Semiconductor light emitting element, semiconductor light emitting device, and semiconductor light emitting device module

Abstract

To provide a semiconductor light emitting element, a semiconductor light emitting device and a semiconductor light emitting device module with excellent heat dissipation characteristics, uniform current injection and light emission, and high light emission efficiency.SOLUTION: It comprises an insulating or semi-insulating substrate, a light emitting functional part 15M in which a first polar first semiconductor layer, a light emitting layer and a second polar second semiconductor layer are sequentially stacked on the substrate, an insulating film covering the light emitting functional part, a first pad electrode 28A electrically connected to the first and second semiconductor layers respectively and the second pad electrode 28B, and at least one intermediate pad 29 electrically insulated from the light emitting functional part, on the insulating film, and a pad separation groove GP separating each of the first pad electrode, the second pad electrode and the intermediate pad and exposing the insulating film.SELECTED DRAWING: Figure 1A

Description

[Technical Field]

[0001] The present invention relates to a semiconductor light emitting element, a semiconductor light emitting device, and a semiconductor light emitting device module, and more particularly to a semiconductor light emitting element such as a light emitting diode (LED), and a semiconductor light emitting device and a semiconductor light emitting device module having the semiconductor light emitting element. [Background technology]

[0002] In recent years, semiconductor light-emitting elements such as light-emitting diodes (LEDs) have been arranged and used in multiple devices in order to achieve higher output and light distribution control.

[0003] For example, adaptive driving beam (ADB) headlamps are known for their variable light distribution, which controls the light distribution according to the driving environment. Also known are high-power LED packages for lighting and LED packages for information and communication devices with high-density LED arrangements.

[0004] However, there is an increasing demand for high-power semiconductor light-emitting elements that have high luminous efficiency and can emit uniform light. There is also a demand for semiconductor light-emitting devices that are less susceptible to element breakdown by providing additional functions such as a protective element while preventing performance degradation of the light-emitting element.

[0005] For example, Patent Document 1 discloses a light-emitting device having a plurality of holes that penetrate an active layer and expose a first semiconductor layer, and a first solder pad and a second solder pad formed in an area other than the positions of the plurality of holes, thereby equalizing the light field distribution and reducing the forward voltage of the light-emitting device.

[0006] Patent Document 2 also discloses a light-emitting element structure that includes a plurality of semiconductor stacks including a plurality of grooves and a flat base having an upper surface, and an electrode is provided on a first semiconductor layer exposed from the bottom of the plurality of grooves.

[0007] Patent Document 3 discloses a nitride semiconductor light-emitting device in which a plurality of electrically separated nitride semiconductor layers are formed on the same substrate, and each nitride semiconductor layer is electrically connected by a conductive wire. Patent Document 4 discloses an LED array in which a plurality of LEDs 1 are formed two-dimensionally monolithically and connected in series. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Publication No. 2017-92477 [Patent Document 2] Japanese Patent Application Laid-Open No. 2014-150188 [Patent Document 3] Japanese Patent Application Laid-Open No. 2001-156331 [Patent Document 4] Japanese Patent Application Laid-Open No. 2004-6582 Summary of the Invention [Problem to be solved by the invention]

[0009] The present invention has been made in consideration of the above-mentioned points, and aims to provide a semiconductor light-emitting element, a semiconductor light-emitting device, and a semiconductor light-emitting device module that have excellent heat dissipation characteristics, uniform current injection and light emission, and high light-emitting efficiency. [Means for solving the problem]

[0010] A semiconductor light emitting device according to one embodiment of the present invention comprises: an insulating or semi-insulating substrate; a light-emitting functional layer in which a first semiconductor layer of a first polarity, a light-emitting layer, and a second semiconductor layer of a second polarity are sequentially stacked on the substrate; an insulating film covering the light-emitting functional layer; a first pad electrode and a second pad electrode electrically connected to the first semiconductor layer and the second semiconductor layer, respectively, provided on the insulating film, and at least one intermediate pad electrically insulated from the light emitting function layer; and a pad isolation groove that separates the first pad electrode, the second pad electrode, and the intermediate pad from each other and exposes the insulating film. [Brief explanation of the drawings]

[0011] [Figure 1A] 1 is a top view schematically showing a semiconductor light emitting device 10 according to a first embodiment of the present invention as viewed from above. [Figure 1B] FIG. 1B is a cross-sectional view schematically showing a cross section taken along line AA in FIG. 1A. [Figure 2A] 1 is a perspective view showing a method for mounting the semiconductor light emitting element 10 on a circuit board. [Figure 2B] FIG. 10 is a top perspective view for explaining the discharge of flux gas. [Figure 2C] FIG. 10 is a cross-sectional view for explaining the discharge of flux gas. [Figure 2D] 10 is a top view of the p-pad electrode 28A, the n-pad electrode 28B, or the intermediate pad electrode 29. FIG. [Figure 3] FIG. 1 is a diagram showing the relationship between the void occupancy rate (%) in a joining member and the thermal resistance (° C. / W). [Figure 4] FIG. 10 is a perspective view showing a semiconductor light emitting device 50 and a semiconductor light emitting device module 60 according to a second embodiment. [Figure 5A] FIG. 10 is a top view schematically showing the top surface of a semiconductor light emitting device module 70 according to a third embodiment. [Figure 5B] FIG. 5B is a cross-sectional view schematically showing a cross section taken along line AA in FIG. 5A. [Figure 6A] 10A to 10C are top views showing the manufacturing process of the semiconductor light emitting device module 70. [Figure 6B] 10A to 10C are top views showing the manufacturing process of the semiconductor light emitting device module 70. [Figure 6C] 10A to 10C are top views showing the manufacturing process of the semiconductor light emitting device module 70. [Figure 7] FIG. 10 is a top view schematically showing the top surface of a semi-semiconductor light emitting element 80 according to a fourth embodiment. [Figure 8]10 is a top view schematically showing a semiconductor light emitting device 85 which is a modified example of the semiconductor light emitting device 80. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0012] In the following, preferred embodiments of the present invention will be described, but these may be modified and combined as appropriate. In the following description and accompanying drawings, substantially the same or equivalent parts are designated by the same reference numerals.

[0013] [First embodiment] (1) Structure of semiconductor light emitting element FIG. 1A is a top view schematically showing a semiconductor light emitting element 10 according to a first embodiment of the present invention as viewed from above (also referred to as a top view). For ease of explanation and understanding, the internal structure of electrodes and the like is also shown. FIG. 1B is a cross-sectional view schematically showing a cross section taken along line AA in FIG. 1A. The structure of the semiconductor light emitting element 10 will be described in detail below.

[0014] 1A, the semiconductor light emitting element 10 has a light emitting functional layer 15 formed on a substrate 11. More specifically, the light emitting functional layer 15 has a plurality of light emitting functional portions 15M formed in a mesa shape.

[0015] 1B, the semiconductor light emitting element 10 has a light-transmitting insulating substrate 11. In this embodiment, the substrate 11 has a rectangular pillar shape, and the surface of the substrate 11 has a rectangular shape when viewed from above. The substrate 11 may be made of, for example, sapphire or aluminum nitride (AlN).

[0016] Furthermore, the substrate 11 may be formed of an insulating substrate, a semi-insulating or high-resistance material, etc. In this specification, a semi-insulating substrate includes a semiconductor substrate such as a high-resistance GaN substrate. Specifically, it refers to a material that exhibits a high resistance of 1 MΩ / □ or more.

[0017] 1A and 1B, the light-emitting functional portions 15M are light-emitting regions separated from one another by crystal separation grooves 15G that reach the substrate 11. The light-emitting functional portions 15M extend in a direction (y direction) parallel to a pair of opposing sides of the semiconductor light-emitting element 10.

[0018] The light-emitting functional portions 15M are formed at predetermined intervals in a direction (x direction) perpendicular to the extending direction of the light-emitting functional portions 15M. The extending direction of the light-emitting functional portions 15M is preferably parallel to a predetermined crystal direction of the light-emitting functional layer 15.

[0019] More specifically, an n-type semiconductor layer 12 (first semiconductor layer of first polarity), a light-emitting layer 13, and a p-type semiconductor layer 14 (second semiconductor layer of second polarity) are stacked in this order on a substrate 11, forming a mesa-shaped light-emitting functional section 15M.

[0020] The mesa-shaped light-emitting functional portion 15M is made of a GaN-based semiconductor layer, and can be formed by etching a crystal growth layer (light-emitting functional layer) formed by, for example, MOCVD (metal organic chemical vapor deposition). Note that the crystal growth method is not limited to MOCVD, and MBE (molecular beam epitaxy) and HVPE (hydride vapor phase epitaxy) methods can also be used. Furthermore, the semiconductor layer is not limited to a GaN-based semiconductor layer, and a compound semiconductor layer capable of forming a light-emitting functional layer can also be used.

[0021] The substrate 11 is exposed at the bottom of the crystal separation grooves 15G between the light emitting functional portions 15M. That is, the light emitting functional portions (semiconductor layers) of the plurality of light emitting functional portions 15M are formed so as to be electrically isolated from one another.

[0022] Furthermore, an electrode formation portion 15C, which is a step that exposes the n-type semiconductor layer 12, is provided on one end side (-x side) in the lateral direction (short side direction) of the light-emitting function portion 15M. The electrode formation portion 15C extends in the extension direction (longitudinal direction) of the light-emitting function portion 15M.

[0023] That is, the n-electrode 22 provided on the n-type semiconductor layer 12 extends in the extension direction of the light-emitting functional portion 15M. Of the multiple light-emitting functional portions 15M, the n-electrode 22 of the light-emitting functional portion 15M located on the outer edge of the semiconductor light-emitting element 10 is connected to a first pad electrode (n-pad electrode) 28B described later, and forms an n-pad connecting portion 22B.

[0024] An n-electrode 22 (first electrode) which is an ohmic electrode is formed on the electrode formation portion 15C of the n-type semiconductor layer 12. The n-electrode 22 is formed as an ohmic electrode in which Ti and Al are formed in this order on the n-type semiconductor layer 12. Note that the n-electrode 22 is not limited to a Ti / Al layer, and may be formed of a material that forms ohmic contact with the n-type semiconductor layer 12, such as Ti / Rh or Ti / Au.

[0025] A p-electrode 23 (second electrode) consisting of an ohmic electrode, a reflective layer, and a protective layer is formed on the p-type semiconductor layer 14 on the mesa of the light-emitting functional section 15M. Specifically, an indium tin oxide (ITO) film is formed as the ohmic electrode, and Ni / Ag / Ti / Au layers are formed as the reflective layer and protective layer on the ITO film.

[0026] The p-electrode 23 at the outer edge of the other end opposite to the one end side of the semiconductor light-emitting element 10 on which the n-pad connection portion 22B is formed is connected to a second pad electrode (p-pad electrode) 28A described later, and forms the p-pad connection portion 23A.

[0027] The sidewalls and upper surfaces of the mesa-shaped light-emitting functional portion 15M and the p-electrode 23 are covered and protected by a first insulating film 25A made of SiO2. A wiring layer 26, which is a connecting wire, is formed on the first insulating film 25A.

[0028] The wiring layer 26 is a light-reflective metal wiring layer, and is formed so as to cover the sidewalls and part of the top surface of the light-emitting functional section 15M via the first insulating film 25A. The first insulating film 25A has an opening that exposes the p-electrode 23 on part of the top surface of the light-emitting functional section 15M.

[0029] In the opening of the first insulating film 25A, one end of the wiring layer 26 is connected to the p-electrode 23, forming a p-electrode connecting portion 23C. The other end of the wiring layer 26 is connected to the n-electrode 22. That is, the wiring layer 26 functions as a transition wiring that connects the n-electrodes 22 and p-electrodes 23 of the adjacent light-emitting functional portions 15M.

[0030] 1A and 1B are connected in series. The light-emitting functional units 15M separated by the crystal separation grooves 15G function as a light-emitting functional layer, and have a rectangular shape in top view. Therefore, in this specification, the light-emitting functional units 15M and the crystal separation grooves 15G are collectively referred to as the light-emitting functional layer 15.

[0031] 1A, the p-electrode connecting portion 23C and the n-electrode 22 are preferably formed from one end to the other in the extension direction (y direction) of the light-emitting functional portion 15M. Also, it is preferable that the wiring layer 26 is formed from one end to the other in the extension direction of the adjacent light-emitting functional portions 15M in terms of reflectivity and current uniformity.

[0032] Specifically, the wiring layer 26 is formed of a Ni / Al / Ti / Pt layer or a Ti / Al / Ti / Pt layer, but the layer structure is not limited to these. For example, Pd or Rh can be used instead of Pt.

[0033] The wiring layer 26 is covered, insulated, and protected by a second insulating film 25B made of SiO formed on the wiring layer 26. That is, the first insulating film 25A and the second insulating film 25B are formed so as to cover the entire surface of the semiconductor light emitting element 10 except for the n-pad connecting portion 22B and the p-pad connecting portion 23A.

[0034] In the following description, the insulating film that is made up of the first insulating film 25A and the second insulating film 25B and covers the entire surface of the semiconductor light emitting element 10 will be referred to as an element insulating film 25.

[0035] Furthermore, the first insulating film 25A and the second insulating film 25B are not limited to SiO2, and may be made of an insulating dielectric such as a SiN film.

[0036] As shown in FIG. 1A, on the surface of the element insulating film 25 of the semiconductor light emitting element 10, a p-pad electrode 28A, an n-pad electrode 28B, and two intermediate pads 29 are formed, extending along the extension direction (y direction) of the light emitting function portion 15M and separated from each other by a gap (pad separation groove GP) in a direction (x direction) perpendicular to the extension direction.

[0037] That is, the p-pad electrode 28A, the n-pad electrode 28B, and the two intermediate pads 29 extending along the extension direction of the light-emitting functional section 15M are separated from each other by pad separation grooves (hereinafter simply referred to as grooves) GP and are arranged side by side in a striped pattern.

[0038] The grooves GP are preferably formed linearly at regular intervals in the extending direction of the light-emitting function portion 15M. The grooves GP are preferably provided extending to reach the opposing outer edges (i.e., outer edges parallel to the x-direction) of the crystal growth layer 15. Furthermore, the grooves GP between adjacent pad electrodes and intermediate pads do not need to have the same width.

[0039] The n-pad electrode 28B and the p-pad electrode 28A may be made of any conductive material, but it is preferable that the surface layer be made of metal. The intermediate pad 29 is formed as an insulating pad insulated from the semiconductor layer of the semiconductor light emitting element 10, i.e., the light emitting function portion 15M.

[0040] Furthermore, the intermediate pad 29 does not need to be a conductor and may be an insulator, but from the viewpoint of bonding and mounting, it is preferable that at least the surface layer be made of metal. Furthermore, it is preferable that the p-pad electrode 28A and the n-pad electrode 28B have the same layer structure, and it is further preferable that the p-pad electrode 28A, the n-pad electrode 28B, and the intermediate pad 29 have the same layer structure.

[0041] When the intermediate pad 29 is made of a conductor such as metal and is mounted by being electrically connected to the p-pad electrode 28A or the n-pad electrode 28B, the intermediate pad 29 functions as an electrode. In the following, a case where the intermediate pad 29 is made of a conductor such as metal will be described, and the intermediate pad 29 will be referred to as the intermediate pad electrode 29.

[0042] 1B, an n-pad electrode 28B (cathode) is provided that is electrically connected to the outermost n-electrode 22 formed at the end of one side of the semiconductor light emitting element 10 through an opening in the element insulating film 25. That is, the connection portion between the n-pad electrode 28B and the n-electrode 22 is an n-pad connection portion 22B (see FIG. 1A).

[0043] Also, a p-pad electrode 28A (anode) is provided that is electrically connected to the outermost p-electrode connection portion 23C formed at the other end of the semiconductor light emitting element 10 through an opening in the element insulating film 25. That is, the connection portion between the p-pad electrode 28A and the p-electrode 23 is the p-pad connection portion 23A (see FIG. 1A).

[0044] Furthermore, two intermediate pad electrodes 29 (insulating pad electrodes) formed on the element insulating film 25 and electrically insulated from the light-emitting functional portion 15M are provided between the n-pad electrode 28B (cathode) and the p-pad electrode 28A (anode).

[0045] More specifically, the pad electrodes 28B, 28A and the two intermediate pad electrodes 29 have an Al layer as a light-reflecting layer, and are formed of, for example, a Ni / Al / Ti / Au layer (the Au layer is the outermost layer), but are not limited thereto. For example, instead of the Al layer, a light-reflecting layer such as an Ag layer can be used.

[0046] As shown in FIG. 1B, the element insulating film 25 (i.e., the first insulating film 25A and the second insulating film 25B) covering the surface of the semiconductor light-emitting element 10 is exposed in the grooves GP between the pad electrodes 28B, 28A and the two intermediate pad electrodes 29.

[0047] Although the following description takes as an example a case where two intermediate pad electrodes 29 are arranged between the n-pad electrode 28B and the p-pad electrode 28A, the number of intermediate pad electrodes 29 is not limited to this. For example, it is sufficient to provide at least one intermediate pad electrode 29. The intermediate pad electrode 29 can be appropriately divided into the n-pad electrode 28B and the p-pad electrode 28A during mounting and connected to the cathode wiring and anode wiring of a circuit board or the like for mounting.

[0048] A part of the light emitted from the light-emitting functional unit 15M is emitted as direct light Ld from the light-emitting surface 11E, which is the rear surface of the light-transmitting substrate 11, and a part of the light is emitted from the light-emitting surface 11E as reflected light Lr by the p-electrode 23. In addition, light emitted in the lateral direction of the light-emitting functional unit 15M is also reflected by the wiring layer 26 and the pad electrodes 28A, 29, and 28B, and is emitted from the light-emitting surface 11E.

[0049] In the above, we have described the case where the light-emitting functional layer 15 is separated into multiple light-emitting functional sections 15M, but the light-emitting functional layer 15 may also be configured as a single plateau-shaped light-emitting functional section 15M without having a crystal separation groove 15G.

[0050] (2) Mounting of semiconductor light emitting elements on a circuit board The following describes how to mount the semiconductor light emitting element 10 on a circuit board: Fig. 2A is a perspective view showing a method for mounting the semiconductor light emitting element 10 on a circuit board.

[0051] With the p-pad electrode 28A, n-pad electrode 28B, and two intermediate pad electrodes 29 of the semiconductor light emitting element 10 facing downward, the semiconductor light emitting element 10 is bonded to the anode wiring 43A and cathode wiring 43B of the circuit board using bonding members 41A and 41B, respectively.

[0052] Specifically, for example, the p-pad electrode 28A and the intermediate pad electrode 29 adjacent to the p-pad electrode 28A are joined to the anode wiring 43A, and the n-pad electrode 28B and the intermediate pad electrode 29 adjacent to the n-pad electrode 28B are joined to the cathode wiring 43B.

[0053] More specifically, first, solder paste solder (joining members 41A and 41B) that serve as joining members is printed on the anode wiring 43A and the cathode wiring 43B that are circuit board wiring. Next, the semiconductor light emitting element 10 is mounted on the solder paste. Next, they are heated and joined in a reflow furnace.

[0054] 2B and 2C are a top perspective view and a cross-sectional view taken along line DD in FIG. 2A, respectively, for explaining the discharge of flux gases volatilized during reflow.

[0055] The solder paste solder of the joining members 41A and 41B contains a volatile flux, which volatilizes during reflow. At this time, as shown in FIG. 2B, the grooves GP between the adjacent pad electrodes of the p-pad electrode 28A, the two intermediate pad electrodes 29, and the n-pad electrode 28B function as gas exhaust paths (ventilation paths).

[0056] That is, the anode wiring 43A and the cathode wiring 43B have shapes corresponding to the bonding configuration of the p-pad electrode 28A, the n-pad electrode 28B, and the two intermediate pad electrodes 29, and are arranged at intervals corresponding to the grooves GP. Therefore, the grooves GP between the anode wiring 43A and the cathode wiring 43B function as ventilation paths during reflow.

[0057] As described above, in the groove GP between the strip-shaped pad electrodes, an insulating film (SiO2 film) with low wettability to the joining material or solder in a molten metal state is exposed, and the groove GP is well formed, allowing gas to be effectively discharged.

[0058] 2B, when the semiconductor light emitting element 10 is heated from the outside, the solder melts and progresses from the outside to the inside (heat propagation curve in the figure). Therefore, by providing the groove GP so that the groove GP passes through the final melting point MP (black circle, center of the light emitting functional layer 15), it becomes possible to more efficiently exhaust the flux gas and form a bonding layer with fewer voids.

[0059] Therefore, mounting with high heat dissipation is possible. When the light-emitting functional layer 15 has a rectangular shape as described above, it is preferable that the groove GP is provided in an arrangement in which the intersection of the diagonal lines of the light-emitting functional layer 15 is included within the groove GP.

[0060] In particular, as shown in FIG. 2C, the groove GP0 between the anode wiring 43A and the cathode wiring 43B (i.e., between the bonding members 41A and 41B) where the bonding members are separated during mounting, and which passes through the final melting point MP, has a greater gas discharge effect. That is, in the case shown in FIG. 2C, the groove GP0 between the two intermediate pad electrodes 29 has a greater discharge effect. By providing the gas discharge path GP0 in this way, flux gas discharge becomes particularly effective, making it possible to form a bonding layer in which the generation of voids is extremely suppressed, and mounting with high heat dissipation is also possible. Note that it is preferable to make the width of the pad separation groove GP0 larger than the widths of the other separation grooves GP.

[0061] 2D is a top view of the p-pad electrode 28A, the n-pad electrode 28B, or the intermediate pad electrode 29. In order to exhaust volatile gases of the flux from between adjacent pad electrodes, it is effective to increase the perimeter L when the area S is constant. For example, the perimeter L can be increased by dividing the pad electrodes into smaller parts.

[0062] Specifically, the ratio R=L / W of the long side (or length) L to the short side (or width) W of the pad electrode is preferably 2≦R. Furthermore, if R is too large, it can make formation and mounting difficult due to misalignment and other reasons, so R≦10 is preferable. Therefore, 2≦R≦10 is preferable. Furthermore, in consideration of the ability to expel volatile gases and ease of formation and mounting, the range of 3≦R≦8 is more preferable.

[0063] Figure 3 shows the relationship between the void occupancy rate (%) and thermal resistance (°C / W) when the joining material (solder) is 1 mm in length and width. The plot shows the simulated values ​​(SIM: dashed line) and the measured values ​​(EX: black circles).

[0064] When a semiconductor light-emitting element is bonded to a wiring (land) of a circuit board via a bonding material (solder), voids (vacant holes) may be formed in the bonding material. Because the semiconductor light-emitting element generates heat when current is applied, if the occupancy rate of the voids formed in the bonding material (the area occupied by the voids when viewed from above) increases, the thermal resistance increases, reducing the heat dissipation characteristics to the circuit board or a heat sink (heat sink) provided on the circuit board, and impairing the reliability (e.g., lifespan) of the semiconductor light-emitting element.

[0065] As shown in Figure 3, for example, in the case of a conventional electrode formed over the entire bottom surface of a light-emitting element, the void occupancy rate is typically 20% to 40%, and the thermal resistance increases by about 10% to 20% compared to when no voids are formed.

[0066] The pad electrode of the semiconductor light emitting element 10 of the present invention has a structure that can discharge gases volatilized from the paste solder, which are a cause of void formation. Therefore, the void occupancy rate can be reduced to 0% to 15% or less. As shown in Figure 3, the semiconductor light emitting element 10 of the present invention can actually achieve a void occupancy rate of 0% to 5%.

[0067] Therefore, mounting with low thermal resistance is possible, and a highly reliable semiconductor light emitting device can be provided with little reduction in optical output even when a high current is injected.

[0068] [Second embodiment] FIG. 4 is a perspective view showing a semiconductor light emitting device 50 and a semiconductor light emitting device module 60 according to a second embodiment of the present invention.

[0069] The semiconductor light emitting device 50 of this embodiment includes the semiconductor light emitting element 10 of the first embodiment and a light guide 51. In the following, an example will be described in which the light guide 51 is a phosphor plate. That is, the semiconductor light emitting device 50 of this embodiment is configured as a light emitting device that emits mixed color light.

[0070] The semiconductor light emitting device 50 includes a semiconductor light emitting element 10 and a light guide provided on the semiconductor light emitting element 10. More specifically, a phosphor plate 51 is adhered to a light emitting surface 11E of the semiconductor light emitting element 10 by an adhesive layer 52 (see FIG. 1B).

[0071] The semiconductor light emitting element 10 is, for example, a light emitting element (LED) that emits blue light, and the phosphor plate 51 is, for example, YAG:Ce, and emits yellow light as wavelength-converted light. Therefore, white mixed color light LM is emitted from the upper surface of the phosphor plate 51. The adhesive layer 52 is made of a light-transmitting adhesive, for example, a light-transmitting silicone resin.

[0072] The semiconductor light emitting element 10 and the phosphor plate 51 have the same outer shape and outer size, e.g., a rectangular plate shape. That is, the semiconductor light emitting element 10 and the phosphor plate 51 have a common outer surface. The outer shape of the phosphor plate 51 may be approximately 5 to 10% smaller or larger than the outer shape of the semiconductor light emitting element 10.

[0073] The semiconductor light emitting device module 60 of this embodiment has a semiconductor light emitting device 50 mounted on a circuit board. More specifically, in the semiconductor light emitting device module 60, the semiconductor light emitting device 50 is mounted with the p-pad electrode 28A, the n-pad electrode 28B, and the two intermediate pad electrodes 29 facing downward and bonded to the anode wiring 43A and the cathode wiring 43B of the circuit board by bonding members 41A and 41B, respectively.

[0074] More specifically, for example, the anode wiring 43A is formed as a land whose width WA is wider than the width WB of the cathode wiring 43B, and the p-pad electrode 28A and two intermediate pad electrodes 29 of the semiconductor light-emitting device 50 are joined to the anode wiring 43A, and the n-pad electrode 28B is joined to the cathode wiring 43B.

[0075] In this way, since the intermediate pad electrode 29 is insulated from the light-emitting function part 15M, the intermediate pad electrode 29 can be used as the electrode (e.g., the anode) for which heat dissipation is desired to be improved, and therefore the junction area can be increased, thereby improving heat dissipation.

[0076] As described above, according to this embodiment, the semiconductor light-emitting device and semiconductor light-emitting device module have high heat dissipation properties, so that even when a high current is injected, there is little reduction in light output, making it possible to provide a high-output, highly reliable semiconductor light-emitting device and semiconductor light-emitting device module.

[0077] [Third embodiment] A semiconductor light emitting device module 70 according to a third embodiment of the present invention will be described in detail below with reference to the drawings. Fig. 5A is a top view schematically showing the upper surface of the semiconductor light emitting device module 70. Fig. 5B is a cross-sectional view schematically showing a cross section taken along line AA in Fig. 5A.

[0078] The semiconductor light emitting device module 70 of this embodiment has a plurality of semiconductor light emitting devices 50 arranged in a frame body 72 that is erected on a circuit board 71. The frame body 72 is formed as a resin dam made of resin, for example, and an example will be described in which four semiconductor light emitting devices 50 are arranged in a row inside the frame body 72.

[0079] The spaces between the semiconductor light emitting devices 50 and the frame body 72, and between adjacent semiconductor light emitting devices 50, are sealed with sealing resin 72F, and an anode terminal 78A, a cathode terminal 78B, and a short circuit detection terminal 78C are provided, which are connected to the semiconductor light emitting devices 50. Fixing holes 71H are also provided for fixing the semiconductor light emitting device module 70.

[0080] 5B, the semiconductor light emitting devices 50 are connected in series by circuit wiring 73 of the circuit board 71. More specifically, the n-pad electrode 28B of the semiconductor light emitting device 50 at one end of the array (the left end in the figure) is connected to the cathode wiring 73B of the circuit wiring 73. The p-pad electrode 28A of the semiconductor light emitting device 50 at the other end of the array (the right end) is connected to the anode wiring 73A of the circuit wiring 73.

[0081] The p-pad electrode 28A of one semiconductor light emitting device 50 and the n-pad electrode 28B of the adjacent semiconductor light emitting device 50 are joined and electrically connected to the connection wiring 73C of the circuit wiring 73. This connection establishes a series connection between the adjacent semiconductor light emitting devices 50.

[0082] Furthermore, the intermediate pad electrodes 29 of all the semiconductor light emitting devices 50 are connected to an intermediate wiring 73I. The intermediate wiring 73I is connected to a back surface metal layer 75 on the back surface of the circuit board 71 through a via wiring 71V made of metal that penetrates the circuit board 71.

[0083] Here, the anode wiring 73A is connected to an anode terminal 78A, and the cathode wiring 73B is connected to a cathode terminal 78B. In addition, the intermediate wiring 73I is connected to a short circuit detection terminal 78C.

[0084] The back surface metal layer 75 is bonded to the heat sink 77 by the heat sink bonding layer 76. Therefore, heat generated by the semiconductor light emitting device 50 is dissipated through the intermediate pad electrode 29, the intermediate wiring 73I, the via wiring 71V, the back surface metal layer 75, and the heat sink 77.

[0085] More specifically, heat generated in the semiconductor light emitting device 50 is dissipated directly to the heat sink 77 via a metal with high thermal conductivity (e.g., copper, silver, or gold) by the intermediate electrode 29 provided on the semiconductor light emitting element 10. This results in high heat dissipation efficiency, and allows the light emitting efficiency to be maintained at a high level.

[0086] Next, a manufacturing process of the semiconductor light emitting device module 70 will be described with reference to the top views shown in Figures 6A to 6C. First, as shown in Figure 6A, a circuit board 71 is prepared, which has circuit wiring 73 including anode wiring 73A, cathode wiring 73B, intermediate wiring 73I, and connecting wiring 73C, and a frame body 72. In the figure, a mounting region 10R on which the semiconductor light emitting element 10 is mounted is indicated by a dashed line.

[0087] For example, the circuit board 71 may be a glass fiber reinforced epoxy resin board, a metal core board such as an insulating layer / copper core board, or a ceramic board such as aluminum nitride or alumina.

[0088] 6B, the semiconductor light emitting elements 10 are mounted in the mounting area 10R by bonding with bonding members 74. At this time, protective elements 79 such as Zener diodes are mounted on the circuit wiring 73 in parallel with each semiconductor light emitting element 10. Note that the bonding members 74 are preferably made of tin-copper based lead-free solder or the like.

[0089] Subsequently, as shown in FIG. 6C, a phosphor plate 51 is adhered onto the semiconductor light emitting element 10 with a light-transmitting adhesive layer 52.

[0090] Finally, sealing resin 72F is injected inside frame 72, filling the spaces between semiconductor light emitting devices 50 and frame 72 and between adjacent semiconductor light emitting devices 50, completing semiconductor light emitting device module 70 shown in FIG. 5A.

[0091] In the above example, the semiconductor light-emitting element 10 is joined to the circuit board 71, and then the phosphor plate 51, which is a light guide, is adhered to the semiconductor light-emitting element 10. However, a semiconductor light-emitting device having a light guide adhered to the semiconductor light-emitting element 10, such as the semiconductor light-emitting device 50 of the second embodiment, may also be mounted on the circuit board 71.

[0092] As described above, according to this embodiment, even when multiple semiconductor light emitting devices are arranged, it is possible to provide a high-output, highly reliable semiconductor light emitting device module that has high heat dissipation properties and little reduction in optical output even when a high current is injected.

[0093] [Fourth embodiment] A semiconductor light emitting device 80 according to a fourth embodiment of the present invention will be described in detail below with reference to the drawings. Figure 7 is a top view schematically showing the top surface of the semiconductor light emitting device 80.

[0094] The semiconductor light emitting element 80 of this embodiment differs from the semiconductor light emitting element 10 of the first embodiment in that the p-pad electrode 28A, the n-pad electrode 28B, and the intermediate pad electrodes 29(1), 29(2) are arranged in a matrix of m rows x n columns (2≦m, 2≦n).

[0095] More specifically, rectangular p-pad electrode 28A, n-pad electrode 28B, and two intermediate pad electrodes 29(1), 29(2) are arranged in two rows and two columns, separated by grooves GP1 (y direction) and grooves GP2 (x direction). These four pad electrodes are also arranged symmetrically with respect to center lines CL1 and CL2 of the semiconductor light emitting element 80, which are perpendicular to each other.

[0096] The groove GP1 in the extension direction of the light emitting function portion 15M and the groove GP2 in the direction perpendicular to the extension direction are provided so as to pass through the final melting point MP, that is, so that the final melting point MP is located within the grooves GP1 and GP2.

[0097] For example, the grooves GP1 and GP2 are formed so as to pass through the intersection of the center lines CL1 and CL2 of the semiconductor light emitting element 80. Alternatively, the grooves GP1 and GP2 may be formed so as to pass through the center of the outer edge (rectangular shape) of all four pad electrodes.

[0098] When pad electrodes are arranged in m rows and n columns as described above, it is effective in terms of gas discharge to provide grooves GP1 and GP2 between the pad electrodes that pass through the final melting point MP. In the case shown in Figure 7, the grooves GP1 and GP2 function as separation grooves GP1 and GP2 that are particularly effective in gas discharge.

[0099] Furthermore, the p-pad electrode 28A and the n-pad electrode 28B are disposed diagonally. In this case, the p-pad electrode 28A and the intermediate pad electrode 29(1) can be connected to the anode wiring of the circuit board, and the n-pad electrode 28B and the intermediate pad electrode 29(2) can be connected to the cathode wiring, i.e., the intermediate pad electrodes can be combined in the row direction (x direction). Alternatively, the intermediate pad electrodes can be combined with the p-pad electrode 28A or the n-pad electrode 28B in the column direction (y direction). Alternatively, combinations can be made according to the heat dissipation design, such as combining the p-pad electrode 28A with the two intermediate pad electrodes 29(1) and 29(2) and using the n-pad electrode 28B alone. Therefore, a semiconductor light-emitting device module with high heat dissipation properties can be provided. Furthermore, the module can be mounted with a 90° rotation, providing excellent mountability.

[0100] In particular, in the case of a semiconductor light-emitting device module in which multiple semiconductor light-emitting elements 80 are arranged, by combining pad electrodes according to the placement position of each semiconductor light-emitting element 80, it is possible to provide a semiconductor light-emitting device module with high heat dissipation properties, as well as high heat dissipation uniformity and light output uniformity.

[0101] Fig. 8 is a top view schematically showing a semiconductor light emitting device 85, which is a modified example of the semiconductor light emitting device 80. The semiconductor light emitting device 85 differs from the semiconductor light emitting device 80 shown in Fig. 7 in that it has chamfered portions CC where the corners of the rectangular p-pad electrode 28A, n-pad electrode 28B, and two intermediate pad electrodes 29(1), 29(2) are chamfered, but the other configurations are the same.

[0102] According to this configuration, the ends of the grooves GP1 and GP2, which serve as gas exhaust paths, are widened, improving the discharge of flux gas. The shape of the chamfered portion CC may be curved or linear. It is also preferable that the four corners of the p-pad electrode 28A, the n-pad electrode 28B, and the two intermediate pad electrodes 29(1) and 29(2) are chamfered.

[0103] Although the semiconductor light emitting element 80 having pad electrodes arranged in a matrix has been described, the present invention is not limited to this. The pad electrode configuration of this embodiment can also be applied to a semiconductor light emitting device in which a light guide such as a phosphor plate is adhered to the semiconductor light emitting element 80, and to a semiconductor light emitting device module in which a plurality of such semiconductor light emitting elements are arranged and mounted, and the same effects as those described above can be obtained.

[0104] As described above in detail, the present invention can provide a semiconductor light-emitting element, a semiconductor light-emitting device, and a semiconductor light-emitting device module that have excellent heat dissipation performance, exhibit little reduction in optical output even when a high current is injected, and are high-output and highly reliable. [Explanation of symbols]

[0105] 10, 80, 85: semiconductor light emitting element, 11: substrate, 12: first semiconductor layer, 13: light emitting layer, 14: second semiconductor layer, 15: light emitting functional layer, 15M: light emitting functional crystal portion, 15G: crystal separation groove 15G, 22: n electrode (first electrode), 22B: n pad connecting portion, 23: p electrode (second electrode), 23A: p pad connecting portion, 25: element insulating film, 25A: first insulating film, 25B: second insulating film, 26: wiring layer, 28A: second pad electrode (p-pad electrode), 28B: first pad electrode (n-pad electrode), 29: intermediate pad, 43A: anode wiring, 43B: cathode wiring, 50: semiconductor light emitting device, 51: light guide (phosphor plate), 60, 70: semiconductor light emitting device module, 71: circuit board, 72: frame, 72F: sealing resin, GP: pad separation groove, MP: final melting point, 77: heat sink

Claims

1. a transparent insulating or semi-insulating substrate; a light-emitting functional layer in which a first semiconductor layer of a first polarity, a light-emitting layer, and a second semiconductor layer of a second polarity are sequentially stacked on one surface of the substrate; an insulating film covering the light-emitting functional layer; a first pad electrode and a second pad electrode provided on the insulating film and electrically connected to the first semiconductor layer and the second semiconductor layer, respectively; at least two intermediate pads located between the first pad electrode and the second pad electrode and electrically insulated from the light-emitting functional layer; a first pad isolation groove that separates the first pad electrode from the intermediate pad and the second pad electrode from the intermediate pad, and exposes the insulating film; the first pad separation grooves are provided along a first extending direction extending toward outer edge portions of the light emitting functional layer that face each other, the light-emitting functional layer has a plurality of mesa-shaped light-emitting functional portions extending along the first extending direction, the insulating film exposed in the first pad isolation groove covers a side surface of the plurality of light-emitting function parts on the first pad electrode side or a side surface of the plurality of light-emitting function parts on the second pad electrode side, the light-emitting function portion is provided between each of the intermediate pads and the substrate, and the light-emitting function portion between the intermediate pad and the substrate is electrically connected to the first pad electrode and the second pad electrode via a wiring layer; The two intermediate pads have at least one second pad separation groove extending in the first extending direction, the second pad isolation groove exposes the insulating film covering the surface of the light emitting function layer of the intermediate pad and has a shallower depth than the first pad isolation groove; A part of the light emitted from the light emitting function part between the intermediate pad and the substrate is emitted from the light emitting surface, which is the other surface of the substrate. Semiconductor light emitting element.

2. The semiconductor light emitting element according to claim 1 , wherein the light emitting functional layer has a rectangular shape in a top view, and the second pad separation grooves are provided in an arrangement including an intersection of diagonals of the light emitting functional layer.

3. The semiconductor light emitting element according to claim 1 , wherein the first pad electrode, the second pad electrode, and the intermediate pad are arranged in a stripe pattern extending in the extension direction of the plurality of light emitting function portions.

4. a transparent insulating or semi-insulating substrate; a light-emitting functional layer in which a first semiconductor layer of a first polarity, a light-emitting layer, and a second semiconductor layer of a second polarity are sequentially stacked on one surface of the substrate; an insulating film covering the light-emitting functional layer; a first pad electrode and a second pad electrode provided on the insulating film and electrically connected to the first semiconductor layer and the second semiconductor layer, respectively; At least two intermediate pads electrically insulated from the light-emitting functional layer; a plurality of pad isolation grooves that separate the first pad electrode, the second pad electrode, and the intermediate pad, and expose the insulating film; At least one of the plurality of pad separation grooves is provided along a first extending direction extending toward outer edge portions of the light emitting functional layer facing each other, the light-emitting functional layer has a plurality of mesa-shaped light-emitting functional portions extending along the first extending direction, the light-emitting function portion is provided between each of the intermediate pads and the substrate, and the light-emitting function portion between the intermediate pad and the substrate is electrically connected to the first pad electrode and the second pad electrode via a wiring layer; the first pad electrode, the second pad electrode, and the intermediate pad are arranged in a matrix, and the first pad electrode and the second pad electrode are disposed at diagonal positions; the plurality of pad separation grooves extend in row and column directions, separating the pads so that the first pad electrodes, the second pad electrodes, and the intermediate pads, which are arranged in a matrix, are arranged in a matrix; among the plurality of pad separation grooves, a pad separation groove separating the first pad electrode from an intermediate pad adjacent to the first pad electrode and a pad separation groove separating the second pad electrode from an intermediate pad adjacent to the second pad electrode are grooves having a depth that reaches a side of the light emitting function layer toward the substrate, A part of the light emitted from the light emitting function part between the intermediate pad and the substrate is emitted from the light emitting surface, which is the other surface of the substrate. Semiconductor light emitting element.

5. The semiconductor light emitting element according to claim 1 , wherein the first pad electrode, the second pad electrode, and the intermediate pad have chamfered corners.

6. 4. The semiconductor light-emitting element according to claim 1, wherein the wiring layer connects the adjacent light-emitting functional portions in series and is provided across from one end to the other end of the adjacent light-emitting functional portions in the extension direction.

7. The semiconductor light emitting element according to any one of claims 1 to 6, a light guide provided on the light exit surface; A semiconductor light emitting device comprising:

8. 8. The semiconductor light emitting device according to claim 7, wherein the light guide is a phosphor plate.

9. a circuit board having first wiring and second wiring on its surface; The semiconductor light-emitting element according to any one of claims 1 to 8, the first pad electrode and the second pad electrode of the semiconductor light emitting element are respectively bonded to the first wiring and the second wiring by a first bonding member and a second bonding member; At least one of the intermediate pads of the semiconductor light emitting element is bonded to the first wiring or the second wiring.

10. a circuit board having a first wiring, a second wiring, and a third wiring on a surface thereof; The semiconductor light-emitting element according to any one of claims 1 to 8, the first pad electrode and the second pad electrode of the semiconductor light emitting element are respectively bonded to the first wiring and the second wiring by a first bonding member and a second bonding member; A semiconductor light emitting module, wherein at least one of the intermediate pads of the semiconductor light emitting element is electrically insulated from the first wiring and the second wiring and joined to the third wiring.

11. A heat sink is provided.

11. The semiconductor light emitting module according to claim 9, wherein the at least one intermediate pad is thermally coupled to the heat sink via a metal.

12. 12. The semiconductor light emitting module according to claim 9, wherein the first and second bonding members are solder paste.

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