JP5988135B2 - Optical semiconductor light source and vehicle lighting device - Google Patents

Description

  Embodiments described herein relate generally to an optical semiconductor light source and a vehicle lighting device.

  An optical semiconductor light source using a semiconductor light emitting element such as a light emitting diode (LED) can reduce power consumption or extend its life compared to a light source using an incandescent bulb, a cold cathode tube, a discharge tube, or the like. Easy.

  As an example, exterior lighting for vehicles using a semiconductor light-emitting element as a light source has begun to be adopted mainly by high-end vehicles of various automobile manufacturers, and is used for front combination lights, rear combination lights, and the like. Furthermore, the use of rear combination lights is expanding to popular vehicles such as the so-called liter car class and minicars, and the number of installed vehicles is steadily increasing.

  In adopting the semiconductor light emitting element, an important item in design is the heat radiation design of the semiconductor light emitting element. The semiconductor light emitting device has a characteristic that the light emission efficiency decreases when the temperature of the device itself increases. Therefore, it is important how to reduce the influence of temperature due to self-temperature rise and heat generation of surrounding parts.

  As means for suppressing heat generation, the mounting interval of heat-emitting elements such as semiconductor light-emitting elements and current limiting resistors is widened to alleviate the thermal effect between adjacent elements, and the drive current of the semiconductor light-emitting elements is lowered to reduce the required light quantity. Means for compensating for the number of semiconductor light-emitting elements used.

  However, according to these means, since the light source itself becomes large, various restrictions are caused by the lamp design, and the light source is not versatile, and it is necessary to design a uniform light source for the lamp. In addition, the cost tends to increase due to the increase in the area of the substrate material to be used and the number of semiconductor light emitting elements used.

  Another way to suppress heat generation is to mount a semiconductor light-emitting element or current limiting resistor on a metal substrate with high thermal conductivity or a ceramic material substrate and bring it into contact with a heat dissipation member to reduce the temperature rise. It is done.

  This means is effective for reducing the size of the light source, and makes the light source versatile. However, since a semiconductor light source, a current limiting resistor, an external power supply component such as a connector, and other necessary components are mounted on a metal substrate or a ceramic substrate, a corresponding substrate area is required, which tends to increase costs.

  On the other hand, by increasing the driving power per semiconductor light emitting element, reducing the number of semiconductor light emitting elements used, and using low cost and low thermal conductivity materials for the semiconductor light emitting element mounting substrate, the material cost can be reduced. A measure to lower it is also conceivable. However, this is also likely to lead to a decrease in the light emission efficiency and long-term reliability of the semiconductor light emitting device.

JP 2003-115208 A

  Provided are an optical semiconductor light source and a vehicle lighting device capable of reducing a decrease in luminous efficiency and a decrease in long-term reliability while suppressing costs.

An optical semiconductor mounting board, a plurality of semiconductor light emitting elements provided on the optical semiconductor mounting board, a reflector surrounding the plurality of semiconductor light emitting elements provided on the optical semiconductor mounting board, the plurality of semiconductor light emitting A wire connected to each of the elements , wherein the plurality of semiconductor light emitting elements are arranged equidistant from the reflector, and from the center of the space surrounded by the reflector to each of the plurality of semiconductor light emitting elements distance, the plurality of much larger than the distance from each to the reflector of the semiconductor light-emitting device, all of the wire is provided inside the space surrounded by the reflector, and, from each of the semiconductor light emitting element An optical semiconductor light source is provided which extends on the side opposite to the adjacent reflector .

Further, an optical semiconductor mounting substrate, a plurality of semiconductor light emitting elements provided on the optical semiconductor mounting substrate, and a reflector provided on the optical semiconductor mounting substrate and surrounding the plurality of semiconductor light emitting elements, In the space surrounded by the reflector, a first region provided on the reflector side, and a second region provided on the center side of the space surrounded by the reflector than the first region; A wire connected to each of the plurality of semiconductor light emitting elements provided in the first region , wherein the plurality of semiconductor light emitting devices are disposed in the first region and the second region. The distance from the center of the space surrounded by the reflector to each of the plurality of semiconductor light emitting elements disposed in the first region is from each of the plurality of semiconductor light emitting elements. Much larger than the distance to the Furekuta, all of the wire is provided inside the space surrounded by the reflector, and, surrounded by the reflector from each of the semiconductor light emitting element disposed in the first region An optical semiconductor light source is provided that extends toward the center of the defined space .

  Moreover, the vehicle lighting device provided with said optical semiconductor light source is provided.

  Provided are an optical semiconductor light source and a vehicle lighting device that can reduce a reduction in luminous efficiency and long-term reliability while suppressing costs.

FIG. 1 is a perspective assembly view of a vehicle lighting device according to an embodiment of the present invention. 2A is a schematic perspective view of the vehicular lighting device according to the embodiment of the present invention as seen from the front side, and FIG. 2B is a schematic view as seen from the back side. FIG. 3 is a schematic perspective view showing the optical semiconductor mounting substrate 10 and the control substrate 50 in an enlarged manner. 4 (a) is a schematic plan view of an optical semiconductor light source according to another embodiment of the present invention, FIG. 4 (b) is an equivalent circuit diagram thereof, and FIG. 4 (c) is subjected to trimming. Represents the state after being performed. FIG. 5 is a schematic view illustrating an optical semiconductor light source according to an embodiment of the present invention, FIG. 5 (a) is a schematic plan view of the optical semiconductor light source 170, and FIG. 5 (b) is an equivalent circuit diagram thereof. is there. FIG. 6 is a schematic plan view showing the arrangement of the semiconductor light emitting elements of the optical semiconductor light source according to the present embodiment. FIG. 7 is a schematic plan view showing another specific example of the arrangement of the semiconductor light emitting elements in the present embodiment. FIG. 8 is a schematic plan view showing another specific example of the arrangement of the semiconductor light emitting elements in the present embodiment. FIG. 9 is a schematic diagram showing another semiconductor light source according to the present embodiment, FIG. 9A is a schematic plan view of the optical semiconductor light source 180, and FIG. 9B is an equivalent circuit diagram thereof. FIG. 10 is a schematic plan view showing another specific example of the arrangement of the semiconductor light emitting elements in the present embodiment. 11A and 11B are schematic views showing another semiconductor light source according to the present embodiment. FIG. 11A is a schematic plan view of the optical semiconductor light source, FIG. 11B is a partially enlarged view thereof, and FIG. ) Is an equivalent circuit diagram thereof. FIG. 12 is a schematic plan view showing another specific example of the arrangement of the semiconductor light emitting elements in the present embodiment. FIG. 13 is a schematic view illustrating another optical semiconductor light source according to this embodiment. FIG. 13A is a schematic plan view of the optical semiconductor light source, FIG. 13B is a schematic cross-sectional view thereof, and FIG. c) is a partially enlarged sectional view thereof. 14A and 14B are schematic views illustrating an optical semiconductor light source as a comparative example according to this embodiment. FIG. 14A is a plan view of the optical semiconductor device, FIG. 14B is a cross-sectional view thereof, and FIG. c) is a partially enlarged sectional view thereof. Fig.15 (a) is the model perspective view which looked at the illuminating device for vehicles which concerns on embodiment of this invention from the front side, FIG.15 (b) is the schematic diagram seen from the back surface side. FIG. 16 is a schematic cross-sectional view of a lamp equipped with the vehicle lighting device of the present embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, in each drawing, the same code | symbol is attached | subjected to the same element, and detailed description is abbreviate | omitted suitably.
FIG. 1 is a perspective assembly view of a vehicular lighting device according to a first embodiment of the present invention.
2A is a schematic perspective view of the vehicular illumination device according to the present embodiment as viewed from the front side, and FIG. 2B is a schematic view as viewed from the back side.

The vehicle lighting device 100 includes an optical semiconductor light source 150 and a cover 700 that covers the light source.
The optical semiconductor light source 150 includes a first heat sink (first heat radiating member) 300, an optical semiconductor mounting substrate 10 mounted thereon, and a control substrate 50. The back surface of the optical semiconductor mounting substrate 10 is in contact with the first heat sink 300. Here, “contact” is not limited to the one in which the optical semiconductor mounting substrate 10 directly contacts the first heat sink 300. For example, the heat generated in the optical semiconductor mounting substrate 10 is the first heat sink. In order to efficiently transmit to 300, heat transfer grease, heat transfer adhesive, and the like are also included.

  On the optical semiconductor mounting substrate 10, a semiconductor light emitting element (not shown) using an LED (Light Emitting Diode) as a light source is mounted. The optical semiconductor mounting substrate 10 can be formed of an inorganic material such as alumina or aluminum nitride, for example. Alternatively, the optical semiconductor mounting substrate 10 can be a substrate in which the surface of a metal plate is covered with an insulating layer. In this case, the insulating layer may be an organic material or an inorganic material.

  A reflector 22 having a recess 27 is mounted on the optical semiconductor mounting substrate 10 so as to surround the semiconductor light emitting element. The region where the semiconductor light emitting element and the reflector 22 are mounted is hereinafter referred to as the light emitting unit 20.

  The reflector 22 is made of, for example, resin or ceramics, and the reflector 22 is mounted on the optical semiconductor mounting substrate 10 so that the semiconductor light emitting element is exposed in the recess 27. And the inner wall surface of the recessed part 27 of the reflector 22 forms the reflective surface. The light emitted from the semiconductor light emitting element can be directly extracted upward, or it can be reflected upward by being reflected by the inner wall surface of the recess 27. Note that the shape of the reflector 22 is not limited to the illustrated shape, and may be, for example, a shape hollowed in a conical shape at the center of a rectangular parallelepiped.

  On the control substrate 50, circuit elements (not shown) such as resistors included in the drive circuit of the light emitting unit 20 mounted on the optical semiconductor mounting substrate 10 are mounted. The control board 50 can be a glass epoxy board, for example.

  The first heat sink 300 releases heat generated in the optical semiconductor mounting substrate 10 and the control substrate 50 to the outside of the optical semiconductor light source 150. The first heat sink 300 is formed of a material having high thermal conductivity such as aluminum. The first heat sink 300 is provided with an engaging convex portion 302 that engages with the cover 700, a flange portion 304, a plurality of fins 306, and a through hole 308.

  The optical semiconductor mounting substrate 10 and the control substrate 50 are electrically connected by the connecting means 40. The connection means 40 is connected to an electrode (not shown) formed on the optical semiconductor mounting substrate 10 and an electrode (not shown) formed on the control substrate 50. As the connection means 40, a metal wire, a ribbon, a strap, or the like can be used. As an example, the connection means 40 can be made of phosphor bronze. Alternatively, soldering can be used as the connecting means 40.

  The control board 50 is provided with power supply terminals 72, 74, and 76. The power supply terminals 72, 74, and 76 extend through a through hole 308 provided in the first heat sink 300, are connected to a connector 720 inserted from the rear of the first heat sink 300, and are supplied with power from the outside. .

  Note that the power supply terminals 72, 74, and 76 are not limited to this example, and for example, two power supply terminals may be configured. In short, the number of power supply terminals is not limited as long as the power supply terminals are provided so that the optical semiconductor light source 150 has desired characteristics.

  The cover 700 has an engagement opening 702 that engages with an engagement protrusion 302 provided in the first heat sink 300. In a state where the engagement opening 702 and the engagement convex portion 302 are engaged, the cover 700 is engaged with the first heat sink 300.

FIG. 3 is a schematic perspective view showing the optical semiconductor mounting substrate 10 and the control substrate 50 in an enlarged manner.
The semiconductor light emitting element 18 mounted on the optical semiconductor mounting substrate 10 emits light by electric power supplied from the outside. The semiconductor light emitting element 18 may be in the form of a semiconductor chip such as an LED diced from a wafer, or may be in the form of a semiconductor chip such as an LED mounted in a package of resin or ceramic. These semiconductor chips and packages can be mounted on the optical semiconductor mounting substrate 10 with solder, conductive adhesive, or the like.

The emission color of the semiconductor light-emitting element 18 such as an LED can be appropriately set according to the application, such as yellow or white, in addition to red light.
In addition, when the semiconductor light emitting element 18 is mounted as a semiconductor chip, the light emitting unit is protected so as to cover the periphery of the semiconductor light emitting element 18, for example, in order to protect the semiconductor light emitting element 18 from moisture or gas derived from the outside. 20 may be sealed with a translucent resin (not shown). Further, when the semiconductor light emitting element 18 is sealed with a resin, for example, the light emitted from the semiconductor light emitting element 18 by being dispersed in the resin sealed in the light emitting portion 20 is absorbed to have different wavelengths. You may have the fluorescent substance (not shown) which emits the light of this.
On the other hand, circuit elements such as resistors (not shown) are appropriately disposed on the control board 50.

  In the specific example described above, when the optical semiconductor mounting substrate 10 is formed of a metal plate coated with alumina, aluminum nitride, or an insulating layer, and the control substrate 50 is formed of a glass epoxy substrate, the optical semiconductor mounting substrate 10 is more heated. It can be said that the conductivity is high.

  The light emitting efficiency of the semiconductor light emitting element 18 tends to decrease as the temperature rises, and the lifetime also decreases. On the other hand, according to the present embodiment, heat radiation can be promoted by mounting the semiconductor light emitting element 18 on the optical semiconductor mounting substrate 10 having high thermal conductivity. By mounting the optical semiconductor mounting substrate 10 on the first heat sink 300, heat dissipation to the first heat sink 300 can be promoted, and a decrease in the light emission efficiency and the life of the semiconductor light emitting element 18 can be suppressed.

  In particular, even when a plurality of semiconductor light emitting elements 18 are used, according to the present embodiment, the semiconductor light emitting element 18 is mounted on the optical semiconductor mounting substrate 10 having high thermal conductivity, thereby reducing the cost and reducing the cost. The heat dissipation from 18 can be promoted, and the decrease in luminous efficiency and the life can be suppressed. In particular, when a plurality of semiconductor light emitting elements 18 are mounted at a high density as in this specific example, heat is also generated at a high density, so heat dissipation is important. On the other hand, according to the present embodiment, heat radiation to the first heat sink 300 can be promoted via the optical semiconductor mounting substrate 10, and high light emission efficiency and good long-term reliability can be maintained.

  When actually used as a light source for a vehicle lighting device or the like, it is necessary to appropriately mount circuit elements such as a diode, a capacitor, a resistor, a protection element, and a connector (not shown). That is, it is necessary to mount circuit elements included in the drive circuit of the semiconductor light emitting element 18. In such a case, if the light source is composed only of a substrate having a high thermal conductivity, it is necessary to secure a mounting area for circuit elements that do not generate heat on the substrate having a high thermal conductivity, which increases the cost of the light source.

  In contrast, in the present embodiment, circuit elements other than the semiconductor light emitting element 18 are mounted not on the optical semiconductor mounting substrate 10 but on the control substrate 50 which has low thermal conductivity but is inexpensive. By doing so, the cost for the component mounting area can be kept low.

  Further, by mounting circuit elements other than the semiconductor light emitting element 18 on the control substrate 50 side, the amount of heat generated on the optical semiconductor mounting substrate 10 is reduced, and the temperature rise of the semiconductor light emitting element 18 disposed adjacent thereto is also reduced. To do. Thereby, the light emission efficiency of the semiconductor light emitting element 18 is improved, the optical semiconductor mounting substrate 10 can be downsized, and the cost can be further reduced.

  Further, compared to the case where a glass epoxy substrate or the like is used as the optical semiconductor mounting substrate 10, heat radiation is improved, so that components can be arranged densely and the light source can be downsized. As a result, it is possible to reduce the restrictions on the mounting of the light source for various lamp designs and to provide a highly versatile light source. Furthermore, cost reduction can be expected by minimizing the substrate area and the quantity of semiconductor light emitting elements used.

Next, the circuit configuration of the optical semiconductor light source according to the present embodiment will be described in more detail.
FIG. 4A is a schematic plan view of an optical semiconductor light source according to the embodiment of the present invention, and FIG. 4B is an equivalent circuit diagram thereof.

  On the optical semiconductor mounting substrate 10, electrodes 12, 14, and 16 are formed. A semiconductor light emitting element 18 is connected between the electrode 12 and the electrode 14, and a light emitting section 20 is formed by arranging a reflector 22 so as to surround the semiconductor light emitting element 18. A first current limiting resistor 30 is connected between the electrode 14 and the electrode 16.

  As shown in FIG. 4B, the semiconductor light emitting element 18 includes two circuits connected in parallel in series in three stages.

However, the number of the semiconductor light emitting elements 18 is not limited to the illustrated one. That is, it is sufficient that at least one semiconductor light emitting element 18 is provided. Further, the connection in the case of providing a plurality of semiconductor light emitting elements 18 may be in series or in parallel.
On the other hand, electrodes 52, 54, and 56 are formed on the control substrate 50. A second current limiting resistor 60 is connected between the electrode 54 and the electrode 56. The electrodes 52 and 56 are connected to power supply terminals 70 and 70 from an external circuit.
The electrodes 12 and 16 of the optical semiconductor mounting substrate 10 and the electrodes 52 and 54 of the control substrate 50 are electrically connected by connecting means 40 and 40.

  Note that the connection locations of the electrodes 12, 16 and 52, 54 and the connection means 40, 40 provided on the optical semiconductor mounting substrate 10 and the control substrate 50 are not limited to the illustrated locations. In short, as long as the connection means 40, 40 electrically connect the optical semiconductor mounting substrate 10 and the control substrate 50, the connection location is not limited.

  As can be seen from the equivalent circuit shown in FIG. 4B, between the pair of power supply terminals 70, 70, the light emitting unit 20, the first current limiting resistor 30, the second current limiting resistor 60, Are connected in series. Therefore, when a driving voltage is applied between the power supply terminals 70 and 70, the current limited by the first and second current limiting resistors 30 and 60 can flow through the light emitting unit 20 to emit light.

  A plurality of the first current limiting resistors 30 may be arranged, and in electrical connection with the semiconductor light emitting device 18, the power source minus (+) on the wiring on the power source plus (+) side as viewed from the semiconductor light emitting device 18. You may arrange | position on both the wiring of a power supply plus (+) side and a power supply minus (-) side on the wiring of (-) side. Examples of the form of the first current limiting resistor 30 include a surface-mounted resistor element and a printing resistor formed on the substrate by printing means.

  Also, a plurality of second current limiting resistors 60 may be arranged, and in the electrical connection with the semiconductor light emitting element 18 shown in FIG. 4B, the power source plus (+ ) Side wiring, power source minus (−) side wiring, power source plus (+) side and power source minus (−) side wiring. Further, examples of the form of the second current limiting resistor 60 include a discrete mounting resistance element and a surface mounting resistance element.

  By mounting the second current limiting resistor 60 on the control substrate 50 side as in the configuration of this embodiment, the amount of heat generated by the first current limiting resistor 30 provided on the optical semiconductor mounting substrate 10 is reduced. In addition, the temperature rise of the semiconductor light emitting element 18 disposed in the vicinity thereof is also reduced. Thereby, the light emission efficiency of the semiconductor light emitting element 18 is improved, the optical semiconductor mounting substrate 10 can be downsized, and the cost can be further reduced.

In the optical semiconductor light source 150 of the present embodiment, the first current limiting resistor 30 can be trimmed.
FIG. 4C shows a state after trimming. That is, the first current limiting resistor 30 has a cut portion 36 formed by trimming. The cut portion 36 can be formed, for example, by removing a part of the current limiting resistor 30 by irradiating a laser. Alternatively, it is possible to remove a part of the current limiting resistor 30 by pressing a jig.

  When a printing resistor formed by printing is formed as the first current limiting resistor 30, such trimming can be easily performed. By trimming the first current limiting resistor 30 on the optical semiconductor mounting substrate 10 with respect to variations in electrical and optical characteristics of the light emitting unit 20, it is possible to suppress variations between the light sources of the respective characteristics. .

Next, the light emitting unit 20 of the optical semiconductor light source according to the embodiment of the present invention will be described in more detail.
FIG. 5 is a schematic view illustrating the light emitting unit of the optical semiconductor light source according to the embodiment of the invention. 5A is a schematic plan view of the optical semiconductor light source 170, and FIG. 5B is an equivalent circuit diagram thereof.
In the present embodiment, the light emitting unit 20 includes a reflector 22 and a plurality of semiconductor light emitting elements 18 such as LEDs provided therein. The main surface on which the semiconductor light emitting element 18 is mounted may be a part of the reflector 22 or the surface of the optical semiconductor mounting substrate 10. The light emitting unit 20 is mounted on the optical semiconductor mounting substrate 10 and appropriately mounted on the heat sink 300.

The electrode 14 and the electrode 12 having a shape surrounding the tip thereof are provided at the bottom of the space surrounded by the reflector 22. Four semiconductor light emitting elements 18 are mounted on the electrode 12. A wire 200 is connected to the tip of the electrode 14 from each of the semiconductor light emitting elements 18. As can be seen from FIG. 5B, the four semiconductor light emitting elements 18 are connected in parallel.
In this embodiment, the distance from the center of the space surrounded by the reflector 22 to each of the plurality of semiconductor light emitting elements 18 is larger than the distance from each of the plurality of semiconductor light emitting elements 18 to the reflector 22. That is, the plurality of semiconductor light emitting elements 18 are arranged near the reflector 22, not near the center, in the space surrounded by the reflector 22.
When arranging a plurality of semiconductor light emitting elements in a space surrounded by the reflector 22, they are usually arranged close to the center of the space. On the other hand, in the present embodiment, conversely, the semiconductor light emitting element 18 is disposed close to the reflector 22.
FIG. 6 is a schematic plan view showing the arrangement of the semiconductor light emitting elements of the optical semiconductor light source according to the present embodiment.
In the present embodiment, the plurality of semiconductor light emitting elements 18 are arranged equidistant from the reflector 22 (distance d2 in FIG. 6). A distance d1 from the center C of the space surrounded by the reflector 22 to each of the semiconductor light emitting elements 18 is larger than a distance d2 from each of the semiconductor light emitting elements 18 to the reflector 22.

  By doing so, the plurality of semiconductor light emitting elements 18 arranged in a limited region in the reflector 22 can be kept away from each other. That is, by disposing and arranging a plurality of semiconductor light emitting elements in a limited space, it is possible to make it less susceptible to the influence of heat emitted from each semiconductor light emitting element 18. Furthermore, by distant each semiconductor light emitting element 18, heat sources can be dispersed to prevent heat concentration and heat dissipation from each semiconductor light emitting element 18 to the first heat sink 300 can be promoted.

  Furthermore, by bringing the semiconductor light emitting element 18 closer to the reflector 22, the light emitted from the semiconductor light emitting element 18 can be efficiently reflected by the reflector 22 and taken out to the outside. That is, the ratio of the light reflected by the reflector 22 among the light emitted from the semiconductor light emitting element 18 can be increased. The light reflectance of the reflector 22 is usually higher than the light reflectance on the mounting surface of the semiconductor light emitting element 18 (the bottom surface of the space surrounded by the reflector 22). Therefore, if the proportion of the light reflected by the reflector 22 is increased, the light extraction efficiency can be increased accordingly.

7 and 8 are schematic plan views showing other specific examples of the arrangement of the semiconductor light emitting elements in the present embodiment.
In the specific example shown in FIG. 7, the planar shape of the reflector 22 is an ellipse or a flat circle. In such a case, the intersection point of the major axis and the minor axis of the ellipse or flat circle can be the center C of the space surrounded by the reflector 22. In addition, the distance d1 from the center C of the space surrounded by the reflector 22 to each of the semiconductor light emitting elements 18 in both the long axis direction and the short axis direction is from each of the semiconductor light emitting elements 18 to the reflector 22. Is greater than the distance d2.

  In the specific example shown in FIG. 8, the planar shape of the reflector 22 is a square. Thus, in the case of a polygon, the intersection of diagonal lines can be the center C of the space surrounded by the reflector 22. The distance d1 from the center C of the space surrounded by the reflector 22 to each of the semiconductor light emitting elements 18, whether viewed in the direction parallel to the four sides of the square or in the diagonal direction, The distance d2 from each of the reflectors 22 is larger than the distance d2.

  By doing so, as described above with reference to FIG. 5, a plurality of semiconductor light emitting elements are dispersed and arranged in a limited space in the reflector 22, and heat sources are dispersed to prevent heat concentration, The heat radiation from the semiconductor light emitting element 18 to the first heat sink 300 can be promoted.

In the case of the specific example shown in FIG. 5, the wire 200 connected to the semiconductor light emitting element 18 is wired in the direction of the center of the space surrounded by the reflector 22 instead of the reflector 22 side as viewed from the semiconductor light emitting element 18. Has been.
By doing so, the region where the wire 200 is bonded can be used efficiently. For example, in the case of the specific example shown in FIG. 5, the wires 200 can be connected from the four semiconductor light emitting elements 18 provided in the periphery to one electrode 14 provided in the center. That is, since it is not necessary to form four electrode pads for the four semiconductor light emitting elements 18 and the wire 200 can be connected to one electrode 14, it is necessary to secure an extra area for wire bonding. Disappear.

  Still further, the light emitted from the semiconductor light emitting element 18 to the reflector 22 adjacent to the semiconductor light emitting element 18 is provided by wiring the wire 200 in the direction of the center of the space surrounded by the reflector 22 instead of the reflector 22 side. On the other hand, light shielding and scattering by the wire 200 can be eliminated, and efficient reflection by the reflector 22 can be further promoted. That is, by not providing the wire 200 in the path of light emitted toward the reflector 22 adjacent to each semiconductor light emitting element 18, it is possible to prevent light from being blocked or scattered on this path.

FIG. 9 is a schematic view showing another semiconductor light source according to the present embodiment. 9A is a schematic plan view of the optical semiconductor light source 180, and FIG. 9B is an equivalent circuit diagram thereof.
The optical semiconductor light source 180 of the present embodiment also includes the light emitting unit 20 including the reflector 22 and a plurality of semiconductor light emitting elements 18A and 18B such as LEDs provided therein. The light emitting unit 20 is mounted on the optical semiconductor mounting substrate 10 and appropriately mounted on the heat sink 300.

  In the space surrounded by the reflector 22, a first region provided on the reflector 22 side, a second region provided on the center side of the space surrounded by the reflector 22 rather than the first region, Is provided. The semiconductor light emitting element 18A is arranged closer to the reflector 22 than the center thereof in the first region, that is, the space surrounded by the reflector 22. On the other hand, the semiconductor light emitting element 18B is disposed in the second region, that is, near the center of the space surrounded by the reflector 22.

The distance from the center of the space surrounded by the reflector 22 to the semiconductor light emitting element 18A arranged in the first region is larger than the distance from each of the semiconductor light emitting elements 18A to the reflector 22. This is the same as the relationship between the distance d1 and the distance d2 described above with reference to FIGS.
When the concentration of heat can be suppressed by dispersing and arranging the semiconductor light emitting elements 18A around the first region, that is, around the semiconductor light emitting element 18B, as shown in FIG. Can also be arranged.
Also, the semiconductor light emitting element 18A and the semiconductor light emitting element 18B adjacent thereto are connected by a wire 200. That is, adjacent semiconductor light emitting element 18A and semiconductor light emitting element 18B are connected in series. This can be achieved, for example, by providing an anode electrode on the upper surface of the semiconductor light emitting element 18A, a cathode electrode on the lower surface, a cathode electrode on the upper surface of the semiconductor light emitting element 18B, and an anode electrode on the lower surface.

  Thus, by connecting the semiconductor light emitting element 18A and the semiconductor light emitting element 18B with the wires 200, the number of the wires 200 can be reduced, and a compact arrangement and efficient electrical connection can be realized.

FIG. 10 is a schematic plan view showing another specific example of the arrangement of the semiconductor light emitting elements in the present embodiment.
In this specific example, four semiconductor light emitting elements 18 </ b> A and four semiconductor light emitting elements 18 </ b> B are mounted in the reflector 22. The semiconductor light emitting element 18A is an LED having an N-up type, that is, an N-type semiconductor on the upper side. The semiconductor light emitting element 18B is an LED having a P-up type, that is, a P-type semiconductor on the upper side. That is, the upper side electrode of the semiconductor light emitting device 18A is a cathode electrode, and the upper side electrode of the semiconductor light emitting device 18B is an anode electrode.
By mixing semiconductor light emitting elements having different polarities in this way, it becomes easy to connect the semiconductor light emitting elements in series. That is, the upper electrode of the adjacent semiconductor light emitting element 18A and the upper electrode of the semiconductor light emitting element 18B are connected by the wire 200. As a result, a series circuit having both ends of the lower electrode of the semiconductor light emitting element 18A and the lower electrode of the semiconductor light emitting element 18B can be formed.

FIG. 11 is a schematic diagram showing a specific example in which semiconductor light emitting elements are connected in series in this way. 11A is a schematic plan view of an optical semiconductor light source, FIG. 11B is a partially enlarged view thereof, and FIG. 11C is an equivalent circuit diagram thereof.
The optical semiconductor light source 185 of the present embodiment also has a light emitting unit 20 having a reflector 22 and a plurality of semiconductor light emitting elements 18A, 18B, 18C such as LEDs provided therein. The light emitting unit 20 is mounted on the optical semiconductor mounting substrate 10 and appropriately mounted on the heat sink 300.

  The four semiconductor light emitting elements 18A and the four semiconductor light emitting elements 18B arranged in the light emitting unit 20 are arranged closer to the reflector 22 than the center in the space surrounded by the reflector 22. The four semiconductor light emitting elements 18C are arranged near the center of the space surrounded by the reflector 22.

Dispersing and arranging the semiconductor light emitting elements 18A and 18B in the periphery can suppress heat concentration, and heat dissipation is ensured even if the semiconductor light emitting element 18C is arranged near the center.
The semiconductor light emitting element 18A is mounted on the electrode 15. That is, the lower electrode of the semiconductor light emitting element 18A is connected to the electrode 15. The semiconductor light emitting element 18B is mounted on the electrode 16. That is, the lower electrode of the semiconductor light emitting element 18B is connected to the electrode 16. The semiconductor light emitting element 18C is mounted on the electrode 17. That is, the lower electrode of the semiconductor light emitting element 18C is connected to the electrode 17.
The upper electrodes of the four semiconductor light emitting elements 18A and the adjacent electrodes 17 are connected by wires 200. Further, the upper electrode of the semiconductor light emitting element 18C and the upper electrode of the semiconductor light emitting element 18B are connected by wires 200, respectively.

  This equivalent circuit is as shown in FIG. That is, the four semiconductor light emitting elements 18A are connected in parallel. The semiconductor light emitting element 18B and the semiconductor light emitting element 18C are connected in series one by one, and four series circuits are connected in parallel.

For example, the semiconductor light emitting element 18A and the semiconductor light emitting element 18C use LEDs having a P-up type, that is, a P-type semiconductor on the upper side, and the semiconductor light emitting element 18B has an N-up type, ie, an N-type semiconductor, on the upper side. This can be realized by using an LED. That is, the upper electrode of the semiconductor light emitting element 18A and the semiconductor light emitting element 18C is an anode electrode, and the upper electrode of the semiconductor light emitting element 18C is a cathode electrode.
As described above, by combining the semiconductor light emitting elements in which the stacked structure of the N-type semiconductor and the P-type semiconductor is reversed, the semiconductor light emitting elements can be directly connected to form a series connection.

According to the present embodiment, by directly connecting the semiconductor light emitting elements, the number of wires 200 is reduced, and an electrode pattern for connecting the wires becomes unnecessary, and a plurality of semiconductor light emitting elements can be efficiently provided in a limited region. Can be placed.
In the case of the specific example shown in FIG. 11, a total of 12 semiconductor light emitting elements can be accommodated in an area of about 4 millimeters in diameter. Further, when the optical semiconductor light source 185 of the present embodiment is used for a tail lamp of a vehicle, a tail lamp (tail light) and a control lamp (stop light) can be displayed by switching a driving current. That is, the tail lamp may be lit with a small current, and the control lamp may be lit with a large current. That is, it is advantageous in that the tail lamp and the control lamp can be lit using the same semiconductor light emitting element, and it is not necessary to provide separate semiconductor light emitting elements and lighting circuits.

  According to the present embodiment, it is possible to efficiently arrange semiconductor light emitting elements while dispersing heat in a limited space in the reflector 22 while connecting the semiconductor light emitting elements to form a series connection. .

FIG. 12 is a schematic plan view showing another specific example of the arrangement of the semiconductor light emitting elements in the present embodiment.
In this specific example, four semiconductor light emitting elements 18 </ b> A and four semiconductor light emitting elements 18 </ b> B are mounted in the reflector 22. The semiconductor light emitting element 18A and the semiconductor light emitting element 18B are semiconductor elements having the same polarity. That is, the semiconductor light emitting element 18A and the semiconductor light emitting element 18B are all N-up type or all P-up type.

  The upper electrode of the adjacent semiconductor light emitting element 18A and the upper electrode of the semiconductor light emitting element 18B are connected by a wire 200, and further connected to the adjacent electrode 17 by a wire 200. Then, a parallel circuit can be formed by commonly connecting the lower electrode of the adjacent semiconductor light emitting element 18A and the lower electrode of the semiconductor light emitting element 18B. That is, the adjacent semiconductor light emitting element 18A and semiconductor light emitting element 18B can be connected in parallel.

According to this specific example, by directly connecting the semiconductor light emitting elements, the number of wires 200 is reduced, and an electrode pattern for connecting the wires becomes unnecessary, and a plurality of semiconductor light emitting elements can be efficiently provided in a limited region. Can be placed.
FIG. 13 is a schematic view illustrating another optical semiconductor light source according to this embodiment. 13A is a schematic plan view of an optical semiconductor light source, FIG. 13B is a schematic sectional view thereof, and FIG. 13C is a partially enlarged sectional view thereof.
The optical semiconductor light source of the present embodiment also includes a light emitting unit 20 having a reflector 22 and a plurality of semiconductor light emitting elements 18 such as LEDs provided therein. The semiconductor light emitting element 18 is disposed closer to the reflector 22 than the center of the space surrounded by the reflector 22. The light emitting unit 20 is mounted on the optical semiconductor mounting substrate 10 and mounted on the first heat sink 300.

  Also in the present embodiment, the plurality of semiconductor light emitting elements 18 are arranged near the reflector 22 rather than near the center in the space surrounded by the reflector 22. That is, as illustrated in FIG. 13B, the distance d <b> 2 between the center of the semiconductor light emitting element 18 and the lower end of the reflector 22 is the distance between the center C of the space surrounded by the reflector 22 and the center of the semiconductor light emitting element 18. smaller than d1. Here, the lower end of the reflector 22 is a position on the mounting surface of the semiconductor light emitting element 18.

  Each of the plurality of semiconductor light emitting elements 18 is individually sealed with a resin 25 in a dome shape. The main surface on which the semiconductor light emitting element 18 is mounted may be a part of the reflector 22 or the surface of the optical semiconductor mounting substrate 10.

According to the present embodiment, the light extraction efficiency can be increased by individually sealing each of the plurality of semiconductor light emitting elements 18 with the resin 25.
FIG. 14 is a schematic view illustrating an optical semiconductor light source as a comparative example according to this embodiment. 14A is a plan view of the optical semiconductor device, FIG. 14B is a sectional view thereof, and FIG. 14C is a partially enlarged sectional view thereof.
In this comparative example, the semiconductor light emitting element 18 is not individually sealed with the resin 25. That is, the plurality of semiconductor light emitting elements 18 are integrally sealed with the resin 25 inside the reflector 22.

  When the plurality of semiconductor light emitting elements 18 are integrally sealed with the resin 25 as described above, the light extraction efficiency decreases. That is, a part of the light emitted from the semiconductor light emitting element 18 is extracted from the sealing resin 25 to the outside as indicated by the arrow T. However, another part of the light emitted from the semiconductor light emitting element 18 is totally reflected on the surface of the resin 25 because the incident angle θ is small, and returns to the resin 25 as indicated by the arrow R. End up. As a result, the light extraction efficiency decreases. However, also in the comparative example shown in FIG. 14, the semiconductor light emitting element 18 is arranged close to the reflector 22, and the wire 200 connected to the semiconductor light emitting element 18 is not the reflector 22 side from the semiconductor light emitting element 18. 22 is included in the scope of the present embodiment in that it is wired in the direction of the central axis C of the space surrounded by 22.

  On the other hand, in the case of the embodiment shown in FIG. 14, among the light emitted from the semiconductor light emitting element 18, the light emitted in the direction of the central axis C is shown in FIGS. As indicated by the arrow R, the light enters the surface of the resin 25 at a shallow angle. When the light enters the surface of the resin 25 at such a shallow angle, it may be reflected and not taken out to the outside.

  On the other hand, the incident angle θ of the light emitted from the semiconductor light emitting element 18 on the surface of the resin 25 is increased by individually sealing each of the plurality of semiconductor light emitting elements 18 with the resin 25 in a dome shape. be able to. As a result, as indicated by an arrow T, the light is extracted from the resin 25 to the outside, and the light extraction efficiency can be increased.

  In the present embodiment, the resin 25 that seals each of the plurality of semiconductor light emitting elements 18 may be partially connected to each other. For example, when two adjacent semiconductor light emitting elements 18 are respectively sealed with the resin 25, the resin 25 extends thinly between the two semiconductor light emitting elements 18 and seals each semiconductor light emitting element 18. It may be connected to the resin 25 to be stopped. If the upper surface of the thin resin 25 layer extending between the two semiconductor light emitting elements 18 is lower than the position of the light emitting layer (or active layer) included in the semiconductor light emitting element 18, the semiconductor light emitting element 18 is laterally moved. This is because there is little influence that the emitted light enters the thin resin 25 layer and the light extraction efficiency decreases. Accordingly, when a thin resin 25 layer extends between the adjacent semiconductor light emitting elements 18 and the upper surface thereof is lower than the position of the light emitting layer (or active layer) included in the semiconductor light emitting element 18 as described above. , "Individually sealed with resin" is defined in this specification.

  On the other hand, also in this embodiment, the wire 200 connected to the semiconductor light emitting element 18 is wired from the semiconductor light emitting element 18 in the direction of the central axis C of the space surrounded by the reflector 22, not on the reflector 22 side. ing.

By arranging the semiconductor light emitting element 18 close to the reflector 22, a region for connecting the wire 200 can be formed in the center of the space surrounded by the reflector 22.
Further, the wire 200 is not provided in the path of light emitted from the respective semiconductor light emitting elements 18 toward the reflector 22 in the vicinity thereof. By doing so, light shielding and scattering by the wire 200 can be eliminated, and efficient reflection by the reflector 22 can be further promoted.

  If the light extraction efficiency can be increased in this way, the number of semiconductor light emitting elements 18 can be reduced. As a result, the optical semiconductor light source can be reduced in size. Furthermore, if the light extraction efficiency can be increased, the drive current supplied to the semiconductor light emitting element 18 can be reduced. As a result, it is possible to reduce power consumption, suppress heat generation of the semiconductor light emitting element 18, and further improve the light emission efficiency and extend the life.

  In addition, you may make it take out the light of a desired wavelength by disperse | distributing a fluorescent substance to the resin 25, for example.

  FIG. 15 is a diagram showing a vehicular illumination device 100 according to an embodiment of the present invention. That is, FIG. 15A is a schematic perspective view of the vehicle lighting device according to the present embodiment as viewed from the front side, and FIG. 15B is a schematic view as viewed from the back side.

In the present embodiment, a second heat sink (second heat radiating member) 310 that engages with the first heat sink 300 is provided outside the first heat sink 300. By using a material having a higher thermal emissivity than that of the first heat sink 300 as the material of the second heat sink 310, heat dissipation from the first heat sink 300 can be promoted.
For example, when the first heat sink 300 is formed of aluminum and the second heat sink 310 is formed of a resin such as PBT (Poly Buthylene Terephthalete), the heat released from the light-emitting portion is the first heat sink 300. The heat sink is efficiently transmitted to the second heat sink 310 and is efficiently discharged from the second heat sink 310 to the outside. The second heat sink 310 may be configured by forming a material having a high thermal emissivity on the surface of the first heat sink 300. For example, the second heat sink 310 may be an alumite layer formed by anodizing the surface of the first heat sink 300 made of aluminum.

  Note that the fin shapes of the first heat sink 300 and the second heat sink 310 are not limited to specific shapes. For example, as illustrated in FIG. 11, the fins of the first heat sink 300 and the second heat sink 310 may be formed in a radial shape along the shape of the optical semiconductor light source 150.

FIG. 16 is a schematic cross-sectional view of a lamp equipped with the vehicle lighting device 100 of the present embodiment.
The lamp 600 includes a reflector 620 and a lens 650. The vehicle lighting device 100 of this embodiment is inserted into an opening 640 provided at a position facing the reflector 620 and the lens 650. The light emitted from the vehicle lighting device 100 is reflected directly or by the reflector 620 and emitted to the outside via the lens 650. This lamp 600 can be provided, for example, in a taillight part of an automobile.

  In the lamp 600, a portion in front of the flange portion 304 formed on the first heat sink 300 is surrounded by the reflector 620 and the lens 650. The vehicle lighting device 100 and the reflector 620 can be engaged in a watertight manner. If necessary, a seal 660 made of a material such as rubber or silicone may be provided between the vehicle lighting device 100 and the reflector 620.

  Note that the vehicular lighting device 100 has a lamp engaging convex portion 350 as shown in FIG. 15A, for example, and the engagement with the lamp 600 is further strengthened as shown in FIG. 16B. Also good. Moreover, you may have an engagement recessed part (not shown) corresponding to the lamp engagement convex part 350 in a lamp. Moreover, you may have an engaging means (not shown) comprised, for example with the elastic body in the lamp. In short, any means may be used to make the engagement between the vehicle lighting device 100 and the lamp 600 stronger.

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

DESCRIPTION OF SYMBOLS 10 Opto-semiconductor mounting board 12, 14, 15, 16, 17 Electrode 18, 18A, 18B, 18C Semiconductor light emitting element 20 Light emission part 22 Reflector 25 Resin 27 Recess 30 Current limiting resistance 36 Cutting part 40 Connection means 50 Control board 52, 54 , 56 Electrode 60 Current limiting resistor 70, 72, 74, 76 Feed terminal 100 Vehicle lighting device 150, 170, 180, 185 Optical semiconductor light source 200 Wire 300 First heat sink 302 Engaging projection 304 Flange 306 Fin 308 Through Hole 310 Second heat sink 350 Lamp engaging convex portion 600 Lamp 620 Reflector 640 Opening 650 Lens 660 Seal 700 Cover 702 Engaging opening 720 Connector

Claims (7)

An optical semiconductor mounting substrate;
A plurality of semiconductor light emitting elements provided on the optical semiconductor mounting substrate;
A reflector provided on the optical semiconductor mounting substrate and surrounding the plurality of semiconductor light emitting elements;
A wire connected to each of the plurality of semiconductor light emitting elements;
With
The plurality of semiconductor light emitting elements are arranged equidistant from the reflector,
The distance from the center of the enclosed space by the reflector to each of the plurality of semiconductor light-emitting device is much larger than the distance from each of the plurality of semiconductor light-emitting element to the reflector,
All the wires are provided in a space surrounded by the reflector, and extend to the opposite side of the reflector adjacent to each of the semiconductor light emitting elements. . An optical semiconductor mounting substrate;
A plurality of semiconductor light emitting elements provided on the optical semiconductor mounting substrate;
A reflector provided on the optical semiconductor mounting substrate and surrounding the plurality of semiconductor light emitting elements;
With
A first region provided on the reflector side in a space surrounded by the reflector; and
A second region provided closer to the center of the space surrounded by the reflector than the first region;
A wire connected to each of the plurality of semiconductor light emitting elements provided in the first region;
Have
The plurality of semiconductor light emitting elements are disposed in the first region and the second region,
Distance to each of the plurality of semiconductor light emitting elements from the center of the enclosed space disposed in said first region by said reflector is much larger than the distance from each to the reflector of the plurality of semiconductor light emitting devices ,
All the wires are provided inside the space surrounded by the reflector, and extend from each of the semiconductor light emitting elements arranged in the first region to the center side of the space surrounded by the reflector. optical semiconductor light source, characterized in that to become to. 3. The optical semiconductor light source according to claim 1, wherein each of the plurality of semiconductor light emitting elements is individually sealed with a resin. Any of the plurality of semiconductor light emitting elements has an anode electrode formed on an upper surface,
Another one of the plurality of semiconductor light emitting elements has a cathode electrode formed on an upper surface,
The optical semiconductor light source according to any one of claims 1 to 3 , wherein the anode electrode and the cathode electrode are connected by a wire. A control substrate having a lower thermal conductivity than the optical semiconductor mounting substrate;
A circuit element provided on the control substrate and included in a drive circuit of the semiconductor light emitting element;
Connection means for electrically connecting the optical semiconductor mounting substrate and the control substrate;
A first heat dissipating member that contacts the back surface of the optical semiconductor mounting substrate and transmits heat emitted from the semiconductor light emitting element to the outside;
The optical semiconductor light source according to any one of claims 1 to 4 , further comprising: 6. The optical semiconductor light source according to claim 5 , further comprising a second heat radiating member formed on the outer side of the first heat radiating member and having a higher heat emissivity than the first heat radiating member. A vehicular lighting device comprising the optical semiconductor light source according to any one of claims 1 to 6 .

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