Patent ID: 12237437

DETAILED DESCRIPTION OF THE EMBODIMENTS

To better and concisely explain the disclosure, the same name or the same reference number given or appeared in different paragraphs or figures along the specification should has the same or equivalent meanings while it is once defined anywhere of the disclosure.

FIG.1shows a light-emitting device1in accordance with a first embodiment of the present application.FIG.1Bshows a cross-sectional view taken along the A-A′ line inFIG.1.

The light-emitting device1includes a substrate10, a semiconductor stack12disposed on the substrate10, a transparent conductive layer18disposed on the semiconductor stack12, a first electrode20, a second electrode30, and a protective layer (not shown) covering the above layers and parts of the electrodes. The protective layer has openings exposing the other parts of the first electrode20and the second electrode30. As shown inFIG.1B, the substrate10includes a base10bhaving a main surface10uand a lower surface101, a plurality of side walls10slocated between the main surface10uand the lower surface101, and a plurality of protrusions P separately disposed on the main surface10u. In the present embodiment, the base10bincludes a plurality of mesas M on the side of the main surface10u, and the protrusions P are correspondingly disposed on the mesas M. In one embodiment, the main surface10uhas a concave-convex surface, and wherein the convex surface forms the surface of the mesa M.

The base10bcan be a growth substrate for growing semiconductor layers thereon. The material of the base10bincludes GaAs or GaP that are used for growing AlGaInP semiconductor thereon. The material of the base10bincludes sapphire, GaN, SiC or MN that are used for growing InGaN or AlGaN thereon.

The material of the protrusion P is selected from a material different from that of the base10b. In one embodiment, the protrusion P includes transparent material, such as silicon dioxide (SiO2), silicon nitride (SixNy). In one embodiment, the refractive index of the protrusion P is smaller than the refractive index of the base10b. The three-dimensional shape of the protrusion P can be a cone (such as a circular cone, a polygonal pyramid, or a truncated cone), a cylinder, or a hemisphere. The top of the mesa M is substantially flat, and the surface of the substrate10between the mesas M is substantially flat. In one embodiment, the surface of the substrate10between the mesas M is the c-plane of sapphire. In a top view, the shapes of the top and the bottom of the mesa M can be circular or polygonal. In the present embodiment, the top and bottom of the mesa M are both circular in a top view, and the protrusion P is circular cone.

In one embodiment, the light emitted from the semiconductor stack12irradiates on the main surface10uof the base10band is refracted and reflected by the protrusion P and/or the mesa M. The ratio of the light that are directly extracted from the lower surface101and the side wall10sof the substrate is reduced. More light can be extracted from the surface of the semiconductor stack, thereby reducing the divergence angle of the light-emitting device and increasing the brightness in a forward direction. In addition, the protrusion P and/or the mesa M lessens or suppress the dislocation due to lattice mismatch between the substrate10and the semiconductor stack12, thereby improving the epitaxial quality of the semiconductor stack12.

In an embodiment of the present application, the semiconductor stack12is formed on the substrate10by epitaxy such as metal-organic chemical vapor deposition (MOCVD), molecular beam epitaxy (MBE), hydride vapor epitaxy (HVPE) or physical vapor deposition such as sputtering or evaporating.

The semiconductor stack12includes a buffer layer125, a first semiconductor layer121, an active layer123, and a second semiconductor layer122sequentially formed on the substrate10. The buffer layer125is conformably formed on the protrusions P and the main surface10u. The thickness of the buffer layer125is greater than 5 nm. In one embodiment, the thickness of the buffer layer125is not greater than 50 nm. In another embodiment, the thickness of the buffer layer125is between 10 nm and 30 nm (both included). The buffer layer125reduces the lattice mismatch and suppresses dislocation so as to improve the epitaxial quality. The material of the buffer layer125includes GaN, AlGaN, or AlN. In an embodiment, the buffer layer125includes two sub-layers (not shown) and wherein a first sub-layer thereof is grown by sputtering and a second sub-layer thereof is grown by MOCVD. In another embodiment, the buffer layer125further includes a third sub-layer. The third sub-layer is grown by MOCVD, and the growth temperature of the second sub-layer is higher or lower than the growth temperature of the third sub-layer. In an embodiment, the first, second, and third sub-layers include the same material, such as AlN. In an embodiment, the first semiconductor layer121and the second semiconductor layer122are, for example, cladding layer or confinement layer. The first semiconductor layer121and the second semiconductor layer122have different conductivity types, different electrical properties, different polarities or different dopants for providing electrons or holes. For example, the first semiconductor layer121is an n-type semiconductor and the second semiconductor layer122is a p-type semiconductor. The active layer123is formed between the first semiconductor layer121and the second semiconductor layer122. Driven by a current, electrons and holes are combined in the active layer123to convert electrical energy into optical energy for illumination. The wavelength of the light generated by the light-emitting device1or the semiconductor stack12can be adjusted by changing the physical properties and chemical composition of one or more layers in the semiconductor stack12.

The material of the semiconductor stack12includes III-V semiconductor with AlxInyGa(1−x−y)N or AlxInyGa(1−x−y)P, where 0≤x, y≤1; x+y≤1. When the material of the active layer of the semiconductor stack12includes AlInGaP, it emits red light having a wavelength between 610 nm and 650 nm or yellow light having a wavelength between 550 nm and 570 nm. When the material of the active layer of the semiconductor stack12includes InGaN, it emits blue light or deep blue light having a wavelength between 400 nm and 490 nm or green light having a wavelength between 490 nm and 550 nm. When the material of the active layer of the semiconductor stack12includes AlGaN, it emits UV light having a wavelength between 250 nm and 400 nm. The active layer123can be a single hetero-structure (SH), a double hetero-structure (DH), a double-side double hetero-structure (DDH), or a multi-quantum well (MQW). The material of the active layer123can be i-type, p-type or n-type.

The semiconductor stack12includes a platform28. The platform28is formed by removing portions of the second semiconductor layer122and the active layer123from the upper surface of the semiconductor stack12to expose the upper surface121aof the first semiconductor layer121. In a cross-sectional view, the portion of the semiconductor stack12above the extending line L (and the extending surface) of the platform28is defined as an upper semiconductor portion12a, and the portion of the semiconductor stack12below the extending line L is defined as a lower semiconductor portion12b. The upper semiconductor portion12aincludes the second semiconductor layer122and the active layer123. In an embodiment, the upper semiconductor portion12afurther includes a portion of the first semiconductor layer121. The lower semiconductor portion12bincludes the buffer layer and the other portion of the first semiconductor layer121or the entire first semiconductor layer121.

The first electrode20is formed on the platform28and is electrically connected to the first semiconductor layer121. The second electrode30is formed on the second semiconductor layer122and is electrically connected to the second semiconductor layer122. In one embodiment, the first electrode20includes a first pad electrode201and a first finger electrode202extending from the first pad electrode201. The second electrode30includes a second pad electrode301and a second finger electrode302extending from the second disk electrode301. The first pad electrode201and the second pad electrode301are used for wire bonding or soldering, so that the light-emitting device1is electrically connected to an external power source or an external electronic component. In the embodiment shown inFIG.1, the substrate10includes a pair of short edges E1and E3and a pair of long edges E2and E4. The first pad electrode201and the second pad electrode301are respectively disposed adjacent to the two short edges E1and E3, and the first finger electrode202and the second finger electrode302extend to the opposite edges E3and E1, respectively. In another embodiment, the first electrode20does not have the first finger electrode201. In the present application, the configurations of the first electrode20and the second electrode30is not limited to that shown in this embodiment. In one embodiment, the second finger electrode302is disposed parallel to the first finger electrode202. In another embodiment, the first pad electrode201and/or the second pad electrode301are respectively disposed near two diagonal corners of the light-emitting device1.

The transparent conductive layer18is formed under the second electrode30, covers the upper surface122aof the second semiconductor layer122, and electrically contacts the second semiconductor layer122for laterally spreading current. The transparent conductive layer18can be metal or transparent conductive material. The metal can be a thin metal layer having light transparency. The transparent conductive material is transparent to the light emitted by the active layer123, such as zinc aluminum oxide (AZO), gallium zinc oxide (GZO), or indium zinc oxide (IZO). In one embodiment, the transparent conductive layer18has an opening180corresponding to the position of the second pad electrode301, so that the second pad electrode301contacts the second semiconductor layer122through the opening180.

In one embodiment, the light-emitting device1further includes a current blocking layer (not shown) between the transparent conductive layer18and the second semiconductor layer122, and/or between the first electrode20and the first semiconductor layer121.

As shown inFIG.1B, the lower semiconductor portion12bincludes a first side wall S1, and the upper semiconductor portion12aincludes a second side wall S2. An included angle θ1between the first side wall S1and the main surface10uof the base10bis an obtuse angle, and an included angle θ3between the first side wall S1and the upper surface121aof the first semiconductor layer is an acute angle. In one embodiment, θ1is between 100 degrees and 160 degrees, and θ3is between 20 degrees and 80 degrees. θ1and θ3are supplementary. In another embodiment, the first side wall S1has a rough surface, which can further improve light extraction of the light-emitting device1.

The main surface10uincludes a peripheral area10dthat is located on the periphery of the substrate10and is not covered by the semiconductor stack12. In a top view, the peripheral area10dsurrounds the semiconductor stack12.FIG.1Cshows a scanning electron microscope image (SEM) of the peripheral area10dand the semiconductor stack12adjacent to the peripheral area10dof the light-emitting device1. As shown inFIG.1BandFIG.1C, there are only mesas M in the peripheral area10d. No protrusions P are on the peripheral area10d. In one embodiment, the height of the mesa M in peripheral area10dis greater than the height of the mesa M under the semiconductor stack12(not shown). In one embodiment, the mesa M in the peripheral area10dand the mesa M under the semiconductor stack12have the same shape. In another embodiment, the mesa M in the peripheral area10dand the mesa M under the semiconductor stack12have different shapes.FIG.5Ashows a top schematic view of the mesa M under the semiconductor stack12andFIG.5Bshows a top schematic view of the mesa M in the peripheral area10d. As shown inFIG.5A, both the top M12and the bottom M11of the mesa M under the semiconductor stack12are circular. As shown inFIG.5B, the top M22of the mesa M in the peripheral area10dis circular, and the bottom M21is polygonal. In an embodiment, as shown inFIG.1C, there is a plurality of holes H between the first side wall S1and the main surface10u. The positions of the holes H correspond to the mesas M, and there are no protrusions P in the holes H.

FIGS.2A and2Bare partial cross-sectional views of a light-emitting device2in accordance with a second embodiment of the present application. The structure of the light-emitting device2is similar to that of the light-emitting device1. The difference is that the first side wall S1of the lower semiconductor portion12bin the light-emitting device2includes a plurality of sub-side walls, such as the first sub-side wall S11and the second sub-side wall S12. As shown inFIG.2AandFIG.2B, the first sub-side wall S11is connected to the second sub-side wall S12, and the included angle (not labeled) between the first sub-side wall S11and the second sub-side wall S12is 100-175 degrees. The included angle θ1between the second sub-side wall S12and the main surface10uof the base10bis an obtuse angle. As shown inFIG.2A, the included angle θ3between the first sub-side wall S11and the upper surface121aof the first semiconductor layer121is 80-100 degrees. In one embodiment, the included angle θ3is substantially a right angle. As shown in another embodiment ofFIG.2B, the included angle θ3is an acute angle.

FIG.3is a cross-sectional view of a light-emitting device3in accordance with a third embodiment of the present application. The structure of the light-emitting device3is similar to that of the light-emitting device1, and the main difference is that the main surface10uof the base10bin the light-emitting device3is a plane without mesas M located thereon. The plurality of protrusions P is separately disposed on the main surface10u. The peripheral area10dof the light-emitting device3is a flat plane which is devoid of the protrusions P formed thereon.

FIG.4is a cross-sectional view of a light-emitting device4in accordance with a fourth embodiment of the present application. The structure of the light-emitting device4is similar to that of the light-emitting device1, and the main difference is that the side wall10sof the base10bin the light-emitting device4has a rough region Tx. The rough region Tx is adjacent to the main surface10uand connected to the main surface10u. The surface roughness of the rough region Tx is greater than that of the region other than the rough region Tx on the side wall10s.

A light-emitting device (not shown) in another embodiment of the present application has a structure similar to that of the light-emitting device1, and the main difference is that the peripheral area10dis devoid of protrusion P and mesas M thereon.

It will be apparent to those having ordinary skill in the art that various modifications and variations can be made to the light-emitting devices in accordance with the present embodiments without departing from the scope or spirit of the application. For example, the side wall10sof the light-emitting device3in the third embodiment may include the rough region Tx as described in the fourth embodiment. For example, the first side walls S1of the light-emitting device3in the third embodiment and of the light-emitting device4in the fourth embodiment may include the plurality of sub-walls as described in the second embodiment.

FIG.6shows a light-emitting device6in accordance with a comparative example.FIG.7shows an experimental comparison between the light-emitting device1of the first embodiment and the light-emitting device6of the comparative example. Referring toFIG.6, the light-emitting device6of the comparative example has a similar structure to that of the light-emitting device1, and the main difference is that the base10b′ of the light-emitting device6is devoid of mesas M thereon, the protrusion P′ of the substrate10′ has the same material as the base10b′, and the protrusion P′ are on the peripheral area10dof the light-emitting device6. The total size (i.e. the total height and the total width) of one mesa M and one protrusion P above it in the light-emitting device1is the same as the size of one protrusion P′ in the light-emitting device6, and the shapes and distributions are the same. The base10bof the light-emitting device1and the base10b′ of the light-emitting device6are made of the same material. As shown inFIG.7, compared with the light-emitting device6of the comparative example, the light-emitting device1in accordance with the first embodiment has 1.56% improvement in optical output power and a smaller divergence angle. Furthermore, compared with the light-emitting device6of the comparative example, the light emitted by the light-emitting device1in the first embodiment in the forward direction (the normal direction of the main surface10uof the base10b, that is, Z-axial direction inFIGS.1A and1B) is more concentrated and the light-emitting device1has higher brightness in the forward direction.FIGS.8A and8Bshow the light distribution curves of the light-emitting device1of the first embodiment and the light-emitting device6of the comparative example along different axels. To be more specific,FIG.8Ashows the light distribution curves of the two light-emitting devices1and6measured in the Y-axis direction from 0 to 180 degrees;FIG.8Bshows the light distribution curves of the two light-emitting devices1and6in the X-axis direction from 0 to 180 degrees. The 90 degrees labeled in the coordinates in the two figures is the positive Z-axis direction inFIG.1A. As shown inFIGS.8A and8B, compared with the comparative example, the light-emitting device1has a higher light intensity near 90 degrees, which means that the light-emitting device1has a higher light intensity in the forward direction. In one embodiment, the divergence angle of the light-emitting device1measured along one axial direction is less than or equal to 130 degrees.

FIGS.9A-9Eshow a manufacturing method of the light emitting device1in accordance with an embodiment of the present application. First, as shown inFIG.9A, the semiconductor stack12is formed on the substrate10to form a wafer. The substrate10includes the base10b, the mesas M, and the protrusions P and the semiconductor stack12covers the protrusions P and the main surface10u. Next, a part of the semiconductor stack12is removed to expose the upper surface121aof the first semiconductor layer121, and the platform28is formed. In a cross-sectional view, the portion of the semiconductor stack12above the extension line L (and the extension surface) of the platform region28is defined as the upper semiconductor portion12a, and the other portion of the semiconductor stack12under the extension line L (and the extension surface) of the platform region28is defined as the lower semiconductor portion12b.

Next, as shown inFIG.9B, a protective layer8is formed on the semiconductor stack12and the platform28. In one embodiment, the thickness of the protective layer8is 500 Å-5000 Å, and the material of the protective layer8can be selected from silicon oxide, silicon nitride, or a combination thereof. The protective layer8can be formed by a chemical vapor deposition (CVD), atomic layer deposition (ALD), or spin-coating.

Next, as shown inFIG.9C, scribing lines13is formed. In one embodiment, as shown inFIG.9C, a laser17is irradiated from the upper surface of the protective layer8. The laser17cuts the semiconductor stack12from the upper surface of the protective layer8down to a depth of the lower semiconductor portion12b; for example, to a surface of the buffer layer125or to a depth into the buffer layer125, to form the scribing lines13. In another embodiments, the laser17cuts the semiconductor stack12from the upper surface of the protective layer8down to a depth into the protrusion P, to a depth into the mesa M, or to the main surface10uof the substrate, to form the scribing lines13. At the same time, the scribing line13defines a plurality of light-emitting devices1on the wafer. That is, the scribing lines13define the periphery of each light-emitting device1. In another embodiment, the laser17cuts the semiconductor stack12from the upper surface of the protective layer8down to a depth into the base10bto form a rough region (not shown) inside the base10b. After individual light-emitting device1is formed, the rough region Tx as shown inFIG.4is correspondingly formed on the side wall10sof the base10b.

In another embodiment, the scribing line13is formed by etching (not shown). A dry etching such as inductively coupled plasma (ICP) etching is performed on the upper surface of the protective layer8to etch the lower semiconductor portion12bdown to a depth of the lower semiconductor portion12b, to a depth into the protrusion P, or to a depth to the main surface10uof the substrate, to form the scribing line13.

Next, as shown inFIG.9D, parts of the lower semiconductor stack12b, parts of the protrusions P and the protective layer8are removed. The steps of removing the parts of the lower semiconductor stack12b, the parts of the protrusions P, and the protective layer8can be completed in the same step or in different steps. The steps of removing the parts of the lower semiconductor stack12b, the parts of the protrusions P, and the protective layer8can be performed by the same method or by different methods. In one embodiment, removing the parts of the lower semiconductor stack12bis by an etching step. In one embodiment, wet etching is applied to remove the parts of the lower semiconductor portion12bin the gaps formed by the scribing lines13to form the first side wall S1. After the first sidewall S1of each light-emitting device1is formed, the substrate10exposed between adjacent light-emitting devices1forms the peripheral area10d. In one embodiment, after the first sidewall S1of each light-emitting device1is formed, a portion of the upper surface of the lower semiconductor portion12bthat is not removed between adjacent light-emitting devices1forms the peripheral area10d. In one embodiment, the etchant can be selected from H2SO4, H3PO4, HCl, HF or a combination thereof. In another embodiment, after the first sidewall S1is formed, a roughening step can be performed on the first sidewall S1. For example, the first side wall S1is etched by KOH to form a rough structure (not shown) thereon. The angle between the first side wall S1and the main surface10ucan be controlled by the composition of the etchant, the etching time, and the etching temperature. In addition, by adjusting the depth of the scribing line13and different etching conditions, a plurality of sub-side walls as shown inFIGS.2A and2Bcan be formed. In one embodiment, the protective layer8can be removed in the etching process that removes the portion of the lower semiconductor portion12b. In one embodiment, the protrusions P on the peripheral area10dcan be removed in the etching process that removes the portion of the lower semiconductor portion12b.

In another embodiment, removing the protective layer8and removing the portion of the lower semiconductor portion12bare performed in different steps. In one embodiment, the protective layer8is removed by a first etchant, and the portion of the lower semiconductor portion12bis removed to form the first sidewall S1by a second etchant. The composition of the first etchant is different from the composition of a second etchant. In one embodiment, removing the protrusions P on the peripheral area10dand removing the portion of the semiconductor stack12are performed in different steps. In one embodiment, removing the protrusions P on the peripheral area10dand removing the protective layer8are performed in different steps. In another embodiment, removing the protrusions P on the peripheral area10dand removing the protective layer8are performed in the same step. That is, during the step while removing the protective layer8, the protrusions P on the peripheral area10dare also removed. As shown inFIG.9D, the mesas M are located on the peripheral area10dbetween adjacent light-emitting devices, but the peripheral area10dis devoid of the protrusions P formed thereon.

In another embodiment, the step of removing the protrusion P on the peripheral area10dmay be affected by factors such as the etchant and/or etching conditions thereof, so that the protrusions P on the peripheral area10dare not completely removed and left on the peripheral area10d. The protrusions P left on the peripheral area10dhave smaller width, smaller height, a deformed appearance or a reduced size compared with the protrusions P under the semiconductor stack12. For example, the protrusions P on one part of the mesas M are removed, while the protrusions P on the other part of the mesas M are left. For example, in the embodiment shown inFIG.3that the base10bwhich main surface10uis substantially flat without the mesas M, the protrusions P on one part of the peripheral area10dis removed, and the protrusions P on the other part of the peripheral area10dare left, or both the mesas M and the protrusions P on the other part of the peripheral area10dare left. In the above-mentioned situations, it can be considered that the peripheral area10dis substantially devoid of the protrusions P formed thereon in the individual light-emitting device.

In one embodiment, the height of the mesas M on the peripheral area10dis greater than the height of the mesas M under the semiconductor stack12. In one embodiment, the mesas M on the peripheral area10dand the mesas M under the semiconductor stack12have the same shape. For example, in a top view, the top and bottom of the mesas M under the semiconductor stack12are circular, and both the top and bottom of the mesas M on the peripheral area10dare circular. In another embodiment, the mesas M on the peripheral area10dand the mesas M under the semiconductor stack12have different shapes. For example, in a top view, the top and bottom of the mesas M under the semiconductor stack12are circular, while the top of the mesas M on the peripheral area10dare circular and the bottom of the mesas M on the peripheral area10dare polygonal, or both the top and bottom of the mesas M on the peripheral area10dare polygonal.

Finally, as shown inFIG.9E, the transparent conductive layer18, the first electrode (represented by the first pad electrode201) and the second electrode (represented by the second pad electrode301) are formed. Then, the wafer is divided into a plurality of light-emitting devices1along the peripheral area10d, that is, along the periphery of the light-emitting devices1. In an embodiment, the lower surface101of the base10bis irradiated with a laser27. The laser27is focused on the interior of the base10bthereby forming modification regions inside the base10b. Cracks are formed along the crystal plane of the base10bfrom the modification regions. Then the plurality of light-emitting devices1is separated with each other along the cracks. The modification regions form the rough regions Tx′ on the side wall10sof the bases10bof each individual light-emitting device1.

FIG.10Ashows a side view of a light-emitting package7in accordance with an embodiment of the present application.FIG.10Bis a cross-sectional view taken along the A-A′ line inFIG.10A.

The light-emitting package7includes a housing16having an opening160, and a pair of lead frames50aand50bis separately disposed in and covered by the housing16, corresponding to the opening160and connected to the housing16. The light-emitting device1is mounted in the opening160and electrically connected to the lead frames50aand50bby wires14. In one embodiment, a filling material such as resin is filled in the opening160and covers the light-emitting device1. The filling material23includes scattering materials (not shown) and/or wavelength converting material such as phosphor. In addition, the lead frames50aand50bextend out of the housing16to be electrically connected to an external power or an external electronic component. The extending lead frames50aand50bmay have various shapes and be bent into various shapes. In one embodiment, as shown inFIGS.10A and10B, the lead frames50aand50bextend out of the housing16and are bent along side surfaces of the housing16, and are mounted on a carrier22. The light-emitting package7is applied to an edge-lit backlight source.

The opening160of the light-emitting package7has an elongated shape and the light-emitting device with a rectangular shape is installed therein. In one embodiment, the light-emitting device1has an aspect ratio (that is, E2to E1) is about 5 to 1. The long-axis direction (X-axis direction) of the opening160is consistent with the long-axis direction of the light-emitting device1. The side wall160aof the opening160can be an inclined surface to reflect the light emitted by the light-emitting device1and thereby increasing the light extraction of the light-emitting package7. The elongated shape light-emitting package7incorporated with the rectangular shaped light-emitting device1is suitable for an edge-lit backlight module. In the light-emitting package7, the distance D2between the light-emitting device1and the side wall160ain the Y-axis direction is smaller than the distance D1between the light-emitting device1and the side wall160ain the X-axis direction. As the tendency of slim edge-lit backlight module rises, the width of the light-emitting package in the Y-axis direction is designed to be smaller. Similarly, the distance D2between the light-emitting device1and the side wall160ain the Y-axis direction is designed to be smaller. If the distance D2between the light-emitting device1and the side wall160ain the Y-axis direction is smaller, the lateral light emitted by the light-emitting device1is more likely absorbed by the side wall160a, so that the brightness of the light-emitting package7decreases. In the experimental comparison as described above, the light-emitting device1in accordance with the embodiment of the present application has a higher light intensity in the forward direction, that is, the light extraction in the forward direction is higher than in the lateral direction. In the embodiment that the light-emitting package7incorporated with the light-emitting device1, because the light extraction in the lateral direction of the light-emitting device1is relatively low, the possibility of the lateral light of the light-emitting device1being absorbed by the side wall160acan be reduced, thereby improving the brightness of the light-emitting package7. In another experimental comparison, compared with the light-emitting package7incorporated with the light-emitting device6in accordance with the comparative example, the light-emitting package7incorporated with the light-emitting device1in accordance with the embodiment of the present application has 2.5%-3% improvement in brightness.

The aspect ratio of the light-emitting device1or the light-emitting devices in the aforementioned embodiments can be adjusted in accordance with the design of the light-emitting package. The light-emitting devices described in the aforementioned embodiments are applicable to the light-emitting package which has a smaller width in the Y-axial direction than in the X-axis direction. In one embodiment, the light-emitting device which has the aspect ratio of greater than or equal to 2 to 1 is suitable for the light-emitting package.

FIG.11shows a schematic diagram of a display device. The display device includes a frame40, an edge-lit backlight module100, and a liquid crystal panel90. The edge-lit backlight module100includes a reflector80, a light guide plate70, a carrier22, the light-emitting package7, and an optical film46. A plurality of light-emitting package7and a circuit (not shown) are disposed on the carrier22, and the circuit is used to control the light-emitting package7. The light-emitting package7disposed on the carrier22is located at the lateral side of the light guide plate70. The light-emitting package7emits light R and the light R enters the light guide plate70from the lateral side of the light guide plate70. The light guide plate70changes or guides the direction of light R toward the optical film46(e.g., light diffuser film) and the liquid crystal panel90, and provides a backlight source for the liquid crystal panel90above it. As shown inFIG.11, the light-emitting package7and the light-emitting device which emit the light R with a higher intensity in the Z-axis direction make the edge-lit backlight module100use the light source more effectively.

It will be apparent to those having ordinary skill in the art that various modifications and variations can be made to the devices in accordance with the present disclosure without departing from the scope or spirit of the disclosure. In view of the foregoing, it is intended that the present disclosure covers modifications and variations of this disclosure provided they fall within the scope of the following claims and their equivalents.