring 55 made of Ti / Pt / Au is formed on an AlN ceramic substrate 50 having an upper surface size of about 14.0 mm × 10.0 mm and a thickness of about 1.0 mm. Further, a metal reflective layer made of Ti / Al and a dielectric multilayer film 58 made of SiO ₂ / Nb ₂ O ₅ are sequentially formed on regions other than the light emitting element mounting portion and the external connection terminal portion. The reflective layer (59). Next, one gallium nitride blue LED chip 10 (with a light emission wavelength of 450 nm) having a size of about 1 mm × 1 mm is mounted on the wiring 55 and flip-chip mounted. At this time, the LED chip 10 and the wiring 55 are bonded by eutectic bonding using paste-like Au—Sn (60) and bonded at a maximum temperature of 320 ° C. by a reflow apparatus in a nitrogen atmosphere. Next, an appropriate amount of a thermosetting silicone resin is applied to the side surfaces (four surfaces) and the upper surface of the LED chip 10 to sinter YAG phosphor that emits yellow light and alumina (Al ₂ O ₃ ). The plate 20 is attached to the side surfaces (four surfaces) and the upper surface of the LED chip 10 and heated at 150 ° C. for 600 seconds to cure the silicone resin. In this manner, the light source unit 30 that can emit white light is obtained, which is composed of the LED chip 10 covered with the phosphor plate 20. Then, the ceramic substrate 50 provided with the light source unit 30 is placed on the lower mold, and a liquid silicone resin is dropped onto the ceramic substrate 50 and the lower mold. Thereafter, the upper mold is closed, and the silicone resin is primarily cured at 150 ° C. for 180 seconds in the mold, taken out from the mold, and further secondarily cured at 150 ° C. for 4 hours. As a result, the light source unit 30 is sealed by the light transmitting member 40 having the light emitting surface 41 corresponding to the lens mold formed on the inner surface of the upper mold. The convex curved surface of each convex portion 45 of the light transmitting member 40 is composed of a part of the surface of the spheroid whose major axis is the major axis of the spheroid having a major axis of about 6 mm and a minor axis of about 5 mm, Four convex portions 45 each having a central axis in the xy plane and equally distributed around the light source unit 30 at intervals of 90 °, and the central axis substantially coincide with the z axis and are disposed immediately above the light source unit 30. One convex portion 45 is provided so as to be inscribed in a spherical surface having a diameter of about 8 mm with the light source portion 30 as the center, and serves as a light emitting surface 41 connected to each other. The light emitting device of Example 1 is obtained as described above.

<Comparative Example 1>
The light emitting device of Comparative Example 1 is the same as the manufacturing method of Example 1 except that the light transmitting member is molded using the upper mold provided with a hemispherical lens mold having a diameter of about 8 mm in Example 1. To make.

  In the light emitting device of the comparative example 1, white light with a yellowish color is observed in the high angle region over substantially the entire circumference of the optical axis (z axis) of the device. Color unevenness is reduced.

  The light emitting device of the present invention can be suitably used for backlight light sources such as illumination light sources, LED displays, liquid crystal display devices, traffic lights, illumination switches, various sensors, various indicators, and the like.

DESCRIPTION OF SYMBOLS 10 ... Light emitting element 20 ... Wavelength conversion member 30 ... Light source part 40 ... Light transmission member (41 ... Light-projection surface, 44 ... 2nd convex part, 45 ... Convex part (1st convex part), 46, 47 ... Convex part _{group, B, C 1 ~C 4,} D 1 ~D 4, E 1 ~E 3, F 1 ~F 4, G 1 ~G 4 ... protrusion center axis of)
50 ... Mounting substrate (55, 56 ... Wiring, 58 ... Insulating film, 59 ... Reflective layer)
60 ... conductive adhesive 70 ... sealing member 100, 200, 300, 400, 500 ... light emitting device (150, 550 ... light emitting device)

Claims (6)

A light source unit having a plate-like light emitting element that is mounted on a mounting surface and emits primary light, and a wavelength conversion member that covers the light emitting element and emits secondary light having a wavelength different from the wavelength of the primary light. When,
A light transmissive member that covers the light source part and has a light emitting surface that emits the primary light and the secondary light to the outside, and
A plurality of convex portions are provided on the light exit surface,
The light transmission member has a region surrounding at a certain distance from the light source unit up to the convex portion, and a plurality of the convex portion protruding outward from the region, and a recess for connecting to each other said protrusion Provided,
The light emitting surface of the light emitting element or the light source unit is substantially square in top view ,
The convex portion is provided in the surface region facing the four sides of the light emitting element or the light source unit and the light emitting element with the central axis of the convex portion of the each said light emitting element also passes through the light source unit Or inclined with respect to the optical axis of the light source unit ,
Furthermore, the convex portion has a convex curved surface having the central axis as a rotation central axis. The light source unit is mounted on a mounting substrate;
The light emitting device according to claim 1, wherein the region is provided so as to surround the mounting substrate and extend outward from the mounting substrate. The light source unit is mounted on a mounting substrate;
The light emitting device according to claim 1, wherein the region is disposed on the mounting substrate. The light source unit is disposed on a mounting substrate,
Based on the upper surface of the mounting substrate,
The light transmitting member extends outside the mounting substrate, and the light exit surface is provided outside the mounting substrate;
The convex portion, the light emitting device according to any one of claims 1 to 3 the central axis is tilted with respect to the optical axis toward above the light source unit. The convex portion, the light emitting device according to any one of claims 1 to 4 inclination angle with respect to the optical axis is 45 ° to 90 °. Wherein the optical axis is substantially perpendicular to the mounting surface, the light transmitting member, as a center axis the optical axis, any one of claims 1 to 5 having a second protrusion protruding in the central axis direction 2. The light emitting device according to item 1.

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