JP7044990B2 - Light emitting device - Google Patents

Description

The present invention relates to a light emitting device, particularly a light emitting device for a headlight.

Semiconductor light emitting devices such as light emitting diodes and laser diodes are used as various light sources, and in recent years, they have been widely used as light sources for car headlights. In addition to having high brightness, the light source for the headlights of this car is required to have a specific light distribution, for example, a lumbar shan. As a light emitting device suitable for this headlight, Patent Document 1 describes a semiconductor light emitting device provided on the surface of a substrate, a light-reflecting frame surrounding the semiconductor light emitting device on the substrate, and a semiconductor light emitting device. A light emitting device including a transparent phosphor layer covering the upper surface and the side surface of the light emitting device is disclosed. Then, according to the light emitting device, the illuminance on the front side of the automobile can be increased by reflecting light from the inner peripheral wall surface of the light-reflecting frame body and emitting light in one direction from the opening of the frame body. , It is said that it is suitable for headlights.

In addition, the headlights of the car need to illuminate the road surface while cutting the light above when the low beam is used so as not to dazzle the oncoming vehicle. The boundary line that cuts the upper light when the low beam is used is called the cutoff line 210, and when the cutoff line 210 is not clear, that is, when the low beam is used, the light is emitted above the cutoff line 210. It is not preferable for safety (Fig. 14). Therefore, the optical system of the car headlight is designed so that the cut-off line 210 becomes clear when the beam is set to low, and the cut-off line 210 becomes clear even for the light emitting device which is the light source for the headlight. Brightness characteristics that enable system design are required. Specifically, for the light emitting device, for example, the boundary between the light emitting surface and the light reflecting frame (covering member) surrounding the outer periphery of the light emitting surface is clear, that is, as shown in FIG. 13, the boundary is clear. The characteristic that the brightness changes suddenly between the outside and the inside is required. In order to clarify the boundary between the light emitting surface and the covering member surrounding the outer periphery of the light emitting surface, as shown schematically in FIG. 15, the wavelength conversion member 207 arranged on the light emitting element 201 is enlarged to emit light. The wavelength conversion member 207 is arranged on the light emitting element 201 so that the outer periphery of the wavelength conversion member 207 is located outside the outer periphery of the light emitting surface of the element 201, and the wavelength conversion member 207 is surrounded on the light emitting element 201. It is said that it is effective to provide a covering member.

Japanese Unexamined Patent Publication No. 2015-76455

However, if the phosphor plate (wavelength conversion member) is arranged on the light emitting element so that the outer periphery of the phosphor plate is located outside the outer periphery of the light emitting surface of the light emitting element, the light emitting surface of the light emitting device inevitably becomes large. .. When the light emitting surface of the light emitting device becomes large, there is a problem that the configuration of the optical system of the headlight becomes large.

Therefore, an object of the present invention is to provide a light emitting device capable of clarifying a cut-off line by a simple and compact optical system configuration when used as a light source of a headlight.

In order to achieve the above object, the light emitting device of one embodiment according to the present invention is
A substrate, a light emitting element provided on the substrate, a plate-shaped translucent member provided so that a lower surface faces the upper surface of the light emitting surface of the light emitting element, and side surfaces and transparency of the light emitting element. A covering member that covers the side surface of the optical member, and
The upper surface of the light emitting element has a rectangular shape having a first side facing each other, a second side, a third side facing each other, and a fourth side.
The upper surface of the translucent member has a rectangular shape having a fifth side facing each other, a sixth side, a seventh side facing each other, and an eighth side.
The translucent member is such that the fifth side is located outside the first side and the sixth side is located inside the second side when viewed in a plan view from above. It is characterized in that it is provided on the light emitting element.

When the light emitting device of one embodiment according to the present invention is used as a light source of a headlight, the cut-off line can be clarified by a simple and compact optical system configuration.

It is a perspective view of the light emitting device of embodiment which concerns on this invention. It is a top view of the light emitting device of an embodiment. It is sectional drawing about the line AA of FIG. It is sectional drawing about BB line of FIG. It is a graph which shows the relative luminance in the light emitting surface of the light emitting device of embodiment. It is a top view of the light emitting device of the modification 1 which concerns on this invention. It is a top view of the light emitting device of the modification 2 which concerns on this invention. It is sectional drawing about the CC line of FIG. It is a top view of the light emitting device of the modification 3 which concerns on this invention. It is a top view of the light emitting device of the modification 4 which concerns on this invention. It is a top view of the light emitting device of the modification 5 which concerns on this invention. It is a top view of the light emitting device of the modification of the modification 5 which concerns on this invention. It is a graph which shows the relative luminance in the light emitting surface of the conventional light emitting device. It is a graph which shows the irradiation characteristic of the low beam of a headlight. It is a top view of the light emitting device of a conventional example.

The present inventor has earnestly studied to provide a light emitting device capable of clarifying a cut-off line by a simple and small optical system when used as a light source of a headlight. As a result, in a light emitting device having a rectangular light emitting surface, the brightness suddenly changes between the outside and the inside of the boundary of one side of the boundary between the light emitting surface and the covering member surrounding the outer periphery of the light emitting surface. By doing so, it was found that when used as a light source for headlights, the cut-off line can be clarified by a simple optical system configuration. That is, on a rectangular light emitting surface, if the boundary is such that the brightness changes sharply for one side, even if the brightness changes gently at the boundary of the other side, the cut-off line is used as the light source of the headlight. Can be clarified. The light emitting device of the present embodiment is made based on the above findings.

Specifically, in the light emitting device of the present embodiment, a translucent member is placed on the light emitting surface of the light emitting element, and a covering member is provided around the translucent member.
(1) A translucent member is placed on the light emitting surface of the light emitting element so that one side of the translucent member is located outside one side of the light emitting surface of the light emitting element. At the boundary between one side and the covering member, the brightness changes sharply between the outside and the inside.
(2) For any one or more of the other three sides excluding that one side, one side of the translucent member is located inside one side of the light emitting surface of the light emitting element. , The area of the light emitting surface is reduced by the amount arranged inside.
In one side of the translucent member (one side of the light emitting surface of the light emitting device) located inside one side of the light emitting surface of the light emitting element, the change in brightness between the outside and the inside of the side is gentle, but cut-off line. The effect on the clarity of is small.
Hereinafter, the light emitting device of the embodiment will be described in detail.

Hereinafter, the light emitting device of the embodiment according to the present invention will be described with reference to the drawings. FIG. 1 is a perspective view of the light emitting device of the embodiment according to the present invention, and FIG. 2 is a plan view of the light emitting device of the embodiment. Further, FIG. 3 is a cross-sectional view taken along the line AA of FIG. 2, and FIG. 4 is a cross-sectional view taken along the line BB of FIG.

The light emitting device 100 of the embodiment is
(A) Substrate 10 and
(B) A light emitting element 1 provided on the substrate 10 and
(C) A plate-shaped translucent member 7 provided so that the lower surface faces the upper surface of the light emitting surface of the light emitting element 1.
(D) A covering member 5 that covers the side surface of the light emitting element 1 and the side surface of the translucent member 7.
It is equipped with. As shown in FIGS. 3 and 4, the light emitting element 1 is flip-chip mounted on the substrate 10 via, for example, a conductive bonding member 20. Although the light emitting element 1 in FIGS. 3 and 4 is shown in a simplified manner, the light emitting element 1 has, for example, a p-side electrode and an n-side electrode on the same surface side, and the p-side electrode and the p-side electrode thereof. The n-side electrodes are connected to the first electrode 11 or the second electrode 12 provided on the substrate 10 via the conductive bonding member 20, respectively. The translucent member 7 is joined to the light emitting surface of the light emitting element 1 via the light guide member 40, as will be described in detail later. Further, the translucent member 7 includes a phosphor 8 that is excited by the light of the light emitting element 1 and emits light having a wavelength longer than the wavelength of the light emitted by the light emitting element 1.

The covering member 5 is, for example, a reflective member containing a white pigment in a base material made of resin or the like, and has a side surface of a light emitting element 1, a side surface of a light guide member 40, and a side surface of a translucent member 7 on a substrate 10. It is covered. The covering member 5 surrounds the side surfaces of the light emitting element 1 and the translucent member 7 over the entire circumference. Further, the upper surface 7s of the translucent member 7 (that is, the light emitting surface of the light emitting device 100) and the upper surface of the covering member 5 form substantially the same surface. In the light emitting device 100 configured as described above, the light emitted laterally from the light emitting element 1 and the translucent member 7 is reflected by the covering member 5 and emitted from above, so that the light extraction efficiency from above is achieved. Can be raised.

Here, in particular, in the light emitting device 100, as can be understood from FIGS. 2 and 4, the translucent member 7 is arranged so as to be offset on the light emitting element 1. When the light emitting device 100 configured in this way is used as the light source module of the headlight, the headlight having a clear cut-off line in the light distribution pattern can be obtained by a simple and small optical system.

<Arrangement of light emitting element 1 and translucent member 7>
As shown in FIG. 2, the upper surface of the light emitting element 1 has a rectangular shape having a first side 1a and a second side 1b facing each other, and a third side 1c and a fourth side 1d facing each other. Is. Further, the upper surface 7s of the translucent member 7 has a rectangular shape having a fifth side 7a and a sixth side 7b facing each other, and a seventh side 7c and an eighth side 7d facing each other. ..

When the translucent member 7 is viewed in a plan view from above, the fifth side 7a is located outside the first side 1a and the sixth side 7b is the second side, as shown in FIG. It is provided on the light emitting element 1 so as to be located inside the side 1b. Here, the light emitting device of the embodiment includes a plurality of light emitting elements 1 as shown in FIG. 2, and the translucent member 7 is a fifth of the translucent member 7 as shown in FIG. Two light emitting elements 1 so that the side 7a is located outside the first side 1a of the two light emitting elements 1 and the sixth side 7b is located inside the second side 1b of the two light emitting elements 1. It is provided on the top.
Here, in the light emitting device 100 of the present embodiment, when a plurality of light emitting elements 1 having the first side 1a to the fourth side 1d are included, each of the plurality of light emitting elements 1 has the first side 1a. It is preferably located on the same straight line (first straight line). Further, the plurality of light emitting elements 1 are placed on the substrate 10 so that the first side 1a is located on the first straight line and the second side 1b is located on the second straight line parallel to the first straight line. It is more preferable that they are arranged.
Further, it is preferable that the upper surface 7s of the translucent member 7 is substantially flat and substantially parallel to the lower surface of the translucent member 7. Further, among the side surfaces connected to the upper surface 7s of the translucent member 7, the side surface connected to the upper surface 7s via the fifth side 7a is preferably a surface connected to the lower surface and substantially perpendicular to the upper surface 7s.

In the light emitting device 100 of the embodiment configured as described above, the fifth side 7a of the translucent member 7 is located outside the first side 1a of the light emitting element 1 when viewed from above in a plan view. Is provided with a translucent member 7. Therefore, the change in brightness between the outside and the inside can be steeply set at the boundary between the light emitting surface corresponding to the fifth side 7a of the translucent member 7 and the covering member 5 (relative to the left side in the graph shown in FIG. 5). Brightness rise). As a result, when the light emitting device 100 is used as a light source for the headlight, the headlight with a clear cut-off line can be obtained by an optical system having a simple configuration.

Further, the light emitting device 100 of the embodiment is translucent so that the sixth side 7b of the translucent member 7 is located inside the second side 1b of the light emitting element 1 when viewed in a plan view from above. Since the member 7 is provided on the light emitting element 1, the width of the upper surface 7s of the translucent member 7 can be narrowed, in other words, the width of the light emitting surface of the light emitting device 100 can be narrowed. That is, the area of the light emitting surface can be reduced. This makes it possible to reduce the size of the optical system when the light emitting device 100 is used as a light source for a headlight. If the translucent member 7 is provided on the light emitting element 1 so that the sixth side 7b of the translucent member 7 is located inside the second side 1b of the light emitting element 1, the translucent member 7 is transparent. The change in brightness between the outside and the inside of the boundary between the light emitting surface corresponding to the sixth side 7b of the light member 7 and the covering member 5 becomes gentle (the rising portion of the relative brightness on the right side in the graph shown in FIG. 5). However, the light emitting device 100 of the embodiment is translucent so that the fifth side 7a of the translucent member 7 is located outside the first side 1a of the light emitting element 1 when viewed in a plan view from above. Since the member 7 is provided, the fact that the sixth side 7b of the translucent member 7 is located inside the second side 1b of the light emitting element 1 has little effect on the clarity of the cut-off line. Here, the graph of the relative luminance shown in FIG. 5 shows the relative luminance in the cross section of the line BB shown in FIG.

As described above, according to the light emitting device 100 of the first embodiment, by using the light emitting device 100 as a light source of the headlight, a headlight having a clear cut-off line can be configured by a simple and small optical system. It will be possible.

In the light emitting device of the above embodiment, the seventh side 7c and the eighth side 7d of the translucent member 7 are located outside the third side 1c and the fourth side 1d of the light emitting element 1, respectively. A translucent member 7 is provided. As a result, the change in brightness between the outside and the inside can be made steep with the seventh side 7c and the eighth side 7d as boundaries, and it is easier when the light emitting device 100 is used as the light source of the headlight. The optical system of the configuration makes it possible to make a headlight with a clear cut-off line.

In the light emitting device of the embodiment, the translucent member 7 is placed on the light emitting element 1 so that the seventh side 7c and the eighth side 7d are located inside the third side 1c and the fourth side 1d, respectively. It may be provided in. By doing so, the area of the light emitting surface of the light emitting device 100 can be made smaller, so that the optical system can be made smaller when the light emitting device 100 is used as the light source of the headlight.

In the light emitting device of the embodiment, the translucent member 7 emits light so that the seventh side 7c is located inside the third side 1c and the eighth side 7d is located outside the fourth side 1d. It may be provided on the element.

In the light emitting device of the above embodiment, one translucent member 7 is configured to cover the plurality of light emitting elements 1.
However, the light emitting device of the embodiment is not limited to this, and one translucent member 7 may be configured to cover one light emitting element 1. Further, as shown in the modification described later, a plurality of translucent members 7 may be provided to cover one or more light emitting elements 1 respectively.

In the light emitting device of the above embodiment, when the translucent member 7 is viewed from above in a plan view, the fifth side 7a is located outside the first side 1a, and the sixth side 7b is the second side. It is provided on the light emitting element 1 so as to be located inside the side 1b.
However, the light emitting device of the embodiment is not limited to this, and the translucent member 7 has a fifth side 7a overlapped with the first side 1a when viewed from above in a plan view. The side 7b may be provided on the light emitting element 1 so as to be located inside the second side 1b.

The light emitting device of the above embodiment is composed of a translucent member 7 including a phosphor 8.
However, the light emitting device of the embodiment is not limited to this, and may be configured by a translucent member 7 that does not contain a phosphor.

Modification 1
FIG. 6 is a plan view of the light emitting device of the first modification according to the present invention.
The light emitting device of the modified example 1 is the same as the light emitting device of the embodiment except that it is different from the light emitting device shown in FIG. 2 and the like in that it is configured by using four light emitting elements 1.
The light emitting device of the modified example 1 configured as described above has the same function and effect as the light emitting device of the embodiment, and can have higher brightness than the light emitting device shown in FIG. 2 and the like.

Modification 2
FIG. 7 is a plan view of the light emitting device of the second modification according to the present invention. Further, FIG. 8 is a cross-sectional view of the light emitting device of the modified example 2, and shows a cross section of the line CC in FIG.
The light emitting device of the modified example 2 is configured in the same manner as the light emitting device of the modified example 1, except that the shape of the translucent member 7 is different from the light emitting device of the modified example 1. In the light emitting device of the modified example 2, the translucent member 7 is a second upper surface located below the first upper surface on the outside of the upper surface 7s (hereinafter referred to as the first upper surface) of the translucent member 7 of the modified example 2. The second upper surface thereof is covered with the covering member 5. Hereinafter, the differences from the embodiment and the first modification will be specifically described.

In the light emitting device of the second modification, the translucent member 7 has a lower surface joined to the light emitting element 1 and an upper surface facing the lower surface. The lower surface of the translucent member 7 is composed of one substantially flat lower surface, whereas the upper surface thereof has at least two upper surfaces, a first upper surface 7s1 and a second upper surface 7s2. The first upper surface 7s1 and the second upper surface 7s2 have a step between them. Specifically, the thickness of the translucent member 7 under the second upper surface 7s2 is thinner than the thickness of the translucent member 7 under the first upper surface 7s1.

In the light emitting device of the second modification, the first upper surface 7s1 of the translucent member 7 has a fifth side 7a and a sixth inner side 7b1 facing the fifth side 7a. The second upper surface 7s2 of the translucent member 7 has a sixth outer side 7b2 located outside the sixth inner side 7b1.

Then, in the light emitting device of the second modification, when the translucent member 7 is viewed from above in a plan view, (a) the fifth side 7a is the first light emitting element 1 as shown in FIGS. 7 and 8. The sixth inner side 7b1 is located inside the second side 1b of the light emitting element 1, and (c) the sixth outer side 7b2 is the second side of the light emitting element 1. It is provided on the light emitting element 1 so as to be located outside the side 1b.
At this time, it is preferable that the first upper surface 7s1 of the translucent member 7 is substantially flat and substantially parallel to the lower surface, and among the side surfaces connected to the first upper surface 7s1 of the translucent member 7. It is preferable that the side surface connected to the first upper surface 7s1 via at least the fifth side 7a is a surface connected to the lower surface and substantially perpendicular to the first upper surface 7s1. Further, the second upper surface 7s2 may be a surface substantially parallel to the lower surface or an inclined surface inclined with respect to the lower surface.

In the light emitting device of the second modification, the covering member 5 is provided so as to expose the first upper surface 7s1 and cover the second upper surface 7s2. As a result, the first upper surface 7s1 of the translucent member 7 becomes the light emitting surface of the light emitting device.

In the light emitting device of the modified example 2 configured as described above, the fifth side 7a of the translucent member 7 is located outside the first side 1a of the light emitting element 1 when viewed from above in a plan view. Since the translucent member 7 is provided, the change in brightness between the outside and the inside of the boundary between the light emitting surface corresponding to the fifth side 7a of the translucent member 7 and the covering member 5 can be steep. As a result, when the light emitting device of the second modification is used as the light source of the headlight, the headlight with a clear cut-off line can be obtained by the optical system having a simple configuration.

Further, the light emitting device of the modified example 2 transmits light so that the sixth inner side 7b1 of the translucent member 7 is located inside the second side 1b of the light emitting element 1 when viewed in a plan view from above. Since the sex member 7 is provided on the light emitting element 1, the width of the first upper surface 7s1 of the translucent member 7 can be narrowed, in other words, the width of the light emitting surface of the light emitting device can be narrowed, and the area of the light emitting surface can be reduced. Can be made smaller. This makes it possible to reduce the size of the optical system when the light emitting device 100 is used as a light source for a headlight.

Further, in the light emitting device of the second modification, when the translucent member 7 contains a phosphor, that is, the desired light emitting color of the light emitting device is obtained by including the light wavelength-converted by the phosphor. In this case, since the lower surface of the translucent member 7 covers the entire light emitting surface of the light emitting element 1, the light emitted from the light emitting element leaks to the outside without passing through the translucent member 7. Can be prevented.

Modification 3
FIG. 9 is a plan view of the light emitting device of the modified example 3 according to the present invention.
The light emitting device of the modification 3 is different from the light emitting device of the embodiment in that it includes three light emitting elements 1 and two translucent members 7.

In the light emitting device of the modification 3, one translucent member 7 is provided on the two light emitting elements 1, and the translucent member 7 is provided on the one light emitting element 1. Specifically, when one of the two translucent members 7 is viewed in a plan view from above, the fifth side 7a is the first side 1a of the two light emitting elements 1, as shown in FIG. It is located on the outside of the two light emitting elements 1 so that the sixth side 7b is located inside the second side 1b of the two light emitting elements 1.
Further, when the other translucent member 7 of the two is viewed in a plan view from above, the fifth side 7a is outside the first side 1a of one light emitting element 1, as shown in FIG. It is located and is provided on the light emitting element 1 so that the sixth side 7b is located inside the second side 1b of one light emitting element 1.
As described above, when the light emitting device has a plurality of light emitting elements 1, the translucent member 7 and the number, spacing, arrangement density, etc. of the light emitting elements 1 can be combined as a light source suitable for a desired light distribution pattern. ..

In the light emitting device of the third modification, the seventh side 7c and the eighth side 7d of the translucent member 7 are located outside the third side 1c and the fourth side 1d of the light emitting element 1, respectively. Two translucent members 7 are provided.

When the light emitting device 100 of the modification 3 configured as described above is used as the light source of the headlight, the headlight can be made into a headlight with a clear cut-off line of the light distribution pattern by an optical system having a simpler configuration. ..
Further, since the light emitting device of the modified example 3 can have a smaller area of the light emitting surface, the optical system can be made smaller when the light emitting device of the modified example 3 is used as a light source of the headlight.

Modification 4
FIG. 10 is a plan view of the light emitting device of the modified example 4 according to the present invention.
In the light emitting device of the modified example 4, the light emitting device of the modified example 4 has the seventh side 7c and the eighth side 7d of the translucent member 7 as the third side 1c and the fourth side of the light emitting element 1, respectively. It is configured in the same manner as the light emitting device of the modified example 3 except that the two translucent members 7 are provided so as to be located inside 1d.
Since the light emitting device of the modified example 4 configured as described above can have a smaller area of the light emitting surface than the light emitting device of the modified example 3, when the light emitting device of the modified example 4 is used as a light source of the headlight. In addition, the optical system can be made smaller.

Modification 5
FIG. 11 is a plan view of the light emitting device of the modified example 5 according to the present invention.
The light emitting device of the modified example 5 is configured in the same manner as the light emitting device of the modified example 4, except that the shapes of the two translucent members 7 are different from the light emitting device of the modified example 4.

Specifically, in the light emitting device of the modified example 5, the translucent member 7 is located outside the upper surface (first upper surface 7s1) of the translucent member 7 of the modified example 4 below the first upper surface. The upper surface 7s2 is included, and the second upper surface 7s2 thereof is covered with the covering member 5. Further, in the translucent member 7 of the light emitting device of the modified example 5, the second upper surface 7s2 is provided so as to surround three sides excluding the fifth side 7a when viewed from above in a plan view. Further, in the light emitting device of the modified example 5, each of the translucent members 7 has a substantially flat lower surface bonded to the light emitting element 1.

In the light emitting device of the modified example 5, the first upper surface 7s1 of the translucent member 7 is the same as the upper surface 7s of the translucent member 7 in the light emitting device of the modified example 4 with respect to the light emitting element 1 in a plan view from above. It is arranged so that it has a positional relationship of. Further, the translucent member 7 is provided on the light emitting element 1 so that the lower surface thereof is located outside the outer periphery of the light emitting element 1.

When the light emitting device of the modified example 5 configured as described above is used as a light source of a headlight, the headlight having a clear cut-off line can be obtained by an optical system having a simpler configuration.
Further, since the light emitting device of the modified example 5 can make the area of the light emitting surface smaller, it becomes possible to make the light emitting device at a higher latitude. Further, when used as a light source for a headlight, the optical system can be made smaller.

The light emitting device of the modified example 5 configured as described above has the same function and effect as the light emitting device of the modified example 4, and further, when the translucent member 7 contains a phosphor, the translucent member 7 has a translucent property. Since the member 7 covers the entire light emitting surface of the light emitting element 1, the light emitted by the light emitting element 1 can efficiently irradiate the phosphor 8.

Modification 6
FIG. 12 is a plan view of the light emitting device of the modified example 6 according to the present invention.
In the light emitting device of the modification 6, the translucent member 7 includes a second upper surface 7s2 located below the first upper surface 7s1 outside the first upper surface 7s1, and the second upper surface 7s2 is covered by the covering member 5. It has been. When the translucent member 7 is viewed in a plan view from above, the fifth side 7a is located outside the first side 1a of the light emitting element 1, and the sixth inner side is located as shown in FIG. Both 7b1 and the sixth outer side 7b2 are provided on the light emitting element 1 so as to be located inside the second side 1b of the light emitting element 1. In the light emitting device of the modification 6, the seventh side 7c and the eighth side 7d of the translucent member 7 are both located outside the third side 1c and the fourth side 1d of the light emitting element 1. ..

When the light emitting device of the modified example 6 configured as described above is used as a light source of a headlight, the headlight having a clear cut-off line can be obtained by an optical system having a simpler configuration.
Further, since the light emitting device of the modified example 6 can have a smaller area of the light emitting surface, the optical system can be made smaller when used as a light source of a headlight.

Hereinafter, each member and structure of the light emitting device in the present embodiment and the modified example will be described.

(Board 10)
The substrate 10 is a member for arranging the light emitting element, and has wiring for electrically connecting the electrode of the light emitting element and the external electrode. As the main material of the substrate 10, an insulating material, which is difficult for light from a light emitting element and external light to pass through, is preferable. For example, ceramics such as alumina and aluminum nitride, phenol resins, epoxy resins, polyimide resins, BT resins, polyphthalamides and other resins can be mentioned. When a resin is used, an inorganic filler such as glass fiber, silicon oxide, titanium oxide, or alumina may be mixed with the resin, if necessary. As a result, it is possible to improve the mechanical strength, reduce the coefficient of thermal expansion, and improve the light reflectance. Further, the substrate 10 may have an insulating material formed on the surface of a metal member. The wiring is formed in a predetermined pattern on the insulating material. The wiring material can be at least one selected from gold, silver, copper and aluminum. Wiring can be formed by plating, vapor deposition, sputtering, or the like.

(Light emitting element 1)
It is preferable to use a light emitting diode as the light emitting element 1. The light emitting element can be selected from any wavelength. For example, as the blue and green light emitting elements, those using ZnSe, a nitride semiconductor (In _X Al _Y Ga _1-XY N, 0 ≦ X, 0 ≦ Y, X + Y ≦ 1), and GaP are used. be able to. Further, as the red light emitting element, GaAlAs, AlInGaP and the like can be used. Further, a semiconductor light emitting device made of a material other than this can also be used. The composition, emission color, size, number, etc. of the light emitting element to be used can be appropriately selected according to the purpose. In the case of a light emitting device having a phosphor, a nitride semiconductor capable of emitting a short wavelength capable of efficiently exciting the phosphor (In _X Al _Y Ga _1-XY N, 0 ≦ X, 0 ≦ Y, X + Y ≦ 1) is preferably mentioned. Various emission wavelengths can be selected depending on the material of the semiconductor layer and its mixed crystalliteness.

The light emitting element of the embodiment has positive and negative electrodes on the same surface side, and the positive and negative electrodes are flip-chip mounted on the substrate via the conductive bonding member. The light emitting element has an upper surface facing the lower surface on which the electrode is formed as a main light emitting surface. Since such a light emitting element is connected on the substrate by using a conductive bonding member such as a bump or a conductive paste, the contact area between the electrode and the substrate is larger than that of the light emitting element connected by a metal wire or the like. It can be made larger and the connection resistance can be lowered.

The light emitting element is, for example, a light emitting element formed by laminating a nitride semiconductor layer on a sapphire substrate for growth of translucency, and the sapphire substrate is on the upper surface side of the light emitting element 1 and is used as a main light emitting surface. Become. The growth substrate may be removed, and can be removed by polishing, LLO (Laser Lift Off), or the like.

(Translucent member 7)
The translucent member 7 is a material capable of transmitting the light emitted from the light emitting element 1 and emitting it to the outside. The translucent member 7 may contain a light diffusing material or a phosphor capable of wavelength-converting at least a part of the incident light. The translucent member 7 can be formed of, for example, a resin, glass, an inorganic substance, or the like. Examples of the translucent member containing a fluorescent substance include a sintered body of a fluorescent substance, a resin, glass, ceramic, or another inorganic substance containing the fluorescent substance. Further, a resin layer containing a phosphor may be formed on the surface of a molded product such as resin, glass or ceramic. The thickness of the translucent member 7 is, for example, about 50 to 300 μm.
The translucent member 7 and the light emitting element can be joined via, for example, a light guide member described later. Further, for the bonding between the translucent member and the light emitting element, a direct bonding method by crimping, sintering, surface activation bonding, atomic diffusion bonding, or hydroxyl group bonding may be used.

(Fluorescent material)
As the phosphor that can be contained in the translucent member 7, a phosphor that can be excited by light emission from a light emitting element is used. For example, as a fluorescent substance that can be excited by a blue light emitting element or an ultraviolet light emitting element, an yttrium aluminum garnet fluorescent substance (Ce: YAG) activated by cerium; a lutethium aluminum garnet fluorescent substance activated by cerium is used. (Ce: LAG); nitrogen-containing calcium aluminosilicate-based fluorescent material activated with europium and / or chromium (CaO-Al ₂ O ₃ -SiO ₂ ); silicate-based fluorescent material activated with europium ((Sr, Ba)). ₂ SiO ₄ ); Nitride-based phosphors such as β-sialon phosphors, CASN-based phosphors, and SCASN _- based phosphors; KSF-based phosphors (K2 SiF ₆ : Mn); Sulfur-based phosphors, quantum dot phosphors And so on. By combining these phosphors with a blue light emitting element or an ultraviolet light emitting element, a light emitting device of various colors (for example, a white light emitting device) can be manufactured.

(Coating member 5)
The covering member 5 covers the side surfaces of the light emitting element 1 and the translucent member 7. The covering member 5 can be formed of, for example, a light-reflecting material having a high light reflectance. Specifically, as the covering member 5, a light-reflecting material having a reflectance of 60% or more, more preferably 80% or 90% or more with respect to light from a light emitting element can be used. The light-reflecting material is made of, for example, a resin containing a light-reflecting substance.
As the base resin constituting the covering member 5, a resin such as a silicone resin, a modified silicone resin, an epoxy resin, a modified epoxy resin, an acrylic resin, or a hybrid resin containing at least one of these resins can be used. It can be formed by containing a reflective substance in the base material made of the resin. As the light-reflecting substance, an oxide containing any one of Ti, Zr, Nb, Al and Si, AlN, MgF and the like can be used. Titanium dioxide (TiO2) is preferably used. Further, preferably, as a light-reflecting substance, particles having a refractive index different from that of the resin of the base material are dispersed in the resin of the base material. Since the amount of light reflected and the amount of transmitted light differ depending on the concentration and density of the light-reflecting substance, the concentration and density can be appropriately adjusted according to the shape and size of the light emitting device.

(Light guide member 40)
The light emitting device may include a light guide member 40 that covers the side surface of the light emitting element 1. When a part of the upper surface of the light emitting element 1 is exposed from the translucent member 7, the light guide member 40 preferably covers the upper surface of the light emitting element exposed from the translucent member 7. Further, the light guide member 40 preferably covers the lower surface of the translucent member 7 exposed from the light emitting element 1. The light guide member 40 is also interposed between the light emitting element and the translucent member 7, and can also be used as an adhesive member for joining the two. By providing such a light guide member 40, the light emitted from the upper surface and the side surface of the light emitting element 1 is reflected on the outer surface of the light guide member 40, and the reflected light can be guided to the translucent member 7. ..

It is preferable to use a resin material for the light guide member 40 from the viewpoint of easy handling and processing. As the resin material, a resin material including a silicone resin, a modified silicone resin, an epoxy resin, a modified epoxy resin, an acrylic resin, a resin containing at least one of a fluororesin, a hybrid resin, or the like can be used. The light guide member 40 can be formed by utilizing the viscosity of the resin material for forming the light guide member 40 and the wettability between the resin material and the light emitting element 1.

The light emitting device may optionally have another element such as a protective element, an electronic component, or the like. It is preferable that these elements and electronic components are embedded in the covering member 5.

1 Light emitting element 1a First side 1a
1b Second side 1b
1c Third side 1c
1d 4th side 1d
5 Covering member 7 Translucent member 7a Fifth side 7a
7b 6th side 7b
7b1 6th inner side 7b2 6th outer side 7c 7th side 7c
7d 8th side 7d
7s Top surface 7s1 First top surface 7s2 Second top surface 8 Fluorescent material 10 Substrate 20 Conductive joining member 40 Light guide member 100 Light emitting device

Claims (11)

With the board
The light emitting element provided on the substrate and
A plate-shaped translucent member provided so that the lower surface faces the upper surface, which is the light emitting surface of the light emitting element.
A covering member that covers the side surface of the light emitting element and the side surface of the translucent member, and
A light guide member interposed between the light emitting element and the translucent member,
Equipped with
The upper surface of the light emitting element has a rectangular shape having a first side facing each other, a second side, a third side facing each other, and a fourth side.
The upper surface of the translucent member has a rectangular shape having a fifth side facing each other, a sixth side, a seventh side facing each other, and an eighth side.
The translucent member is such that the fifth side is located outside the first side and the sixth side is located inside the second side when viewed in a plan view from above. Provided on the light emitting element,
The light guide member is a light emitting device characterized in that it covers the upper surface of the light emitting element exposed from the translucent member when viewed in a plan view from above .
The upper surface of the translucent member is a light emitting surface of the light emitting device . The first aspect of the present invention is the translucent member provided on the light emitting element so that the seventh side and the eighth side are located outside the third side and the fourth side, respectively. The light emitting device described. The first aspect of the present invention is the translucent member provided on the light emitting element so that the seventh side and the eighth side are located inside the third side and the fourth side, respectively. The light emitting device described. The translucent member is provided on the light emitting element so that the seventh side is located inside the third side and the eighth side is located outside the fourth side. The light emitting device according to claim 1. The light emitting element includes a plurality of light emitting elements each having the first side to the fourth side, and the first side of each of the plurality of light emitting elements is located on a first straight line, and the second side thereof is located on the first straight line. The light emitting device according to any one of claims 1 to 4, wherein the sides are arranged on the substrate so as to be located on a second straight line parallel to the first straight line. The light emitting device according to claim 5, wherein the translucent member covers the plurality of light emitting elements with one translucent member. The light emitting device according to any one of claims 1 to 6, wherein the translucent member includes a phosphor. The translucent member according to any one of claims 1 to 7, wherein the translucent member includes a second upper surface located below the upper surface on the outside of the upper surface, and the second upper surface is covered with the covering member. Light emitting device. With the board
The light emitting element provided on the substrate and
A plate-shaped translucent member provided so that the lower surface faces the upper surface, which is the light emitting surface of the light emitting element.
A covering member that covers the side surface of the light emitting element and the side surface of the translucent member, and
A light guide member interposed between the light emitting element and the translucent member,
Equipped with
The upper surface of the light emitting element has a rectangular shape having a first side facing each other, a second side, a third side facing each other, and a fourth side.
The upper surface of the translucent member has a rectangular shape having a fifth side facing each other, a sixth side, a seventh side facing each other, and an eighth side.
In the translucent member, the light emitting element is such that the fifth side overlaps the first side and the sixth side is located inside the second side when viewed in a plan view from above. Provided on top of
The light guide member is a light emitting device characterized in that it covers the upper surface of the light emitting element exposed from the translucent member when viewed from above in a plan view .
The upper surface of the translucent member is a light emitting surface of the light emitting device . The light emitting device according to any one of claims 1 to 9, wherein the covering member covers the upper surface of the light guide member exposed from the translucent member when viewed from above in a plan view. The light emitting device according to claim 10, wherein the upper surface of the light guide member exposed from the translucent member is an inclined surface.

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