JP2010283152A - Luminaire and light emitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light emitting device allowing efficient mounting work of a light emitting element and for enhancing light extraction efficiency. <P>SOLUTION: The light emitting device 1 includes: a light emitting part 20; and a substrate 10 on which the light emitting part 20 is provided. The light emitting part 20 includes a longitudinally shaped LED chip 21, which is attached on a longitudinally shaped reflection part 23 formed on the substrate 10. The LED chip 21 is arranged so that its longitudinal direction crosses with the longitudinal direction of the reflection part 23. Moreover, the LED chip 21 is attached on the reflection part so that its short side S faces to a wiring layer 13 (a positive electrode or a negative electrode of the wiring side). In addition, the LED chip 21 and the wiring layer 13 are electrically connected by bonding wires 22. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a lighting device and a light emitting device using a light emitting element.

Various light emitting devices using a light emitting element such as a light emitting diode (LED) as a light source have been put into practical use. Such a light-emitting device is widely used as a light source for a streetlight or a backlight of a liquid crystal display device or the like.
As for the light emitting device, a so-called package type in which a light emitting element is mounted on a package having a lead frame, or a light emitting element is directly mounted on a mounting substrate on which wiring or the like is formed as described in Patent Document 1, for example. A so-called chip on board (COB) type is known.

  Among these, since the chip-on-board type light emitting device can directly mount the light emitting element on a circuit board with good heat dissipation, the temperature of the light emitting element can be increased even when a large current is passed compared to the package type, for example. The rise can be suppressed. As described above, in the chip-on-board type light emitting device, the heat dissipation efficiency can be increased, and thus it is possible to suppress a decrease in the light emitting performance of the light emitting element due to the temperature rise. Accordingly, the chip-on-board type light emitting device is required not only for backlight use such as general illumination and liquid crystal display devices, but also for high heat dissipation such as low temperature storage, fresh product display illumination, or plant growing use. This is particularly effective when used for applications.

International Publication WO2004 / 071141

  By the way, when mounting the light emitting element, the light emitting element is fixed to a mounting member such as a substrate or a lead frame, and further, an electrode provided on the light emitting element and a power feeding portion in a power feeding path such as a wiring or a lead frame are bonded to a bonding wire or the like. The connection member is electrically connected. At this time, the connection work becomes easier when the length of the connection member is shorter. Further, in the light emitting device, it is required to increase the light extraction efficiency, and contrivances such as forming a reflection surface that reflects light emitted from the light emitting element are made.

  It is an object of the present invention to provide an illumination device or the like that can efficiently perform a mounting operation of a light emitting element and can improve light extraction efficiency.

  For this purpose, an illumination device to which the present invention is applied is an illumination device including a plurality of light emitting devices, and the light emitting device intersects one side and one side and is on one side. A light emitting element having another side with a smaller amount of light emission than the side, a reflecting portion formed around the light emitting element for reflecting light emitted from the light emitting element, and the other side of the light emitting element The power supply unit is provided to face each other and forms a power supply path to the light emitting element, and a connection member that electrically connects the light emitting element and the power supply unit.

  In such a lighting device, the other side can be characterized by being shorter than one side. Further, the connection member may be made of a material that absorbs light emitted from the light emitting element. In this case, the light-emitting element may include a group III nitride semiconductor layer, and the connection member may be made of Au. Furthermore, the sealing part which seals a light emitting element is provided, and the sealing part contains the fluorescent substance which converts the light irradiated from the light emitting element into long wavelength light, It can be characterized by the above-mentioned.

  From another viewpoint, the light emitting device to which the present invention is applied has a light emitting element having a vertically long shape, and a reflection that is formed around the light emitting element and reflects light emitted from the light emitting element. And a power supply part that is provided outside the reflection part and serves as a power supply path to the light emitting element, wherein the light emitting element is arranged with the longitudinal direction of the light emitting element intersecting the longitudinal direction of the reflection part. And

  In such a light-emitting device, the light-emitting element can be characterized in that the short side of the light-emitting element is disposed facing the long side of the reflecting portion. In addition, the power feeding unit may be provided at a central portion in the longitudinal direction of the reflecting portion outside the reflecting portion, and the light emitting element may be disposed at the central portion of the reflecting portion. Furthermore, it is possible to provide a mounting substrate on which the light emitting element is mounted, and a part of the mounting substrate functions as a reflection portion. In this case, the reflection part may be made of Al, Ag, or an alloy containing any of these metals. In addition, a plurality of light-emitting elements can be provided.

  ADVANTAGE OF THE INVENTION According to this invention, while being able to perform the mounting operation | work of a light emitting element efficiently, the illuminating device etc. with which the light extraction efficiency was raised more can be provided.

It is a figure of an example for demonstrating the whole structure of an illuminating device. It is a figure of an example for demonstrating the whole structure of a light-emitting device. It is a figure of an example for demonstrating the detail of a board | substrate and a light emission part. It is a figure of an example for demonstrating the board | substrate of this embodiment. It is a fragmentary sectional view as an example of the light-emitting device to which this embodiment is applied. It is a figure of an example for demonstrating the other example about a light-emitting device. It is a figure of an example for demonstrating a comparative example.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a diagram for explaining an example of the configuration of the illumination device 100.
As shown in FIG. 1, the illuminating device 100 has a light emitting device 1 including a substrate 10 on which wiring and the like are formed, and a light emitting unit 20 provided on the surface of the substrate 10, and a concave cross-sectional shape. The shade 100a is configured so that the light emitting device 1 can be attached to the bottom inside the recess. In addition, the illuminating device 100 of this embodiment has the six light-emitting devices 1 as shown in FIG. The illuminating device 100 can be used as a light source for various devices such as a room light, a street light, a backlight of a liquid crystal display device, and a plant growing illumination.

FIG. 2 is a diagram illustrating an example of the overall configuration of the light emitting device 1.
As illustrated in FIG. 2, the light emitting device 1 includes a substrate 10 as an example of a mounting substrate, and a light emitting unit 20 provided on the substrate 10. Further, the light emitting device 1 of the present embodiment includes a plurality (18 in the present embodiment) of light emitting units 20. Each of the plurality of light emitting units 20 is provided with an LED chip 21 (see FIG. 3 described later) as an example of a light emitting element. And when the LED chip 21 in the light emission part 20 receives electric power feeding, the light emission part 20 light-emits, respectively.

  Further, as shown in FIG. 2, a white resist 14 is formed on the surface of the substrate 10 on the side where the light emitting unit 20 is provided. In the present embodiment, the white resist 14 is formed on the surface of the substrate 10 on which the light emitting unit 20 is provided, so that light emitted from the light emitting unit 20 is efficiently irradiated toward the irradiation target direction. . Further, as shown in FIG. 2, the light emitting device 1 is provided with a connector 40. The light emitting device 1 receives power supply from the outside through the connector 40 and supplies power to the LED chip 21 through the wiring layer 13 (see FIG. 3 described later).

FIG. 3 is a diagram illustrating an example for explaining details of the substrate 10 and the light emitting unit 20. FIG. 3A is a perspective view of the substrate 10 and the light emitting unit 20. FIG. 3B is an enlarged view of the LED chip 21. In FIG. 3, the white resist 14 is not shown.
As shown in FIG. 3A, the substrate 10 includes a base material 11, a wiring layer 13 serving as a power feeding path to the light emitting unit 20, and an insulating layer 12 formed between the base material 11 and the wiring layer 13. I have. Note that the white resist 14 (see FIG. 2), which is not shown in FIG. 3A, is formed so as to open the region where the light emitting unit 20 is provided and cover the insulating layer 12 and the wiring layer 13.
On the other hand, as shown in FIG. 3A, the light emitting unit 20 seals the LED chip 21, the bonding wire 22 that electrically connects the wiring layer 13 and the LED chip 21, the LED chip 21, the bonding wire 22, and the like. And a sealing member 24 to be stopped.

  First, the substrate 10 will be described. The base material 11 in the substrate 10 of the present embodiment is an aluminum (Al) plate. Generally, it is known that the luminous efficiency of the LED (the LED chip 21 in the present embodiment) decreases as the temperature of the LED increases. Therefore, the material used for the base material 11 is preferably a material having a high thermal conductivity in terms of enhancing the heat dissipation of the heat generated with the light emission of the LED chip 21. Further, as will be described later, in the present embodiment, a part of the base material 11 is exposed, and the exposed portion functions as a reflecting surface (reflecting portion 23). In this case, it is preferable that the base material 11 is a material with a high reflectance (low absorptivity) of the light from the LED chip 21 in that the light irradiated from the LED chip 21 is efficiently reflected.

  From the above, the base material 11 of this embodiment is made of aluminum (Al), which has a high thermal conductivity and a high reflectance of light emitted from the LED chip 21. From the viewpoint of reflectivity, silver (Ag) may be used as the base material 11, and an alloy mainly composed of aluminum (Al) or silver (Ag) may be used as the base material 11. In this case, it is preferable that the reflectance of the light irradiated from the LED chip 21 of the base material 11 is 85% or more, for example. From the viewpoint of heat dissipation, the base material 11 can be made of a material having high thermal conductivity such as copper (Cu), iron (Fe), stainless steel, aluminum nitride (AlN), or silicon carbide (SiC). .

  The insulating layer 12 is provided between the base material 11 and the wiring layer 13 as shown in FIG. As described above, in this embodiment, the base material 11 is an aluminum plate, that is, a conductive material. Therefore, the wiring layer 13 cannot be directly formed on the substrate 11. Therefore, in this embodiment, the insulating layer 12 is formed on the surface of the substrate 11 and the wiring layer 13 is provided on the insulating layer 12.

  Further, as shown in FIG. 3A, the insulating layer 12 has an opening 12h. The opening 12h is formed so as to surround the LED chip 21 based on the position where the LED chip 21 is mounted. Moreover, as shown to Fig.3 (a), the opening 12h of this embodiment has an elliptical shape. Thus, by providing the opening 12h in the insulating layer 12, a part of the base material 11 is exposed. As described above, the base material 11 of the present embodiment has a high reflectance of light emitted from the LED chip 21. Therefore, the exposed portion of the base material 11 formed by providing the opening 12h realizes a function as a reflective surface (reflecting portion 23 described later) for reflecting light emitted from the LED chip 21.

FIG. 4 is a diagram illustrating an example of the substrate 10 according to the present embodiment.
As shown in FIG. 4, an insulating layer 12 is formed on the base material 11. As described above, the opening 12h is provided in the insulating layer 12 so that the reflective portion 23 is formed around the LED chip 21 based on the position where the LED chip 21 is mounted on the substrate 10. As shown in FIG. 4, in the present embodiment, openings 12 h are also formed at 18 locations for mounting 18 LED chips 21.

Then, the wiring layer 13 is formed on the insulating layer 12. The wiring layer 13 can be formed using a metal having high electrical conductivity such as copper. In the present embodiment, the plurality of LED chips 21 provided in the light emitting device 1 are all connected in series. Therefore, as shown in FIG. 4, the wiring layer 13 is formed between the adjacent openings 12h. Further, as shown in an enlarged view in FIG. 4, in the wiring layer 13, on the side facing each LED chip 21, the wiring-side positive electrode 13 </ b> P and the wiring-side negative electrode used when electrically connecting to the LED chip 21 are provided. Each of the electrodes 13N is provided. The wiring-side positive electrode 13P and the wiring-side negative electrode 13N are provided so as to face the edges along the longitudinal direction (major axis direction) of the reflecting portion 23, respectively.
In the present embodiment, the wiring-side positive electrode 13P or the wiring-side negative electrode 13N in the wiring layer 13 functions as a power feeding unit.

When the LED chip 21 is attached to each of the plurality of openings 12h in the substrate 10 and further electrically connected to the wiring-side positive electrode 13P and the wiring-side negative electrode 13N, the plurality of LED chips 21 are connected via the wiring layer 13. Connected in series.
As shown in FIG. 4, a connector electrode 13 c for connecting a connector 40 (see FIG. 2) is provided at the end of the substrate 10. The wiring layer 13 receives power from the connector 40 via the connector electrode 13c.

Next, the light emitting unit 20 will be described in detail with reference to FIG.
The LED chip 21 of the present embodiment includes, for example, a semiconductor layer made of a group III nitride semiconductor. Specifically, an n-type semiconductor layer, a light-emitting layer, and a p-type semiconductor layer are formed on a sapphire substrate or the like. Each layer is laminated in this order. Further, the LED chip 21 of the present embodiment emits blue light (center wavelength: about 450 to 460 nm).
As shown in FIG. 3B, the LED chip 21 includes a positive electrode pad 21P connected to the p-type semiconductor layer via a transparent electrode such as ITO, and a negative electrode pad 21N connected to the n-type semiconductor layer. Is provided. In the LED chip 21 of the present embodiment, blue light is emitted from the light emitting layer by passing a current through the positive electrode pad 21P and the negative electrode pad 21N.

  As shown in FIG. 3B, the LED chip 21 of the present embodiment has a vertically long shape (rectangular shape) when viewed from the side where the positive electrode pad 21P is provided, for example. Specifically, the thickness H of the LED chip 21 is about 0.15 mm. When viewed from the positive electrode pad 21P side, the LED chip 21 has a long side (hereinafter referred to as a long side L) and a short side (hereinafter referred to as a short side S). In the present embodiment, the long side L corresponds to “one side”, and the short side S corresponds to “other side”.

  As shown in FIG. 3B, when the LED chip 21 emits light, the LED chip 21 emits light in all directions. At this time, since the LED chip 21 of the present embodiment has a vertically long shape, the light distribution on the side surfaces (the surface on the long side L side and the surface on the short side S side) of the LED chip 21 is The amount of light irradiated on the long side L side is larger than that on the short side S side.

As shown in FIG. 3A, the LED chip 21 configured as described above is provided on the base material 11 inside the opening 12h. That is, the LED chip 21 is mounted on the reflection part 23 having an elliptical shape. At this time, in this embodiment, the LED chip 21 is attached to the central portion of the reflecting portion 23. The LED chip 21 can be bonded to the base material 11 by a die bonding material having high thermal conductivity, for example.
And the LED chip 21 of this embodiment is attached so that the longitudinal direction of the LED chip 21 and the longitudinal direction of the reflection part 23 may be substantially orthogonal. Note that “orthogonal” here does not mean that the angle is strictly 90 °. For example, the longitudinal direction of the LED chip 21 and the longitudinal direction of the reflecting portion 23 may intersect at an angle of 80 ° to 100 °.

  That is, in this embodiment, as shown in FIG. 3A, the long side L (longitudinal) of the LED chip 21 is such that the short side S (short side) side of the LED chip 21 faces the long side of the light emitting unit 23. The LED chip 21 is disposed on the reflecting portion 23 so that the side faces the short side of the light emitting portion 23.

  In the present embodiment, gold (Au) is used for the bonding wire 22 as an example of the connection member. Aluminum (Al) or copper (Cu) may be used for the bonding wire 22, but gold (Au) is preferably used for reasons such as good mechanical connectivity.

  The LED chip 21 mounted on the substrate 11 is electrically connected to the wiring layer 13 by the bonding wire 22. Specifically, the bonding wire 22 is used to electrically connect the positive electrode pad 21P of the LED chip 21 and the wiring side positive electrode 13P in the wiring layer 13, and the negative electrode pad 21N and the wiring side negative electrode 13N, respectively. (See FIGS. 3A and 3B).

  The sealing member 24 as an example of a sealing portion is a member that protects the LED chip 21, the bonding wire 22, and the like. As a material of the sealing member 24, a transparent resin in the visible region such as a silicone resin or an epoxy resin can be used. In particular, it is preferable to use a silicone resin that is less deteriorated by light. In addition, a phosphor that emits green light when excited by blue light and a phosphor that excites red light when excited by blue light are added to the sealing member 24 so that white light is emitted from the light emitting unit 20. It may be configured. Alternatively, a phosphor that emits yellow light when excited by blue light may be added to the sealing member 24 so that white light is emitted from the light emitting unit 20.

FIG. 5 is a partial cross-sectional view as an example of the light emitting device 1 to which the present embodiment is applied. 5A is a IIIa-IIIa cross section shown in FIG. 3A, and FIG. 5B is a IIIb-IIIb cross section shown in FIG. 3A.
As shown in FIG. 5A, in the present embodiment, the LED chip 21 is arranged so that the two short sides S of the LED chip 21 face the wiring-side positive electrode 13P and the wiring-side negative electrode 13N, respectively. ing. At this time, the wiring-side positive electrode 13P and the wiring-side negative electrode 13N in the wiring layer 13 are based on at least a distance that does not contact the LED chip 21 or a distance that does not hinder the LED chip 21 from being mounted on the base material 11 Thus, the LED chip 21 is formed as close as possible. That is, the length of the bonding wire 22 is made as short as possible. By doing so, in this embodiment, the work of electrically connecting the LED chip 21 and the wiring layer 13 using the bonding wires 22, that is, the workability of the wire bonding work is improved.

  Here, as described above, in order to insulate the base material 11 and the wiring layer 13, it is necessary to provide the insulating layer 12 between the base material 11 and the wiring layer 13. When the wiring-side positive electrode 13P and the wiring-side negative electrode 13N in the wiring layer 13 are brought closer to the LED chip 21, the insulating layer 12 needs to be brought closer to the LED chip 21 side. As a result, the width of the reflecting portion 23 in the long side L direction of the LED chip 21 is reduced (see FIG. 5A).

  On the other hand, as shown in FIG. 5B, the LED chip 21 is not disposed on the long side L side to face the wiring-side positive electrode 13P and the wiring-side negative electrode 13N in the wiring layer 13. Therefore, it is not necessary to form the insulating layer 12 on the long side L side of the LED chip 21 in order to provide the wiring layer 13. That is, on the long side L side of the LED chip 21, there is no restriction on the width of the reflecting portion 23 based on the formation of the wiring layer 13.

  In order to efficiently irradiate the light emitted from the LED chip 21 toward the target direction, it is effective to form a reflection surface around the LED chip 21. However, as described above, on the short side S side of the LED chip 21, the edge of the reflecting portion 23 can be expanded only to the position where the wiring layer 13 is provided. Therefore, in the present embodiment, the area of the reflection portion 23 on the long side L side of the LED chip 21 where the wiring layer 13 is not located is increased. For this reason, the reflecting portion 23 of the present embodiment has a vertically long shape that extends longer on the side where the wiring layer 13 is not formed than on the side where the wiring layer 13 is provided.

  Furthermore, as described above, since the LED chip 21 of the present embodiment has a vertically long shape, the amount of light irradiated from the long side L side of the LED chip 21 is larger than that of the short side S side. Therefore, in the present embodiment, the long side L (longitudinal) of the LED chip 21 is the short axis of the reflecting portion 23 so that the short side S (short) of the LED chip 21 is along the long axis direction of the reflecting portion 23. The LED chip 21 is attached to the reflecting portion 23 so as to follow the direction. Thereby, the long side L side where the light quantity is large on the side surface of the LED chip 21 is arranged so as to face the relatively wide side of the reflection area in the reflecting portion 23, and the light extraction efficiency from the LED chip 21 is further enhanced.

  5A, the wiring layer 13 (the wiring-side positive electrode 13P, the wiring-side negative electrode 13N) and the insulating layer 12 are brought closer to the LED chip 21, so that the wiring layer 13 and the insulating layer 12 are LED. The LED chip 21 stands near the LED chip 21 so as to block (absorb) light emitted from the chip 21. Therefore, in the present embodiment, the LED chip 21 is disposed so that the short side S side where the light emission amount is small compared to the long side L side faces the wiring layer 13, thereby suppressing a decrease in light extraction efficiency. . On the other hand, the LED chip 21 is arranged so that the wiring layer 13 does not face the long side L side where the amount of light emission is relatively large, thereby efficiently extracting light.

  Further, as shown in FIG. 3A, the LED chip 21 is disposed at the central portion in the major axis direction of the reflecting portion 23. Thereby, in this embodiment, the light irradiated from the two long side L side in LED chip 21 is reflected uniformly on each side, and generation | occurrence | production of the brightness nonuniformity in each light emission part 20 is suppressed.

  In the present embodiment, the emission color of the LED chip 21 is blue, and the material of the bonding wire 22 is gold (Au). Here, gold (Au) has a characteristic of absorbing blue light. On the other hand, in this embodiment, since the length of the bonding wire 22 is made as short as possible, the absorption of the light irradiated from the LED chip 21 by the bonding wire 22 is reduced and the light is irradiated from the LED chip 21. It is possible to suppress a decrease in light extraction efficiency.

  Note that the bonding wire 22 has a characteristic of absorbing a part of the light emitted from the LED chip 21 without being limited to the combination of the LED chip 21 that emits blue light and the bonding wire 22 made of gold (Au). In this case, by configuring the light emitting device 1 as described above, a decrease in light emission efficiency due to the light emitted from the LED chip 21 being absorbed by the bonding wires 22 is suppressed.

  In the present embodiment, as shown in FIG. 3A, the wiring-side positive electrode 13P (or the wiring-side negative electrode 13N) is provided so as to face the short side S of the LED chip 21. There is no need to let them. For example, the wiring-side positive electrode 13P may be formed at a position excluding the end in the longitudinal direction of the reflecting portion 23. By setting the range of the formation position of the wiring-side positive electrode 13P (or wiring-side negative electrode 13N) provided around the reflecting portion 23 to a position excluding the longitudinal end of the reflecting portion 23, at least the outermost portion of the reflecting portion 23 is formed. The length of the bonding wire 22 can be shortened as compared with the case where the wiring-side positive electrode 13P is disposed at the end in the longitudinal direction of the reflecting portion 23, which becomes large.

FIG. 6 is an example diagram for explaining another example of the light emitting device 1.
As described with reference to FIG. 3 and the like, in the above-described embodiment, the LED chip 21 provided in the light emitting unit 20 is single. Here, as shown to Fig.6 (a), the LED chip 21 provided in the light emission part 20 may be two or more plurality. Also in this case, each LED chip 21 is arranged so that the longitudinal direction of the LED chip 21 and the longitudinal direction of the reflecting portion 23 are substantially orthogonal to each other. By doing so, as shown in FIG. 6A, the length of the bonding wire 22 connected to each LED chip 21 can be shortened, and the light irradiated from the long side L side of the LED chip 21. Can be efficiently reflected.

  Further, as described with reference to FIG. 3 and the like, the reflection portion 23 of the above-described embodiment has an elliptical shape. Here, the shape of the reflection part 23 can shorten the distance between the wiring layer 13 and the short side S of the LED chip 21, and the area on the long side L side of the LED chip 21 is at least the short side of the LED chip 21. It only needs to be wider than the S side. For example, as shown in FIG. 6B, the reflecting portion 23 may have a rectangular shape (rectangular shape). Even when the shape of the reflection portion 23 is configured in this way, the bonding wire 22 connected to the LED chip 21 is arranged by arranging the longitudinal direction of the LED chip 21 and the longitudinal direction of the reflection portion 23 to intersect. The length can be shortened. Furthermore, the light irradiated from the LED chip 21 can be reflected effectively.

FIG. 7 is a diagram illustrating an example for explaining a comparative example.
In the comparative example shown in FIG. 7A, the shape of the opening 112h formed in the substrate 11 is circular. That is, the shape of the reflecting portion 123 is circular. The LED chip 21 having a vertically long shape is disposed on the reflecting portion 123.
In the case of the example shown in FIG. 7A, not only the light irradiated from the long side L side of the LED chip 21 but also the light irradiated from the short side S can be reflected and used. However, by making the shape of the reflecting portion 123 circular, the distance between the LED chip 21, the wiring-side positive electrode 13P, and the wiring-side negative electrode 13N is increased. If it does so, the length of the bonding wire 22 will become long compared with the light-emitting device 1 of this embodiment shown, for example to Fig.3 (a). Thus, when the length of the bonding wire 22 is increased, the work efficiency of the wire bonding work is reduced.

  Next, in the example shown in FIG. 7B, the LED chip 21 is arranged so that the longitudinal direction of the LED chip 21 is along the longitudinal direction of the reflecting portion 23. In this example, if the wiring-side positive electrode 13P (or the wiring-side negative electrode 13N) is brought closer to the LED chip 21, it is necessary to form the insulating layer 12 in the vicinity of the LED chip 21. The area of the reflection part 23 on the long side L side is reduced. Then, in the case of the example shown in FIG. 7B, the light irradiated on the side surface of the LED chip 21 cannot be sufficiently reflected and extracted, leading to a decrease in light extraction efficiency from the LED chip 21.

  In the above-described embodiment, the example in which the LED chip 21 emits blue light has been described. However, the emission color of the LED chip 21 is not limited to blue light. For example, even when the LED chip 21 emits green light, it is necessary to consider light absorption by the bonding wire 22 if gold (Au) is used for the bonding wire 22. In addition, even when the LED chip 21 emits red light, the bonding workability of the bonding wire 22 can be improved, so that the configuration of this embodiment is effective.

  Further, the LED chip 21 may be irradiated with ultraviolet light. Also in this case, for example, when gold (Au) is adopted as the material of the bonding wire 22, absorption of the emitted light by the bonding wire 22 can be suppressed.

  Furthermore, in said embodiment, regarding the light distribution characteristic of LED chip 21, the light emitting element which has a vertically long shape as an example in which the light emission amount on the side surface differs depending on the side was used as an example. Here, the shape of the light emitting element is not limited to a vertically long shape. For example, even in the case of a light emitting element having a square shape, an electrode pad provided on the light emitting element (corresponding to the positive electrode pad 21P of the LED chip 21 in the present embodiment, see FIG. 2) is arranged on the side where the electrode pad is provided. In some cases, the amount of light on the side is larger than that on the side where no electrode pad is provided. Thus, when using a light emitting element having a light distribution characteristic such that the magnitude of the light emission amount varies depending on each side, as described above, the side with the smaller light emission amount faces the wiring layer 13 and the light emission amount is reduced. By disposing the large side so as to face the side where the area of the reflecting portion 23 is wide, the length of the bonding wire 22 can be shortened and the light emission efficiency can be increased.

  As described above, for example, a material having high thermal conductivity such as aluminum nitride (AlN), silicon carbide (SiC), or copper (Cu) is used for the base material 11 in order to improve heat dissipation in the substrate 10. It doesn't matter. Here, the light reflectance of these materials is lower than that of, for example, aluminum (Al) or silver (Ag). Therefore, when a material having a relatively low light reflectance as described above is used for the base material 11, a layer (film) for improving the reflectance such as silver (Ag), aluminum (Al) or the like is used as the LED chip. By providing separately around 21, the light emission efficiency of the light emitting unit 20 can be improved. In this case, the above-described layer (film) functions as the reflecting portion 23.

  In the above-described embodiment, an example of a so-called chip on board in which the LED chip 21 is directly mounted on the substrate 10 is used. However, the embodiment is not limited to the chip on board. That is, when the LED chip 21 having a rectangular shape is used, the light emitting device adopting the configuration in which the power supply path such as the wiring is formed outside the reflecting surface formed around the LED chip 21 is described above. Thus, by specifying the shape of the reflective surface (corresponding to the reflecting portion 23) and the positional relationship between the power supply portion (corresponding to the wiring-side positive electrode 13P) provided in the wiring path and the LED chip 21, the work efficiency of the wire bonding work can be improved. It is possible to improve the light emission efficiency (light extraction efficiency) as well as improving the light emission efficiency.

DESCRIPTION OF SYMBOLS 1 ... Light-emitting device, 10 ... Board | substrate, 11 ... Base material, 12 ... Insulating layer, 12h ... Opening, 13 ... Wiring layer, 20 ... Light emission part, 21 ... LED chip, 23 ... Reflection part, 24 ... Sealing member, 100 ... Lighting device

Claims (11)

A lighting device comprising a plurality of light emitting devices,
The light emitting device
A light-emitting element having one side and another side that intersects the one side and has a smaller light emission amount than the one side;
A reflection part that is formed around the light emitting element and reflects light emitted from the light emitting element;
A power feeding unit provided opposite to the other side of the light emitting element and forming a power feeding path to the light emitting element;
An illumination device comprising: a connection member that electrically connects the light emitting element and the power feeding unit.   The lighting device according to claim 1, wherein the other side is shorter than the one side.   The lighting device according to claim 1, wherein the connection member is made of a material that absorbs light emitted from the light emitting element. The light emitting device has a group III nitride semiconductor layer,
The lighting device according to claim 3, wherein the connection member is made of Au. A sealing portion for sealing the light emitting element;
5. The lighting device according to claim 1, wherein the sealing portion includes a phosphor that converts light emitted from the light emitting element into long wavelength light. 6. A light emitting device having a vertically long shape;
A reflective portion that has a vertically long shape and is formed around the light emitting element and reflects light emitted from the light emitting element;
A power supply unit provided outside the reflection unit and serving as a power supply path to the light emitting element;
The light-emitting device is arranged such that a longitudinal direction of the light-emitting element intersects with a longitudinal direction of the reflecting portion.   The light emitting device according to claim 6, wherein the light emitting element is disposed such that a short side of the light emitting element is opposed to a length of the reflecting portion. The power supply unit is provided at the center in the longitudinal direction of the reflection unit outside the reflection unit,
The light emitting device according to claim 6, wherein the light emitting element is disposed at a central portion of the reflecting portion. A mounting substrate on which the light emitting element is mounted;
The light-emitting device according to claim 6, wherein a part of the mounting substrate functions as the reflecting portion.   The light-emitting device according to claim 6, wherein the reflection portion is made of Al, Ag, or an alloy containing any of these metals.   The light emitting device according to claim 6, wherein a plurality of the light emitting elements are provided.

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