JP2014096549A - Light-emitting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light-emitting device with improved light intensity per unit area.SOLUTION: There is provided a light-emitting device including a first light-emitting element and a second light-emitting element. The first light-emitting element includes a first semiconductor layer of a first conductivity type, a second semiconductor layer of a second conductivity type, and a first light-emitting layer provided between the first semiconductor layer and the second semiconductor layer. The second light-emitting element includes a third semiconductor layer of the first conductivity type, a fourth semiconductor layer of the second conductivity type, and a second light-emitting layer. The second semiconductor layer is disposed between the third semiconductor layer and the first light-emitting layer. The fourth semiconductor layer is provided between the third semiconductor layer and the second semiconductor layer. The second light-emitting layer is provided between the third semiconductor layer and the fourth semiconductor layer. At least a part of first light emitted from the first light-emitting layer passes through at least a part of the second light-emitting element, and is emitted to the external of the second light-emitting element.

Description

  Embodiments described herein relate generally to a light emitting device.

  For example, there is a light emitting device that emits white light by combining a semiconductor light emitting element that emits blue light and a phosphor that converts the wavelength of light. Such a light emitting device is applied to a lighting device or the like. In light emitting devices, it is required to increase the amount of light per unit area.

JP-A-55-93276

  Embodiments of the present invention provide a light emitting device with an increased amount of light per unit area.

  According to an embodiment of the present invention, a light emitting device including a first light emitting element and a second light emitting element is provided. The first light emitting element includes a first conductivity type first semiconductor layer, a second conductivity type second semiconductor layer, and a first light emission provided between the first semiconductor layer and the second semiconductor layer. And a layer. The second light emitting element includes a third semiconductor layer of the first conductivity type, a fourth semiconductor layer of the second conductivity type, and a second light emitting layer. The second semiconductor layer is disposed between the third semiconductor layer and the first light emitting layer. The fourth semiconductor layer is provided between the third semiconductor layer and the second semiconductor layer. The second light emitting layer is provided between the third semiconductor layer and the fourth semiconductor layer. At least a part of the first light emitted from the first light emitting layer passes through at least a part of the second light emitting element and is emitted to the outside of the second light emitting element.

  According to the embodiment of the present invention, a light emitting device having an increased amount of light per unit area is provided.

FIG. 1A to FIG. 1C are schematic views showing a light emitting device according to the first embodiment. FIG. 2 is a schematic cross-sectional view showing the light emitting device according to the first embodiment. FIG. 3A and FIG. 3B are schematic plan views showing another light emitting device according to the first embodiment. FIG. 4A and FIG. 4B are schematic plan views showing another light emitting device according to the first embodiment. FIG. 5A and FIG. 5B are schematic plan views showing another light emitting device according to the first embodiment. FIG. 6 is a schematic plan view showing another light emitting device according to the first embodiment. FIG. 7 is a schematic cross-sectional view showing another light emitting device according to the first embodiment. FIG. 8A to FIG. 8F are schematic views illustrating another light emitting device according to the first embodiment. FIG. 9A and FIG. 9B are schematic views showing another light emitting device according to the first embodiment. FIG. 10 is a schematic cross-sectional view showing another light emitting device according to the first embodiment. FIG. 11A and FIG. 11B are schematic views showing a light emitting device according to the second embodiment.

Embodiments of the present invention will be described below with reference to the drawings.
The drawings are schematic or conceptual, and the relationship between the thickness and width of each part, the size ratio between the parts, and the like are not necessarily the same as actual ones. Further, even when the same part is represented, the dimensions and ratios may be represented differently depending on the drawings.
Note that, in the present specification and each drawing, the same elements as those described above with reference to the previous drawings are denoted by the same reference numerals, and detailed description thereof is omitted as appropriate.

(First embodiment)
FIG. 1A to FIG. 1C are schematic views illustrating the light emitting device according to the first embodiment. FIG. 1C is a plan view. FIG. 1A is a cross-sectional view taken along line A1-A2 of FIG. FIG. 1B is a cross-sectional view taken along line B1-B2 of FIG.

  As illustrated in FIG. 1A to FIG. 1C, the light emitting device 110 according to the present embodiment includes a first light emitting element 10 and a second light emitting element 20.

  In this example, the light emitting device 110 further includes a mounting component 50. The mounting component 50 includes a board portion 55.

  The first light emitting element 10 is provided on the substrate unit 55. A second light emitting element 20 is provided on the first light emitting element 10.

  In the specification of the present application, the state provided above includes a state provided in direct contact and a state provided by inserting another element therebetween.

  A direction (stacking direction) from the first light emitting element 10 toward the second light emitting element 20 is defined as a Z-axis direction. One direction perpendicular to the Z-axis direction is taken as an X-axis direction. A direction perpendicular to the Z-axis direction and the X-axis direction is taken as a Y-axis direction.

  The first light emitting element 10 includes a first semiconductor layer 11 having a first conductivity type, a second semiconductor layer 12 having a second conductivity type, and a first light emitting layer 15. The first light emitting layer 15 is provided between the first semiconductor layer 11 and the second semiconductor layer 12. In this example, the first light emitting layer 15 is provided on the first semiconductor layer 11. A second semiconductor layer 12 is provided on the first light emitting layer 15.

  For example, the first conductivity type is p-type and the second conductivity type is n-type. The first conductivity type may be n-type and the second conductivity type may be p-type. In the following, it is assumed that the first conductivity type is p-type and the second conductivity type is n-type.

  The first light emitting element 10 has a first main surface 10a and a second main surface 10b. The first main surface 10a is a main surface on the second light emitting element 20 side. The second main surface 10b is a main surface opposite to the first main surface 10a. The first major surface 10a is, for example, an upper surface. The second major surface 10b is, for example, a lower surface. The second major surface 10 b faces the substrate portion 55.

  The first light emitting element 10 includes a first electrode 11e and a second electrode 12e. The first electrode 11e and the second electrode 12e are provided on the second main surface 10b side. The first electrode 11 e is electrically connected to the first semiconductor layer 11. The second electrode 12e is electrically connected to the second semiconductor layer 12. The first electrode 11e and the second electrode 12e face the substrate unit 55.

  As shown in FIG. 1A, for example, the second semiconductor layer 12 includes a first portion 12p and a second portion 12q. The second portion 12q is aligned with the first portion 12p along the XY plane (a first plane perpendicular to the direction from the first semiconductor layer 11 toward the second semiconductor layer 12). The first light emitting layer 15 is disposed between the first portion 12 p and the first semiconductor layer 11.

  The first light emitting element 10 is, for example, a semiconductor light emitting element having a flip chip structure. The first light emitting element 10 is, for example, a semiconductor light emitting element having a face-down structure. On the lower surface (second main surface 10b) of the first light emitting element 10, at least one electrode connected to the p-type semiconductor layer and at least one electrode connected to the n-type semiconductor layer are provided.

  The second light emitting element 20 includes a first conductivity type third semiconductor layer 23, a second conductivity type fourth semiconductor layer 24, and a second light emitting layer 25. The second light emitting layer 25 is provided between the third semiconductor layer 23 and the fourth semiconductor layer 24. The second semiconductor layer 12 of the first light emitting element 10 is disposed between the third semiconductor layer 23 and the first light emitting layer 15. The fourth semiconductor layer 24 is provided between the third semiconductor layer 23 and the second semiconductor layer 12. That is, the fourth semiconductor layer 24 is provided on the first light emitting element 10. A second light emitting layer 25 is provided on the fourth semiconductor layer 24. A third semiconductor layer 23 is provided on the second light emitting layer 25.

  The second light emitting element 20 has a third main surface 20a and a fourth main surface 20b. The third major surface 20a is a major surface on the first light emitting element 10 side. The fourth main surface 20b is a main surface opposite to the third main surface 20a. The third major surface 20a is, for example, a lower surface, and the fourth major surface 20b is, for example, an upper surface.

  The second light emitting element 20 includes a third electrode 23e and a fourth electrode 24e. The third electrode 23e and the fourth electrode 24e are provided on the fourth main surface 20b (upper surface) side. The third electrode 23e is electrically connected to the third semiconductor layer 23. The fourth electrode 24e is electrically connected to the fourth semiconductor layer 24.

  As illustrated in FIG. 1B, for example, the fourth semiconductor layer 24 includes a third portion 24p and a fourth portion 24q. The fourth portion 24q is aligned with the third portion 24p along the XY plane (a second plane perpendicular to the direction from the fourth semiconductor layer 24 toward the third semiconductor layer 23). The second light emitting layer 25 is disposed between the third portion 24 p and the third semiconductor layer 23.

  The second light emitting element 20 is, for example, a semiconductor light emitting element having a face-up structure. The second light emitting element 20 is, for example, a semiconductor light emitting element having a bonding wire structure. At least one electrode connected to the p-type semiconductor layer and at least one electrode connected to the n-type semiconductor layer are provided on the upper surface (fourth main surface 20b) of the second light emitting element 20.

  In this example, the mounting component 50 further includes first to fourth connection members 51 c to 54 c in addition to the board portion 55.

  The substrate unit 55 includes, for example, a mounting substrate 50 s and first to fourth substrate electrodes 51 to 54. The mounting substrate 50s has a mounting main surface 50a. The first to fourth substrate electrodes 51 to 54 are provided on the mounting main surface 50a. The second substrate electrode 52 is separated from the first substrate electrode 51 on the mounting main surface 50a. The third substrate electrode 53 is separated from the first substrate electrode 51 and the second substrate electrode 52 on the mounting main surface 50a. The fourth substrate electrode 54 is separated from the first substrate electrode 51, the second substrate electrode 52, and the third substrate electrode 53 on the mounting main surface 50a.

  The mounting main surface 50 a of the mounting substrate 50 s faces the first light emitting element 10. The mounting main surface 50a is substantially perpendicular to the Z-axis direction.

  In this example, the planar shape of the mounting main surface 50a of the mounting substrate 50s is a rectangle. In this example, one side of the mounting main surface 50a is along the X-axis direction. Another side of the mounting main surface 50a is along the Y-axis direction.

  In this example, the second substrate electrode 52 is separated from the first substrate electrode 51 along the X-axis direction. The position of the first substrate electrode 51 and the second substrate electrode 52 in the Y-axis direction within the mounting main surface 50a is the center of the mounting main surface 50a in the Y-axis direction.

In this example, the fourth substrate electrode 54 is separated from the third substrate electrode 53 along the Y-axis direction. The position of the third substrate electrode 53 and the fourth substrate electrode 54 in the mounting main surface 50a in the X-axis direction is the central portion of the mounting main surface 50a in the X-axis direction.
As described later, the shape and arrangement of the substrate electrode can be variously modified.

  At least a part of the first connection member 51 c is provided on the first substrate electrode 51. At least a part of the second connection member 52 c is provided on the second substrate electrode 52.

  At least a part of the first connection member 51 c is provided between the first electrode 11 e and the first substrate electrode 51. The first connection member 51 c electrically connects the first electrode 11 e and the first substrate electrode 51.

  At least a part of the second connection member 52 c is provided between the second electrode 12 e and the second substrate electrode 52. The second connection member 52c electrically connects the second electrode 12e and the second substrate electrode 52.

  The third connection member 53c electrically connects the third substrate electrode 53 and the third electrode 23e. The fourth connection member 54c electrically connects the fourth substrate electrode 54 and the fourth electrode 24e. The third connection member 53c and the fourth connection member 54c are, for example, conductive wires. The third connection member 53c is, for example, a first wiring, and the fourth connection member 54c is, for example, a second wiring.

  In this example, the second light emitting element 20 further includes a first pad portion 23f provided on the third electrode 23e, and a second pad portion 24f provided on the fourth electrode 24e. .

  One end of the third connection member 53c is connected to the third substrate electrode 53, and the other end is connected to the first pad portion 23f. One end of the fourth connection member 54c is connected to the fourth substrate electrode 54, and the other end is connected to the second pad portion 24f.

  In the light emitting device 110, at least a part of the light (first light) emitted from the first light emitting layer 15 passes through at least a part of the second light emitting element 20 and is emitted to the outside of the second light emitting element 20. To do. For example, the first light sequentially passes through the fourth semiconductor layer 24, the second light emitting layer 25, and the third semiconductor layer 23.

  The light (second light) emitted from the second light emitting layer 25 is mainly emitted from the upper surface (fourth main surface 20b).

  In the light emitting device 110, the first light emitting element 10 and the second light emitting element 20 are stacked on each other. The light emitted from the first light emitting element 10 (first light) and the light emitted from the second light emitting element 20 (second light) are mainly emitted upward in the light emitting device 110. In the light emitting device 110, the amount of light per unit area can be increased.

  For example, the light amount of the unit area value in the light emitting device 110 is higher than the configuration in which only one of the first light emitting element 10 and the second light emitting element 20 is provided. Compared with the configuration in which the first light emitting element 10 and the second light emitting element 20 are not stacked and juxtaposed in the XY plane, the light amount of the unit area value in the light emitting device 110 is high.

  There is an attempt to obtain a light emitting device that mounts a plurality of semiconductor light emitting elements at high density in an XY plane and emits high intensity light with a narrow light emitting area. In such a configuration, the amount of light obtained depends on the light emission efficiency of the light emitting element. For this reason, the brightness exceeding the value corresponding to each luminous efficiency of a light emitting element cannot be obtained. In such a configuration, there is a limit to the amount of light per unit area.

  On the other hand, in the light emitting device according to the embodiment, a plurality of light emitting elements are stacked on each other. For this reason, the light quantity per unit area can be increased.

  A first electrode 11 e and a second electrode 12 e are provided on the lower surface of the first light emitting element 10. For example, a light reflective material can be used as at least one of the first electrode 11e and the second electrode 12e. At least one of the first electrode 11e and the first electrode 12e reflects at least a part of the light (first light) emitted from the first light emitting layer 15. The reflected first light passes through at least a part of the second light emitting element 20 and is emitted to the outside of the second light emitting element 20.

  On the other hand, a part of the light (second light) emitted from the second light emitting layer 25 travels upward and is emitted to the outside of the second light emitting element 20. Another part of the second light travels downward and enters the first light emitting element 10. The light is reflected by the light-reflective first electrode 11e and the second electrode 12e. That is, at least one of the first electrode 11 e and the second electrode 12 e reflects at least a part of the second light emitted from the second light emitting layer 25. The reflected light is emitted from the upper surface of the first light emitting element 10, passes through the second light emitting element 20, and is emitted to the outside of the second light emitting element 20.

  Thus, in the embodiment, at least one of the first electrode 11e and the second electrode 12e is light reflective, and at least one of the first electrode 11e and the second electrode 12e is emitted from the second light emitting layer 25. The reflected second light can be reflected at least partly. Thereby, the light quantity per unit area can be raised more.

  The heat generated in the first light emitting element 10 is transmitted to the first substrate electrode 51 and the second substrate electrode 52, respectively, via the first connection member 51c and the second connection member 52c, for example. The heat is further transmitted to the mounting substrate 50s. Heat is dissipated efficiently. Thereby, in the 1st light emitting element 10, a high light emission rate is obtained. The lifetime of the first light emitting element 10 is extended.

  When the first connecting member 51c and the second connecting member 52c have a large cross-sectional area (area when cut along the XY plane), heat dissipation is enhanced. When the lengths of the first connecting member 51c and the second connecting member 52c (the length in the Z-axis direction) are short, the heat dissipation is improved.

  As illustrated in FIG. 1C, in this example, at least part of the second light emitting element 20 is at least one of the first substrate electrode 51 and the second substrate electrode 52 when projected onto the XY plane. It overlaps. At least a part of the second light emitting element 20 overlaps at least one of the first connecting member 51c and the second connecting member 52c when projected onto the XY plane.

  The heat generated in the second light emitting element 20 is further transferred to the mounting substrate 50s via, for example, the first light emitting element 10, the first connection member 51c, and the second connection member 52c. Thereby, heat is efficiently radiated. In the 2nd light emitting element 20, a high light emission rate is obtained and the lifetime in the 2nd light emitting element 20 becomes long.

  As shown in FIGS. 1A and 1B, in this example, the light emitting device 110 further includes an intermediate layer 40. The intermediate layer 40 is provided between the first light emitting element 10 and the second light emitting element 20. The intermediate layer 40 is provided between the second semiconductor layer 12 and the fourth semiconductor layer 24. The intermediate layer 40 is transmissive to the light (first light) emitted from the first light emitting layer 15. The intermediate layer 40 (at least a part thereof) is electrically insulating.

  At least part of the light (first light) emitted from the first light emitting layer 15 further passes through the intermediate layer 40. The light that has passed through the intermediate layer 40 passes through at least a part of the second light emitting element 20 and is emitted to the outside of the second light emitting element 20.

  A material having high thermal conductivity can be used for the intermediate layer 40. The intermediate layer 40 joins the first light emitting element 10 and the second light emitting element 20 to each other. For the intermediate layer 40, for example, a silicone resin or the like is used.

  The heat generated in the second light emitting element 20 is transmitted to the mounting substrate 50s via, for example, the intermediate layer 40, the first light emitting element 10, the first connection member 51c, and the second connection member 52c. Thereby, heat is efficiently radiated. In the 2nd light emitting element 20, a high light emission rate is obtained and the lifetime in the 2nd light emitting element 20 becomes long.

  As shown in FIGS. 1A and 1B, the first light emitting element 10 may further include a first element substrate 10s. The second semiconductor layer 12 is disposed between the first element substrate 10 s and the first light emitting layer 15. The second light emitting element 20 may further include a second element substrate 20s. The fourth semiconductor layer 24 is disposed between the second element substrate 20 s and the second light emitting layer 25. The first element substrate 10s and the second element substrate 20s may be omitted.

  As shown in FIGS. 1A and 1B, the substrate unit 55 may further include a reflective layer 57. In FIG. 1C, the reflective layer 57 is omitted for easy understanding of the drawing. The reflective layer 57 is provided on the mounting main surface 50a. At least a part of each of the first to fourth substrate electrodes 51 to 54 is not covered with the reflective layer 57. The reflective layer 57 reflects at least a part of the light emitted from the first light emitting layer 15. The reflective layer 57 reflects at least part of the light emitted from the second light emitting layer 25. By providing the reflective layer 57, the amount of light per unit area can be further increased.

  In this example, the reflective layer 57 covers the outer edge portions of the first to fourth substrate electrodes 51 to 54. In the embodiment, the reflective layer 57 may be separated from at least one of the first to fourth substrate electrodes 51 to 54. A part of the reflective layer 57 may be provided between at least one of the first to fourth substrate electrodes 51 to 54 and the mounting substrate 50s.

  The reflective layer 57 preferably has an insulating property. For the reflective layer 57, for example, a resin that reflects light is used. The reflective layer 57 includes, for example, a plurality of fine particles of a metal compound (for example, including a metal oxide or the like and also includes a ceramic) and a resin in which the fine particles are dispersed.

  The substrate unit 55 may further include a back layer 58. The back surface layer 58 is provided on the back surface 50b (lower surface) of the mounting substrate 50s. The back surface 50b is opposite to the mounting main surface 50a (the surface on the side facing the first light emitting element 10). A mounting substrate 50s is provided on the back layer 58, and first to fourth substrate electrodes 51 to 54 are provided on the mounting substrate 50s.

  For the back layer 58, for example, a metal layer is used. For example, the back surface layer 58 is fixed to a component included in a lighting device or the like where the light emitting device 110 is used. Heat generated in the light emitting device 110 is transmitted to the component through the back surface layer 58 and is radiated.

  In this example, the direction from the first electrode 11e toward the second electrode 12e is along the X-axis direction. The direction from the third electrode 23e toward the fourth electrode 24e is along the Y-axis direction. For example, the angle between the direction from the third electrode 23e toward the fourth electrode 24e and the direction from the first electrode 11e toward the second electrode 12e is about 90 degrees. The direction from the third electrode 23e to the fourth electrode 24e intersects the direction from the first electrode 11e to the second electrode 12e. The angle between the direction from the third electrode 23e toward the fourth electrode 24e and the direction from the first electrode 11e toward the second electrode 12e may be 45 degrees or greater and 90 degrees or less.

  As will be described later, in the embodiment, the relationship between the direction from the first electrode 11e toward the second electrode 12e and the direction from the third electrode 23e toward the fourth electrode 24e is arbitrary.

FIG. 2 is a schematic cross-sectional view illustrating the light emitting device according to the first embodiment.
FIG. 2 is a schematic cross-sectional view of a region including the A1-A2 line and the B1-B2 line in FIG. FIG. 2 shows an example in which the intermediate layer 40, the first element substrate 10s, and the second element substrate 20s are provided.

  As illustrated in FIG. 2, the first semiconductor layer 11 is provided on the first electrode 11 e. A first light emitting layer 15 is provided on the first semiconductor layer 11. The second semiconductor layer 12 is provided on the first light emitting layer 15. A first element substrate 10 s is provided on the second semiconductor layer 12. An intermediate layer 40 is provided on the first element substrate 10s. A second element substrate 20 s is provided on the intermediate layer 40. The fourth semiconductor layer 24 is provided on the second element substrate 20s. A second light emitting layer 25 is provided on the fourth semiconductor layer 24. A third semiconductor layer 23 is provided on the second light emitting layer 25. A third electrode 23 e is provided on the third semiconductor layer 23.

  The first light emitting layer 15 includes, for example, a plurality of first barrier layers 15a and a second well layer 15b provided between the two first barrier layers 15a. The first light emitting layer 15 has, for example, a multiple quantum well (MQW) structure. In the MQW structure, a plurality of barrier layers and a plurality of well layers are alternately stacked. The first light emitting layer 15 may have, for example, a single quantum well (SQW) structure. In the SQW structure, the number of well layers is one.

  The second light emitting layer 25 includes, for example, a plurality of second barrier layers 25a and a second well layer 25b provided between the two second barrier layers 25a. The second light emitting layer 25 has, for example, a multiple quantum well structure or a single quantum well structure.

  The plurality of first barrier layers 15a are stacked on each other along the Z-axis direction. The plurality of second barrier layers 25a are stacked on each other along the Z-axis direction. In the specification of the present application, the state of being stacked includes a state of being directly overlapped and a case of being provided with another layer inserted therebetween.

Examples of the first light emitting element 10 and the second light emitting element 20 will be described.
For example, sapphire, spinel, GaAs, InP, ZnO, Ge, Si, SiGe, or SiC is used for the first element substrate 10s and the second element substrate 20s.

  The first element substrate 10s is, for example, a crystal growth substrate. For example, the second semiconductor layer 12, the first light emitting layer 15, and the first semiconductor layer 11 are epitaxially grown sequentially in this order on the first element substrate 10s. The second semiconductor layer 12 includes, for example, an n-type nitride semiconductor (for example, n-type GaN). The first semiconductor layer 11 includes, for example, a p-type nitride semiconductor (for example, p-type GaN). The first barrier layer 15a includes, for example, a nitride semiconductor (for example, GaN). The first well layer 15b includes, for example, a nitride semiconductor containing In (for example, InGaN). The band gap energy of the first well layer 15b is smaller than the band gap energy of the first barrier layer 15a.

  In the stacked body (first stacked body) including the first semiconductor layer 11, the first light emitting layer 15, and the second semiconductor layer 12, a part of the first semiconductor layer 11 and a part of the first light emitting layer 15 are removed, A part of the second semiconductor layer 12 is exposed. A first electrode 11 e is formed on the first semiconductor layer 11. A second electrode 12 e is formed on the second semiconductor layer 12.

  Thereby, the 1st light emitting element 10 is formed. The first light emitting element 10 is inverted and the first light emitting element 10 is disposed on the substrate portion 55.

  The second element substrate 20s is, for example, a crystal growth substrate. For example, the fourth semiconductor layer 24, the second light emitting layer 25, and the third semiconductor layer 23 are epitaxially grown sequentially in this order on the second element substrate 20s. The fourth semiconductor layer 24 includes, for example, an n-type nitride semiconductor (for example, n-type GaN). The third semiconductor layer 23 includes, for example, a p-type nitride semiconductor (for example, p-type GaN). The second barrier layer 25a includes, for example, a nitride semiconductor (for example, GaN). The second well layer 25b includes, for example, a nitride semiconductor containing In (for example, InGaN). The band gap energy of the second well layer 25b is smaller than the band gap energy of the second barrier layer 25a.

  In the stacked body (second stacked body) including the fourth semiconductor layer 24, the second light emitting layer 25, and the third semiconductor layer 23, a part of the third semiconductor layer 23 and a part of the second light emitting layer 25 are removed, A part of the fourth semiconductor layer 24 is exposed. A fourth electrode 24 e is formed on the fourth semiconductor layer 24. A third electrode 23 e is formed on the third semiconductor layer 23.

  At least one of the first to fourth electrodes 11e, 12e, 23e, and 24e is, for example, at least one of aluminum (Al), silver (Ag), gold (Au), palladium (Pd), and rhodium (Rh). Can be included. An alloy containing any two or more of Al, Ag, Au, Pd, and Rh may be used for at least one of the first to fourth electrodes 11e, 12e, 23e, and 24e. At least one of the first to fourth electrodes 11e, 12e, 23e, and 24e includes a layer including at least one of an Al film, an Ag film, an Au film, a Pd film, and an Rh film, and a conductive layer laminated on the layer. A laminated film of layers can be used. High light reflectivity can be obtained in the first to fourth electrodes 11e, 12e, 23e, and 24e. Furthermore, ohmic contact with the semiconductor layer can be obtained.

  The first electrode 11 e may include a Ti layer that is in contact with the first semiconductor layer 11. The second electrode 12 e may include a Ti layer in contact with the second semiconductor layer 12. The third electrode 23 e may include a Ti layer in contact with the third semiconductor layer 23. The fourth electrode 24 e may include a Ti layer in contact with the fourth semiconductor layer 24. By using the Ti layer, high ohmic contact can be obtained between the electrode layer and the semiconductor layer.

  At least one of the first to fourth electrodes 11e, 12e, 23e, and 24e may include a light-transmitting conductive film. At least one of the first to fourth electrodes 11e, 12e, 23e, and 24e can include, for example, an oxide that includes at least one element selected from the group consisting of In, Sn, Zn, and Ti. At least one of the first to fourth electrodes 11e, 12e, 23e, and 24e may include, for example, an ITO (Indium Tin Oxide) film.

  For example, the first electrode 11 e is a reflection film including at least one of an Al film, an Ag film, an Au film, a Pd film, and an Rh film, and a light provided between the reflection film and the first semiconductor layer 11. A transparent conductive film. The second electrode 12e is a light transmissive film provided between a reflective film including at least one of an Al film, an Ag film, an Au film, a Pd film, and an Rh film, and the reflective film and the second semiconductor layer 12. A conductive film. The third electrode 23e is a light transmissive film provided between a reflective film including at least one of an Al film, an Ag film, an Au film, a Pd film, and an Rh film, and the reflective film and the third semiconductor layer 23. A conductive film. The fourth electrode 24e is a light-transmitting film provided between a reflective film including at least one of an Al film, an Ag film, an Au film, a Pd film, and an Rh film, and the reflective film and the fourth semiconductor layer 24. A conductive film.

  At least one of the first pad portion 23f and the second pad portion 24f can include, for example, an Au film. Good connectivity can be obtained between the first pad portion 23f and the third connection member 53c and between the second pad portion 24f and the fourth connection member 54c.

  The first to fourth substrate electrodes 51 to 54 can use the same material. At least a part of the first to fourth substrate electrodes 51 to 54 can be formed by plating, for example. At least a part of the first to fourth substrate electrodes 51 to 54 can be formed by, for example, a vapor phase forming method such as sputtering.

  Each of the first to fourth substrate electrodes 51 to 54 can include, for example, copper (Cu).

  Each of the first to fourth substrate electrodes 51 to 54 includes, for example, a first metal film provided on the mounting main surface 50a of the mounting substrate 50s and a second metal film provided on the first metal film. And can be included. For example, Ti can be used for the first metal film. The first metal film can be formed by sputtering, for example. For example, Cu can be used for the second metal film. The second metal film can be formed by plating, for example.

  Each of the first to fourth substrate electrodes 51 to 54 may further include, for example, a third metal film provided on the second metal film. The third metal film can include a nickel (Ni) film and an Au film provided on the Ni film. The third metal film can include a Ni film, palladium (Pd) provided on the Ni film, and an Au film provided on the Pd film. At least a part of the third metal film can be formed by plating, for example.

  Each thickness of the first to fourth substrate electrodes 51 to 54 is, for example, not less than 16 μm and not more than 500 μm (for example, about 50 μm).

  The configuration and materials described with respect to the first to fourth substrate electrodes 51 to 54 can be applied to the back surface layer 58.

  For example, solder can be used for at least one of the first connection member 51c and the second connection member 52c. At least one of the first connection member 51c and the second connection member 52c includes, for example, an AuSn alloy.

  For example, a conductive wire containing at least one of Au, Cu, Ag, and Al can be used for at least one of the third connection member 53c and the fourth connection member 54c.

  A resin substrate or a ceramic substrate can be used as the mounting substrate 50s. For example, a substrate including a conductive substrate and an insulating layer provided on the conductive substrate may be used as the mounting substrate 50s. The thickness of the mounting substrate 50s is, for example, 150 μm or more and 3,000 μm or less (for example, about 1,000 μm).

  In the present embodiment, for example, the area of the first light emitting layer 15 is larger than the area of the second light emitting layer 25. For example, part of the light emitted from the first light emitting layer 15 passes through the second light emitting layer 25 and is emitted to the outside of the second light emitting layer 25. Other part of the light emitted from the first light emitting layer 15 may be emitted outside the light emitting device without passing through the second light emitting layer 25.

  For example, the third electrode 23e and the fourth electrode 24e are light-shielding. For example, when at least one of the third electrode 23e and the fourth electrode 24e overlaps the first light emitting layer 15 when projected onto the XY plane, the light extraction efficiency may be reduced. For example, when the area of the region where at least one of the third electrode 23e and the fourth electrode 24e overlaps with the first light emitting layer 15 is reduced when projected onto the XY plane, a decrease in light extraction efficiency can be suppressed. When the area of the first light emitting layer 15 is set larger than the area of the second light emitting layer 25, a decrease in light extraction efficiency can be suppressed.

  As illustrated in FIG. 1C, in this example, the outer shape of the first light emitting element 10 is rectangular when projected onto the XY plane. The outer edge side of the first light emitting element 10 is substantially parallel to or substantially perpendicular to the side of the mounting substrate 50s. In this example, the outer shape of the second light emitting element 20 is a rectangle when projected onto the XY plane. The outer edge side of the second light emitting element 20 is substantially parallel to or substantially perpendicular to the side of the mounting substrate 50s. As will be described later, the extending direction of the outer edge side of the first light emitting element 10, the extending direction of the outer edge side of the second light emitting element 20, and the extending direction of the side of the mounting substrate 50s are mutually. The relationship is arbitrary.

FIG. 3A and FIG. 3B are schematic plan views illustrating another light emitting device according to the first embodiment.
As shown in FIG. 3A, in another light emitting device 111 according to this embodiment, the direction from the first electrode 11e toward the second electrode 12e is along the X-axis direction. The direction from the third electrode 23e toward the fourth electrode 24e is also along the X-axis direction. The other configuration is the same as that of the light emitting device 110.

  In the light emitting device 111, for example, when projected onto the XY plane, at least a part of the third electrode 23e overlaps at least a part of the first electrode 11e. For example, when projected onto the XY plane, at least a part of the fourth electrode 24e overlaps with at least a part of the second electrode 12e. In this configuration, for example, the third semiconductor layer 23 of the first conductivity type is disposed on the first semiconductor layer 11 of the first conductivity type (for example, p-type). On the other hand, a portion (fourth portion 24q) of the second conductivity type fourth semiconductor layer 24 is formed on a portion (second portion 12q) of the second semiconductor layer 12 of the second conductivity type (for example, n-type). Be placed.

  In a semiconductor light emitting device, for example, an electrode connected to a semiconductor layer of a first conductivity type (for example, p-type) and an electrode connected to a semiconductor layer of a second conductivity type (for example, n-type) by heat generated around the electrode And may be greater than the heat generated in and around it. At this time, there is a configuration in which the cross-sectional area of the electrode connected to the semiconductor layer of the first conductivity type and the connecting member connected to the electrode is increased to increase the thermal conductivity. That is, there exists a structure which changes the cross-sectional area of an electrode and a connection member with a conductivity type. At this time, in the light emitting device 111, for example, two electrodes (for example, the first electrode 11e and the third electrode 23e) having a large cross-sectional area and a high thermal conductivity are stacked on each other. Thereby, the efficiency of heat conduction in the thickness direction (Z-axis direction) can be increased. Thereby, the efficiency of heat dissipation increases.

  As shown in FIG. 3B, in another light emitting device 112 according to the present embodiment, the direction from the first electrode 11e toward the second electrode 12e is along the X-axis direction. The direction from the third electrode 23e toward the fourth electrode 24e is opposite to the X-axis direction. The other configuration is the same as that of the light emitting device 110.

  In the light emitting device 112, for example, when projected onto the XY plane, at least part of the third electrode 23e overlaps with at least part of the second electrode 12e. For example, when projected onto the XY plane, at least part of the fourth electrode 24e overlaps with at least part of the first electrode 11e. For example, a part (fourth portion 24q) of the fourth semiconductor layer 24 of the second conductivity type (eg, n-type) is disposed on the first semiconductor layer 11 of the first conductivity type (eg, p-type). For example, the third semiconductor layer 23 of the first conductivity type is disposed on a part (second portion 12q) of the second semiconductor layer 12 of the second conductivity type.

  As already described, in the semiconductor light emitting device, for example, heat generated in and around the electrode connected to the semiconductor layer of the first conductivity type (for example, p-type) is generated in the semiconductor of the second conductivity type (for example, n-type). It may be greater than the heat generated at and around the electrodes connected to the layer. In the light emitting device 112, at least a part of the third electrode 23e (for example, a large amount of heat generation) is laminated with the second electrode 12e (for example, a small amount of heat generation). At least a part of the fourth electrode 24e (for example, a small amount of heat generation) is laminated with the first electrode 11e (for example, a large amount of heat generation). For this reason, the generated heat is averaged, and a local temperature rise is suppressed. Thereby, the efficiency of heat dissipation increases and high luminous efficiency can be obtained.

  Thus, in the embodiment, when projected onto a plane perpendicular to the direction from the first semiconductor layer 11 to the second semiconductor layer 12, at least one of the third electrode 23 and the fourth electrode 24 is used. A part of the first electrode 11e overlaps with the second electrode 12e, and at least a part of either the third electrode 23 or the fourth electrode 24 overlaps with the second electrode 12e.

  For example, the angle between the direction from the third electrode 23e toward the fourth electrode 24e and the direction from the first electrode 11e toward the second electrode 12e is approximately 0 degrees or approximately 180 degrees. For example, the absolute value of the angle between the direction from the third electrode 23e toward the fourth electrode 24e and the direction from the first electrode 11e toward the second electrode 12e is less than 45 degrees.

  In the light emitting devices 110 to 112 described above, the direction from the first electrode 11e toward the second electrode 12e is parallel or perpendicular to the outer edge side of the mounting main surface 50a. The direction from the third electrode 23e toward the fourth electrode 24e is parallel or perpendicular to the outer edge side of the mounting main surface 50a.

FIG. 4A and FIG. 4B are schematic plan views illustrating another light emitting device according to the first embodiment.
As shown in FIG. 4A, in another light emitting device 113 according to this embodiment, the direction from the first electrode 11e toward the second electrode 12e is along the X-axis direction. The direction from the third electrode 23e toward the fourth electrode 24e is along the Y-axis direction. The mounting main surface 50a of the mounting substrate 50s is rectangular, and the outer edge side of the mounting main surface 50a is inclined with respect to the X-axis direction and the Y-axis direction. The other configuration is the same as that of the light emitting device 110.

  In the light emitting device 113, when the outer edge side of the mounting main surface 50a is a reference direction, the direction from the first electrode 11e to the second electrode 12e and the direction from the third electrode 23e to the fourth electrode 24e are the reference. Inclined with respect to direction.

  Thus, the relationship between the direction from the first electrode 11e toward the second electrode 12e and the direction of the side of the mounting main surface 50a is arbitrary. The relationship between the direction from the third electrode 23e toward the fourth electrode 24e and the direction of the side of the mounting main surface 50a is arbitrary.

  In the light emitting devices 113 and 114, the outer shape of the first light emitting element 10 is rectangular when projected onto the XY plane. The outer edge side of the first light emitting element 10 is inclined with respect to the side of the mounting substrate 50s. When projected onto the XY plane, the outer shape of the second light emitting element 20 is rectangular. The outer edge side of the second light emitting element 20 is inclined with respect to the side of the mounting substrate 50s. In this example, the extending direction of the outer edge side of the first light emitting element 10 is parallel or perpendicular to the extending direction of the outer edge side of the second light emitting element 20. In the embodiment, the extending direction of the outer edge side of the first light emitting element 10 may be inclined with respect to the extending direction of the outer edge side of the second light emitting element 20.

FIG. 5A and FIG. 5B are schematic plan views illustrating another light emitting device according to the first embodiment.
As illustrated in FIG. 5A, in another light emitting device 115 according to the present embodiment, in the mounting component 50, the first to third substrate electrodes 51 to 53 and the first to third connection members 51 c. -53c are provided. The fourth substrate electrode 54 is not provided. The third connection member 53 c (for example, the first wiring) electrically connects the third electrode 23 e and the third substrate electrode 53. A fourth connection member 54c (for example, a second wiring) is further provided. The fourth connection member 54 c is electrically connected to the fourth electrode 24 e and is electrically connected to the second substrate electrode 52. Other configurations are the same as those of the light emitting device 111, for example.

  As illustrated in FIG. 5B, in another light emitting device 116 according to the present embodiment, in the mounting component 50, the first to third substrate electrodes 51 to 53 and the first to third connection members 51 c. -53c are provided. In this example, the third connection member 53c (for example, the first wiring) electrically connects the fourth electrode 24e and the third substrate electrode 53. A fourth connection member 54c (for example, a second wiring) is further provided. The fourth connection member 54 c is electrically connected to the third electrode 23 e and is electrically connected to the first substrate electrode 51.

  As described above, in the embodiment, the substrate unit 55 can further include the third substrate electrode 53 provided on the mounting main surface 50 a in addition to the first and second substrate electrodes 51 and 52. The mounting component 50 can further include a first wiring (for example, a third connection member 53 c) that electrically connects one of the third electrode 23 e and the fourth electrode 24 e and the third substrate electrode 53. In the light emitting device 115, the first wiring (for example, the third connection member 53c) electrically connects the third electrode 23e and the third substrate electrode 53. In the light emitting device 116, the first wiring (for example, the third connection member 53c) electrically connects the fourth electrode 24e and the third substrate electrode 53.

  The second wiring (fourth connection member 54c) is electrically connected to either the third electrode 23e or the fourth electrode 24e. In the light emitting device 115, the second wiring (fourth connection member 54c) is connected to the fourth electrode 24e. In the light emitting device 116, the second wiring (fourth connection member 54c) is connected to the third electrode 23e.

The second wiring (fourth connection member 54c) can be electrically connected to either the first substrate electrode or the second substrate electrode. In the light emitting device 115, the second wiring (fourth connection member 54 c) is connected to the second substrate electrode 52. In the light emitting device 115, the second wiring (fourth connection member 54 c) may be connected to the first substrate electrode 51. In the light emitting device 116, the second wiring (fourth connection member 54 c) is connected to the first substrate electrode 51. In the light emitting device 116, the second wiring (fourth connection member 54 c) may be connected to the second substrate electrode 52.
Thus, in the light emitting devices 115 and 116, three substrate electrodes are provided on the mounting main surface 50a.

  In the light emitting devices 110 to 114 already described, four substrate electrodes are provided on the mounting main surface 50a. That is, the substrate unit 55 includes the third substrate electrode 53 and the fourth substrate electrode 54 provided on the mounting main surface 50a. The mounting component 50 includes a first wiring (for example, a third connection member 53c) that electrically connects one of the third electrode 23e and the fourth electrode 24e to the third substrate electrode 53. The mounting component 50 further includes a second wiring (for example, a fourth connection member 54c) that electrically connects either the third electrode 23e or the fourth electrode 24e and the fourth substrate electrode 54.

FIG. 6 is a schematic plan view illustrating another light emitting device according to the first embodiment.
As shown in FIG. 6, in another light emitting device 117 according to this embodiment, two substrate electrodes (first substrate electrode 51 and second substrate electrode 52) are provided on the mounting main surface 50a. The third substrate electrode 53 and the fourth substrate electrode 54 are not provided. In the light emitting device 117, the first wiring (for example, the third connection member 53c) electrically connects, for example, the third electrode 23e and the first substrate electrode 51. For example, the second wiring (for example, the fourth connecting member 54c) electrically connects the fourth electrode 24e and the second substrate electrode 52, for example.

  In the embodiment, the first light emitting element 10 may be driven by a first power source, and the second light emitting element 20 may be driven by a second power source different from the first power source. In the embodiment, the first light emitting element 10 may be driven by the first power source, and the second light emitting element 20 may be driven by the first power source.

  In the semiconductor light emitting devices 115, 116, and 117 illustrated in FIGS. 5A, 5B, and 6, for example, the circuit can be simplified. Thereby, it can reduce in size.

FIG. 7 is a schematic cross-sectional view illustrating another light emitting device according to the first embodiment.
FIG. 7 is a cross-sectional view corresponding to the cross section along line A1-A2 of FIG.
As shown in FIG. 7, in another light emitting device 110 a according to this embodiment, the side surface of the first light emitting element 10 has a tapered shape. For example, the area of the surface on the first main surface 10a side of the first element substrate 10s included in the first light emitting element 10 is larger than the area of the surface on the second main surface 10b side of the first element substrate 10s. The side surface of the first element substrate 10s has a tapered shape that is inclined along the Z-axis direction.

  Furthermore, the side surface of the second light emitting element 20 is tapered. For example, the area of the surface on the third main surface 20a side of the second element substrate 20s included in the second light emitting element 20 is larger than the area of the surface on the fourth main surface 20b side of the second element substrate 20s. The side surface of the second element substrate 20s has a tapered shape that is inclined along the Z-axis direction.

By making the side surface of the light emitting element have a tapered shape, coverage such as a protective layer on the side surface of the light emitting element is improved, and for example, reliability is improved. By making the side surface of the light emitting element have a tapered shape, for example, reflection or emission of light on the side surface of the light emitting element can be controlled, and light extraction efficiency from the light emitting element is improved.
The tapered side surface may be provided in the light emitting devices 111 to 117.

FIG. 8A to FIG. 8F are schematic cross-sectional views illustrating other light emitting devices according to the first embodiment.
These drawings show the configurations of the first element substrate 10s and the second element substrate 20s, and other portions are omitted.

FIG. 8C is a plan view illustrating the light emitting device 110b. FIG. 8A is a cross-sectional view corresponding to the cross section along line A1-A2 of FIG. FIG. 8B is a cross-sectional view corresponding to the cross section along line B1-B2 of FIG.
As shown in FIG. 8A to FIG. 8C, in another light emitting device 110 b according to the present embodiment, the thickness of a part of the peripheral portion of the first element substrate 10 s of the first light emitting element 10. However, it is thinner than the thickness of the inner part of the first element substrate 10s.

  The first element substrate 10s has a first edge portion 70r. The first edge portion 70r corresponds to the outer edge when the first element substrate 10s is projected onto the XY plane. The first edge portion 70r is along the outer edge. The first edge portion 70r extends substantially in the XY plane. The first edge portion 70r includes, for example, a first lower substrate side 71, a second lower substrate side 72, a third lower substrate side 73, and a fourth lower substrate side 74. The second lower substrate side 72 is separated from the first lower substrate side 71. The third lower substrate side 73 is connected to one end of the first lower substrate side 71 and one end of the second lower substrate side 72. The fourth lower substrate side 74 is separated from the third lower substrate side 73 and connected to the other end of the first lower substrate side 71 and the other end of the second lower substrate side 72.

  The first element substrate 10s has a first substrate upper surface 10sa and a first substrate lower surface 10sb. The first substrate upper surface 10sa is a surface facing the second light emitting element 20. The first substrate upper surface 10sa is a surface on the first main surface 10a side of the first element substrate 10s. The first substrate lower surface 10sb is a surface opposite to the first substrate upper surface 10sa. The first substrate lower surface 10sb is a surface on the second main surface 10b side of the first element substrate 10s. The first substrate upper surface 10sa and the first substrate lower surface 10sb are substantially perpendicular to the XY plane. At least a part of the first substrate upper surface 10sa is separated from the first edge portion 70.

  In this example, the first element substrate 10s further includes a first lower substrate slope 71s and a second lower substrate slope 72s. The first lower substrate slope 71 s is connected to the first substrate upper surface 10 sa and the first lower substrate side 71. The second lower substrate slope 72 s is connected to the first substrate upper surface 10 sa and the second lower substrate side 72. The first lower substrate slope 71s and the second lower substrate slope 72s are inclined with respect to the XY plane.

  The angle θ1 between the first lower substrate slope 71s and the XY plane is, for example, not less than 10 degrees and not more than 89 degrees. The angle between the second lower substrate slope 72s and the XY plane may be the same as or different from the angle θ1 between the first lower substrate slope 71s and the XY plane.

  The distance along the Z-axis direction between the first substrate upper surface 10sa and the first substrate lower surface 10sb is longer than the length along the Z-axis direction of the first edge portion 70r. The first element substrate 10s has a convex shape that is convex upward.

  By providing the slope on the first element substrate 10s, the area of the first substrate upper surface 10sa is smaller than the area of the first substrate lower surface 10sb.

  By providing a slope on the first element substrate 10s, the reflection or emission of light at the periphery of the first element substrate 10s can be controlled, and the light extraction efficiency from the first light emitting element 10 is improved. In particular, the light extraction efficiency to the upper side of the light emitting device is improved.

  That is, by inclining the main surface of the first element substrate 10 s in the peripheral part (with a tapered shape), it is possible to control the reflection or emission of light in the peripheral part of the first element substrate 10 s, and from the first light emitting element 10. The light extraction efficiency is improved.

  The peripheral part of the first element substrate 10s of the first light emitting element 10 is a part connected to the first edge part 70r. The inner portion of the first element substrate 10s is separated from the first edge portion 70r and is, for example, a portion between the first substrate upper surface 10sa and the first substrate lower surface 10sb. The distance between the inner side portion and the first edge portion 70r is longer than the distance between the peripheral portion and the first edge portion 70r. In the peripheral portion, the main surface of the second element substrate 20s is inclined with respect to the Z-axis direction.

  In this example, the thickness of a part of the peripheral part of the second element substrate 20s of the second light emitting element 20 is thinner than the thickness of the inner part of the second element substrate 20s.

  The second element substrate 20s has a second edge 80r. The second edge portion 80r corresponds to an outer edge when the second element substrate 20s is projected onto the XY plane. The second edge portion 80r is along the outer edge. The second edge portion 80r extends substantially in the XY plane. The second edge 80r includes, for example, a first upper substrate side 81, a second upper substrate side 82, a third upper substrate side 83, and a fourth upper substrate side 84. The second upper substrate side 82 is separated from the first upper substrate side 81. The third upper substrate side 83 is connected to one end of the first upper substrate side 81 and one end of the second upper substrate side 82. The fourth upper substrate side 84 is separated from the third upper substrate side 83 and is connected to the other end of the first upper substrate side 81 and the other end of the second upper substrate side 82.

  The second element substrate 20s has a second substrate lower surface 20sa and a second substrate upper surface 20sb. The second substrate lower surface 20sa is a surface facing the first light emitting element 10. The second substrate lower surface 20sa is a surface on the third main surface 20a side of the second element substrate 20s. The second substrate upper surface 20sb is the surface opposite to the second substrate lower surface 20sa. The second substrate upper surface 20sb is a surface on the fourth main surface 20b side of the second element substrate 20s. The second substrate lower surface 20sa and the second substrate upper surface 20sb are substantially perpendicular to the XY plane. At least a part of the second substrate upper surface 20 sb is separated from the second edge 80.

  In this example, the second element substrate 20s further includes a first upper substrate slope 81s and a second upper substrate slope 82s. The second upper substrate slope 81s is connected to the second substrate upper surface 20sb and the first upper substrate side 81. The second upper substrate slope 82s is connected to the second substrate upper surface 20sb and the second upper substrate side 82. The first upper substrate inclined surface 81s and the second upper substrate inclined surface 82s are inclined with respect to the XY plane.

  The angle θ2 between the first upper substrate slope 81s and the XY plane is, for example, not less than 10 degrees and not more than 89 degrees. The angle between the second upper substrate slope 82s and the XY plane may be the same as or different from the angle θ2 between the first upper substrate slope 81s and the XY plane.

  The distance along the Z-axis direction between the second substrate upper surface 20sb and the second substrate lower surface 20sa is longer than the length of the second edge 80r along the Z-axis direction. The second element substrate 20s has a convex shape that is convex upward.

  By providing the inclined surface on the second element substrate 20s, the area of the second substrate upper surface 20sb is smaller than the area of the second substrate lower surface 20sa.

  By providing a slope on the second element substrate 20s, the reflection or emission of light at the peripheral portion of the second element substrate 20s can be controlled, and the light extraction efficiency from the second light emitting element 20 is improved. In particular, the light extraction efficiency to the upper side of the light emitting device is improved.

  That is, by inclining the main surface of the second element substrate 20 s in the peripheral part (with a tapered shape), it is possible to control the reflection or emission of light in the peripheral part of the second element substrate 20 s. The light extraction efficiency is improved.

  The peripheral part of the second element substrate 20s of the second light emitting element 20 is a part connected to the second edge 80r. The inner portion of the second element substrate 20s is separated from the second edge 80r, and is, for example, a portion between the second substrate upper surface 20sb and the second substrate lower surface 20sa. The distance between the inner side portion and the second edge portion 80r is longer than the distance between the peripheral portion and the second edge portion 80r. In the peripheral portion, the main surface of the second element substrate 20s is inclined with respect to the Z-axis direction.

  In this example, the shape of the second element substrate 20s when projected onto the XY plane is a rectangle. That is, the length of the first upper substrate side 81 is longer than the length of the third upper substrate side 83 and longer than the length of the fourth upper substrate side 84. In other words, the length of the second upper substrate side 82 is longer than the length of the third upper substrate side 83 and longer than the length of the fourth upper substrate side 84. The first upper substrate side 81 and the second upper substrate side 82 are rectangular long sides.

  As described above, when the shape of the second element substrate 20s is a rectangle, the inclined surfaces (the first lower substrate inclined surface 71s and the second lower substrate inclined surface 72s) are provided on the first element substrate 10s along the long side of the rectangle. . Providing a slope on the first element substrate 10s along the long side of the rectangle is more effective in improving the light extraction efficiency than providing a slope on the first element substrate 10s along the short side of the rectangle.

FIG. 8F is a plan view illustrating the light emitting device 110c. FIG. 8D is a cross-sectional view corresponding to the cross section along line A1-A2 of FIG. FIG. 8E is a cross-sectional view corresponding to the cross section along line B1-B2 of FIG.
As shown in FIG. 8D to FIG. 8F, in another light emitting device 110 c according to the present embodiment, the thickness of the vicinity of the four sides of the peripheral portion of the first element substrate 10 s is as follows. It is thinner than the thickness of the inner part of the one-element substrate 10s.

  In this example, the first element substrate 10s further includes a third lower substrate slope 73s and a fourth lower substrate slope 74s. The third lower substrate slope 73 s is connected to the first substrate upper surface 10 sa and the third lower substrate side 73. The fourth lower substrate slope 74 s is connected to the first substrate upper surface 10 sa and the fourth lower substrate side 74. The third lower substrate slope 73s and the fourth lower substrate slope 74s are inclined with respect to the XY plane.

  The angle θ3 between the third lower substrate slope 73s and the XY plane is, for example, not less than 10 degrees and not more than 89 degrees. The angle between the fourth lower substrate slope 74s and the XY plane may be the same as or different from the angle θ3 between the third lower substrate slope 73s and the XY plane.

  Also in this case, the area of the first substrate upper surface 10sa is smaller than the area of the first substrate lower surface 10sb.

  By providing a slope on the first element substrate 10s, the reflection or emission of light at the periphery of the first element substrate 10s can be controlled, and the light extraction efficiency from the first light emitting element 10 is improved. In particular, the light extraction efficiency to the upper side of the light emitting device is improved.

  In this example, the thickness of the vicinity of the four sides of the peripheral part of the second element substrate 20s of the second light emitting element 20 is thinner than the thickness of the inner part of the second element substrate 20s.

  In this example, the second element substrate 20s further includes a third upper substrate slope 83s and a fourth upper substrate slope 84s. The third upper substrate slope 83s is connected to the second substrate upper surface 20sb and the third upper substrate side 83. The fourth upper substrate slope 84s is connected to the second substrate upper surface 20sb and the fourth upper substrate side 84. The third upper substrate inclined surface 83s and the fourth upper substrate inclined surface 84s are inclined with respect to the XY plane.

  An angle θ4 between the third upper substrate slope 83s and the XY plane is, for example, not less than 10 degrees and not more than 89 degrees. The angle between the fourth upper substrate slope 84s and the XY plane may be the same as or different from the angle θ4 between the third upper substrate slope 83s and the XY plane.

  Also in this case, the area of the second substrate upper surface 20sb is smaller than the area of the second substrate lower surface 20sa.

  By providing a slope on the second element substrate 20s, the reflection or emission of light at the peripheral portion of the second element substrate 20s can be controlled, and the light extraction efficiency from the second light emitting element 20 is improved. In particular, the light extraction efficiency to the upper side of the light emitting device is improved.

  Such a slope may be provided on the first element substrate 10s and may not be provided on the second element substrate 20s. Such a slope may be provided on the second element substrate 20s and may not be provided on the first element substrate 10s. Such a slope may be provided in the light emitting devices 111 to 117 and the light emitting device 118 described later.

FIG. 9A and FIG. 9B are schematic views illustrating another light emitting device according to the first embodiment.
FIG. 9B is a plan view. FIG. 9A is a cross-sectional view corresponding to the cross section along line A1-A2 of FIG.
As shown in FIG. 9A and FIG. 9B, in another light emitting device 118 according to this embodiment, the second light emitting element 20 has the first electrode when projected onto the XY plane. 11e and the first connecting member 51c. When projected onto the XY plane, the second light emitting element 20 does not overlap the second electrode 12e and does not overlap the second connection member 52c.
Also in the light emitting device 118, the amount of light per unit area can be improved.

  In the light emitting device 118, the area of the first electrode 11e is larger than the area of the second electrode 12e. The first semiconductor layer 11 corresponding to the first electrode 11e is p-type, and the second semiconductor layer 12 corresponding to the second electrode 12e is n-type. The area of the second semiconductor layer 12 is designed to be large. That is, the area of the first light emitting layer 15 can be enlarged. Thereby, the luminous efficiency in the 1st light emitting element 10 can be improved.

  In the light emitting device 118, for example, the heat dissipation path of the second light emitting element 20 can be increased. Thereby, the luminous efficiency in the 2nd light emitting element 20 can be improved.

FIG. 10 is a schematic cross-sectional view illustrating another light emitting device according to the first embodiment.
FIG. 10 is a cross-sectional view corresponding to the cross section along line A1-A2 of FIG.
As shown in FIG. 10, in the light emitting device 110 d according to the present embodiment, a wavelength conversion layer 60 is further provided. The wavelength conversion layer 60 covers at least a part of the first light emitting element 10. The wavelength conversion layer 60 may further cover at least a part of the second light emitting element 20. The wavelength conversion layer 60 absorbs at least part of the first light emitted from the first light emitting layer 15 and emits light having a wavelength (for example, peak wavelength) different from the wavelength (for example, peak wavelength) of the first light. . The wavelength conversion layer 60 absorbs at least part of the second light emitted from the second light emitting layer 25 and further emits light having a wavelength (for example, peak wavelength) different from the wavelength of the second light (for example, peak wavelength). You may do it.

  The wavelength conversion layer 60 includes, for example, phosphor particles and a resin (for example, silicone resin) in which the phosphor particles are dispersed.

  The wavelength (for example, peak wavelength) of the light emitted from the wavelength conversion layer 60 is longer than the wavelength of the first light (for example, peak wavelength). The wavelength (for example, peak wavelength) of the light emitted from the wavelength conversion layer 60 is longer than the wavelength of the second light (for example, peak wavelength).

  The wavelength conversion layer 60 may be provided in the light emitting devices 110 to 118 and 110a to 110c.

  In the light emitting devices 110 to 118 and 110 a to 110 d, the peak wavelength of the second light emitted from the second light emitting layer 25 is the same as the peak wavelength of the first light emitted from the first light emitting layer 15. Can do. For example, the absolute value of the difference between the peak wavelength of the second light and the peak wavelength of the first light is 10 nm or less. In this case, the intensity can be further increased with respect to the light having the peak wavelength.

  The peak wavelength of the second light may be different from the peak wavelength of the first light. For example, the peak wavelength of the second light is longer than the peak wavelength of the first light, and the difference between the two exceeds 10 nm. The difference between the two may be 30 nm or more. For example, when the first light passes through the second light emitting layer 25, it can be suppressed that a part of the first light is absorbed by the second light emitting layer 25. Thereby, efficiency can be improved.

  When the peak wavelength of the second light is different from the peak wavelength of the first light, the wavelength of the light obtained from the light emitting device by changing at least one of the intensity of the first light and the intensity of the second light Control the characteristics.

(Second Embodiment)
FIG. 11A and FIG. 11B are schematic views illustrating the light emitting device according to the second embodiment.
FIG. 11A is a plan view. FIG.11 (b) is the C1-C2 sectional view taken on the line of Fig.11 (a).
As shown in FIGS. 11A and 11B, the light emitting device 120 according to the present embodiment further includes a third light emitting element 30 in addition to the first light emitting element 10 and the second light emitting element 20. . The first light emitting element 10 and the second light emitting element 20 are the same as the light emitting device 110, for example, and thus the description thereof is omitted.

  The third light emitting element 30 includes a first conductivity type fifth semiconductor layer 35, a second conductivity type sixth semiconductor layer 36, and a third light emitting layer 301. The second semiconductor layer 12 of the first light emitting element 10 is disposed between the fifth semiconductor layer 35 and the first light emitting layer 15. The sixth semiconductor layer 36 is provided between the fifth semiconductor layer 35 and the second semiconductor layer 12. The third light emitting layer 301 is provided between the fifth semiconductor layer 35 and the sixth semiconductor layer 36.

  The third light emitting element 30 has a fifth main surface 30a and a sixth main surface 30b. The fifth major surface 30a is a major surface on the first light emitting element 10 side. The sixth major surface 30b is a major surface opposite to the fifth major surface 30a. The fifth major surface 30a is, for example, a lower surface, and the sixth major surface 30b is, for example, an upper surface.

  The third light emitting element 30 includes a fifth electrode 35e and a sixth electrode 36e. The fifth electrode 35e and the sixth electrode 36e are provided on the sixth main surface 30b (upper surface) side. The fifth electrode 35e is electrically connected to the fifth semiconductor layer 35. The sixth electrode 36e is electrically connected to the sixth semiconductor layer 36.

  For example, the sixth semiconductor layer 36 includes a fifth portion 36p and a sixth portion 36q. The sixth portion 36q is aligned with the fifth portion 36p along the XY plane (a third plane perpendicular to the direction from the sixth semiconductor layer 36 to the fifth semiconductor layer 35). The third light emitting layer 301 is disposed between the fifth portion 36p and the fifth semiconductor layer 35.

  In this example, the third light emitting element 30 further includes a third pad portion 35f provided on the fifth electrode 35e, and a fourth pad portion 36f provided on the sixth electrode 36e. .

  In this example, the substrate unit 55 further includes a fifth substrate electrode 55e and a sixth substrate electrode 56e provided on the mounting main surface 50a. For example, the fifth substrate electrode 55e is separated from the first to fourth substrate electrodes 51 to 54. For example, the sixth substrate electrode 56e is separated from the first to fifth substrate electrodes 51 to 54, 55e.

  The mounting component 50 further includes a fifth connection member 55c (for example, a third wiring) and a sixth connection member 56c (for example, a fourth wiring) in addition to the substrate portion 55. The fifth connection member 55c electrically connects the fifth substrate electrode 55e and the fifth electrode 35e. The fifth connection member 55c is connected to, for example, the third pad portion 35f. The sixth connection member 56c electrically connects the sixth substrate electrode 56e and the sixth electrode 36e. The sixth connection member 56c is connected to, for example, the fourth pad portion 36f.

  For example, at least a part of the first light emitted from the first light emitting layer 15 passes through at least a part of the third light emitting element 30 and is emitted to the outside of the third light emitting element 30. Also in the light emitting device 120, a light emitting device with an increased amount of light per unit area can be provided.

  In this example, the intermediate layer 40 extends between the first light emitting element 10 and the third light emitting element 30. At least a part of the first light emitted from the first light emitting layer 15 passes through the intermediate layer 40 and enters the third light emitting element 30.

  Thus, a plurality of light emitting elements can be provided on the first light emitting element 10. The number of light emitting elements provided on the first light emitting element 10 is arbitrary.

  In the light emitting device 120, the peak wavelength of the third light emitted from the third light emitting layer 301, the peak wavelength of the first light emitted from the first light emitting layer 15, and the second wavelength emitted from the second light emitting layer 25. The relationship with the peak wavelength of light is arbitrary.

  For example, the peak wavelength of the third light is longer than the peak wavelength of the first light, and the difference between both exceeds 10 nm. The difference between the two may be 30 nm or more. For example, when the first light passes through the third light emitting layer 301, it can be suppressed that a part of the first light is absorbed by the third light emitting layer 301. Thereby, efficiency can be improved.

  The light emitting device according to the embodiment can be used as a light source such as a lighting device or a display device.

  According to the embodiment, a light emitting device having an increased amount of light per unit area is provided.

In this specification, “nitride semiconductor” means B _x In _y Al _z Ga _1-xyz N (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ z ≦ 1, x + y + z ≦ 1) Semiconductors having all compositions in which the composition ratios x, y, and z are changed within the respective ranges are included. Furthermore, in the above chemical formula, those further containing a group V element other than N (nitrogen), those further containing various elements added for controlling various physical properties such as conductivity type, and unintentionally Those further including various elements included are also included in the “nitride semiconductor”.

  In the present specification, “vertical” and “parallel” include not only strictly vertical and strictly parallel, but also include, for example, variations in the manufacturing process, and may be substantially vertical and substantially parallel. is good.

The embodiments of the present invention have been described above with reference to specific examples. However, embodiments of the present invention are not limited to these specific examples. For example, each element included in a light emitting device, such as a light emitting element, a semiconductor layer, a light emitting layer, an electrode, a pad portion, an element substrate, a mounting component, a substrate portion, a mounting substrate, a substrate electrode, a connection member, a wiring, a reflective layer, and a back layer With respect to the specific configuration, as long as a person skilled in the art can carry out the present invention in a similar manner and appropriately obtain the same effect by appropriately selecting from the well-known ranges, it is included in the scope of the present invention.
Moreover, what combined any two or more elements of each specific example in the technically possible range is also included in the scope of the present invention as long as the gist of the present invention is included.

  In addition, all light-emitting devices that can be implemented by a person skilled in the art based on the light-emitting device described above as an embodiment of the present invention are also included in the scope of the present invention as long as they include the gist of the present invention. .

  In addition, in the category of the idea of the present invention, those skilled in the art can conceive of various changes and modifications, and it is understood that these changes and modifications also belong to the scope of the present invention. .

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 10 ... 1st light emitting element, 10a ... 1st main surface, 10b ... 2nd main surface, 10s ... 1st element substrate, 10sa ... 1st substrate upper surface, 10sb ... 1st substrate lower surface, 11 ... 1st semiconductor layer, 11e 1st electrode, 12 ... 2nd semiconductor layer, 12e ... 2nd electrode, 12p ... 1st part, 12q ... 2nd part, 15 ... 1st light emitting layer, 15a ... 1st barrier layer, 15b ... 1st well layer 20 ... second light emitting element, 20a ... third main surface, 20b ... fourth main surface, 20s ... second element substrate, 20sa ... second substrate lower surface, 20sb ... second substrate upper surface, 23 ... third semiconductor layer, 23e ... third electrode, 23f ... first pad portion, 24 ... fourth semiconductor layer, 24e ... fourth electrode, 24f ... second pad portion, 24p ... third portion, 24q ... fourth portion, 25 ... first 2 light emitting layers, 25a... Second barrier layer, 25 2nd well layer, 30 ... 3rd light emitting element, 30a ... 5th main surface, 30b ... 6th main surface, 30l ... 3rd light emitting layer, 35 ... 5th semiconductor layer, 35e ... 5th electrode, 35f ... 35th ... 3, 36 ... sixth semiconductor layer, 36 e ... sixth electrode, 36 f ... fourth pad part, 36 p ... fifth part, 36 q ... sixth part, 40 ... intermediate layer, 50 ... mounting component, 50 a ... Mounting main surface, 50b ... back surface, 50s ... mounting substrate, 51-54 ... first to fourth substrate electrodes, 51c ... first connecting member, 52c ... second connecting member, 53c ... third connecting member (first wiring) 54c ... fourth connection member (second wiring), 55 ... substrate portion, 55c ... fifth connection member, 55e ... fifth substrate electrode, 56c ... sixth connection member, 56e ... sixth substrate electrode, 57 ... reflective layer 58 ... Back layer, 60 ... Wavelength conversion layer, 7 r ... 2nd edge, 71-74 ... 1st-4th lower board | substrate side, 71s-74s ... 1st-4th lower board | substrate slope, 80r ... 2nd edge, 81-84 ... 1st-4th upper Substrate sides, 81 s to 84 s... First to fourth upper substrate slopes, θ 1 to θ 4, angles, 110 to 118, 110 a to 110 e, 120.

Claims (12)

A first semiconductor layer of a first conductivity type;
A second semiconductor layer of a second conductivity type;
A first light emitting layer provided between the first semiconductor layer and the second semiconductor layer;
A first light emitting device including:
A third semiconductor layer of the first conductivity type, wherein the second semiconductor layer is disposed between the third semiconductor layer and the first light emitting layer;
A fourth semiconductor layer of the second conductivity type provided between the third semiconductor layer and the second semiconductor layer;
A second light emitting layer provided between the third semiconductor layer and the fourth semiconductor layer;
A second light emitting device comprising:
With
A light emitting device in which at least part of the first light emitted from the first light emitting layer passes through at least part of the second light emitting element and is emitted to the outside of the second light emitting element. An intermediate layer which is provided between the second semiconductor layer and the fourth semiconductor layer and is transmissive and insulating with respect to the first light;
The light emitting device according to claim 1, wherein the at least part of the first light further passes through the intermediate layer. The first light emitting element includes:
A first main surface on the second light emitting element side;
A second main surface opposite to the first main surface;
Have
The first light emitting element includes:
A first electrode provided on the second main surface side and electrically connected to the first semiconductor layer;
A second electrode provided on the second main surface side and electrically connected to the second semiconductor layer;
The light-emitting device according to claim 1, further comprising:   4. The light emitting device according to claim 3, wherein at least one of the first electrode and the second electrode reflects at least part of the second light emitted from the second light emitting layer. A mounting board having a mounting main surface;
A first substrate electrode provided on the mounting main surface; a second substrate electrode provided on the mounting main surface and spaced apart from the first substrate electrode;
A substrate portion including:
A first connecting member provided between the first electrode and the first substrate electrode and electrically connecting the first electrode and the first substrate electrode;
A second connecting member provided between the second electrode and the second substrate electrode and electrically connecting the second electrode and the second substrate electrode;
The light emitting device according to claim 3, further comprising a mounting component including   At least a part of the second light emitting element is projected onto a plane perpendicular to a direction from the first semiconductor layer toward the second semiconductor layer, and at least one of the first substrate electrode and the second substrate electrode. The light emitting device according to claim 5, which overlaps any one of them. The second light emitting element includes:
A third principal surface on the first light emitting element side;
A fourth main surface opposite to the third main surface;
Have
The second light emitting element includes:
A third electrode provided on the fourth main surface side and electrically connected to the third semiconductor layer;
A fourth electrode provided on the fourth main surface side and electrically connected to the fourth semiconductor layer;
The light emitting device according to claim 5, further comprising: The substrate portion is
A third substrate electrode provided on the mounting main surface;
A fourth substrate electrode provided on the mounting main surface and spaced apart from the third substrate electrode;
Further including
The mounting component is
A first wiring that electrically connects any one of the third electrode and the fourth electrode to the third substrate electrode;
A second wiring that electrically connects either the third electrode or the fourth electrode to the fourth substrate electrode;
The light emitting device according to claim 7, further comprising:   When projected onto a plane perpendicular to the direction from the first semiconductor layer toward the second semiconductor layer, at least part of either the third electrode or the fourth electrode is the first electrode and The light-emitting device according to claim 7 or 8, wherein at least a part of the other one of the third electrode and the fourth electrode overlaps the second electrode. The first light emitting device further includes a first device substrate,
The second semiconductor layer is disposed between the first element substrate and the first light emitting layer;
The first element substrate is
A first edge when projected onto a plane perpendicular to the direction from the first semiconductor layer toward the second semiconductor layer;
An upper surface of a first substrate facing the second light emitting element and at least partially spaced from the first edge;
A first substrate lower surface opposite to the first substrate upper surface;
An inclined surface provided between the upper surface of the first substrate and the first edge and inclined with respect to the plane;
Including
The distance along the said direction between the said 1st board | substrate upper surface and the said 1st board | substrate lower surface is longer than the length along the said direction of the said 1st edge part, It is any one of Claims 1-9 Light-emitting device. The second light emitting device further includes a second device substrate,
The fourth semiconductor layer is disposed between the second element substrate and the second light emitting layer;
The second element substrate is
A second edge when projected onto a plane perpendicular to the direction from the first semiconductor layer toward the second semiconductor layer;
A second substrate lower surface facing the first light emitting element;
A second substrate upper surface opposite to the second substrate lower surface and at least partially spaced from the second edge;
An inclined surface provided between the upper surface of the second substrate and the second edge and inclined with respect to the plane;
Including
The distance along the said direction between the said 2nd board | substrate upper surface and the said 2nd board | substrate lower surface is longer than the length along the said direction of the said 2nd edge part, It is any one of Claims 1-10. Light-emitting device.   Covering at least part of the first light emitting element and at least part of the second light emitting element, part of the first light and part of the second light emitted from the second light emitting layer; The light-emitting device according to claim 1, further comprising a wavelength conversion layer that absorbs light and emits light having a wavelength different from that of the second light unlike the first light.

Images