JP7518373B2 - Light-emitting device - Google Patents

Description

This embodiment relates to a light emitting device.

As a light-emitting device, Patent Document 1 discloses a light source (light-emitting element) disposed on a base, a first frame disposed around the light source on the base, a first sealing layer disposed in the area surrounded by the first frame, a second frame disposed on the first frame, and a second sealing layer disposed on the first sealing layer in the area surrounded by the second frame.

JP 2014-138185 A

The purpose of this embodiment is to provide a light-emitting device that can efficiently emit light from a light source to the outside, in addition to preventing unnecessary expansion of the light-emitting area.

To achieve the above object, the light emitting device according to one aspect of the present embodiment includes a base, and on the base, a light source, a light-reflective first frame body arranged around the light source, a first sealing layer arranged in an area surrounded by the first frame body, covering the light source and having an upper surface, a light-transmitting second frame body arranged on the first frame body, a light-reflective third frame body located outside the second frame body, and a second sealing layer arranged in an area surrounded by the third frame body and located on the first sealing layer, with the second frame body in contact with the upper surface of the first sealing layer.

The light-emitting device of this embodiment not only prevents unnecessary expansion of the light-emitting area, but also efficiently emits light from the light source to the outside.

1 is a plan view showing a light emitting device according to first and second embodiments of the present invention. 2 is a cross-sectional view of the light-emitting device according to the first embodiment of the present invention taken along line II-II in FIG. 2 is a cross-sectional view of a light-emitting device according to a second embodiment of the present invention taken along line II-II in FIG. FIG. 4 is an enlarged cross-sectional view of a main part of the light emitting device of FIG. 3. FIG. 4 is a cross-sectional view showing a modified example of the light emitting device according to the first embodiment of the present invention. FIG. 4 is a cross-sectional view showing a modified example of the light emitting device according to the first embodiment of the present invention. FIG. 7A is a cross-sectional view showing a manufacturing process of the light emitting device according to the second embodiment. FIG. 7B is a cross-sectional view showing a manufacturing process of the light emitting device according to the second embodiment. FIG. 7C is a cross-sectional view showing a manufacturing process of the light emitting device according to the second embodiment. FIG. 7D is a cross-sectional view showing a manufacturing process of the light emitting device according to the second embodiment. FIG. 7E is a cross-sectional view showing a manufacturing process of the light emitting device according to the second embodiment. FIG. 7F is a cross-sectional view showing a manufacturing process of the light emitting device according to the second embodiment. FIG. 7G is a cross-sectional view showing a manufacturing process of the light emitting device according to the second embodiment. FIG. 7H is a cross-sectional view showing a manufacturing process of the light emitting device according to the second embodiment. FIG. 11 is a cross-sectional view showing a light-emitting device according to a third embodiment of the present invention.

A light emitting device according to one aspect of the present invention comprises a base, and on the base, a light source, a light-reflective first frame arranged around the light source, a first sealing layer arranged in an area surrounded by the first frame, covering the light source and having an upper surface, a light-transmitting second frame arranged on the first frame, a light-reflective third frame located outside the second frame, and a second sealing layer arranged in an area surrounded by the third frame and located on the first sealing layer, with the second frame in contact with the upper surface of the first sealing layer.

The light emitting device described above can efficiently emit light from the light source to the outside in addition to suppressing unnecessary expansion of the light emitting region. To explain in more detail, for example, when the second sealing layer needs to have a thickness in order to suppress uneven light emission by propagating light in a wide area in the second sealing layer, the frame body used to block the second sealing layer also needs to have a height similar to that of the second sealing layer. To make the frame body taller, the resin constituting the frame body can be supplied in a ring shape using a discharge device, and this can be repeated several times to stack the resin, but if the resin located at the upper side is stacked so as to spread outward, the light emitting region will be expanded. Therefore, by arranging a second light-transmitting frame body on the first frame body so as to be in contact with the first sealing layer and moving it toward the inside (toward the center of the frame body) and arranging a third light-reflective frame body covering the outside of the second frame body, it is possible to ensure the height of the frame body while suppressing unnecessary expansion of the light emitting region. In this specification, the "light emitting region" refers to the region where the sealing layer located at the outermost part of the sealing layer, which is a multi-layer structure, is exposed to the outside. If the light-emitting region is unnecessarily enlarged, the luminance of the light-emitting region is reduced, and when the light-emitting device is used for lighting purposes, the illuminance may be reduced. In addition, in this specification, the term "uneven light emission" includes at least one of uneven luminance and uneven color.
Furthermore, if the second frame body is translucent as in the above-mentioned light-emitting device, the light from the light source that enters the second frame body is transmitted through the second frame body without being blocked by the second frame body, thereby improving the light extraction efficiency.

In another aspect of the light emitting device of the present invention, the second sealing layer includes a second lower sealing layer disposed in an area surrounded by a second frame body, and a second upper sealing layer disposed in an area surrounded by a third frame body and positioned on the second lower sealing layer.

The above light emitting device can use the second frame to place a second lower sealing layer with a predetermined thickness in the area surrounded by the second frame, and can further use the third frame to place a second upper sealing layer with a predetermined thickness in the area surrounded by the third frame.

In a light emitting device according to another aspect of the present invention, the second upper sealing layer is a layer containing a light diffusing material. In a light emitting device according to another aspect of the present invention, the first sealing layer is a layer containing a light diffusing material. In a light emitting device according to another aspect of the present invention, the second lower sealing layer is a layer that does not substantially contain a light diffusing material.

The light emitting device is not limited to the above embodiments, and may be a combination of the above embodiments. A light emitting device including a second lower sealing layer that does not substantially contain a light diffusing material and is disposed between a second upper sealing layer that includes a light diffusing material and a first sealing layer that includes a light diffusing material can suppress uneven light emission in the light emitting region. In more detail, when the sealing layer has the above configuration, light from the light source is diffused in the first sealing layer and enters the second lower sealing layer. Since the second lower sealing layer does not substantially contain a light diffusing material, the light that enters the second lower sealing layer propagates over a wide area in the second lower sealing layer. The light that propagates in the second lower sealing layer enters the second upper sealing layer. The light that enters the second upper sealing layer is diffused and then emitted to the outside. This can suppress uneven light emission in the light emitting region.

In another aspect of the light emitting device of the present invention, the first sealing layer includes a first lower sealing layer located on the base side and a first upper sealing layer located on the first lower sealing layer, and the first upper sealing layer is a layer that includes a light diffusing material.

In the light emitting device described above, the first sealing layer is a laminated structure of a first lower sealing layer and a first upper sealing layer, and the first upper sealing layer is a layer containing a light diffusing material (the layer containing a light diffusing material is also simply called a "light diffusing layer"). This makes it possible to reduce uneven light emission by diffusing light from the light source and allowing it to enter the second sealing layer while thinning the film thickness of the first upper sealing layer. In particular, when the second sealing layer is a laminated structure of a second upper sealing layer containing a light diffusing material and a second lower sealing layer that does not substantially contain a light diffusing material, the layer that does not contain a light diffusing material (the second lower sealing layer) is sandwiched between layers that contain a light diffusing material (the second upper sealing layer and the first upper sealing layer), so that uneven light emission can be more efficiently suppressed while thinning the film thickness of the sealing layer.

In another aspect of the light emitting device of the present invention, the first frame includes an inner frame disposed on the base and an outer frame disposed on the inner frame, and the first lower sealing layer is disposed in the area surrounded by the inner frame.

The light emitting device described above can utilize the inner frame to place a first lower sealing layer with a predetermined thickness in the area surrounded by the inner frame.

In another aspect of the light emitting device of the present invention, the first sealing layer is a layer containing a light diffusing material, and the second sealing layer contains a light-transmitting layer.

In the above light emitting device, the first sealing layer is a layer containing a light diffusing material. As a result, light from the light source is diffused by the first sealing layer and then enters the second sealing layer. In addition, since the second sealing layer contains a light-transmitting layer, the light diffused by the first sealing layer propagates over a wide area of the second sealing layer, reducing unevenness in light emission.

In another aspect of the light emitting device of the present invention, the third frame is in contact with the first frame and is spaced apart from the base.

In the above light emitting device, since both the first frame and the third frame are light reflective, the third frame comes into contact with the first frame, thereby preventing light from the light source from leaking out through the gap between the first and third frames. In addition, since the third frame is separated from the base, the outermost edge of the third frame is prevented from expanding.

In another aspect of the light emitting device of the present invention, the area where the lower surface of the second frame contacts the first sealing layer is larger than the area where the lower surface of the second frame contacts the first frame.

In the above light emitting device, the second frame is positioned closer to the inside (toward the center of the frame) than when the area where the lower surface of the second frame contacts the first sealing layer is smaller than the area where the lower surface of the second frame contacts the first frame, so that the third frame positioned outside the second frame can be prevented from expanding. This prevents unnecessary expansion of the light emitting area. Furthermore, even if the position where the second frame is placed is slightly deviated from the desired position when the second frame is formed, it is possible to prevent fluctuations in the height from the upper surface of the first sealing layer to the top of the second frame. This prevents fluctuations in the film thickness of the second sealing layer placed in the area surrounded by the second frame.

A light-emitting device according to another aspect of the present invention includes a plurality of light sources arranged on a substrate.

The light emitting device described above diffuses light from each of the multiple light sources within the light emitting device, allowing light with reduced brightness unevenness to be extracted from the light emitting device.

A light-emitting device according to another aspect of the present invention includes multiple light sources with different emission colors arranged on a base.

The light emitting device described above diffuses light from multiple light sources with different emission colors within the device, allowing light with reduced color unevenness to be extracted from the device.

The following describes an embodiment of the present invention based on the drawings. However, the following embodiment is an example of a light-emitting device for embodying the technical concept of the present invention, and the present invention does not specify the light-emitting device as described below. In addition, this specification does not specify the members shown in the claims to the members of the embodiment. The dimensions, materials, shapes, and relative positions of the components described in the embodiment are merely explanatory examples, and are not intended to limit the scope of the present invention unless otherwise specified. The size and positional relationship of the components shown in each drawing may be exaggerated to clarify the explanation. Furthermore, in the following explanation, the same name and symbol indicate the same or similar components, and detailed explanations will be omitted as appropriate. Furthermore, each element constituting the present invention may be configured with the same material so that multiple elements are used by one member, or conversely, the function of one member may be shared by multiple members. In addition, the contents described in some embodiments may be applicable to other embodiments, etc.

(Embodiments 1 and 2)
FIG. 1 is a plan view of light emitting devices 100 and 200 according to embodiments 1 and 2. FIG. 2 is a cross-sectional view of the light emitting device 100 according to embodiment 1, which corresponds to the cross section along line II-II in FIG. 1. FIG. 3 is a cross-sectional view of the light emitting device 200 according to embodiment 2, which corresponds to the cross section along line II-II in FIG. 1. FIG. 1 illustrates a base and a light source through a sealing layer and a frame. The light emitting devices 100 and 200 shown in these figures include a base 50, a light source 10 arranged on the base 50, a frame 20 surrounding the light source 10, and a sealing layer 30 arranged in a region surrounded by the frame 20. 2 and 3 include, on a base 50, a light source 10, a light-reflective first frame 21 arranged around the light source 10, a first sealing layer 31 arranged in a region surrounded by the first frame 21 and covering the light source 10, a light-transmitting second frame 26 arranged on the first frame 21, a light-reflective third frame 27 positioned outside the second frame 26, and a second sealing layer 35 arranged in a region surrounded by the third frame 27 and positioned on the first sealing layer 31. The second frame 26 contacts an upper surface of the first sealing layer 31.

2 and 3 include a plurality of light sources (light source 10) arranged in an area surrounded by a frame body 20. In the light emitting device 100, 200, the light source 10 having different emission colors is composed of a first light source 11 and a second light source 12. The first light source 11 and the second light source 12 may each be multiple or single. In addition, the number of the first light source 11 and the second light source 12 may be the same or different. The first light source 11 and the second light source 12 are each connected in series, and the first light source 11 and the second light source 12 can be driven independently. This allows the emission color of the entire light emitting device to be changed (adjusted color) by controlling the current value supplied to each light source of the first light source 11 and the second light source 12. In this embodiment, the color can be adjusted in a range from white to incandescent light. In addition, by appropriately changing the light emitting element and wavelength conversion layer described later, the color can be adjusted within a range between different incandescent colors with different color temperatures, or within a range between different white colors with different color temperatures.

In this embodiment, two light colors are emitted from the light source 10, but three or more light colors may be emitted from the light source 10. Also, in this embodiment, there are multiple light sources 10, but there may be only one light source 10. The first light source 11 and the second light source 12 may emit the same light color. In this case, the luminance of the entire light-emitting device can be changed (dimmed) by controlling the current value supplied to the first light source and the second light source.

(Base 50)
The base 50 includes a plate-shaped base material and a wiring layer 53 disposed on the base material. The wiring layer 53 forms a wiring pattern that electrically connects to each light source 10. The wiring pattern is a pattern in which the first light source and the second light source are connected in series. The wiring layer includes an external connection portion that is electrically connected to the outside on the outside of the frame body 20. The planar shape of the base 50 can be rectangular, for example, as shown in FIG. 1. The base material of the base 50 can be appropriately made of ceramic such as alumina, glass epoxy, aluminum nitride, metal (aluminum, copper), or the like. When the base material is a metal, it is preferable to provide an insulating film on the surface.

It is preferable to provide a light reflecting film on the upper surface of the base 50 other than the area electrically connected to the wiring layer 53 of the light source 10. This allows the light from the light source 10 that travels toward the base 50 to be reflected, improving the light extraction efficiency. The light reflecting film is preferably made of an insulating material, and for example, a resin containing titanium oxide or the like can be used.

In the light-emitting device 100 in FIG. 1, the light sources 10 are arranged two-dimensionally. When the light sources 10 are arranged two-dimensionally, they can be arranged in a manner that corresponds to the inner peripheral shape of the frame body 20. For example, the two-dimensional arrangement of the light sources 10 can also be arranged in an octagonal outer shape in correspondence with an octagonal frame body (dotted line in FIG. 1). In FIG. 1, the light source 10 is composed of a plurality of first light sources 11 and a plurality of second light sources 12. In FIG. 1, the first light source 11 and the second light source 12 are alternately arranged in the longitudinal direction and the lateral direction of the rectangular base body 50. When the emission colors of the first light source 11 and the second light source 12 are different, color unevenness can be improved by arranging the first light source 11 and the second light source 12 alternately. In FIG. 1, 12 first light sources 11 and 12 second light sources 12 are arranged two-dimensionally in the area surrounded by the frame body 20. However, any number of light sources and arrangement pattern can be used.

(Light source 10)
As the light source 10, a light emitting element 15 or a light emitting element 15 having one or more wavelength conversion layers on its surface can be used. The light emitting element 15 includes a semiconductor laminate having a light emitting portion. The semiconductor laminate has light emitting properties, and is formed by laminating a plurality of semiconductor layers such as ZnS, SiC, GaN, GaP, InN, AlN, ZnSe, GaAsP, GaAlAs, InGaN, GaAlN, AlInGaP, AlInGaN, or the like on a growth substrate by liquid phase growth, HDVPE, or MOCVD, and forming a light emitting portion in any of the semiconductor layers. By selecting the material of the semiconductor layer and its mixed crystal degree, ultraviolet light or visible light can be emitted from the light emitting portion. As the material of the light emitting portion, In _x Al _y Ga _1-XY N (0≦X≦1, 0≦Y≦1, X+Y≦1) or the like can be used. Furthermore, light source 10 may be a combination of light-emitting element 15 and wavelength conversion layer 16 containing a phosphor that is excited by the light emitted by light-emitting element 15 and emits light having a peak wavelength different from the peak wavelength of light-emitting element 15. When multiple phosphors are used, the multiple phosphors may be arranged in one layer, or the wavelength conversion layer may be composed of multiple layers with different phosphors arranged in each layer.

The first light source 11 and the second light source 12 may have different emission colors or the same emission color. When the first light source 11 and the second light source 12 have different emission colors, the light-emitting element 15 of the first light source 11 and the light-emitting element 15 of the second light source 12 may have different peak wavelengths to obtain different emission colors. Alternatively, the light-emitting element 15 of the first light source 11 and the light-emitting element 15 of the second light source 12 may have the same peak wavelength, and a wavelength conversion layer may be disposed on the upper surface of either the light-emitting element 15 of the first light source 11 or the light-emitting element 15 of the second light source 12.

In the light-emitting devices 100 and 200 shown in Figs. 2 and 3, the first light source 11 is composed of a light-emitting element 15, and the second light source 12 is composed of a light-emitting element 15 and one wavelength conversion layer 16A. In the second light source 12, the first wavelength conversion layer 16A and a translucent member 17 (e.g., glass) are laminated in this order on the light-emitting element 15. For the second light source 12, a laminate is prepared in which the first wavelength conversion layer 16A is formed on the surface of the translucent member 17 by a printing method, and this laminate is joined to the light-emitting element 15.

In the light-emitting devices 100 and 200 shown in Figures 2 and 3, the wavelength conversion material contained in the first sealing layer 31 settles and covers the upper surfaces of the base 50, the first light source 11, and the second light source 12, thereby forming the second wavelength conversion layer 16B. Note that the wavelength conversion material contained in the first sealing layer 31 may be dispersed within the first sealing layer 31.

In this embodiment, by driving the first light source 11, white light can be emitted from the light emitting device, and by driving the second light source 12, light of an incandescent color can be emitted from the light emitting device. By controlling the current value supplied to each of the first light source 11 and the second light source 12, the light emission color of the entire light emitting device can be adjusted in the range from white to incandescent color. In this embodiment, the light source 10 (the first light source 11 and the second light source 12) is combined with the wavelength conversion layer 16B included in the first sealing layer to adjust the light emission color of the entire light emitting device.

2 and 3, a configuration in which a wavelength conversion layer (second wavelength conversion layer 16B) is arranged on the light-emitting element 15 may be prepared by arranging the second wavelength conversion layer 16B on the light-emitting element 15 and placing this on the base 50 as a first light source. Also, in order to obtain a configuration in which the first wavelength conversion layer 16A, the translucent member 17 (e.g., glass), and the second wavelength conversion layer 16B are stacked in this order on the light-emitting element 15 shown in FIG. 2 and FIG. 3, a configuration in which the first wavelength conversion layer 16A, the translucent member 17, and the second wavelength conversion layer 16B are stacked in this order on the light-emitting element 15 may be prepared and placed on the base 50 as a second light source. In this case, white light can be emitted from the first light source. Also, light of a light bulb color can be emitted from the second light source. By appropriately changing the light-emitting element and the wavelength conversion layer, white light can be emitted from the first light source 11, and white light having a color temperature different from that of the white light emitted from the first light source 11 can be emitted from the second light source 12. Alternatively, the first light source 11 may emit light of a warm white color, and the second light source 12 may emit light of a warm white color that has a different color temperature from the light of a warm white color emitted from the first light source 11.

The light source 10 has a pair of electrodes formed on one surface of the light emitting element 15. The light source 10 is bonded to the base 50 via bumps, solder, or the like, with the electrode formation surface, which is the surface of the light emitting element 15 on which the electrodes are formed, facing the base 50. The light source 10 may also be bonded to the base 50 via an adhesive, with the surface of the semiconductor laminate 15 opposite the surface on which the electrodes are formed facing the base 50. In this case, it is preferable to electrically connect the electrodes provided in the light source and the wiring layer arranged on the base with wires.

(Frame body 20)
The light emitting devices 100 and 200 each include a frame 20 on a base 50. The frame 20 in the light emitting device 100 is composed of a first frame 21, a second frame 26, and a third frame 27. The frame 20 in the light emitting device 200 is composed of a first frame 21 (inner frame 22, outer frame 23), a second frame 26, and a third frame 27. In the light emitting device 100, the first frame 21 is disposed on the base 50, the second frame 26 is disposed on the first frame 21, and the third frame 27 is disposed at a position outside the second frame 26. In the light emitting device 200, the inner frame 22 is disposed on the base 50, the outer frame 23 is disposed on the inner frame 22, the second frame 26 is disposed on the outer frame 23, and the third frame 27 is disposed at a position outside the second frame 26. The outer frame 23 covers the outside of the inner frame 22 and contacts the base 50. In a cross-sectional view, the third frame 27 is preferably in contact with the first frame 21 on the outside of the second frame 26. Since both the first frame 21 and the third frame 27 are light reflective, the third frame 27 is in contact with the first frame 21 on the outside of the second frame 26, so that the light emitted from the light source 10 and passing through the translucent second frame 26 can be prevented from leaking out from the gap between the first frame 21 and the third frame 27. Furthermore, it is preferable that the third frame 27 is separated from the base 50. This can prevent unnecessary expansion of the outermost edge of the frame 20.

The cross-sectional shape of the second frame 26 may be such that the width is greater than the thickness, as shown in FIG. 3, or the thickness may be greater than the width. By making the thickness greater than the width in the cross-sectional shape of the second frame 26, the thickness of the second lower sealing layer 36 can be increased without increasing the size of the outermost edge of the second frame 26.

As shown in Figures 2 and 3, each of the frames 20 has an arc-shaped outer shape in a cross section cut in a direction perpendicular to the circumferential direction of the frame. In the light-emitting device 100 of Figure 2, the top of the second frame 26 is higher than the top of the first frame 21, and the top of the third frame 27 is higher than the top of the second frame 26. In the light-emitting device 200 of Figure 3, the top of the outer frame 23 is higher than the top of the inner frame 22, the top of the second frame 26 is higher than the top of the outer frame 23, and the top of the third frame 27 is higher than the top of the second frame 26. By raising the tops of the frames as they are stacked as described above, they can be used as a dam for arranging each layer of the sealing layer 30, which is a multi-layer structure. Here, "top" refers to the apex located at the highest point from the base 50 if the outer shape of the frame is arc-shaped in cross section, and refers to that plane if the upper part of the frame has a plane parallel to the base in cross section.

The inner and outer periphery shapes of the frame body 20 in plan view are not limited to an octagonal shape as shown in FIG. 1, but may be circular or rectangular. The inner and outer periphery shapes of the frame body may be the same or different.

The third frame 27 may or may not cover the top of the second frame 26. By having the third frame cover the top of the second frame, the third frame can be made taller. Also, by having the third frame not cover the top of the second frame, light that passes through the translucent second frame is less likely to be blocked by the light-reflective third frame.

The material of the first frame 21 and the third frame 27 can be a resin (white resin) containing a light-reflecting material such as inorganic white powder such as titanium oxide. The resin can be a silicone resin, an epoxy resin, or the like. The second frame 26 is translucent, and in order to reduce the light transmission loss, it is preferable that the content of the light-reflecting material is less than that of the other light-reflective frames (the first frame 21 and the third frame 27), and it is more preferable that the second frame 26 does not substantially contain a light-reflecting material. It is preferable that the first frame 21, the second frame 26, and the third frame 27 are made of the same resin. This can improve the adhesion between the frames.

Figure 4 is a cross-sectional view showing the state in which the second frame 26 is disposed on the upper surface of the first sealing layer 31 and the first frame 21. It is preferable that the area of the second frame 26 that contacts the upper surface of the first sealing layer 31 is larger than the area of the second frame 26 that contacts the first frame 21. As a result, compared to when the area of the lower surface of the second frame that contacts the first sealing layer is smaller than the area of the lower surface of the second frame that contacts the first frame, the second frame 26 is disposed closer to the inside (toward the center of the frame), and the third frame 27 located outside the second frame 26 can be prevented from expanding. As a result, the light-emitting region of the light-emitting device 100 can be prevented from expanding unnecessarily.

As another effect, since the second frame 26 is disposed on the upper surface of the first sealing layer 31, which has a gentler gradient than the surface outside the top of the first frame 21, even if the resin supply that constitutes the second frame 26 is slightly shifted inward (toward the center of the frame) or outward (away from the center of the frame) from the desired position when the resin is supplied by the discharge device, it is possible to suppress fluctuations in the thickness from the upper surface of the first sealing layer 31 to the top of the second frame 26. This makes it possible to suppress fluctuations in the film thickness of the second lower sealing layer 36 that is disposed in the area surrounded by the second frame 26.

The second frame 26 can also be placed on the upper surface of the first sealing layer 31 without contacting the first frame 21.

In the light emitting device 200 shown in FIG. 3, the first frame body 21 is composed of two frame bodies, an inner frame body 22 and an outer frame body 23, but is not limited to this and may be composed of three or more frame bodies. When the first frame body 21 is composed of multiple frame bodies, the frame body located on the inside (the side toward the center of the frame body) may be translucent.

(Sealing layer 30)
The light emitting devices 100 and 200 include a sealing layer 30 in a region surrounded by the frame 20. The sealing layer 30 of the light emitting device 100 in Fig. 2 is composed of two layers, a first sealing layer 31 and a second sealing layer 35, where the first sealing layer 31 covers the light source 10 and the second sealing layer 35 is disposed on the first sealing layer 31. In the light emitting device 100, the first sealing layer 31 is disposed in a region surrounded by the first frame 21, and the second sealing layer 35 is disposed in a region surrounded by the third frame 27. 3 is composed of four layers, namely, a first lower sealing layer 32, a first upper sealing layer 33, a second lower sealing layer 36, and a second upper sealing layer 37. The first lower sealing layer 32 covers the light source 10, and the first lower sealing layer 32, the first upper sealing layer 33, the second lower sealing layer 36, and the second upper sealing layer 37 are laminated in this order from the side of the base 50. In the light emitting device 200, the first lower sealing layer 32 is disposed in a region surrounded by the inner frame 22, the first upper sealing layer 33 is disposed in a region surrounded by the outer frame 23, the second lower sealing layer 36 is disposed in a region surrounded by the second frame 26, and the second upper sealing layer 37 is disposed in a region surrounded by the third frame 27.

It is preferable that the sealing layer 30 contains a light diffusing material. When the sealing layer 30 is a laminate, it can have a laminate structure including a layer containing a light diffusing material (light diffusion layer) and a light-transmitting layer. The "light-transmitting layer" refers to a layer containing a light diffusing material at a content lower than the content of the light diffusing material contained in the light diffusion layer, or a layer that does not substantially contain a light diffusing material. In the light emitting device 200 of FIG. 3, the sealing layer 30 is a laminate structure composed of a first lower sealing layer 32, a first upper sealing layer 33, a second lower sealing layer 36, and a second upper sealing layer 37. The sealing layer 30 of the laminate structure has a structure in which the first lower sealing layer 32 and the second lower sealing layer 36 are light-transmitting layers, and the first upper sealing layer 33 and the second upper sealing layer 37 are light-diffusing layers, sandwiching a light-transmitting layer between the light-diffusing layers. The structure in which the light-transmitting layer is sandwiched between the light-diffusing layers allows light to be diffused over a wider range within the sealing layer 30, suppressing unevenness in the light-emitting region. In addition, since unevenness in light emission can be suppressed without increasing the thickness of the sealing layer 30, the size of the light-emitting device can be reduced. Any known material can be used as the light-diffusing material. For example, inorganic white powder such as titanium oxide can be used as the light-diffusing material.

The sealing layer 30 may contain a wavelength conversion material such as a phosphor. The wavelength conversion material may be dispersed or precipitated. In the first embodiment, the first sealing layer 31 contains a wavelength conversion material. The wavelength conversion material contained in the first sealing layer 31 is precipitated on the upper surface sides of the first light source 11, the second light source 12, and the base 50. In the second embodiment, the first lower sealing layer 32 contains a wavelength conversion material. The wavelength conversion material contained in the first lower sealing layer 32 is precipitated on the upper surface sides of the first light source 11, the second light source 12, and the base 50.

The light emitting device 200 shown in FIG. 3 has the first upper sealing layer 33 and the second upper sealing layer 37 as light diffusing layers and the second lower sealing layer 36 as a light transmitting layer, and each sealing layer can diffuse light as a layer containing a light diffusing material, and can increase transmittance as a layer not containing a light diffusing material. Furthermore, since the light diffusion effect and transmittance of the sealing layer 30 can be controlled by the content of the light diffusing material, each sealing layer 30 can control the content of the light diffusing material taking into account the required light diffusion effect and transmittance to create a light emitting device optimal for the application.

(Modifications of the first and second embodiments)
The light emitting device 300 shown in Figure 5 includes a light-reflective first frame body 21, a first sealing layer 31 containing a light diffusing material arranged in an area surrounded by the first frame body 21, a light-transmitting second frame body 26 arranged on the first frame body 21, a light-reflective third frame body 27 located outside the second frame body 26, and a second sealing layer 35 not containing a light diffusing material arranged in an area surrounded by the third frame body 27.
The light emitting device 400 shown in Figure 6 includes a light-reflective first frame body 21, a first sealing layer 31 arranged in an area surrounded by the first frame body 21, a light-transmitting second frame body 26 arranged on the first frame body 21, a second lower sealing layer 36 arranged in an area surrounded by the second frame body 26, a third frame body 27 located outside the second frame body 26, and a second upper sealing layer 37 including a light diffusing material arranged in an area surrounded by the third frame body 27.
The first sealing layer 31 may or may not contain a light diffusing material. Alternatively, the first sealing layer 31 may be divided into a first lower sealing layer 32 and a first upper sealing layer 33, in which the first lower sealing layer 32 does not contain a light diffusing material and the first upper sealing layer 33 contains a light diffusing material.

(Method of Manufacturing the Light Emitting Device 200)
7A to 7H are cross-sectional views showing the manufacturing process of the light emitting device 200 shown in FIG. 3, illustrating the process of arranging the frame body 20 and the sealing layer 30 on the base body 50.
(1) A resin containing a light reflecting material is applied around the light source 10 on the base 50, and the inner frame 22 is disposed (see FIG. 7A).
(2) Using the inner frame 22 as a dam, a region surrounded by the inner frame 22 is filled with a translucent resin containing a phosphor, and the first lower sealing layer 32 is disposed. Then, the phosphor contained in the first lower sealing layer 32 is allowed to settle onto the upper surfaces of the light source 50, the first light source 11, and the second light source 12 (see FIG. 7B).
(3) A light-reflective resin is applied so as to cover the outside of the inner frame 22 and the surface of the base 50, and the outer frame 23 is then positioned. When applying the resin containing a light-reflecting material, it is applied so that the top of the outer frame 23 is higher than the top of the inner frame 22. (See FIG. 7C)
(4) A resin containing a light diffusing material is filled into the area surrounded by the outer frame 23, with the outer frame 23 acting as a dam, and the first upper sealing layer 33 is disposed on the first lower sealing layer 32. The thickness of the first upper sealing layer 33 is the height difference between the top of the inner frame 22 and the top of the outer frame 23, since it is laminated on the first lower sealing layer 32 and disposed with the outer frame 23 acting as a dam (see FIG. 7D).
(5) A light-transmitting resin is applied to the top surface of the first upper sealing layer 33 and the outer frame 23 to form the light-transmitting second frame 26 (see FIG. 7E).
(6) Using the light-transmitting second frame 26 as a dam, the area surrounded by the second frame 26 is filled with light-transmitting resin that does not contain a light diffusing material, and the second lower sealing layer 36 is disposed. The film thickness of the second lower sealing layer 36 is determined by the height of the top of the light-transmitting second frame 26 (see FIG. 7F).
(7) A resin containing a light-reflecting material is applied so as to straddle the outside of the light-transmitting second frame 26 and the outer frame 23, and the light-reflective third frame 27 is disposed. When applying the resin containing a light-reflecting material, it is applied so that the top of the third frame 27 is higher than the top of the second frame 26. (See FIG. 7G)
(8) The area surrounded by the light-reflective third frame 27 as a dam is filled with a resin containing a light diffusing material, and the second upper sealing layer 37 is disposed. Since the second upper sealing layer 37 is layered on the second lower sealing layer 36 and disposed with the light-reflective third frame 27 as a dam, the thickness of the second upper sealing layer 37 is the height difference between the top of the second frame 26 and the top of the third frame 27 (see FIG. 7H).

In the above manufacturing process, the resin that is the base material of the frame body 20 is one that has excellent adhesion between the base body 50 and the frame body 20, and also has excellent adhesion with each member and the sealing layer 30. Silicone resin, epoxy resin, etc. are preferably used as such resin.

The light-emitting device 200 has a translucent second frame 26 disposed on the upper surface of the first upper sealing layer 33, the top of the second frame 26 disposed inside (towards the center of the frame) the top of the outer frame 23, and a light-reflective third frame 27 disposed outside the translucent second frame 26. The light-emitting device 200 suppresses unnecessary expansion of the light-emitting area with the translucent second frame 26 and the light-reflective third frame 27 disposed outside the frame, while allowing light from the light source 10 to pass through the sealing layer 30 without being blocked by the second frame 26 and to be efficiently emitted to the outside.

(Method of manufacturing the light emitting device 100)
The manufacturing process of the light emitting device 100 shown in Fig. 2 is as follows: A resin containing a light reflecting material is applied onto the base 50, and the first frame 21 is disposed, and the area surrounded by the first frame 21 with the first frame 21 acting as a dam is filled with a light-transmitting resin not containing a light diffusing material to dispose the first sealing layer 31. Thereafter, the light-transmitting second frame 26 and the light-reflective third frame 27 are disposed, and the area surrounded by the third frame 27 with the third frame 27 acting as a dam is filled with a light-transmitting resin to dispose the second sealing layer 35.

(Embodiment 3)
The light emitting device 500 shown in the cross-sectional view of FIG. 8 includes, in addition to the configuration of the light emitting device 200, a fourth light-transmitting frame 28, a fifth light-reflective frame 29, a third lower sealing layer 39, and a third upper sealing layer 40. The fourth frame 28 is disposed on the third frame 27 and contacts the upper surface of the second upper sealing layer. The third lower sealing layer 39 is disposed in an area surrounded by the fourth frame 28. The fifth frame 29 is located outside the fourth frame 28. The top of the fifth frame 29 is higher than the top of the fourth frame 28. The third upper sealing layer 40 is disposed in an area surrounded by the fifth frame 29. In other words, the structure of the light-transmitting fourth frame 28, the light-reflective fifth frame 29, the third lower sealing layer 39, and the third upper sealing layer 40 is a repeated structure of the light-transmitting second frame 26, the light-reflective third frame 27, the second lower sealing layer 36, and the second upper sealing layer 37 in the light-emitting device 200.
The third lower sealing layer 39 is preferably a light-transmitting layer, and the third upper sealing layer 40 is preferably a light-diffusing layer. This allows the sealing layer 30 to have a configuration in which the light-transmitting layer and the light-diffusing layer are alternately repeated, which further promotes light diffusion within the sealing layer and suppresses uneven light emission in the light-emitting region. When the light-diffusing layer and the light-transmitting layer are alternately repeated, they may be arranged one layer at a time or multiple layers at a time.
The repetition of the structure of the light-transmitting second frame 26, the light-reflective third frame 27, the second lower sealing layer 36, and the second upper sealing layer 37 is not limited to once, and may be multiple times.

The light emitting device according to the present invention can be used in a wide range of applications, including light sources 10 such as LEDs and laser elements used in lighting light sources, LED displays, backlight light sources, traffic signals, illuminated switches, various sensors, and various indicators, as well as in the manufacture of light sources 10.

100, 200, 300, 400, 500...light emitting device 10...light source 11...first light source 12...second light source 15...light emitting element 16A...first wavelength conversion layer 16B...second wavelength conversion layer 17...light-transmitting member 20...frame 21...first frame 22...inner frame 23...outer frame 26...second frame 27...third frame 28...fourth frame 29...fifth frame 30...sealing layer 31...first sealing layer 32...first lower sealing layer 33...first upper sealing layer 35...second sealing layer 36...second lower sealing layer 37...second upper sealing layer 38...third sealing layer 39...third lower sealing layer 40...third upper sealing layer 50...base 53...wiring layer

Claims (12)

A substrate;
On the substrate,
A light source;
A light-reflective first frame body arranged around the light source;
a first sealing layer that is disposed in a region surrounded by the first frame, covers the light source, and has an upper surface;
a second light-transmitting frame disposed on the first frame;
a light-reflective third frame body located outside the second frame body;
a second sealing layer disposed in a region surrounded by the third frame and located on the first sealing layer;
Equipped with
the second frame is in contact with an upper surface of the first sealing layer,
The light emitting device , wherein the third frame is in contact with the first frame . The second sealing layer is
a second lower sealing layer disposed in a region surrounded by the second frame;
a second upper sealing layer disposed in a region surrounded by the third frame and located on the second lower sealing layer;
The light emitting device of claim 1 . The light emitting device according to claim 2, wherein the second upper sealing layer includes a light diffusing material. The light-emitting device according to claim 3, wherein the first sealing layer includes a light diffusing material. The light-emitting device according to claim 4, wherein the second lower sealing layer is substantially free of a light diffusing material. The first sealing layer is
A first lower sealing layer located on the base body side;
a first upper encapsulation layer located on the first lower encapsulation layer;
Including,
The light emitting device according to claim 1 , wherein the first upper encapsulation layer includes a light diffusing material. The first frame is
an inner frame disposed on the base;
an outer frame body disposed on the inner frame body;
Including,
The light emitting device according to claim 6 , wherein the first lower sealing layer is disposed in a region surrounded by the inner frame. the first sealing layer includes a light diffusing material;
The light emitting device of claim 1 , wherein the second encapsulation layer includes a light-transmitting layer. The light emitting device according to claim 1 , wherein the third frame is spaced apart from the base. 10 . The light emitting device according to claim 1 , wherein an area where the lower surface of the second frame is in contact with the first sealing layer is larger than an area where the lower surface of the second frame is in contact with the first frame. The light-emitting device according to any one of claims 1 to 10, comprising a plurality of light sources arranged on the base. The light emitting device according to claim 11, wherein the light sources have different light emission colors.

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