Semiconductor light emitting device

Abstract

To provide a semiconductor light emitting device which uses an optical element that can control light distribution and stably emits light having the desired light distribution characteristic by the optical element over a long period.SOLUTION: A semiconductor light emitting device comprises: a substrate 11 which has a bottom part 14 having an upper surface and a wall part 15 formed so as to surround one region of the bottom part on the upper surface and including an opening OP1 exposing the one region; a light emitting element 13 which is arranged in the one region of the bottom part of the substrate; and a light distribution member 17 which is held in a manner of being in contact with the wall part. The wall part has a holding surface which faces upward. The light distribution member is placed on the holding surface and is arranged on the upper side of the light emitting element. The light distribution member comprises: a light transmissive member 29 which has the light transmissivity to the emission light from the light emitting element; and an optical function layer 31 which is in a region of the light emitting element on the lower surface of the light transmissive member and is formed of a resin material whose surface forms protrusions. The optical function layer extends to the contact surface between the holding surface of the wall part and the light distribution member.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a semiconductor light emitting device including a light emitting element such as a light emitting diode (LED) or a semiconductor laser (LD). [Background technology]

[0002] 2. Description of the Related Art In a semiconductor light emitting device, a technique is known in which light emitted from a light emitting element is passed through an optical element such as a diffractive optical element (DOE) to control the light distribution.

[0003] For example, Patent Document 1 discloses a light emitting device in which an optical component including a diffuser is disposed above a light emitting element. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] US Patent Application Publication No. 2017 / 0353004 Summary of the Invention [Problem to be solved by the invention]

[0005] In the light-emitting device as described above, if a light distribution plate having a fine structure pattern made of resin formed on a glass substrate is used as an optical element for light distribution control, heat generated by driving the light-emitting element is transmitted to the light distribution plate, and the fine structure pattern made of resin is deteriorated by the heat, resulting in the desired light distribution characteristics not being obtained.

[0006] The present invention has been made in consideration of the above-mentioned points, and aims to provide a semiconductor light-emitting device that uses an optical element capable of controlling light distribution, and that is capable of stably emitting light having the desired light distribution characteristics over a long period of time due to the optical element. [Means for solving the problem]

[0007] The semiconductor light-emitting device according to the present invention comprises a substrate having a bottom having an upper surface, and a wall portion formed on the upper surface to surround a region of the bottom and having an opening exposing the region, a light-emitting element arranged in the region of the bottom portion of the substrate, and a light distribution member held in contact with the wall portion, the wall portion having an upwardly facing holding surface, the light distribution member being placed on the holding surface and arranged above the light-emitting element, the light distribution member comprising: a light-transmitting member having translucency with respect to light emitted from the light-emitting element, and an optical functional layer formed on the lower surface of the light-transmitting member in an area above the light-emitting element and made of a resin material having a surface forming protrusions, the optical functional layer extending to a contact surface of the wall portion of the light distribution member with the holding surface. [Brief description of the drawings]

[0008] [Figure 1] 1 is a top view of a semiconductor light emitting device according to a first embodiment. [Diagram 2] 1 is a cross-sectional view of a semiconductor light emitting device according to a first embodiment. [Diagram 3] FIG. 3 is an enlarged schematic view of a portion of FIG. 2. [Figure 4] FIG. 11 is a top view of a semiconductor light emitting device according to a second embodiment. [Diagram 5] FIG. 11 is a cross-sectional view of a semiconductor light-emitting device according to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] In the following, preferred embodiments of the present invention will be described, which 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. EXAMPLES

[0010] The configuration of a semiconductor light emitting device 10 according to a first embodiment of the present invention will be described with reference to Fig. 1 to Fig. 3. Fig. 1 is a top view that typically illustrates the semiconductor light emitting device 10 according to the first embodiment of the present invention. Fig. 2 is a cross-sectional view that typically illustrates the surface of the semiconductor light emitting device 10 shown in Fig. 1 cut along line 2-2. Fig. 3 is an enlarged view of part A surrounded by a dashed dotted line in Fig. 2.

[0011] [Light emitting device] As shown in Figures 1 and 2, the semiconductor light-emitting device 10 (hereinafter also referred to as light-emitting device 10) of Example 1 includes a substrate 11 having a cavity (recess) and providing high heat dissipation properties, a light-emitting element 13 arranged on the bottom surface of the cavity, a light distribution member 17 that converts linear light emitted from the light-emitting element 13 into diffuse light, and an adhesive member 19 that bonds the substrate 11 and the light distribution member 17 together to hermetically seal the light-emitting element 13 arranged on the bottom surface of the cavity.

[0012] [substrate] As shown in Figures 1 and 2, the substrate 11 is rectangular when viewed from above, and has a plate-shaped bottom 14 having an upper surface (a surface including the bottom surface of the cavity) and a lower surface that are parallel to each other, and a frame-shaped (cylindrical) wall 15 that surrounds a mounting region PR (the bottom surface of the cavity) on which the light-emitting element 13 is mounted in the center of the upper surface 14S of the bottom 14.

[0013] The wall portion 15 has a layered structure in which a lower portion 15A, a middle portion 15B, and an upper portion 15C are arranged in this order from the bottom portion 14 side.

[0014] The lower part 15A extends along the outer periphery of the upper surface 14S of the bottom part 14, and is a frame-shaped part having an opening OP1 exposing the central region of the upper surface 14S. The middle part 15B is disposed on the upper surface S1 of the lower part 15A, and is a frame-shaped part having an opening OP2 exposing the peripheral frame-shaped region of the opening OP1 of the upper surface S1 of the lower part 15A. The upper part 15C is disposed on the upper surface S2 of the middle part 15B, and is a frame-shaped part having an opening OP3 exposing the peripheral frame-shaped region of the opening OP2 of the upper surface S2. The region exposed by the opening OP3 of the upper surface S2 is a support region or support surface (holding surface) that supports the light distribution member 17. The upper surface S3 of the upper part 15C is the upper surface of the substrate 11.

[0015] In other words, the wall 15 has a cross section in the shape of a three-step staircase with the inner surface ascending outward. In other words, the wall 15 has an extension portion made up of an upper portion 15C protruding upward from the upper surface S2 of the middle portion 15B. The wall 15 also has a shelf portion made up of a lower portion 15A protruding inward from the inner surface S4 of the middle portion 15B. The wall 15 also has an opening formed by the openings OP1, OP2, and OP3, exposing the mounting area PR of the upper surface 14S of the bottom portion 14.

[0016] The base material of the substrate 11 is a ceramic made of aluminum nitride (AlN) which has high thermal conductivity, insulating properties and airtightness. The base material of the substrate 11 can also be ceramics such as aluminum oxide (Al2O3) and silicon nitride (Si3N4) which have properties similar to those of aluminum nitride. For example, the thermal conductivity of AlN is 150 (W / m·k), the thermal conductivity of Al2O3 is 32 (W / m·k), and the thermal conductivity of Si3N4 is 27 (W / m·k). By using such base materials with high thermal conductivity, it becomes possible to efficiently dissipate heat generated from the light emitting element 13 to an external heat dissipation member such as a mounting substrate or a heat sink.

[0017] Next, the wiring and electrodes provided on the substrate 11 will be described with reference to Fig. 2. A cathode wiring 21 is provided on the upper surface 14S of the bottom part 14 of the substrate 11. A portion of the cathode wiring 21 formed in the mounting region PR is exposed from the lower part 15A by an opening OP1, and a portion formed in an area outside the mounting region PR is covered by the lower part 15A.

[0018] An anode wiring 25 is provided on the upper surface S1 of the lower portion 15A of the wall portion 15 of the substrate 11. A portion of the anode wiring 25 formed in an inner region of the upper surface S1 is exposed from the middle portion 15B by the opening OP2, and a portion formed outside the portion is covered by the middle portion 15B.

[0019] A cathode device electrode 23 and an anode device electrode 27 are provided at a distance from each other on the rear surface of the substrate 11, i.e., the lower surface of the bottom portion 14. The cathode device electrode 23 is electrically connected to a cathode wiring 21 provided on the upper surface 14S of the bottom portion 14 through a conductive via 23H penetrating the bottom portion 14. The anode device electrode 27 is electrically connected to an anode wiring 25 through a conductive via 27H penetrating the bottom portion 14 and the lower portion 15A.

[0020] In other words, there is electrical conduction between the cathode wiring 21, the conductive via 23H, and the cathode device electrode 23 and the anode wiring 25, the conductive via 27H, and the anode device electrode 27. The cathode system of the cathode wiring 21, the conductive via 23H, and the cathode device electrode 23 and the anode system of the anode wiring 25, the conductive via 27H, and the anode device electrode 27 are insulated from each other by being separated via the insulating substrate 11.

[0021] For example, the cathode wiring 21, the anode wiring 25, the cathode device electrode 23, and the anode device electrode 27 are made of a tungsten (W) alloy, and a surface metal layer (not shown) of nickel / gold (Ni / Au) is applied to the surface portion exposed from the substrate 11 in this order from the surface side. In addition, the conductive via 23H and the conductive via 27H are made of a tungsten alloy. In addition to tungsten (W), metals with low electrical resistivity and high thermal conductivity such as copper (Cu) and silver (Ag) can be used for the wiring (21, 25), the conductive via (23H, 27H), and the device electrode (23, 27). For example, if the electrical resistivity is low, the heat generated by the wiring during current flow can be reduced. In addition, if the thermal conductivity is high, it functions as a heat spreader.

[0022] The substrate 11 having the above-mentioned wiring and electrodes is formed, for example, by firing a laminate of a plurality of sheets of pre-fired ceramic materials (e.g., green sheets). Specifically, the substrate 11 can be formed by firing a laminate of a plate-shaped green sheet (first layer) that forms the bottom 14 made of pre-fired ceramic material having the conductive vias 23H and conductive vias 27H formed therein, the cathode wiring 21 formed on the upper surface, and the cathode device electrode 23 and the anode device electrode 27 formed on the lower surface, a frame-shaped green sheet (second layer) that forms the lower portion 15A of the wall portion 15 having the conductive vias 27H formed therein and the anode wiring 25 formed on the upper surface, a frame-shaped green sheet (third layer) that forms the middle portion 15B of the wall portion 15, and a frame-shaped green sheet (fourth layer) that forms the upper portion 15C of the wall portion 15, in that order, and then plating a surface metal layer on the exposed surfaces of the wiring and electrodes.

[0023] The substrate 11 thus formed is integrated and has an airtight property for blocking oxygen, moisture, and corrosive gases. The cathode wiring 21, the cathode device electrode 23, the anode wiring 25, the anode device electrode 27, and the conductive vias 23H and 27H can be reversed depending on the polarity of the light emitting element 13.

[0024] [Light emitting element] In this embodiment, the light emitting element 13 is a Vertical Cavity Surface Emitting Laser (VCSEL) (hereinafter also referred to as VCSEL) element.

[0025] The light emitting element 13 used in this embodiment has a light conversion layer made of an n-type semiconductor layer, a light emitting layer, and a p-type semiconductor layer disposed on an element substrate. A first element electrode pad (not shown) is provided on the upper surface (surface of the light conversion layer) of the light emitting element 13, and a second element electrode pad (not shown) is provided on the lower surface (surface opposite to the surface of the element substrate on which the light conversion layer is provided) of the light emitting element 13.

[0026] The light emitting element 13 is an array-type VCSEL in which a plurality of laser light emission regions are provided in a lattice pattern on the upper surface (surface of the light conversion layer) of the light emitting element 13, and emits linear laser light in a direction perpendicular to a plane including the upper surface of the light emitting element 13. The light conversion layer of the light emitting element 13 includes a GaAs-based semiconductor layer, and emits infrared light with an emission wavelength of 780 nm to 1700 nm.

[0027] The second element electrode pad provided on the lower surface of the light emitting element 13 is fixed and electrically connected to a cathode wiring 21 exposed on the mounting region PR (bottom surface of the cavity) on the upper surface 14S of the bottom part 14 of the substrate 11 via a conductive bonding member 20. Also, the first element electrode pad provided on the upper surface of the light emitting element 13 and an anode wiring 25 exposed on the upper surface S1 of the lower part 15A of the wall part 15 are electrically connected via a bonding wire 28. In this embodiment, a gold-tin alloy (Au-Sn 20 wt%) is used as the bonding member 20, and gold (Au) is used as the bonding wire 28.

[0028] With this structure, by passing electricity between the cathode device electrode 23 and the anode device electrode 27 provided on the back surface of the substrate 11, a laser beam is emitted from the upper surface of the light emitting element 13. In other words, by passing electricity, a linear laser beam is emitted toward the cavity opening direction of the substrate 11 perpendicular to the surface including the surface of the bottom part 14 of the substrate 11 (the surface of the light conversion layer).

[0029] In addition, the structure in which the anode wiring 25 is provided on the upper surface S1 of the lower portion 15A makes it possible to shorten the bonding wire 28. For example, when the anode wiring 25 is provided on the upper surface 14S of the bottom portion 14, the bonding wire 28 drawn upward from the first element electrode pad on the upper surface of the light emitting element 13 is bent in the direction opposite to the direction in which it was drawn and connected to the anode wiring 25 on the upper surface 14S.

[0030] In contrast, in this embodiment, the anode wiring 25 is provided on the upper surface S1 of the lower portion 15A, so the height difference between the light emitting element 13 and the anode wiring 25 is small. As a result, the path of the bonding wire 28 is shorter when connecting to the anode wiring on the upper surface S1, which has a smaller height difference, than when connecting to the upper surface 14S, which is located below and has a larger height difference, and the length of the bonding wire 28 required for connection can be shortened. The length of the bonding wire 28 can be shortened generally in the range where the height of the upper surface S1 of the lower portion 15A is higher than the upper surface 14S of the bottom 14 and is not more than twice the height from the bottom 14 to the upper surface of the light emitting element 13.

[0031] Moreover, by providing the lower portion 15A and providing the anode wiring 25 on the upper surface S1, the anode wiring 25 can also be provided in a region overlapping with the cathode wiring 21 in a direction perpendicular to the bottom 14. This allows the anode wiring 25 to be provided around the light emitting element 13, making it possible to provide multiple bonding wires 28.

[0032] For example, gold wire has a high thermal conductivity of 320 (W / m·k) and is therefore preferable as a heat dissipation member. Therefore, by shortening the length of the Au bonding wire 28 and increasing the number of Au bonding wires 28 to increase the cross-sectional area, it is possible to improve the efficiency of dissipating heat generated in the light emitting element 13. In addition, the anode wiring 25 to which the Au bonding wire 28 is connected is disposed so as to surround the light emitting element 13, and therefore acts as a heat spreader (buffer), improving the heat dissipation efficiency.

[0033] [Light distribution component] The light distribution member 17 is a flat optical member, and has an incident surface on the light emitting element 13 side and an exit surface (the upper surface of the light emitting device 10) parallel to the incident surface. The light distribution member 17 controls the light distribution while transmitting the laser light emitted from the light emitting element 13. The light distribution member 17 is, for example, an optical diffusion element (LSD: Light Shaping Diffuser) including a light transmissive member 29 having two surfaces parallel to each other, and an optical function layer 31 made of fine protrusions on at least one surface of the light transmissive member 29 for diffracting the laser light emitted from the light emitting element 13.

[0034] 1 and 2, the light distribution member 17 is disposed in a frame groove defined by the upper surface S2 of the middle part 15B of the wall part 15 of the substrate 11 and the inner surface of the upper part 15C extending upward from the periphery of the upper surface S2, so that the optical functional layer 31 faces the support region of the upper surface S2 of the middle part 15B. As a result, the incident surface of the light distribution member 17 on which the optical functional layer 31 is provided is disposed parallel to the upper surface of the light emitting element 13. In addition, the incident surface of the light distribution member 17 (the surface on which the optical functional layer 31 is disposed) is disposed perpendicular to the linear laser light emitted from the light emitting element 13.

[0035] The light distribution member 17 used in this embodiment converts a plurality of linear laser beams emitted from the array-type VCSEL, which is the light-emitting element 13, into rectangular beams spreading at a predetermined angle (vertical angle, horizontal angle), and emits the beams with a substantially uniform in-plane intensity distribution from the emission surface of the light distribution member 17. The light converted in this manner forms a rectangular light distribution pattern that is small in the vicinity and large in the distance on a screen perpendicular to the irradiation optical axis of the light-emitting device 10.

[0036] The light-transmitting member 29 of the light distribution member 17 used in this embodiment is made of glass, and the optical function layer 31 is made of epoxy resin. In particular, the optical function layer 31 forms the above-mentioned light distribution pattern by optical diffraction caused by arranging in a predetermined pattern countless protrusions with a horizontal dimension of several tens of microns and a vertical height deviation of several tens of nanometers. That is, the surface of the optical function layer 31 in this embodiment has a fine structure pattern in which a large number of protrusions designed with vertical height differences to cause the desired optical diffraction are arranged in a predetermined pattern.

[0037] In addition to the above-mentioned materials, inorganic materials such as quartz and sapphire, and resin materials such as silicone, acrylic, and polycarbonate can be used for the light-transmitting member 29. In addition, the optical function layer 31 can also be made of the same inorganic materials and resin materials as the light-transmitting member 29.

[0038] The light distribution member 17 of this embodiment is formed, for example, as follows. Uncured epoxy resin that will become the optical functional layer 31 is applied to a glass plate that will become the light-transmitting member 29, and then a mold having recesses that are the inverse shape of the protrusions of the optical functional layer 31 is pressed against the uncured epoxy resin to transfer it. Thereafter, UV light is irradiated to cure the epoxy resin and simultaneously bond it to the glass plate. Finally, the mold having the recesses is removed, and the light distribution member 17 can be formed.

[0039] The optical function layer 31 of the light distribution member 17 may be provided only in the area where the linear laser light emitted from the light emitting element 13 is incident (irradiated), but in this embodiment, it is provided on the entire surface of the light distribution member 17. Therefore, as shown in Fig. 2, the light distribution member 17 is disposed in the support area of ​​the upper surface S2 of the middle part 15B of the wall part 15 via the optical function layer 31 made of epoxy resin.

[0040] As shown in Fig. 3, the optical function layer 31 has the above-mentioned fine protrusions on the underside. Therefore, the contact area between the light distribution member 17 and the wall portion 15 including the middle portion 15B is small. In addition, as shown in Fig. 2, the side surface of the light distribution member 17 is adhered to the inner surface of the upper portion 15C by a resin adhesive member 19 described later.

[0041] The thermal conductivities of the AlN substrate 11, the glass translucent member 29, the epoxy resin optical function layer 31, and the silicone resin adhesive member 19 used in this embodiment are 150 (W / m·K), 1.0 (W / m·K), 0.3 (W / m·K), and 0.2 (W / m·K), respectively. Therefore, the epoxy resin optical function layer 31 and the silicone resin adhesive member 19 act as heat shields against heat transmitted through the AlN substrate 11. This prevents the light distribution pattern from being disturbed by thermal distortion of the translucent member 29 and thermal deformation of the protrusions of the optical function layer 31. In particular, the optical function layer 31 made of resin with a plurality of protrusions has a small contact area with the upper surface S2 of the middle portion 15B, so that heat is not easily transmitted from the upper surface S2 to the optical function layer 31, and an excellent heat insulating effect is obtained. The upper surface S2 and the optical function layer 31 of the light distribution member 17 may be bonded via an adhesive member made of epoxy resin or silicone resin. In this case, a resin adhesive layer is provided between the upper surface S2 and the optical function layer 31, and the adhesive layer acts as a heat shield in addition to the optical function layer 31, so that an excellent heat insulation effect is obtained.

[0042] In this embodiment, the optical function layer 31 is made of a resin having a property of being cured by ultraviolet light, for example, a UV-cured epoxy resin. In this embodiment, the oscillation wavelength of the light-emitting element 13 is in the infrared region, and in this case, the wavelength at which the resin is cured is shorter than the oscillation wavelength of the light-emitting element 13. In this way, by forming the optical function layer 31 from a resin that is cured by light with a shorter wavelength than the oscillation wavelength of the light-emitting element 13, even if the optical function layer 31 is irradiated with light emitted from the light-emitting element 13, the optical function layer 31 is prevented from being deteriorated due to over-curing.

[0043] In this embodiment, the upper surface S3 of the upper portion 15C of the wall portion 15 is higher (protrudes) than the upper surface of the light distribution member 17. This can block the laser light leaking from the side surface of the light distribution member 17. In addition, it can prevent the light distribution member 17 from falling off due to unintentional contact with the light distribution member 17 during the manufacture or use of the light emitting device 10, or the airtightness from being broken due to damage to the adhesive member 19.

[0044] Although an LSD has been described above as the light distribution member 17, for example, a diffractive optical element (DOE), a holographic optical element (HOE), etc. can be used instead of an LSD. These optical elements have a microstructure with unevenness formed on the surface, and this microstructure can convert linear laser light into a light distribution pattern such as a lattice line pattern, a lattice dot pattern, or a character pattern.

[0045] [Adhesive material] The adhesive member 19 is a resin member, and as shown in Figs. 1 and 2, is filled between the light distribution member 17 and the inner surface of the upper portion 15C of the wall portion 15, and bonds the light distribution member 17 and the upper portion 15C. This hermetically seals the inner space of the light-emitting device 10 defined by the cavity of the substrate 11 and the light distribution member 17, and prevents the light-emitting element 13 and the optical function layer 31 of the light distribution member 17 housed in the inner space from being deteriorated by oxygen or moisture. In particular, by hermetically sealing the inner space, it is possible to prevent moisture or the like from penetrating into the gaps of the protrusions of the optical function layer 31, causing the light distribution pattern to be disturbed. The inner space other than the light-emitting element 13 is filled with an inert gas such as nitrogen (N2), argon (Ar), neon (Ne), or helium (He).

[0046] The resin material for forming the adhesive member 19 may be a photocurable resin that is cured by ultraviolet (UV) light to visible light (e.g., blue to green light) having a shorter wavelength than the wavelength of the laser light emitted by the light emitting element 13. Examples include photocurable silicone resin, photocurable epoxy resin, photocurable acrylic resin, etc. In this way, by using a resin that is cured by a shorter wavelength than the light emitted by the light emitting element 13, deterioration such as shrinkage and cracking due to overcuring of the adhesive member 19 can be prevented. In this embodiment, an ultraviolet (UV) curable silicone resin was used as the adhesive member 19.

[0047] [Heat dissipation from light-emitting devices] 2 and 3, the heat dissipation of the light emitting device 10 will be described. The light emitting element 13 generates heat when current is applied. The heat generation increases in proportion to the increase in light emission output (increase in the amount of current applied). In this embodiment, the heat generated from the light emitting element 13 is dissipated to an external heat dissipation member such as a circuit board on which the light emitting device 10 is mounted or a heat sink via the substrate 11 on which the light emitting element 13 is placed, mainly via the bottom 14. The heat transferred to the lower portion 15A of the wall portion 15 via the bonding wire 28 connected to the upper surface of the light emitting element 13 is dissipated mainly via the lower portion 15A and the bottom 14 to an external heat dissipation member such as a circuit board on which the light emitting device 10 is mounted or a heat sink, as described above.

[0048] When the thermal conductivity of the substrate 11 is high, high heat dissipation is obtained, and the temperature of the substrate 11 decreases in proportion to the heat dissipation capacity of an external heat dissipation member such as a circuit board or a heat sink. On the other hand, the temperature difference between the various parts of the substrate 11 also decreases and becomes approximately uniform. Therefore, as the light emitting element 13 is energized, the temperatures of the middle portion 15B and the upper portion 15C also rise above the temperatures before energization.

[0049] In this embodiment, the light distribution member 17 is in contact with the upper surface of the middle portion 15B via a resin optical functional layer 31, and is in contact with the inner surface of the upper portion 15C via a resin adhesive member 19. With this structure, the resin optical functional layer 31 and adhesive member 19 act as heat insulating materials. This prevents the light-transmitting member 29 of the light distribution member 17 and the optical functional layer 31 on the inner side of the opening OP2 of the wall portion 15 from being heated. As a result, disturbance of the light distribution pattern due to thermal distortion of the light-transmitting member 29, thermal deformation of the protrusions of the optical functional layer 31, etc. is prevented.

[0050] As described above in detail, the semiconductor light emitting device 10 according to the first embodiment has a light distribution member arranged above a light emitting element that emits laser light. The light emitting element is arranged on the bottom surface of a cavity in a substrate, and the light distribution member is held on a holding surface of a wall portion that surrounds the bottom surface of the cavity in the substrate. The light distribution member has a translucent member and an optical function layer made of resin formed on the bottom surface of the translucent member. The bottom surface of the optical function layer has fine protrusions made of resin that diffract the laser light.

[0051] An optical functional layer made of resin formed on the underside of the light-transmitting member of the light distribution member extends to the contact surface with the holding surface of the light distribution member, so that the light-transmitting member is in contact with the substrate via the optical functional layer.

[0052] With this configuration, the optical function layer made of a resin with low thermal conductivity acts as a heat shield, preventing the optical function layer in the region inside the contact surface from being heated by heat generated by driving the light-emitting element. This makes it possible to prevent the optical function of the light distribution member from being impaired by thermal distortion of the translucent member or thermal deformation of the protrusions of the optical function layer, and the like, making it impossible to obtain a desired light distribution pattern. In particular, since the optical function layer has fine protrusions, the contact area between the optical function layer and the holding surface of the substrate is small, and a high heat insulating effect is obtained by the optical function layer.

[0053] Therefore, according to the semiconductor light-emitting device 10 of the present embodiment, it is possible to provide a semiconductor light-emitting device that uses an optical element capable of controlling light distribution, and that can stably emit light having the desired light distribution characteristics over a long period of time due to the optical element.

[0054] Furthermore, the semiconductor light emitting device 10 has an adhesive member that bonds the side surface of the light distribution member and the inner surface of the extension part of the wall of the substrate to hermetically seal the internal space of the semiconductor light emitting device 10 defined by the cavity of the substrate and the light distribution member. The adhesive member hermetically seals the space to prevent the light emitting element and the optical functional layer of the light distribution member from being deteriorated due to oxidation, moisture, etc. In addition, the adhesive member is made of resin and acts as a heat insulator, so that heat transfer from the substrate to the side surface of the light distribution member is also prevented. EXAMPLES

[0055] A configuration of a semiconductor light emitting device 40 according to a second embodiment of the present invention will be described with reference to Fig. 4 and Fig. 5. Fig. 4 is a top view showing a schematic view of the semiconductor light emitting device 40 according to the second embodiment of the present invention. Fig. 5 is a cross-sectional view showing the surface of the semiconductor light emitting device 40 taken along line 6-6 in Fig. 4.

[0056] [Semiconductor light-emitting device 40] The semiconductor light emitting device 40 is configured similarly to the semiconductor light emitting device 10 of Example 1, except that it has a package cover 41 that prevents the light distribution member 17 from falling off and a sealing member 43 that seals the adhesive member 19. Therefore, in the following description, only the differences will be described.

[0057] [Package cover] 4 and 5, the package cover 41 covers the outer side surface of the substrate 11 of the semiconductor light emitting device 10, and further extends above the upper surface S3 of the upper portion 15C of the wall portion 15 so as to overlap the outer edge of the light distribution member 17. The package cover 41 also covers the outer edge of the light distribution member 17 and has a cover opening 41OP that exposes an area that emits the emitted light converted by the light distribution member 17. That is, the laser light emitted from the light emitting element 13 passes through the light distribution member 17, is converted into diffused light, and is emitted from the cover opening 41OP.

[0058] The package cover 41 protects the semiconductor light emitting device 10 from the external environment. In addition, the cover opening 41OP of the package cover 41 defines an emission area as an area through which the light emitted from the light emitting element 13 is extracted from the semiconductor light emitting device 40, and suppresses the emission of stray light.

[0059] The package cover 41 is made of a plate material made of metal or resin. From the viewpoint of heat dissipation, it is preferable that the package cover 41 is made of metal. Note that the package cover 41 can be provided with fins for heat dissipation to improve heat dissipation.

[0060] The package cover 41 also has a device fixing portion 41C. The device fixing portion 41C is a portion that extends inward from the lower end of the package cover 41 along a direction parallel to the upper surface of the bottom portion 14 of the substrate 11. The device fixing portion 41C comes into contact with the bottom portion 14 of the substrate 11 to fix the semiconductor light emitting device 10 to the package cover 41.

[0061] For example, the bottom portion 14 of the substrate 11 has a shape in which an end portion of the lower surface is partially cut away. A device fixing portion 41C extends in a direction perpendicular to the side surface in the cut away portion.

[0062] In addition, the package cover 41 can be provided with one or more pairs of symmetrical circuit board fixing portions 41E, which are portions that extend from a portion of the lower end of the package cover 41 in a direction parallel to the bottom 14 of the substrate 11, as shown in Figure 4.

[0063] For example, the package cover 41 is fixed to the circuit board by fixing the circuit board fixing portion 41E to the circuit board with a screw or the like. In addition, the circuit board is provided with a detection wire corresponding to the circuit board fixing portion 41E and fixed with a screw or the like so as to be electrically connected, thereby making it possible to detect the detachment of the package cover 41. Fig. 4 shows an example in which two circuit board fixing portions 41E are provided at point-symmetric positions.

[0064] [Sealing member] 5, the sealing member 43 is an O-ring-shaped (annular) structure formed continuously in contact with the inner surface of the upper portion 15C of the wall portion 15 and the outer edge of the upper surface of the light distribution member 17. The sealing member 43 is attached so as to be sandwiched between the package cover 41 and the upper surface of the light distribution member 17. In this way, the sealing member 43 hermetically seals the space between the substrate 11 and the light distribution member 17.

[0065] The sealing member 43 is made of a material with low thermal conductivity, and blocks heat from the substrate 11 and the package cover 41, preventing the light distribution member 17 from being heated. In addition to the airtight sealing by the adhesive member 19, the sealing member 43 provides double sealing (double sealing) to improve the airtightness of the light-emitting device 40. Thus, the sealing member 43 has a function of protecting the light-emitting element 13 and wiring on the substrate provided inside the light-emitting device 40, and the optical function layer 31 of the light distribution member 17 from oxygen, moisture, corrosive gas, and the like. Furthermore, the sealing member 43 fixes the light distribution member 17 to the support region of the upper surface S2 of the middle part 15B of the wall part 15 of the substrate 11, preventing the light distribution member 17 from coming off above the upper part 15C.

[0066] For example, a material with low thermal conductivity such as rubber or resin can be used as a material constituting the sealing member 43. From the viewpoint of ensuring airtightness between the upper portion 15C of the substrate 11 and the light distribution member 17, the sealing member 43 is preferably made of a material that is difficult for gas to permeate, and for example, a fluorine-based rubber material such as tetrafluoroethylene-perfluorovinyl ether-based (FFKM), vinylidene fluoride-based (FKM), or tetrafluoroethylene-propylene-based (FEPM) is preferable.

[0067] As described above, the semiconductor light emitting device 40 of this embodiment is configured by attaching a package cover and a sealing member to the semiconductor light emitting device 10. The semiconductor light emitting device 10 has a configuration in which the optical function layer of the light distribution member extends to the contact surface between the light distribution member and the substrate, and at the contact surface, the optical function layer made of resin prevents heat generated by driving the light emitting element from being transmitted from the substrate to the light distribution member.

[0068] The sealing member is made of a material with low thermal conductivity, and prevents heat from the substrate from being transmitted to the light distribution member. Furthermore, the sealing member provides an airtight seal between the light distribution member and the substrate, and can ensure high airtightness of the semiconductor light emitting device 40. Furthermore, the sealing member is sandwiched between the light distribution member and the package cover, and can prevent the light distribution member from falling off.

[0069] Therefore, similar to the semiconductor light-emitting device 10 of the above-mentioned Example 1, the semiconductor light-emitting device 40 can prevent the effects of heat generated by driving the light-emitting element from reaching the optical functional layer, thereby preventing deterioration of the optical functional layer and enabling the stable emission of light having the desired light distribution characteristics by the optical elements capable of controlling the light distribution.

[0070] In addition, in the light emitting device 40, due to the sealing structure using the above-mentioned sealing member, the light emitting elements and optical functional layers sealed inside the light emitting device 40 are less susceptible to the effects of oxygen, moisture, corrosive gases, etc. Therefore, it is possible to provide a semiconductor light emitting device in which the light emitting elements and optical functional layers have long life and are capable of emitting light with a stable light distribution pattern over a long period of time.

[0071] The configurations in the above-described embodiment and manufacturing method are merely examples and can be appropriately changed depending on the application, etc. [Explanation of symbols]

[0072] 10. Semiconductor light-emitting device 11 Substrate 13 Light emitting element 14 Bottom 15 Wall 15A Lower 15B Chubu 15C upper part OP1, OP2, OP3 opening 17 Light distribution components 19 Adhesive materials 20 Joint material 21 Cathode wiring 23 Cathode device electrode 23H, 27H Conductive via 25 Anode wiring 27 Anode device electrode 28 Bonding Wire 29 Translucent material 31 Optical functional layer 41 Package Cover 41OP Cover opening 43 Sealing member

Claims

1. A substrate, a wall portion disposed on the substrate so as to surround a first region on the substrate and having an opening portion exposing the first region; A light emitting element disposed in the one region on the substrate; a light distribution member disposed above the light emitting element, the wall portion includes a first portion disposed on an upper surface of the substrate and having a first wiring electrode on the upper surface, and a second portion disposed on the upper surface of the first portion and having a light distribution member holding surface on the upper surface, The light distribution member is held in contact with the light distribution member holding surface, a second wiring electrode extending from the first region on the upper surface of the substrate to a region overlapping with the first wiring electrode in a top view; the light distribution member includes a light-transmitting member having translucency with respect to light emitted from the light-emitting element, and an optical function layer formed on a lower surface of the light-transmitting member in an area above the light-emitting element and made of a resin material having a surface formed with protrusions; The semiconductor light emitting device, wherein the optical function layer extends to a contact surface of the wall of the light distribution member that contacts the light distribution member holding surface.

2. 2. The semiconductor light emitting device according to claim 1, wherein the optical function layer is formed over the entire lower surface of the light-transmitting member.

3. 3. The semiconductor light emitting device according to claim 1, wherein the protrusions formed on the lower surface of the optical function layer form a fine structure pattern for diffracting laser light.

4. the wall portion has an extension portion that extends upward from the second portion so as to surround the light distribution member, 4. The semiconductor light emitting device according to claim 1, further comprising an adhesive member provided between a side surface of the light distribution member and the extension portion to bond the light distribution member and the extension portion.

5. 5. The semiconductor light emitting device according to claim 1, further comprising two or more bonding wires electrically connecting said light emitting element and said first wiring electrode.

6. 6. The semiconductor light emitting device according to claim 1, wherein the first wiring electrode is annular in top view.

7. 7. The semiconductor light emitting device according to claim 1, wherein the light emitting element is a VCSEL element.

8. a substrate having a bottom having an upper surface, and a wall formed on the upper surface so as to surround one region of the bottom and having an opening exposing the one region; A light emitting element disposed in the one region of the bottom portion of the substrate; a light distribution member held in contact with the wall portion, The wall portion has a holding surface facing upward, and the light distribution member is placed on the holding surface and disposed above the light emitting element, the light distribution member includes a light-transmitting member having translucency with respect to light emitted from the light-emitting element, and an optical function layer formed on a lower surface of the light-transmitting member in an area above the light-emitting element and made of a resin material having a surface formed with protrusions; The optical function layer extends to a contact surface between the wall portion of the light distribution member and the holding surface, The wall portion has an extension portion that extends upward from the wall portion so as to surround the light distribution member, an adhesive member provided between a side surface of the light distribution member and the extension portion, the adhesive member adhering the light distribution member and the extension portion; a package cover in contact with an outer surface of the substrate, covering the outer surface, extending from the outer surface to above the extension portion, and having a cover opening exposing the light distribution member; a sealing member which is a ring-shaped structure formed continuously along the inner surface of the extension portion and the outer edge of the light distribution member, and which is sandwiched between the package cover and the light distribution member to seal the space between the substrate and the light distribution member.

9. a substrate having a bottom having an upper surface, and a wall formed on the upper surface so as to surround one region of the bottom and having an opening exposing the one region; A light emitting element disposed in the one region of the bottom portion of the substrate; a light distribution member held in contact with the wall portion, The wall portion has a holding surface facing upward, and the light distribution member is placed on the holding surface and disposed above the light emitting element, the light distribution member includes a light-transmitting member having translucency with respect to light emitted from the light-emitting element, and an optical function layer formed on a lower surface of the light-transmitting member in an area above the light-emitting element and made of a resin material having a surface formed with protrusions; The optical function layer extends to a contact surface between the wall portion of the light distribution member and the holding surface, The wall portion has an extension portion that extends upward from the wall portion so as to surround the light distribution member, an adhesive member provided between a side surface of the light distribution member and the extension portion, the adhesive member adhering the light distribution member and the extension portion; a package cover covering an outer surface of the substrate, extending from the outer surface of the substrate above the extension portion, and having a cover opening exposing the light distribution member; a sealing member that is an annular structure formed continuously along an inner surface of the extension portion and an outer edge of the light distribution member, and is sandwiched between the package cover and the light distribution member to seal the gap between the substrate and the light distribution member; The package cover is bent and extends from an outer surface of the substrate to a rear surface of the bottom, and includes a device fixing portion that contacts the rear surface.

10. 10. The semiconductor light emitting device according to claim 8, wherein the upper surface of the extension portion is higher than the upper surface of the light distribution member in a direction perpendicular to the upper surface of the bottom portion.

11. 11. The semiconductor light emitting device according to claim 8, wherein the sealing member is made of a fluorine-based rubber material.

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