US20170345983A1 - Light-emitting device and light-emitting apparatus comprising the same - Google Patents

Abstract

The present application discloses a light-emitting device comprising a light-emitting unit and a flexible carrier supporting the light-emitting unit. The light-emitting unit comprises a LED chip, a first reflective layer on the LED chip and an optical diffusion layer formed between the first reflective layer and the LED chip.

Description

BACKGROUNDTechnical Field
• The present disclosure relates to a light-emitting device having multiple LED units formed on a substrate and a light-emitting apparatus comprising a light-emitting device.
Description of the Related Art
• Light-emitting diode (LED) is more sustainable, longevous, light and handy, and less power consuming, and therefore it is considered as a new light source for illumination. LED applies to various applications like the traffic signal, backlight module, street light, and medical instruments, and becomes a major lighting source. When LED applies to indoor lighting, efforts are required to reduce the dimension, such as thickness, and the increase of the light field of LED.
SUMMARY
• One aspect of the present application discloses a light-emitting device comprising a light-emitting unit and a flexible carrier supporting the light-emitting unit. The light-emitting unit comprises a LED chip, a first reflective layer on the LED chip and an optical diffusion layer formed between the first reflective layer and the LED chip.
• Another aspect of the present application discloses a light-emitting apparatus comprising a frame, a flexible carrier and a light-emitting unit on the flexible carrier. The flexible carrier has a first end and a second end connected to the frame. The light-emitting unit comprises a LED chip, a reflective layer between the LED chip and the frame and an optical diffusion layer formed on the LED chip.
• Another aspect of the present application discloses a light-emitting apparatus comprising a light guide, a light-emitting unit, a cover formed on the light-emitting unit and a flexible carrier connected to the light-emitting unit. The light guide has a top surface, a bottom surface opposite to the top surface and a lateral surface connecting the top surface and the bottom surface. The light-emitting unit comprises a LED chip, a reflective layer on the LED chip, and an optical diffusion layer formed between the reflective layer and the LED chip. The cover is connected to the light guide.
BRIEF DESCRIPTION OF DRAWINGS
• FIG. 1A shows a first embodiment of a light-emitting device in accordance with this disclosure.
• FIG. 1B shows a first embodiment of a light-emitting unit included in a light-emitting device in accordance with this disclosure.
• FIG. 1C shows a light field pattern of the light-emitting unit ofFIG. 1B.
• FIG. 1D shows a luminous intensity distribution curve of the light-emitting unit ofFIG. 1B.
• FIG. 1E shows a schematic view of the light-emitting device ofFIG. 1A in a bent situation.
• FIG. 2A shows a top view of a first example of the light-emitting device ofFIG. 1A.
• FIG. 2B shows a top view of a second example of the light-emitting device ofFIG. 1A.
• FIG. 2C shows a top view of a third example of the light-emitting device ofFIG. 1A.
• FIG. 2D shows a top view of a fourth example of the light-emitting device ofFIG. 1A.
• FIG. 3A-1 shows a top view of a first embodiment of a series of light-emitting devices in accordance with this disclosure.
• FIG. 3A-2 shows a lateral view of the series of light-emitting devices ofFIG. 3A-1.
• FIG. 3B shows a lateral view of a second embodiment of a series of light-emitting devices in accordance with this disclosure.
• FIG. 3C shows a lateral view of a third embodiment of a series of light-emitting devices in accordance with this disclosure.
• FIG. 4A shows a second embodiment of a light-emitting device in accordance with this disclosure.
• FIG. 4B shows a first embodiment of a light-emitting apparatus having the light-emitting device ofFIG. 4A.
• FIG. 5A shows a third embodiment of a light-emitting device in accordance with this disclosure.
• FIG. 5B shows the connectors ofFIG. 5A.
• FIG. 6A shows a fourth embodiment of a light-emitting device in accordance with this disclosure.
• FIG. 6B shows a second embodiment of a light-emitting unit included in a light-emitting device in accordance with the disclosure.
• FIG. 7 shows a third embodiment of a light-emitting unit included in a light-emitting device in accordance with this disclosure.
• FIGS. 8A-8D show a method of manufacturing a light-emitting device in accordance with this disclosure.
• FIG. 9A shows a second embodiment of a light-emitting apparatus having a light-emitting device in accordance with this disclosure.
• FIG. 9B shows a lateral view of the light-emitting apparatus depicted inFIG. 9A.
• FIG. 10A shows a third embodiment of a light-emitting apparatus having a light-emitting device in accordance with this disclosure.
• FIG. 10B shows a lateral view of the light-emitting apparatus inFIG. 10A.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
• Reference is made in detail to the preferred embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts.
• 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. 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.
• FIG. 1A shows a first embodiment of a light-emittingdevice1000 in accordance with this disclosure. The light-emittingdevice1000 has anupper surface106, aside surface108, multiple light-emittingunits20 formed on afirst surface102 of acarrier10, anadhesive layer18 formed on the second surface104, and acover12 covering the multiple light-emittingunits20 and thecarrier10. The top-view shape of the light-emittingdevice1000 can be elongated, such as a rectangular shape with a ratio of a length to a width of the light-emittingdevice1000 greater than 1.1, for example, a size of 300 mm*400 mm. The multiple light-emittingunits20 are separated from each other on thecarrier10. To be more specific, a distance between two light-emittingunits20 is less than 10 mm, and preferably, the distance is between 3 mm and 10 mm. The light-emittingunits20 are arranged in a 2-dimensional array. The thickness of the light-emittingdevice1000 except theadhesive layer18 is less than 7 mm. Preferably, the thickness of the light-emitting device except theadhesive layer18 is between 1 mm and 7 mm. The light-emittingdevice1000 can be used as a planar light-emitting device, such as a troffer or a backlight source of an LCD display. The multiple light-emittingunits20 are electrically connected to each other by a wiring pattern on thefirst surface102. The wiring pattern is further electrically connected to an external power source. In another embodiment, the wiring pattern is formed on thesecond surface104 and connected to thefirst surface102 of the carrier through metal plugs penetrating thecarrier10 to electrically connect to the multiple light-emittingunits20 on thefirst surface102. In an embodiment, thecover12 and thecarrier10 are both flexible such that the light-emittingdevice1000 is flexible. Theadhesive layer18 has an adhesive outer surface for easily attaching the light-emittingdevice1000 to other parts. In another embodiment, theadhesive layer18 can be omitted from the light-emittingdevice1000. It is noted that the light-emittingdevice1000 includes light-emittingunits20 which can be replaced by the light-emitting unit disclosed in the following embodiments in accordance with the present disclosure.
• Referring toFIG. 1A, a normal line L1 denotes a line normal to a top surface of one light-emittingunit20 passes through the geometric center GC of the light-emittingunit20. The light emitted from the light-emittingdevice1000 travels in various directions. For example, the light beam L2 travels in a direction from thecarrier10 to thecover12 and passes theupper surface106, and the light beam L3 travels in a direction from thecarrier10 to thecover12 and passes theside surface108.
• When measuring the optical property, such as light-emitting efficiency, color temperature, CRI, illumination uniformity, unified glare rating (UGR) or light intensity, of the light-emittingdevice1000 at a measuring point MP, an offset angle9 is formed between the normal line L1 and a virtual line VL connecting the geometric center GC of the light-emittingunit20 to the measuring point MP. The illumination uniformity of the light-emitting device is measured at a specific measuring point MP having an offset angle θ is defined by dividing an average light intensity with the maximum light intensity measured at an area with respect to the measuring point MP. The measuring area locates at a virtual plane being parallel to thefirst surface102 of the carrier. That is, the normal line L1 is perpendicular to thefirst surface102 and the virtual plane where the measuring area locates. Moreover, the “measuring point” represents the geometric central point of the measuring area, and the maximum light intensity and the average light intensity respectively represent the maximum value and the average value of the light intensity within the measuring area. The light-emittingdevice1000 has a light-emitting efficiency larger than 80 lm/W while emitting white light of a color temperature between 3000K and 8000K. For example, the light-emittingdevice1000 has a light-emitting efficiency about 136 lm/W with a color temperature of 3000K. The CRI of the light-emittingdevice1000 is larger than 80. The UGR of the light-emittingdevice1000 is larger than 19. The illumination uniformity of the light-emittingdevice1000 measured at the measuring point MP having an offset angle θ between 0° and 90° is larger than or equal to 80%.For example, the illumination uniformity measured at a measuring point MP with an offset angle θ of 30° is larger than 85.1%. The area is larger than 1 mm2 and less than 250000 mm2. Preferably, the area is between 10000 mm2 and 240000 mm2. Besides the light-emittingdevice1000 has an illumination uniformity larger than 91.2% at the measuring point having an offset angle θ of 0°, larger than 82.5% at the measuring point having an offset angle θ of 60° and larger than 80.1% at the measuring point having an offset angle θ of 90°. It is noted, the measuring point having an offset angle θ of 0° locates directly above thecover12 and can be passed by the normal line L1. Generally, the illumination uniformity measured at a measuring point with an offset angle θ between 30° and 90° is larger than 80%.FIG. 1B shows a first embodiment of a light-emitting unit included in a light-emitting device in accordance with this disclosure. The light-emittingunit20 has anLED chip2, awavelength conversion layer4, anoptical diffusion layer6 and areflective layer8 sequentially stacked on the top surface of theLED chip2. Thewavelength conversion layer4 covers a top surface and a lateral surface of theLED chip2 without covering the bottom surface of theLED chip2. Thewavelength conversion layer4 is directly connected to theLED chip2. Theoptical diffusion layer6 is formed on thewavelength conversion layer4 and covers only the top surface of theLED chip2. Thereflective layer8 is formed on theoptical diffusion layer6 and covers only the top surface of theLED chip2. Theoptical diffusion layer6 and thereflective layer8 are not directly connected to theLED chip2. The side surfaces of thewavelength conversion layer4, theoptical diffusion layer6 and thereflective layer8 are substantially coplanar with each other. In other words, the side surfaces of thewavelength conversion layer4, theoptical diffusion layer6 and thereflective layer8 form the side surfaces of the light-emittingunit20. In another embodiment, the light-emittingunit20 has two ormore LED chips2, such as a blue LED chip and a red LED chip or two blue LED chips. The light-emittingunit20 has afirst bonding pad202 and asecond bonding pad204 on the bottom surface, and connected to theLED chip2. Light emitted from theLED chip2 are reflected by thereflective layer8 toward the lateral surface of the light-emittingunit20.FIG. 1C shows a light field pattern of the light-emittingunit20 ofFIG. 1B. To be more specific, the light intensity around the top region of the light-emittingunit20, e.g. between 30 and 330 degree inFIG. 1C, is lower than that around the lateral region of the light-emittingunit20, e.g. 270˜330 degree or 30˜90 degree inFIG. 1C. The light intensity around the lateral region is at least 10% higher than that around the top region of the light-emittingunit20. The light-emittingunit20 disclosed herein can be applied to and included in the light-emitting device or the light-emitting apparatus disclosed in the foregoing or following embodiments in accordance with the present disclosure.
• FIG. 1D shows a luminous intensity distribution curve of the light-emittingunit20 ofFIG. 1B. Referring toFIG. 1D, the view angle of the light-emittingunit20 is about 166°. Preferably, the light-emitting unit is designed to have a view angle larger than 140°. The view angle represents a widest range confined by two boundary angles each having a light intensity at least 50% of the maximum light intensity among the emitting spectrum of the light-emittingunit20. For example, when the light-emittingunit20 has light intensities at the angle of 10° and 210° both greater than or equal to 50% of the maximum light intensity, the light-emittingunit20 has the two boundary angles of being 10° and 210° and has a view angle of being 200°. TheLED chip2 comprises a semiconductor stack with an active layer for emitting an incoherent light, such as a red light, a blue light, or a green light depending on the material of the active layer. Thewavelength conversion layer4 on theLED chip2 has one or more phosphor materials, and the one or more phosphor materials are stimulated by a first light beam from theLED chip2 and emit a second light beam with a color different from that of the first light beam. The one or more phosphor materials include, but not limited to, yellow-greenish phosphor or red phosphor. The yellow-greenish phosphor includes aluminum oxide (such as YAG or TAG), silicate, vanadate, alkaline-earth metal selenide, or metal nitride. The red phosphor includes silicate, vanadate, alkaline-earth metal sulfide, oxynitride, fluoride (K₂TiF₆:Mn⁴⁺,K₂SiF₆:Mn⁴⁺), or a mixture of tungstate and molybdate.
• TheLED chip2 has a first conductivity-type semiconductor layer, a second conductivity-type semiconductor layer, and an active layer between the first conductivity-type semiconductor layer and the second conductivity-type semiconductor layer. The first conductivity-type semiconductor layer and the second conductivity-type semiconductor layer each perform as a cladding layer or a confinement layer for respectively providing electrons and holes to be combined in the active layer and emit light accordingly. The first conductivity-type semiconductor layer, the active layer, and the second conductivity-type semiconductor layer include group III-V semiconductor material, such as Al_xIn_yGa_(1−x−y)N or Al_xIn_yGa_(1−x−y)P, wherein 0≦x, y≦1; (x+y)≦1. Based on the material of the active layer, theLED chip2 can emit a red light with a peak wavelength between 610 nm and 650 nm, a green light with a peak wavelength between 530 nm and 570 nm, or a blue light with a peak wavelength between 450 nm and 490 nm.
• Theoptical diffusion layer6 and thecover12 are transparent to the light emitted from theLED chip2. The composition of theoptical diffusion layer6 is similar to that of thecover12. Theoptical layer6 or thecover12 has a transparency larger than 60% and includes a matrix. The matrix comprises a material having refractive index of 1.4˜1.6, such as polymer or oxide. The polymer includes silicone, epoxy, PI, BCB, PFCB, SU8, acrylic resin, PMMA, PET, PC, polyetherimide, or fluorocarbon. The oxide includes Al₂O₃, SINR, SU8, or SOG. In another embodiment, theoptical layer6 or thecover12 further comprises a plurality of refractive particles (not shown) dispersed in the matrix. The refractive particles have a refractive index higher than that of the matrix, such as titanium dioxide, silicon dioxide, aluminum oxide, zinc oxide, or zirconium dioxide. Thebonding pad202 and thesecond bonding pad204 include metal or metal alloy, such as Cu, Ti, Au, Ni or combinations thereof.
• Thereflective layer8 can be a DBR (Distributed Bragg Reflector) layer or a metal reflective layer. In another embodiment, theoptical diffusion layer6 can be omitted from the light-emittingunit20, and thereflective layer8 directly contacts thewavelength conversion layer4.
• Thecarrier10 can be flexible and is transparent to the light emitted from the light-emittingelement20. For example, thecarrier10 has a transparency larger than 90% corresponded to a light from theLED chip2. Preferably, the transparency of the carrier is larger than 92% with respect to a light having a peak wavelength of 550 nm. The carrier can be formed of PET, PI(polyimide), HPVDF(hyper-polyvinylidene fluoride), or ETFE (ethylene-tetrafluoro ethylene). Preferably, the carrier has a transparency between 92%˜100% with respect to the light from the light-emitting unit, and the carrier is fully cured at a curing temperature between 160° C.˜200° C. to resist diverse environment during operation. Preferrably, thecarrier10 has a transparency larger than 90% and a glass transition temperature larger than 160° C. In one embodiment, thecarrier10 is formed of HPVDF and particles having a particle size around 1100 nm for adjusting the transparency of the carrier. Preferably, the particle size of one particle is less than 50 nm.
• FIG. 1E shows a schematic view of the light-emittingdevice1000 ofFIG. 1A in a bent situation. Thecarrier10 is flexible, and the surface of thecarrier10 can be bent to be a curve having various concaves and protrusions (such as having different sizes, radius or depth) as shown inFIG. 1E. Moreover, the surfaces of thecarrier10 and theadhesive layer18 parallel to theupper surface106 are bent to be a curved surface. Though thecarrier10 is bent, the light-emittingunits20 are tightly connected to thecarrier10 by having thecover12 tightly connecting to the carrier. Moreover, the optical property, such as light-emitting efficiency, color temperature, CRI, illumination uniformity, unified glare rating (UGR) or light intensity, measured from the bent light-emittingdevice1000 inFIG. 1E are similar to those measured from the unbent light-emitting device inFIG. 1A. That is, the variation of the optical properties are not perceptive whether the light-emittingdevice1000 is bent or not, therefore the light-emittingdevice1000 can be applied to specific applications, such as high resolution display, medical surgery and wearable device.
• FIG. 2A shows a top view of a first example of the light-emittingdevice1000 ofFIG. 1A. Referring toFIG. 2A, the difference between the light-emittingdevice1000 ofFIG. 1A and the light-emittingdevice1000A of the present embodiment is that the light-emittingdevice1000A further comprises afirst wiring pattern160A, asecond wiring pattern160B, a first string S1 having three light-emittingunits20 connected in series and a second string S2 having two light-emittingunits20 connected in series on thecarrier10A, afirst metal pad140A on thecarrier10A, and asecond metal pad140B on thecarrier10A wherein each of thefirst metal pad140A and thesecond metal pad140B has a metal plug penetrating thecarrier10A. The light-emittingunits20 and thewiring patterns160A and160B are covered by thecover12 as shown inFIG. 1A while themetal pads140A and140B are not covered by thecover12. Thefirst wiring pattern160A is directly connected to thefirst metal pad140A and thesecond wiring pattern160B is directly connected to asecond metal pad140B. The arrangement offirst wiring pattern160A is different from that of thesecond wiring pattern160B, such as the layout and their positions in the light-emittingdevice1000A. In another embodiment, thefirst wiring pattern160A has a spring shape or a wave shape to improve the mechanical strength and prevent the wiring patterns from being broken when the light-emitting device is bent. The first string S1 and the second string S2 are electrically connected in parallel.
• FIG. 2B shows a top view of a second example of the light-emittingdevice1000 ofFIG. 1A. Referring toFIG. 2B, the difference between the light-emittingdevice1000 ofFIG. 1A and the light-emittingdevice1000B of the present embodiment is that the light-emittingdevice1000B further comprises athird wiring pattern162A, afourth wiring pattern162B, a first string S3 having one light-emittingunits20 and a fourth string S4 having four light-emittingunits20 electrically connected in parallel on thecarrier10B, athird metal pad142A on thecarrier10B, and afourth metal pad142B on thecarrier10B wherein each of thethird metal pad142A and thefourth metal pad142B has a metal plug penetrating thecarrier10B. The light-emittingunits20 and thewiring patterns162A and162B are covered by thecover12 as shown inFIG. 1A while themetal pads142A and142B are not covered by thecover12. Thethird wiring pattern162A is directly connected to thethird metal pad142A and thefourth wiring pattern162B is directly connected to thefourth metal pad142B. The light-emittingunits20 in the strings S1-S4 are electrically connected in parallel or in series depending on the application thereto. Similarly, the connections between the strings S1-S4 in light-emittingdevice1000A or in light-emittingdevice1000B can be modified for different applications.
• FIG. 2C shows a top view of a third example of the light-emittingdevice1000 ofFIG. 1A. The difference between the light-emittingdevice1000 ofFIG. 1A and the light-emittingdevice1000C of the present embodiment is that the light-emittingdevice1000C further comprises anelectrical power source22, afirst wiring pattern164A, asecond wiring pattern164B formed on the top surface of thecarrier10D, afifth metal pad144A on thecarrier10D, and asixth metal pad144B on thecarrier10D wherein each of thefifth metal pad144A and the sixth metal pad146B has a metal plug penetrating thecarrier10D. The light-emittingunits20 and thewiring patterns164A and164B are covered by thecover12 as shown inFIG. 1A while themetal pads144A and144B and thepower source22 are not covered by thecover12. Theelectrical power source22 is electrically connected to the light-emittingunits20 and thewiring patterns164A and164B. The light-emittingdevice1000C further includes other electrical elements (not shown in the figure), such as capacitor, inductor or resistor etc. for protecting or rectifying purpose. Theelectrical power source22 can be a battery or a photovoltaic cell to provide electrical power. In another embodiment, the wiring pattern can be formed on top and bottom surfaces of the carrier such that the light-emittingunits20 are only formed on one side of thecarrier10D and the electrical elements are only formed on the other side of thecarrier10D.FIG. 2D shows a top view of a fourth example of the light-emittingdevice1000 ofFIG. 1A. The light-emittingdevice1000A′ inFIG. 2D has a similar structure compared with the light-emittingdevice1000A inFIG. 2A. The difference is that the light-emittingdevice1000A′ further comprises aseventh metal pad140A′ formed on the opposite end of thefirst wiring pattern160A with respect to thefirst metal pad140A and aneighth metal pad140B′ formed on the opposite end of thesecond wiring pattern160B with respect to thesecond metal pad140B. Therefore, one metal pad (e.g. metal pad140B) is used to connect to another light-emitting device (e.g. light-emittingdevice1000B) and the other metal pad (e.g. metal pad140B′) is used to connect to another light-emitting device. That is, one light-emitting device can be connected to another light-emitting device in both ends such that light-emitting devices can be connected in series to a desired number of the serially-connected light-emitting devices. Furthermore, the connection type on one end of the wiring pattern, such as connection on thefirst metal pad140A, can be different from the connection type on the other end of the same wiring pattern, such as connection on theseventh metal pad140A′.
• FIG. 3A-1 shows a top view of a first embodiment of a series of light-emitting devices in accordance with this disclosure. Referring toFIG. 3A-1, a series of light-emittingdevices1000D is formed by connecting multiple light-emitting devices selected from the light-emittingdevices1000A,1000B, and1000C. For example, the light-emittingdevice1000D comprises the light-emittingdevice1000A ofFIG. 2A-1 and the light-emittingdevice1000B ofFIG. 2A-2 connected to each other through metal pads. In another embodiment, metal pads are added at two opposite ends of the wiring patterns so the light-emitting device can be connected in both sides. Referring toFIG. 3A-1, thethird wiring pattern162A is electrically connected to thefirst wiring pattern160A by bonding thefirst metal pad140A to thethird metal pad142A. Likely, thefourth wiring pattern162B is electrically connected to thesecond wiring pattern160B by bonding thesecond metal pad140B to thefourth metal pad142B.FIG. 3A-2 shows a lateral view of the light-emitting device ofFIG. 3A-1. Thefirst metal pad140A is bonded to thethird metal pad142A and the light-emittingdevice1000A has a portion being overlapped with a portion of the light-emittingdevice1000B.
• FIG. 3B shows a lateral view of a second embodiment of a series of light-emitting devices in accordance with this disclosure. The series of light-emittingdevices1000D inFIG. 3B is formed by connecting multiple light-emitting devices selected from the light-emittingdevices1000A,1000B, and1000C. For example, the light-emittingdevice1000D comprises the light-emittingdevice1000A ofFIG. 2A-1 and the light-emittingdevice1000B ofFIG. 2A-2 connected to each other through anadhesive layer144 and a wire W1. The wire W1 physically and electrically connects themetal pad140A to themetal pad142A.
• FIG. 3C shows a lateral view of a third embodiment of a series of light-emitting devices in accordance with this disclosure. The series of light-emittingdevices1000D inFIG. 3B is formed by connecting multiple light-emitting devices selected from the light-emittingdevices1000A,1000B, and1000C. For example, the light-emittingdevice1000D comprises the light-emittingdevice1000A ofFIG. 2A-1 and the light-emittingdevice1000B ofFIG. 2A-2 connected to each other through anadhesive layers144A and144B and a wire W2. The wire W2 connects themetal pad140A and themetal pad142A. Theadhesive layer144, or144A and144B are formed between lateral surfaces of the light-emittingdevice1000A and the light-emittingdevice1000B as shown inFIG. 3B andFIG. 3C. The lateral surface can be a flat surface as shown inFIG. 3B or a curved surface as shown inFIG. 3C wherein the curved surfaces on two sides of one light-emitting device are complementary to each other. In another embodiment, the wire, such as the wire W1 or W2, and the wiring patterns, such as thewiring pattern160A,160B,162A and162B are all formed on the bottom side of a light-emitting device which is opposite to the top side of the light-emitting device where thecover12 locates. In another embodiment, theadhesive layer18 can be included in one or more light-emitting devices in the embodiments shown inFIGS. 3A-1, 3B and 3C.
• In an embodiment, multiple light-emitting devices are connected with each other in a shape, such as a curve, a circle or a rectangle from a top view for specific purpose. The light-emittingunits20 in a light-emitting device can be arranged in various shapes for different application, such as showing specific picture, pattern or word. In another embodiment, the light-emitting device is bended, and has a radius of curvature not more than 25 cm. The connection between light-emitting devices disclosed herein can be applied to and included in the light-emitting device in the foregoing or following embodiments in accordance with the present disclosure.
• FIG. 4A shows a second embodiment of a light-emitting device in accordance with this disclosure. Referring toFIG. 4A, the light-emittingdevice1000 ofFIG. 1A is connected to an attachingplane30, such as a surface of a wall. The detail of the light-emittingdevice1000 can be referred toFIG. 1A and the description thereof, and is omitted for brevity. Thefirst end1001 and thesecond end1002 of the light-emittingdevice1000 are connected to the attachingplane30 so a gap is formed between the light-emittingdevice1000 and the surface of the attachingplane30. The light-emittingdevice1000 is bent to form a curvature. The gap is an air gap. The attachingplane30 can be a surface of a wall or a ceiling. In another embodiment, theadhesive layer18 can be omitted from the light-emittingdevice1000.
• FIG. 4B shows a first embodiment of a light-emitting apparatus having the light-emittingdevice1000 ofFIG. 1A. Referring toFIG. 4B, the light-emittingapparatus2000 includes a light-emittingdevice1000 and aframe34, wherein the light-emittingdevice1000 has afirst end1001 and asecond end1002 connected to theframe34 to form a curvature R. Theframe34 has aninner surface342 close to the light-emittingdevice1000 and anouter surface340 opposite to the inner surface. Theouter surface340 of theframe34 can be sticky or has an adhesive layer formed thereon for practical use. Theframe34 can be further attached to the ceiling with the light-emittingdevice1000 protruding out of the ceiling. Similarly, a gap is formed between the light-emittingdevice1000 and theframe34. In another embodiment, the light-emittingapparatus2000 is embedded in a cavity formed in the ceiling or the wall such that a part of the light-emittingdevice1000 is surrounded by a side wall of the cavity. In another embodiment, a reflective layer having a reflectivity more than 80% to the light emitted from the light-emittingunits20 is formed on theinner surface342 of the frame. In another embodiment, theadhesive layer18 can be omitted from the light-emittingdevice1000.
• Referring toFIG. 4A, the illumination uniformity of the light-emittingdevice1000 is measured at different angles. The method of measuring the illumination of uniformity of the light-emittingdevice1000 is well defined in the foregoing embodiments. The first measuring point MP1 is directly under the light-emittingdevice1000, wherein an offset angle θ of the first measuring point MP1 is 0°. The offset angle θ of the measuring point MP2 is 30° and the offset angle θ of the measuring point MP2 is 60°. The measuring points MP1˜MP3 locates on thesurface32. The offset angle θ of the measuring point MP4 is 90°. The illumination uniformity is 91.2% at the first measuring point MP1, 85.2% at the second measuring point MP2, 82.5% at the third measuring point MP3, and 80.1% at the fourth measuring point MP4 while the radius of curvature R of the light-emittingdevice1000 is substantially 32 mm. It is noted that the illumination uniformity at one measuring point with an offset angle between 30° and 90° is larger than 80% while the radius of curvature R is larger than 25 mm. Besides, the radius of curvature is infinite while the light-emittingdevice1000 is unbent. It is noted that the light-emittingdevice1000 has a similar illumination uniformity (e.g. difference less than 10%) measured at measuring point with same offset angle compared with the light-emittingapparatus2000.
• FIG. 5A shows a third embodiment of a light-emitting device in accordance with this disclosure. Similar to the light-emittingdevice1000 depicted inFIG. 1A, the light-emittingdevice1000E has multiple light-emittingunits20 formed on acarrier10, acover12 on the light-emittingunits20. The difference between the light-emittingdevice1000 ofFIG. 1A and the light-emittingdevice1000E of the present embodiment is that the light-emittingdevice1000E further comprises amale connector26aon thesecond surface104 of thecarrier10 and afemale connector26bon thefirst surface102 of thecarrier10. Theconnectors26aand26bare formed on two ends of thecarrier10 and being separated from thecover12. The shape of the light-emittingdevice1000E can elongated, such as a rectangular for being used as a planar light-emitting device, such as a troffer or a backlight source of an LCD display. Two ends of thecarrier10 can be bent to be a ring by connecting themale connector26bto thefemale connector26aand having the light-emittingunits20 on an outer surface of thecarrier10. Themale connector26ahas afirst protrusion260aand asecond protrusion262abeing opposite with each other as shown in the right figure ofFIG. 5B. Thefemale connector26bhas afirst cavity260b,asecond cavity262bbeing opposite with each other and an opening between thefirst cavity260band thesecond cavity262bas shown in the left figure ofFIG. 5B. Themale connector26acan be inserted into the opening of thefemale connector26bwith respectively connecting theprotrusion260ato thecavity262band connectingprotrusion262ato thecavity260b.The combination of the protrusions and the cavities provides connection with good mechanical strength so two light-emittingdevices1000E can be connected with each other by inserting amale connector26aof one light-emittingdevice1000E into afemale connector26bof another light-emittingdevice1000E. In another embodiment, the two light-emittingdevices1000E face with each other and the light-emittingunits20 are formed between twocarriers10. The contour of the cavity of the male connector is complementary to the contour of the corresponding protrusion of the female connector. The contour of the protrusion can be a cylinder, a pillar, or a cone. The cavity and the protrusion can be formed on the same side of thecarrier10, such as on thefirst surface102 or thesecond surface104, or on the opposite side of the carrier respectively.
• FIG. 6A shows a fourth embodiment of a light-emittingdevice1000F in accordance with this disclosure. Similar to the light-emittingdevice1000 depicted inFIG. 1A, the light-emittingdevice1000F has multiple light-emittingunits20 formed on acarrier10 and acover12′ on the light-emittingunits20. The difference between the light-emittingdevice1000 ofFIG. 1A and the light-emittingdevice1000F of the present embodiment is that theadhesive layer18 is omitted from the light-emittingdevice1000F and thecover12′ is formed on thecarrier10 along the contour of the light-emittingunits20 and thecarrier10 so the compatibility of the contour of thecover12′ matching with the contour of the light-emittingunits20 is better than that of thecover12′ covering the light-emittingunits20 inFIG. 1A. The light-emitting device1000G can be used as a planar light source, such as a troffer or a backlight source of an LCD display. Thecover12′ can be translucent or transparent to light emitted from the light-emittingunit20. In an embodiment, scattering particles are added in thecover12′ to enhance light scattering effect. In another embodiment, a reflective layer can be formed between thecarrier10 and the light-emittingunits20. Furthermore, an adhesive layer is formed on the surface of thecarrier10 opposite to the surface where the light-emittingunit20 locates on.
• FIG. 6B shows a second embodiment of the light-emitting unit included in a light-emitting device in accordance with the disclosure. The light-emittingunit20 included in the light-emitting device can be replaced by the light-emittingunit20′ in the foregoing or following embodiments in accordance with the present disclosure. As shown inFIG. 6B, the difference between the light-emittingunit20 ofFIG. 1B and the light-emittingunit20′ of the present embodiment is that the light-emittingunit20 is devoid of theoptical diffusion layer6 and thereflective layer8 of the light-emittingunit20′ is directly connected to thewavelength conversion layer4 so the thickness of the light-emittingunit20′ is less than that of the light-emittingunit20 for applying to electronic devices requiring ultra-thin dimension. The light-emittingunit20′ has anLED chip2, areflective layer8, awavelength conversion layer4 on the top surface of theLED chip2, and afirst bonding pad202 and asecond bonding pad204 connected to the bottom surface of theLED chip2. Similarly, the light emitted from theLED chip2 is reflected by thereflective layer8 so the light intensity at the top surface of the light-emittingunit20′ is lower than that at the lateral surface of the light-emittingunit20′. The light-emittingunit20′ has an optical property similar to that of the light-emittingunit20, such as a view angle greater than160°. It is noted that the light from theLED chip2 is not absorbed by the optical diffusion layer so the light-emittingunit20′ has a higher light-emitting intensity compared with that of the light-emittingunit20. The material of thereflective layer8, thewavelength conversion layer4, thepads202 and204 in the light-emittingunit20′ is similar to that in the light-emittingunit20, so the descriptions are omitted for brevity. The light-emittingunit20′ disclosed herein can be applied to and included in the light-emitting device or the light-emitting apparatus disclosed in the foregoing or following embodiments in accordance with the present disclosure.
• FIG. 7 shows a third embodiment of a light-emitting unit included in a light-emitting device in accordance with this disclosure. Referring toFIG. 7, the light-emittingunit40 has a LED chip2d,awavelength conversion layer4 composed ofwavelength conversion particles120, insulating layers5 having insulating portions5-1 and5-3, areflective layer114, anoptical layer11 andbonding pads202 and204. Thereflective layer114 can be a DBR (Distributed Bragg Reflector) layer or a reflective metal layer, and thereflective layer114 can be formed on the optical layer11D by coating, attaching or spraying process. TheLED chip2 has anelectrode60 connected to thebonding pad202 and anelectrode62 connected to thebonding pad204. Thebonding pads202 and204 are separated from theelectrodes60 and62 by the insulating layer5. Thebonding pads202 and204 are physically separated from the wavelength conversion layer4d by the insulating portions5-1, respectively. Thebonding pad202 has a first portion connected to the insulating portion5-1 and theelectrode60, and a second portion connected to the insulating portion5-3. Besides, the first portion has a side surface being coplanar with a side surface of the light-emittingunit40. The insulating layer5 has a curved surface connected to thebonding pads202 and204, wherein the curved surface is near a side surface of the light-emittingunit40. Similarly, the insulating layer5 has a side surface being coplanar with a side surface of thewavelength conversion layer4. The insulating layer5 has a non-uniform thickness wherein the largest thickness of the insulating portion5-3 is larger than the largest thickness of the insulating portion5-1. Thebonding pads202 and204 are used to electrically connect to an external power. Thewavelength conversion layer4 is transparent to light emitted from theLED chip2. The composition of thewavelength conversion layer4 inFIG. 7 to the same as thewavelength conversion layer4 inFIG. 1, and the detail description is omitted here for brevity. In the present embodiment, light is capable of emitting through five major emitting surfaces of the light-emittingunit40 and has a view angle between 100° and 160°. The material of the insulating layer5 can be oxide, nitride or polymer. The oxide includes silicon oxide (SiOx), titanium oxide (TiOx), tantalum oxide (TaOx), or aluminum oxide (AlOx). The nitride includes aluminum nitride (AlNx) or silicon nitride (SiNx). The polymer includes polymide or benzocyclobutane (BCB). In another embodiment, the insulating layer5 includes multiple sublayers having alternately stacked low refractive-index layers and high refractive-index layers to form a Distributed Bragg Reflector (DBR). Theoptical layer11 includes sapphire, diamond, glass, epoxy, quartz, acrylic resin, SiOx, AlOx, ZnOx, or silicone. In another embodiment, theoptical layer11 can be omitted from the light-emittingunit40. TheLED chip2 has atop surface400, andside surfaces402 and404. Thewavelength converting particles120 covers thetop surface400, andside surfaces402 and404. Furthermore, thewavelength converting particles120 covers the portion of the insulating layers5 extending laterally beyond a lateral side of theLED chip2. The light-emittingunit40 disclosed herein can be applied to and included in the light-emitting device or the light-emitting apparatus disclosed in the foregoing or following embodiments in accordance with the present disclosure.
• FIGS. 8A-8D show a method of manufacturing a light-emitting device in accordance with an embodiment of this disclosure. Specifically,FIGS. 8A-8D show a method of manufacturing the light-emittingdevice1000 ofFIG. 1A. Referring toFIG. 8A, the method comprises a first step of disposing multiple light-emittingunits20 on a top surface of thecarrier10, a second step of providing and forming anuncured cover12acovering the light-emittingunit20 as shown inFIG. 8B andFIG. 8C wherein theuncured cover12ais a sheet with a uniform thickness, a third step of curing theuncured cover12ato form thecover12, a fourth step of forming anadhesive layer18 on a bottom surface opposite to the top surface of thecarrier10 as shown inFIG. 8C, and a fifth step o f cutting the structure formed in the fourth step as shown inFIG. 8D, and therefore a light-emittingdevice1000 is formed as shown inFIG. 1A. Thecover12 is formed on the light-emittingunits20 with a uniform height from thecarrier10. To be more specific, the curved portion of thecover12 is removed in the fourth step. In an embodiment, part of theuncured cover12ais removed to decrease the thickness of the entire structure by method of wet blasting, grinding or lapping. Referring toFIG. 1A, theupper surface106 is flat on the light-emittingunit20. Moreover, the method described inFIGS. 8A-8D can be applied to the method for forming the light-emittingdevice1000F ofFIG. 6A. The difference between the method for forming the light-emittingdevice1000 and that for forming the light-emittingdevice1000F is that thecover12 of the light-emittingdevice1000 is formed by attaching anuncured cover12aof a thin film type on the light-emittingunits20 while thecover12′ of the light-emittingdevice1000F is formed by conformal coating, e.g. spray coating, a thin layer to cover the light-emittingunits20. The material ofcover12′ of the present embodiment has less viscosity compared with that of theuncured cover12aduring manufacturing the light-emitting device. Besides, the thickness of thecover12 is thicker than thecover12′, but both the thickness of thecover12 and that of thecover12′ are less than 600 um. Preferably, the thickness of thecover12 or cover12′ is between 100 um and 500 um. Thecover12 comprises polymer
• FIG. 9A shows a second embodiment of a light-emitting apparatus having a light-emitting device in accordance with this disclosure. The light-emittingapparatus2002 has alight guide50 and a light-emittingdevice1000. Referring toFIG. 9A, a light-emittingdevice1000 is connected to a side surface of alight guide50 to form a light-emittingapparatus2002. Theadhesive layer18 is formed on another side of the light-emittingdevice1000 opposite to the side where thelight guide50 is formed. The light-emittingdevice1000 can be replaced by any light-emitting device disclosed in the foregoing embodiments in accordance with the present disclosure. Thelight guide50 has a light-emittingsurface501. Thecover12 has a uniform thickness measured from an interface between thelight guide50 and thecover12 to thecarrier10. It is noted that the light-emittingdevice1000 includes light-emittingunits20 which can be replaced by the light-emittingunit20′ disclosed in the foregoing embodiments in accordance with the present disclosure. In another embodiment, theadhesive layer18 can be omitted from the light-emittingdevice1000.
• FIG. 9B shows a lateral view of the light-emittingapparatus2002 depicted inFIG. 9A. Thelight guide50 has atop surface501501, abottom surface503, a lateral surface connecting thetop surface501 and thebottom surface503, andoptical structures503 on thebottom surface502 opposite to thetop surface501 to redirect, reflect, refract, and/or scatter the light from the light-emittingunits20 toward and through thetop surface501. The lateral surface is connected to the light-emittingdevice1000. To be more specific, thecover12 is connected to the lateral surface. Theoptical structures503 embedded in thelight guide50 are configured to distribute light uniformly in the entirelight guide50, and the shape of theoptical structure503 comprises triangle, arc or trapezoid in a cross-sectional view. Thestructure503 can be transparent or translucent. The light-emittingapparatus2002 can be used as a light source, such as a back light module of a display. In another embodiment, the light-emittingdevice1000 further comprises a reflective layer formed between the carrier and the cover and between the carrier and the light-emitting unit to enhance light intensity provided by the light-emitting device.
• FIG. 10A shows a third embodiment of a light-emitting apparatus having a light-emitting device in accordance with this disclosure. The light-emittingapparatus2004 has alight guide52 and a light-emittingdevice1000. The light-emittingdevice1000 having multiple light-emittingunis20 is entirely formed under the light-emittingapparatus2000. It is noted that the positions of the light-emittingunits20 are substantially overlapped with the geometric center line of the light-emittingapparatus2004. In another aspect, the geometric center of thelight guide50 is overlapped with that of the light-emittingapparatus2004. That is, the positions of the light-emittingunits20 are substantially overlapped with the geometric center line of thelight guide50. The light-emittingdevice1000 can be replaced by any light-emitting device disclosed in the foregoing embodiments in accordance with the present disclosure. The light-emittingunits20 can be replaced by any light-emitting unit disclosed in the foregoing embodiments in accordance with the present disclosure.
• FIG. 10B shows a lateral view of the light-emittingapparatus2004 inFIG. 10A. Theadhesive layer18 is formed on another side of the light-emittingdevice1000 opposite to the side where thelight guide52 is formed. Thelight guide52 has atop surface521 and abottom surface522 opposite to thetop surface521, wherein light is majorly extracted outside the light-emittingapparatus2004 through thetop surface521. The light-emittingdevice1000 is connected to thebottom surface522. The light-emittingdevice1000 has multiple light-emittingunits20, acarrier10, and acover12. Thebottom surface522 is connected to the light-emittingdevice1000. To be more specific, thecover12 is connected to thebottom surface522. It is noted that the light-emittingdevice1000 inFIGS. 9A-9B provide light majorly from the lateral side of thelight guide50, and the light-emittingdevice1000 inFIGS. 10A-10B provide light from thebottom surface522 of thelight guide52. Thetop surface102 of thecarrier10 can be a rough surface to reflect, refract or redirect light, or comprises an optical structure as shown inFIG. 9B. Thelight guide52 is used to enhance optical performance, such as uniformity of the light-emitting device1004. The light-emittingapparatus2004 can be used as a light source, such as a back light module of a display. In another embodiment, the light-emittingdevice1000 further comprises a reflective layer formed between the carrier and the cover and between the carrier and the light-emitting unit to enhance light intensity provided by the light-emitting device. In another embodiment, theadhesive layer18 can be omitted from the light-emittingdevice1000.
• Although the drawings and the illustrations above are corresponding to the specific embodiments individually, the element, the practicing method, the designing principle, and the technical theory can be referred, exchanged, incorporated, collocated, coordinated except they are conflicted, incompatible, or hard to be put into practice together.
• Although the present disclosure has been explained above, it is not the limitation of the range, the sequence in practice, the material in practice, or the method in practice. Any modification or decoration for present disclosure is not detached from the spirit and the range of such.

Claims (12)

1. A light-emitting device, comprising:

a first light-emitting unit, comprising,

an LED chip having a first top surface, a bottom surface, and a side surface arranged between the first top surface and the bottom surface;

a first reflective layer arranged on the LED chip and having a second top surface substantially parallel with the first top surface from a first edge to a second edge of the second top surface; and

an optical diffusion layer formed between the first reflective layer and the first LED chip; and

a flexible carrier facing the bottom surface and supporting the first light-emitting unit.

2. The light-emitting device ofclaim 1, wherein the flexible carrier comprises hyper-polyvinylidene fluoride.

3. The light-emitting device ofclaim 1, wherein the light-emitting device has an illumination uniformity larger than 80%, and the illumination uniformity is measured at a measuring point with an offset angle between 30° and 90°, the offset angle is measured with respect to a virtual line normal to a top surface of the light-emitting device, is larger than 80%.

4. The light-emitting device ofclaim 1, wherein the first light-emitting unit has an light intensity increasing at a range of the offset angle between 0° and 30° and decreasing at a rage of the offset angle between 40° and 70° further comprises a wavelength conversion layer between the LED chip and the optical diffusion layer.

5. The light-emitting device ofclaim 1, wherein the flexible carrier has a transparency larger than 90% and a glass transition temperature larger than 160° C.

6. The light-emitting device ofclaim 1, wherein the flexible carrier has a radius of curvature not larger than 25 cm.

7. The light-emitting device ofclaim 1, wherein the light-emitting device has a thickness less than 7 mm.

8. The light emitting device ofclaim 1, further comprising a second reflective layer formed between the flexible carrier and the light emitting unit.

9. The light-emitting device ofclaim 1, further comprising a second light-emitting unit having a second LED chip, a second reflective layer arranged on the second LED chip, and an insulating layer, wherein the second reflective layer and the insulating layer are formed on opposite sides of the second LED chip.

10. The light-emitting device ofclaim 9, wherein the insulating layer further comprises a curved surface below the second LED chip.

11. The light-emitting device ofclaim 9, further comprising a bonding pad arranged on the insulating layer and electrically connected to the second LED chip.

12-20. (canceled).

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