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, particularly 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 Art

[0002] In recent years, for high output and light distribution control, a plurality of semiconductor light-emitting elements such as light-emitting diodes (LEDs) are arranged and used in a plurality of devices.

[0003] For example, in an automotive headlight, a light distribution variable type headlamp (ADB: Adaptive Driving Beam) that controls the light distribution according to the driving environment is known. Also known are high-output lighting LED packages and LED packages for information and communication devices in which LEDs are arranged at high density.

[0004] However, there is a further demand for a high-output semiconductor light-emitting element that has high luminous efficiency and can obtain uniform light emission. Also, there is a demand for a semiconductor light-emitting device that has an additional function such as a protective element while preventing performance degradation of the light-emitting element and is difficult to cause element breakage.

[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 a region other than the positions of the plurality of holes, which equalizes the light field distribution and reduces the forward voltage of the light-emitting device.

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

[0007] Furthermore, Patent Document 3 discloses a nitride semiconductor light-emitting element in which multiple nitride semiconductor layers are electrically separated on the same film-depositing substrate, and each nitride semiconductor layer is electrically connected by conductive wires. Patent Document 4 discloses an LED array in which multiple LEDs 1 are formed monolithically in two dimensions and multiple LEDs are connected in series. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Publication No. 2017-92477 [Patent Document 2] Japanese Patent Publication No. 2014-150188 [Patent Document 3] Japanese Patent Publication No. 2001-156331 [Patent Document 4] Japanese Patent Publication No. 2004-6582 [Overview of the Initiative] [Problems that the invention aims to solve]

[0009] The present invention has been made in view 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 luminous efficiency. [Means for solving the problem]

[0010] A semiconductor light-emitting element according to one embodiment of the present invention is An insulating or semi-insulating substrate, A light-emitting functional layer is formed by sequentially stacking a first semiconductor layer of first polarity, a light-emitting layer, and a second semiconductor layer of second polarity on the substrate, An insulating film covering the light-emitting functional layer, A first pad electrode and a second pad electrode are provided on the insulating film, electrically connected to the first semiconductor layer and the second semiconductor layer, respectively, and at least one intermediate pad is electrically insulated from the light-emitting functional layer. It has pad separation grooves that separate each of the first pad electrode, the second pad electrode, and the intermediate pad and expose the insulating film.

Brief Description of the Drawings

[0011] [Figure 1A] It is a top view schematically showing a case where the semiconductor light-emitting element 10 according to the first embodiment of the present invention is viewed from above. [Figure 1B] It is a cross-sectional view schematically showing a cross-section along line A-A of FIG. 1A. [Figure 2A] It is a perspective view showing a method of mounting the semiconductor light-emitting element 10 on a circuit board. [Figure 2B] It is a top perspective view for explaining the discharge of the flux gas. [Figure 2C] It is a cross-sectional view for explaining the discharge of the flux gas. [Figure 2D] It is a top view of the p-pad electrode 28A, the n-pad electrode 28B, or the intermediate pad electrode 29. [Figure 3] It is a diagram showing the relationship between the void occupancy (%) and the thermal resistance (°C / W) in the bonding member. <00000​​​​​​​​​​​​​​​​​​​​​It is a top view schematically showing a semiconductor light-emitting device 85 which is a modified example of the semiconductor light-emitting device 80.

Mode for Carrying Out the Invention

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

[0013] [First Embodiment] (1) Structure of Semiconductor Light-Emitting Device FIG. 1A is a top view schematically showing a semiconductor light-emitting device 10 according to the 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 such as electrodes is also shown. FIG. 1B is a cross-sectional view schematically showing a cross-section along line A-A of FIG. 1A. The structure of the semiconductor light-emitting device 10 will be described in detail below.

[0014] As shown in FIG. 1A, the semiconductor light-emitting device 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] As shown in FIG. 1B, the semiconductor light-emitting device 10 has a translucent insulating substrate 11. In the present embodiment, the substrate 11 has a rectangular column shape, and the surface of the substrate 11 has a rectangular shape in a top view. For the substrate 11, for example, substrates such as sapphire and aluminum nitride (AlN) can be used.

[0016] In addition to the insulating substrate, the substrate 11 may be formed of a semi-insulating or high-resistance material. In this specification, the semi-insulating substrate includes semiconductor substrates such as high-resistance GaN. Specifically, it refers to a material having a high resistance with a resistivity of 1 MΩ / □ or more.

[0017] As shown in Figures 1A and 1B, the multiple light-emitting functional units 15M are light-emitting regions separated from each other by crystal separation grooves 15G that reach the substrate 11. Furthermore, the multiple light-emitting functional units 15M extend in a direction (y-direction) parallel to a pair of opposing sides of the semiconductor light-emitting element 10.

[0018] Furthermore, the multiple light-emitting functional units 15M are formed at predetermined intervals from each other in a direction perpendicular to the extension direction (x direction). Preferably, the extension direction of the light-emitting functional units 15M is 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 with first polarity), a light-emitting layer 13, and a p-type semiconductor layer 14 (second semiconductor layer with second polarity) are stacked on the substrate 11 in this order to form a light-emitting functional section 15M having a mesa shape.

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

[0021] The substrate 11 is exposed at the bottom of the crystal separation groove 15G between the light-emitting functional parts 15M. In other words, each light-emitting functional part (semiconductor layer) of the multiple light-emitting functional parts 15M is formed to be electrically isolated from one another.

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

[0023] In other words, the n-electrode 22 provided on the n-type semiconductor layer 12 extends in the direction of extension of the light-emitting functional section 15M. Of the multiple light-emitting functional sections 15M, the n-electrode 22 of the light-emitting functional section 15M located at the outer edge of the semiconductor light-emitting element 10 is connected to a first pad electrode (n-pad electrode) 28B, which will be described later, and constitutes an n-pad connection section 22B.

[0024] An ohmic electrode, an n-electrode 22 (first 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 by forming Ti and Al in that order on the n-type semiconductor layer 12. Note that it may be formed not only from a Ti / Al layer, but also from 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 of the mesa upper layer 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 on the ITO film as the reflective layer and protective layer.

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

[0027] The mesa-shaped light-emitting functional section 15M and the p electrode 23 are protected by covering their side walls and top surfaces with a first insulating film 25A made of SiO2. A wiring layer 26, which is a connecting wiring, is formed on the first insulating film 25A.

[0028] The wiring layer 26 is a light-reflective metal wiring layer and is formed to cover a portion of the side wall and top surface of the light-emitting functional unit 15M via the first insulating film 25A. The first insulating film 25A has an opening on a portion of the top surface of the light-emitting functional unit 15M through which the p electrode 23 is exposed.

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

[0030] Therefore, the multiple light-emitting functional units 15M shown in Figures 1A and 1B are connected in series. Furthermore, the entirety of the multiple light-emitting functional units 15M separated by the crystal separation grooves 15G functions as a light-emitting functional layer, which has a rectangular shape when viewed from above. Accordingly, in this specification, the entirety of the multiple light-emitting functional units 15M and the crystal separation grooves 15G will be referred to as the light-emitting functional layer 15.

[0031] Furthermore, as shown in Figure 1A, it is preferable that the p-electrode connection portion 23C and the n-electrode 22 are formed extending from one end to the other in the extending direction (y-direction) of the light-emitting functional portion 15M. In addition, it is preferable in terms of reflection performance and current uniformity that the wiring layer 26 is formed extending from one end to the other in the extending direction of adjacent light-emitting functional portions 15M.

[0032] The wiring layer 26 is specifically formed by 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 and insulated and protected by a second insulating film 25B made of SiO2 formed on the wiring layer 26. That is, the first insulating film 25A and the second insulating film 25B are formed to cover the entire surface of the semiconductor light-emitting element 10, excluding the n-pad connection portion 22B and the p-pad connection portion 23A.

[0034] In the following description, the insulating film consisting of the first insulating film 25A and the second insulating film 25B, which covers the entire surface of the semiconductor light-emitting element 10, will be referred to as the element insulating film 25.

[0035] Furthermore, the first insulating film 25A and the second insulating film 25B are not limited to SiO2. For example, insulating dielectrics such as SiN films can be suitably used.

[0036] As shown in Figure 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 functional part 15M and spaced apart from each other by gaps (pad separation grooves GP) in a direction perpendicular to the extension direction (x direction).

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

[0038] Furthermore, it is preferable that the grooves GP are formed linearly at regular intervals in the direction of extension of the light-emitting functional section 15M. It is also preferable that the grooves GP extend to the opposing outer edges of the crystal growth layer 15 (i.e., the outer edges parallel to the x-direction). Moreover, the grooves GP between adjacent pad electrodes and intermediate pads do not have to be of equal width.

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

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

[0041] Furthermore, if the intermediate pad 29 is made of a conductive material such as metal and is 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, we will describe the case where the intermediate pad 29 is made of a conductive material such as metal, and the intermediate pad 29 will be referred to as the intermediate pad electrode 29.

[0042] Specifically, as shown in Figure 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 via an opening in the element insulating film 25. That is, the connection between the n-pad electrode 28B and the n-electrode 22 is the n-pad connection portion 22B (see Figure 1A).

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

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

[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 (with the Au layer as the outermost layer), but are not limited to these. For example, a light-reflecting layer such as an Ag layer can be used instead of the Al layer.

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

[0047] The explanation will use the example of two intermediate pad electrodes 29 placed between the n-pad electrode 28B and the p-pad electrode 28A, but the number of intermediate pad electrodes 29 is not limited to this. For example, at least one intermediate pad electrode 29 is sufficient. The intermediate pad electrodes 29 can be appropriately distributed between 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.

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

[0049] In the above description, the case in which the light-emitting functional layer 15 is separated into multiple light-emitting functional sections 15M has been explained, but the light-emitting functional layer 15 may also be configured as a single plateau-shaped light-emitting functional section 15M without having crystal separation grooves 15G.

[0050] (2) Mounting of semiconductor light-emitting elements onto circuit boards The mounting of the semiconductor light-emitting element 10 onto the circuit board is described below. Figure 2A is a perspective view showing the method of mounting the semiconductor light-emitting element 10 onto the circuit board.

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

[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 (bonding members 41A and 41B) that will serve as bonding members is printed onto the anode wiring 43A and cathode wiring 43B, which are circuit board wirings. Next, the semiconductor light-emitting element 10 is mounted onto the solder paste. Then, it is heated in a reflow oven to bond them together.

[0054] Figures 2B and 2C are top perspective views and cross-sectional views along line DD in Figure 2A, illustrating the discharge of flux gas volatilized during reflow.

[0055] The solder paste, which is the joining member 41A and 41B, contains volatile flux, which evaporates during reflow. At this time, as shown in Figure 2B, the groove GP between adjacent pad electrodes of the p-pad electrode 28A, the two intermediate pad electrodes 29, and the n-pad electrode 28B functions as a gas discharge passage (ventilation passage).

[0056] In other words, the anode wiring 43A and 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 groove GP. Therefore, the groove GP between the anode wiring 43A and cathode wiring 43B functions as a ventilation path during reflow.

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

[0058] As shown in Figure 2B, when the semiconductor light-emitting element 10 is heated from the outside, the solder melts and progresses from the outside inward (heat propagation curve in the figure). Therefore, by providing a groove GP such that it passes through the final melting point MP (black circle, center of the light-emitting functional layer 15), more efficient discharge of flux gas becomes possible, and a bonding layer with fewer voids can be formed.

[0059] Therefore, it becomes possible to implement a mounting system with high heat dissipation. Furthermore, when the light-emitting functional layer 15 has a rectangular shape as described above, it is preferable that the groove GP is provided in such a way that the intersection of the diagonals of the light-emitting functional layer 15 is included within the groove GP.

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

[0061] Figure 2D is a top view of the p-pad electrode 28A, the n-pad electrode 28B, or the intermediate pad electrode 29. To discharge volatile flux gases from between adjacent pad electrodes, it is effective to increase the perimeter length L while keeping the area S constant. For example, the perimeter length L can be increased by subdividing the pad electrodes.

[0062] Specifically, the ratio R = L / W of the pad electrode to the length (or width) W is preferably 2 ≤ R. Furthermore, if R becomes too large, formation and mounting become difficult due to alignment issues, so R ≤ 10 is preferred. Therefore, 2 ≤ R ≤ 10 is preferred. Moreover, considering the ease of volatile gas emission and formation and mounting, the range 3 ≤ R ≤ 8 is even more preferred.

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

[0064] When semiconductor light-emitting elements are joined to the wiring (lands) of a circuit board via a bonding member (solder), voids (vacancies) may be formed in the bonding member. Since semiconductor light-emitting elements generate heat when current is applied, if the occupancy rate of the voids formed in the bonding member (the area occupied by voids in a top view) increases, the thermal resistance increases, reducing the heat dissipation characteristics to the circuit board or a heat sink (heat dissipator) 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 conventional electrodes formed across 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 cases where no voids are formed.

[0066] The pad electrodes of the semiconductor light-emitting element 10 of the present invention have a structure that can discharge gases volatile 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, since implementation with low thermal resistance is possible, the decrease in optical output is minimal even with high current injection, making it possible to provide a highly reliable semiconductor light-emitting element.

[0068] [Second Embodiment] Figure 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 has the semiconductor light-emitting element 10 and the light guide 51 of the first embodiment. In the following description, the case in which the light guide 51 is a phosphor plate will be used as an example. 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 bonded to the light-emitting surface 11E of the semiconductor light-emitting element 10 by an adhesive layer 52 (see Figure 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. A translucent adhesive, such as a translucent silicone resin, is used for the adhesive layer 52.

[0072] The semiconductor light-emitting element 10 and the phosphor plate 51 have the same external shape and size, for example, a rectangular plate shape. That is, the semiconductor light-emitting element 10 and the phosphor plate 51 have a common outer surface. The external shape of the phosphor plate 51 may be 5-10% smaller or larger than the external 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 by bonding the p-pad electrode 28A, the n-pad electrode 28B, and two intermediate pad electrodes 29 downwards to the anode wiring 43A and cathode wiring 43B of the circuit board using bonding members 41A and 41B, respectively.

[0074] More specifically, for example, the anode wiring 43A is formed as a land with a width WA wider than the cathode wiring 43B's width WB, 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] Thus, since the intermediate pad electrode 29 is insulated from the light-emitting function unit 15M, the intermediate pad electrode 29 can be used as the electrode (for example, the anode) for which heat dissipation is desired. Therefore, the bonding area can be increased, and thus heat dissipation can be improved.

[0076] As described above, according to this embodiment, since the heat dissipation of the semiconductor light-emitting device and semiconductor light-emitting device module is high, the decrease in optical output is small even when high current is injected, and a high-output and highly reliable semiconductor light-emitting device and semiconductor light-emitting device module can be provided.

[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. Figure 5A is a schematic top view showing the top surface of the semiconductor light-emitting device module 70. Figure 5B is a schematic cross-sectional view showing a cross section along line AA in Figure 5A.

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

[0079] Multiple semiconductor light-emitting devices 50 and the frame 72, and between adjacent semiconductor light-emitting devices 50, are sealed with sealing resin 72F. Anode terminals 78A, cathode terminals 78B, and short-circuit detection terminals 78C connected to the multiple semiconductor light-emitting devices 50 are provided. Fixing holes 71H for fixing the semiconductor light-emitting device module 70 are also provided.

[0080] As shown in Figure 5B, multiple semiconductor light-emitting devices 50 are connected in series by circuit wiring 73 on a circuit board 71. More specifically, the n-pad electrode 28B of the semiconductor light-emitting device 50 at one end of the array (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 (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 an adjacent semiconductor light-emitting device 50 are joined to the connecting wiring 73C of the circuit wiring 73 and are electrically connected. This connection establishes a series connection between adjacent semiconductor light-emitting devices 50.

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

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

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

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

[0086] Next, the manufacturing process of the semiconductor light-emitting device module 70 will be explained 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 72. In the figure, the mounting area 10R on which the semiconductor light-emitting element 10 is mounted is shown by a dashed line.

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

[0088] Next, as shown in Figure 6B, the semiconductor light-emitting elements 10 are bonded to the mounting region 10R by a bonding member 74 and mounted. At this time, protective elements 79 such as Zener diodes are mounted in parallel to each semiconductor light-emitting element 10 on the circuit wiring 73. A tin-copper lead-free solder is preferred as the bonding member 74.

[0089] Next, as shown in Figure 6C, a phosphor plate 51 is bonded onto the semiconductor light-emitting element 10 by a translucent adhesive layer 52.

[0090] Finally, sealing resin 72F is injected into the inside of the frame 72, filling the space between the semiconductor light-emitting device 50 and the frame 72, and between adjacent semiconductor light-emitting devices 50, to complete the semiconductor light-emitting device module 70 shown in Figure 5A.

[0091] Although the example described was one in which a phosphor plate 51, which is a light guide, is bonded to the semiconductor light-emitting element 10 after it has been bonded to the circuit board 71, a semiconductor light-emitting device in which a light guide is bonded 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 semiconductor light-emitting device module that has high heat dissipation, less decrease in optical output even with high current injection, and is highly reliable with high output.

[0093] [Fourth Embodiment] A semiconductor light-emitting element 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 schematic top view showing the top surface of the semiconductor light-emitting element 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, n-pad electrode 28B, and intermediate pad electrodes 29(1) and 29(2) are arranged in an m-row × n-column (2≦m, 2≦n) matrix.

[0095] More specifically, the rectangular p-pad electrode 28A, n-pad electrode 28B, and two intermediate pad electrodes 29(1) and 29(2) are arranged in a 2x2 grid, separated by grooves GP1 (y-direction) and GP2 (x-direction). Furthermore, these four pad electrodes are arranged symmetrically with respect to mutually orthogonal centerlines CL1 and CL2 of the semiconductor light-emitting element 80.

[0096] Furthermore, the groove GP1 in the extending direction of the light-emitting functional section 15M and the groove GP2 in the direction perpendicular to the extending 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 grooves GP1 and GP2.

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

[0098] As described above, when pad electrodes are arranged in an m x n grid, providing grooves GP1 and GP2 that pass through the final melting point MP among the grooves GP between the pad electrodes is effective in terms of gas discharge. In the case shown in Figure 7, grooves GP1 and GP2 function as separation grooves GP1 and GP2, which have a particularly high gas discharge effect.

[0099] Furthermore, the p-pad electrode 28A and the n-pad electrode 28B are positioned diagonally opposite each other. In this case, the p-pad electrode 28A and the intermediate pad electrode 29(1) are connected to the anode wiring of the circuit board, and the n-pad electrode 28B and the intermediate pad electrode 29(2) are 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, the p-pad electrode 28A can be combined with the two intermediate pad electrodes 29(1) and 29(2), and the n-pad electrode 28B can be used alone, or the combination can be adjusted according to the heat dissipation design. Therefore, a semiconductor light-emitting device module with high heat dissipation can be provided. In addition, it has high mountability, such as being mountable after rotating by 90°.

[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 arrangement position of each semiconductor light-emitting element 80, it is possible to provide a semiconductor light-emitting device module with high heat dissipation, high heat dissipation uniformity, and high light output uniformity.

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

[0102] With this configuration, the ends of the grooves GP1 and GP2, which serve as gas discharge passages, are widened, thereby improving the discharge efficiency of flux gas. The shape of the chamfered portion CC may be curved or straight. Furthermore, it is 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 a semiconductor light-emitting element 80 with pad electrodes arranged in a matrix has been described, the invention is not limited to this. The pad electrode configuration of this embodiment can also be applied to semiconductor light-emitting devices in which a light guide such as a phosphor plate is bonded to the semiconductor light-emitting element 80, and to semiconductor light-emitting device modules mounted by arranging multiple such semiconductor light-emitting devices, and the same effects as described above can be obtained.

[0104] As described in detail above, the present invention provides a semiconductor light-emitting element, a semiconductor light-emitting device, and a semiconductor light-emitting device module that have high heat dissipation performance, minimal decrease in optical output even with high current injection, and high output and reliability. [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 part, 15G: Crystal separation groove 15G, 22: n electrode (first electrode), 22B: n pad connection part, 23: p electrode (second electrode), 23A: p pad connection part, 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. 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; 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; The light-emitting functional layer has a pair of sides facing each other, is separated by a crystal separation groove in which the substrate is exposed, and has a plurality of mesa-shaped light-emitting functional portions extending in a direction parallel to the pair of sides.

2. The semiconductor light emitting device according to claim 1 , wherein the pad separation grooves are provided so as to extend to outer edge portions of the light emitting functional layer that face each other.

3. 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 pad separation grooves are provided in an arrangement including an intersection of diagonals of the light emitting functional layer.

4. 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 shape extending in an extending direction of the plurality of light emitting function portions.

5. The semiconductor light emitting device according to claim 1 , wherein the first pad electrode, the second pad electrode, and the intermediate pad are arranged in a matrix.

6. 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.

7. 7. The semiconductor light emitting element according to claim 4, further comprising a wiring layer that 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 an extension direction.

8. The semiconductor light emitting device according to claim 1 , wherein the first pad electrode, the second pad electrode and the intermediate pad have the same layer structure.

9. A semiconductor light emitting device according to any one of claims 1 to 8, a light guide provided on the semiconductor light emitting element; A semiconductor light emitting device comprising:

10. 10. The semiconductor light emitting device according to claim 9, wherein the light guide is a phosphor plate.

11. a circuit board having a first wiring and a second wiring on a surface thereof; The semiconductor light emitting device according to claim 1 , the first pad electrode and the second pad electrode of the semiconductor light emitting element are respectively joined to the first wiring and the second wiring by a first joining member and a second joining member, At least one of the intermediate pads of the semiconductor light emitting element is joined to the first wiring or the second wiring.

12. a circuit board having a first wiring, a second wiring, and a third wiring on a surface thereof; The semiconductor light emitting device according to claim 1 , the first pad electrode and the second pad electrode of the semiconductor light emitting element are respectively joined to the first wiring and the second wiring by a first joining member and a second joining 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.

13. a circuit board having a first wiring and a second wiring on a surface thereof; The semiconductor light emitting device according to claim 9 or 10, the first pad electrode and the second pad electrode of the semiconductor light emitting device are respectively joined to the first wiring and the second wiring by a first joining member and a second joining member, At least one of the intermediate pads of the semiconductor light emitting device is joined to the first wiring or the second wiring.

14. a circuit board having a first wiring, a second wiring, and a third wiring on a surface thereof; The semiconductor light emitting device according to claim 9 or 10, the first pad electrode and the second pad electrode of the semiconductor light emitting device are respectively joined to the first wiring and the second wiring by a first joining member and a second joining member, At least one of the intermediate pads of the semiconductor light emitting device is electrically insulated from the first wiring and the second wiring and joined to the third wiring.

15. A heat sink is provided.

15. The semiconductor light emitting module of claim 12 or 14, wherein the at least one of the intermediate pads is thermally coupled to the heat sink.

16. The semiconductor light-emitting module according to claim 11 or 13, wherein the first wiring and the second wiring have shapes corresponding to the first pad electrode and the second pad electrode, respectively, and are arranged at an interval corresponding to the pad separation groove.

17. The semiconductor light-emitting module described in claim 12, 14 or 15, wherein the first wiring, the second wiring and the third wiring have shapes corresponding to the first pad electrode, the second pad electrode and the intermediate pad, respectively, and are arranged at intervals corresponding to the pad separation groove.

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