TWI666406B - Light-emitting device - Google Patents

Abstract

A light-emitting device includes a carrier board having a first surface, a second surface opposite to the first surface, and a light-emitting unit, which is disposed on the first surface and emits light toward but does not pass through the first surface. The light emitting device can measure a first brightness above the first surface, and can measure a second brightness below the second surface. The ratio of the first brightness to the second brightness is 2-9.

Description

Light emitting device

The invention discloses a light-emitting device, especially a light-emitting device having an optical structure.

Light-Emitting Diodes (LEDs) used in solid-state lighting devices have the characteristics of low energy consumption, long life, small size, fast response speed, and stable optical output, so light-emitting diodes are slowly replacing traditional ones. Lighting products are also used in general domestic lighting.

In recent years, filaments made of light-emitting diodes have gradually been used in light-emitting diode bulbs. However, the cost and efficiency of light-emitting diode filaments still need to be improved. Furthermore, it is still the development goal to make the light emitting diode filament emit an omnidirectional light field and deal with the heat dissipation problem.

In order to make the above and other objects, features, and advantages of the present invention more comprehensible, embodiments are described below with reference to the accompanying drawings, as follows.

A light emitting device includes a carrier board having a first surface, a second surface opposite to the first surface, and a light emitting unit, which is disposed on the first surface and emits light toward but does not pass through the first surface. The light emitting device can measure a first brightness above the first surface, and can measure a second brightness below the second surface. The ratio of the first brightness to the second brightness is 2-9.

100‧‧‧light-emitting device

10‧‧‧ Optical Structure

101‧‧‧ top surface

102‧‧‧side surface

103‧‧‧side bottom surface

1031‧‧‧Part I

1032‧‧‧ Part Two

104‧‧‧ bottom surface

11‧‧‧ Carrier Board

111‧‧‧ top surface

112‧‧‧ lower surface

12, 12A, 12B, 12D‧‧‧ Light-emitting units

120A‧‧‧First connection pad

120B‧‧‧Second connection pad

121‧‧‧lighting subject

1211‧‧‧electrode

122‧‧‧The first transparent body

123‧‧‧Fluorescent powder layer

124‧‧‧Second transparent body

125, 125 ’‧‧‧ third transparent body

1251‧‧‧ Part I

1251S‧‧‧Side surface

1252‧‧‧ Part Two

1253‧‧‧plane

1254‧‧‧ bevel

126‧‧‧ Insulation

127‧‧‧Extended electrode

129‧‧‧Reflective structure

13‧‧‧Circuit Structure

131‧‧‧First electrode pad

132‧‧‧Second electrode pad

133, 1331, 1331A, 1332, 1332B ‧‧‧ conductive line

134‧‧‧Third electrode pad

135‧‧‧Fourth electrode pad

151‧‧‧The first through hole

152‧‧‧Second through hole

21‧‧‧ bracket

211‧‧‧Frame

30‧‧‧ bulb

301‧‧‧light housing

302‧‧‧Circuit Board

303‧‧‧support column

304‧‧‧ heat sink

305‧‧‧Electrical connection

307‧‧‧electrode parts

308, 309‧‧‧ metal wire

FIG. 1A is a schematic perspective view of a light-emitting device according to an embodiment of the present invention.

FIG. 1B shows a schematic top view of the carrier board in FIG. 1A.

Figure 1C shows a schematic bottom view of the carrier board in Figure 1A.

Figure 1D shows a schematic cross-sectional view of Figure 1A and along the line I-I of Figure 1B.

Figure 1E shows a schematic cross-section of Figure 1A.

Figure 1F is an enlarged view of Figure 1E.

Figures 2A to 2D are schematic diagrams showing different travel paths of light emitted by the light emitting unit in the optical structure.

FIG. 2E shows a light distribution curve diagram of the light emitting device according to an embodiment of the present invention.

FIG. 3A is a schematic cross-sectional view of a light-emitting unit according to an embodiment of the present invention.

FIG. 3B is a schematic cross-sectional view of a light emitting unit in another embodiment of the present invention.

Figure 3C is a top view of Figure 3B.

FIG. 3D is a schematic cross-sectional view of a light-emitting unit in another embodiment of the present invention.

FIG. 4 is a schematic perspective view of a light bulb according to an embodiment of the present invention.

FIG. 5A shows a manufacturing flow chart of a light emitting device according to an embodiment of the present invention.

Figures 5B-5E show three-dimensional schematic diagrams of the manufacturing process of the light-emitting device according to an embodiment of the present invention.

The following embodiments will illustrate the concept of the present invention along with drawings. In the drawings or description, similar or identical parts are denoted by the same reference numerals, and in the drawings, the shape or thickness of elements can be enlarged or reduced. It is important to note that components not shown or described in the figures may be in a form known to those skilled in the art.

FIG. 1A is a schematic perspective view of a light emitting device 100 according to an embodiment of the present invention. FIG. 1B only shows a schematic top view of the carrier plate 11 in FIG. 1A. FIG. 1C only shows a schematic bottom view of the carrier plate 11 in FIG. 1A. Figure 1D shows a schematic cross-sectional view of Figure 1A and along the line I-I of Figure 1B. FIG. 1E is a schematic cross-sectional view in the YZ direction in FIG. 1A. Referring to FIGS. 1A to 1E, the light emitting device 100 includes an optical structure 10, a carrier plate 11, and a plurality of light emitting units 12. The carrier board 11 has an upper surface 111 and a lower surface 112. A circuit structure 13 is formed on the upper surface 111 and has a first electrode pad 131, a second electrode pad 132 and a conductive line 133. The light emitting units 12 are disposed on the conductive lines 133 on the upper surface 111 and are connected in series with each other through the conductive lines 133. In other embodiments, the light-emitting units 12 may be connected to each other in parallel, series-parallel, or in a bridge-type structure by designing other conductive lines 133. In this embodiment, the carrier board 11 is not penetrated (opaque) by the light emitted from the light emitting unit 12, so even if the light emitted from the light emitting unit 12 is directed toward the upper surface 111, it does not pass through the upper surface 111. The carrier board 11 may be a circuit board. The core layer of the circuit board includes a metal, a thermoplastic material, a thermosetting material, or a ceramic material. The metal includes an alloy such as aluminum, copper, gold, and silver, a laminate, or a single layer. The thermosetting material includes a phenolic resin (Phonetic), an epoxy resin (Epoxy), a bismaleimide triazine resin (Bismaleimide Triazine), or a combination thereof. The thermoplastic material includes polyimide resin, polytetrafluorethylene, and the like. Ceramic materials include alumina, aluminum nitride, silicon aluminum carbide, and the like.

As shown in FIGS. 1A, 1B, and 1C, a reflective layer 14 is formed on the upper surface 111 and the circuit structure 13, and only the conductive lines 1331 and 1332 and the electrode pads 131 and 132 to be electrically connected to the light-emitting unit 12 are exposed. The conductive lines 1331 and 1332 are physically separated from each other. In this embodiment, the conductive wiring 1332A and the electrode pad 131 are physically separated from each other and the conductive wiring 1331B and the electrode pad 132 are physically separated from each other. Each light-emitting unit 12 includes a first connection pad 120A and a second connection pad 120B that are physically and electrically connected to the exposed conductive lines 1331 and 1332, respectively. In this embodiment, the exposed conductive lines 1331 and 1332 are rectangular and the long sides thereof are parallel to the long sides of the carrier plate 11. In another embodiment, the long sides of the exposed conductive lines 1331 and 1332 are parallel to the short sides of the carrier board 11, or an angle between 0 and 90 ° is formed with the long sides. Alternatively, the exposed conductive lines 1331 and 1332 may be circular, oval, or polygonal. In addition, the arrangement of the reflective layer 14 can help reflect the light emitted from the light emitting unit 12 toward the carrier plate 11 to increase the luminous efficiency of the entire light emitting device 100.

As shown in FIGS. 1C and 1D, the light emitting unit 12 is not provided on the lower surface 112. The circuit structure 13 further includes a third electrode pad 134 and a fourth electrode pad 135 formed on the lower surface 112 of the carrier board 11. The third electrode pad 134 and the fourth electrode pad 135 correspond to positions of the first electrode pad 131 and the second electrode pad 132, respectively. A first through hole 151 penetrates the carrier board 11 and has a conductive substance formed completely or partially therein to electrically connect the first electrode pad 131 and the third electrode pad 134. A second through hole 152 penetrates the carrier plate 11 and has a conductive substance formed completely or partially therein to electrically connect the second electrode pad 132 and the fourth electrode pad 135. In one implementation, an external power supply is connected to the first electrode pad 131 and the second electrode pad 132 respectively to make the plurality of light emitting units 12 emit light. The third electrode pad 134 and the fourth electrode pad 135 may not be directly physically connected to an external power source. When the electrode pads 131, 132 and the external power source are electrically connected by an electric welding (bump welding) method, since a metal clip is required to sandwich the carrier plate 11, the arrangement of the electrode pads 134, 135 can help to clamp the light emitting device 100 during the manufacturing process Robustness and provide a conductive path. In one embodiment, when the electrode pads 131 and 132 are electrically connected to an external power source using a bonding wire, the third electrode pad 134 and the fourth electrode pad 135 may not be formed.

As shown in FIGS. 1A and 1E, the optical structure 10 covers the upper surface 111, the lower surface 112 of the carrier plate 11, and the side walls 113 on both sides of the long side of the carrier plate 11, but the electrode pads 131, 132, 134, and 135 are exposed. . The optical structure 10 has a rectangular cross-section. Figure 1F is an enlarged view of Figure 1E. The optical structure 10 has a curved top surface 101; two side surfaces 102 that are substantially linear and parallel to each other; and bottom surfaces 103 on both sides; And a substantially planar bottom surface 104 connecting the bottom surfaces 103 on both sides. The top surface 101 is located above the upper surface 111 of the carrier board 11, and the bottom surface 104 is located below the lower surface 112 of the carrier board 11. The side surface 102 extends from the top surface 101 to the lower surface 112 of the carrier plate 11 in the Z direction. Each bottom surface 103 includes a first portion 1031 extending from the side surface 102 toward the bottom surface 104 at an inclined angle; and a second portion 1032. The left and right second portions 1032 in the figure are respectively connected to the first portion 1031 and extend in an arc shape toward the bottom surface 104. The lower surface 112 of the carrier plate 11 is at a first distance (D1) between the bottom surface 104 of the optical structure 10 and 0.3 mm to 0.7 mm; the upper surface 111 of the carrier plate 11 is at a distance of 0.8 between the top surface 101 of the optical structure 10 mm ~ 0.13mm second distance (D2). The second distance (D2) is greater than the first distance (D1). The arc of the top surface 101 has a radius of curvature between 0.4mm and 0.7mm, and has an arc angle θ 1 (the central angle corresponding to the arc) of 40 ° ~ 60 ° or an arc of 2 π / 9 ~ π / 3. The arc of the second part of the side bottom surface 103 has a curvature radius between 0.2 and 0.4 mm, and has an arc angle θ 2 (the center angle corresponding to the arc) is between 5 ° to 20 ° or one arc. At π / 36 ~ π / 9. A diffusing powder (such as titanium dioxide, zirconia, zinc oxide, or aluminum oxide) can be selectively filled into the optical structure 10 to help diffuse and scatter the light emitted by the light emitting unit 12. The weight percentage concentration (w / w) of the diffusing powder in the optical structure 10 is between 0.1 and 0.5% and has a particle size of 10 nm to 100 nm or 10 to 50 μm. In one embodiment, the weight-per-powder concentration of the diffusing powder in the colloid can be measured by a thermogravimetric analyzer (TGA). In brief, during the heating process, the colloid will be removed (evaporation or thermal cracking) because the temperature gradually increases and reaches a specific temperature, and the diffusing powder remains. At this time, the change in weight can be known, so it can be obtained The weight of the colloid and the diffusing powder and the weight percentage concentration of the diffusing powder in the colloid are calculated. Alternatively, the total weight of the colloid and the diffusing powder may be measured first, the colloid may be removed by using a solvent, and then the weight of the diffusing powder may be measured to obtain the weight percentage concentration of the diffusing powder in the colloid. In Figure 1A, although visible 得 luminescent unit 12. However, when the diffusing powder is filled into the optical structure 10 and reaches a certain concentration, the optical structure 10 will appear white and the internal light emitting unit 12 cannot be seen.

The optical structure 10 is transparent to the light emitted by the sunlight or the light emitting unit 12. Optical structure 10 includes Silicone, Epoxy, Polyimide (PI), Benzocyclobutene (BCB), Perfluorocyclobutane (PFCB), SU8, Acrylic Resin , Polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), polycarbonate (PC), polyetherimide, fluorocarbon polymer, alumina (Al ₂ O ₃ ), SINR, or spin-on-glass (SOG).

FIG. 2A is a schematic diagram illustrating a travel path of light emitted by the light emitting unit 12 in the optical structure 10. It should be noted that the path in the diagram is only one of many possible paths. It is not the only path, the same below. For example, the light (L) from the light emitting unit 12 strikes the curved top surface 101, and the light (L) generates a first refracted light (L11) and a first reflected light (L12) on the top surface 101. The first reflected light (L12) is incident on the side surface 102, and a second refracted light (L21) and a second reflected light (L22) are generated on the side surface 102. The second reflected light (L22) strikes the bottom surface 104, and a third refracted light (L31) and a third reflected light (L32) are generated on the bottom surface 104. Alternatively, as shown in FIG. 2B, for example, the light (M) from the light emitting unit 12 strikes the curved top surface 101, and the light (M) generates a first refracted light (M11) and a first reflected light on the top surface 101. (M12). The first reflected light (M12) is incident on the first portion 1031 of the side bottom surface 103, and a second refracted light (M21) and a second reflected light (M22) are generated in the first portion 1031. The second reflected light (M22) strikes the bottom surface 104, and a third refracted light (M31) and a third reflected light (M32) are generated on the bottom surface 104. Figures 2C and 2D show schematic diagrams of other possible travel paths of light in the optical structure 10. By designing the shape of the optical structure 10 of the present invention, the probability that light is emitted from the lower surface 112 of the carrier plate 10 and the probability that light is emitted from the bottom surface 104 are increased. Light emitting device 100 can measure a first brightness above the upper surface 111 (first side), and can measure a second brightness below the lower surface 112 (second side). The ratio of the first brightness to the second brightness is between Between 2 and 9. For the definition of the first brightness and the second brightness, refer to the subsequent description. It should be noted that the path in the diagram is only one of many possible paths, not the only one. In the above description, light is refracted and reflected on the surface at the same time. However, light may only be refracted or reflected on the surface, depending on the refractive index difference, incident angle, light wavelength, etc. of the material interface.

FIG. 2E shows a light distribution curve obtained when the light emitting device 100 is in a thermally stable state under the operation of a current of 10 mA. In detail, when the light-emitting device 100 emits light, the light-emission brightness of an imaginary circle (such as the circle P1 in FIG. 1A) can be measured by using a light distribution curve meter. Further, a light distribution curve graph can be obtained by plotting the light emission brightness and angle. During the measurement, the geometric center of the light-emitting device 100 is located approximately at the center of the circle of P1. In this embodiment, the weight percentage concentration of the diffusing powder in the optical structure 10 is 0.3%. As shown in the figure, the maximum brightness of the light emitting device 100 is about 4.53 candela (cd), and the brightness from 0 degrees to 180 degrees is roughly in a Lambertian distribution. Specifically, the brightness of -90 degrees is the smallest and is about 0.5 candle (cd), the brightness of -90 degrees to -80 degrees is about the same, and the brightness of -80 degrees to 90 degrees is gradually increasing. The curve of -90 ~ 0 ~ 90 degrees is roughly similar to the curve of 90 ~ 180 ~ -90 degrees, and the distribution of light intensity at -90 ~ 0 ~ 90 degrees is opposite to the distribution of light intensity at 90 ~ 180 ~ -90 degrees Straight axis symmetry at 90 ~ -90 degrees. In addition, the total brightness of 0 to 90 to 180 degrees in the light distribution curve chart is defined as the first brightness, and the total brightness of 0 to -90 to -180 degrees is defined as the second brightness, and the ratio of the first brightness to the second two degrees About 4. It can be calculated from the light distribution graph that the light emitting angle of the light emitting device 100 is about 160 degrees.

The light emitting angle is defined as when the brightness is 50% of the maximum brightness, and the angle range included at this time is the light emitting angle. For example: first convert the light distribution curve (polar coordinates) measured on the circle P1 in Figure 2E into a right-angled coordinate chart to obtain a brightness curve; where the X-axis is the brightness and the Y-axis is the angle (Figure Not shown). Next, draw a line parallel to the X axis at about 2.265 candlelights (50% of the maximum brightness) and intersect the brightness curve at two points; calculate the angle range between the two points, which is defined as the light emission angle.

FIG. 3A is a schematic cross-sectional view of a light-emitting unit 12A according to an embodiment of the present invention. The light-emitting unit 12A includes a light-emitting body 121, a first transparent body 122, a phosphor layer 123, a second transparent body 124, and a third transparent body 125. The light-emitting body 121 includes a substrate, a first-type semiconductor layer, an active layer, a second-type semiconductor layer (not labeled above), and two electrodes 1211. When the light-emitting body 121 has a heterostructure, the first-type semiconductor layer and the second-type semiconductor layer are, for example, a cladding layer and / or a confinement layer, which can respectively provide electrons and holes and have a It is larger than the energy gap of the active layer, thereby increasing the probability that electrons and holes are combined in the active layer to emit light. The first type semiconductor layer, the active layer, and the second type semiconductor layer may include a III-V semiconductor material, such as Al _x In _y Ga _(1-xy) N or Al _x In _y Ga _(1-xy) P, where 0 ≦ x, y ≦ 1; (x + y) ≦ 1. Depending on the material of the active layer, the light emitting body 121 can emit a red light with a peak wavelength or dominant wavelength between 610nm and 650nm, and a green light with a peak or dominant wavelength between 530nm and 570nm. Or blue light with a peak or dominant wavelength between 450nm and 490nm. The phosphor structure 123 includes a plurality of phosphor particles. The phosphor particles have a particle size (diameter) of about 5um to 100um and may include one or two or more kinds of phosphor materials. The phosphor material includes, but is not limited to, yellow-green phosphor and red phosphor. The composition of the yellow-green phosphor is, for example, aluminum oxide (YAG or TAG), silicate, vanadate, alkaline earth metal selenide, or metal nitride. The composition of the red phosphor is, for example, fluoride (K ₂ TiF ₆ : Mn ⁴⁺ , K ₂ SiF ₆ Mn ⁴⁺ ), silicate, vanadate, alkaline earth metal sulfide, metal nitrogen oxide, or tungsten molybdenum. Acid salt mixture. The phosphor structure 123 can absorb the first light emitted by the light emitting body 121 and convert it into a second light with a different frequency spectrum from the first light. Mixing the first light with the second light produces a mixed light, such as white light. In this embodiment, the light generated by the light emitting unit 12 under the thermal steady state has a white light color temperature of 2200K ~ 6500K (for example: 2200K, 2400K, 2700K, 3000K, 5700K, 6500K), and its color point value (CIE x, y ) Will fall within the range of seven MacAdam ellipse and have a color rendering (CRI) greater than 80 or greater than 90. In another embodiment, the first light and the second light are mixed to generate purple, yellow, or other non-white light.

The light-emitting unit 12 further includes two electrodes 1211 formed under the first transparent body 122, a phosphor layer 123, and the second transparent body 124 without covering the light-emitting body 121; and two extension electrodes 127 are formed on The two electrodes 1211 are electrically connected to the two electrodes 1211. The two extension electrodes 127 are respectively used as the first connection pad 120A and the second connection pad 102B (as shown in FIG. 1D). The insulating layer 126 is a mixture including a matrix and a highly reflective material. The matrix may be either a silicone matrix or an epoxy matrix. The highly reflective material may include titanium dioxide, silicon dioxide, or aluminum oxide. In addition, the insulating layer 126 may have a function of reflecting light or diffusing light. The extension electrode 127 includes a metal such as copper, titanium, gold, nickel, silver, an alloy thereof, or a stack thereof. The first transparent body 122, the second transparent body 124, and the third transparent body 125 are transparent to the light emitted by the sunlight or the light emitting unit 12. The first transparent body 122 or the second transparent body 124 may include Silicone, Epoxy, Polyimide (PI), Benzocyclobutene (BCB), Perfluorocyclobutane (PFCB) , SU8, Acrylic Resin, Polymethyl Methacrylate (PMMA), Polyethylene Terephthalate (PET), Polycarbonate (PC), Polyetherimide, Fluorocarbon Polymer (Fluorocarbon Polymer), alumina (Al ₂ O ₃ ), SINR, or spin-on-glass (SOG). The third transparent body 125 may include Sapphire, Diamond, Glass, Epoxy, quartz, Acrylic Resin, SiOx, and alumina ( Al ₂ O ₃ ), zinc oxide (ZnO), or silicone.

As shown in FIG. 3A, the third transparent body 125 has a shape that is wide at the top and narrow at the bottom. In detail, the third transparent body 125 has a first portion 1251 and a second portion 1252. The second part 1252 is closer The second transparent body 124 has a width smaller than that of the first portion 1251. The thickness of the first part 1251 is about 1% to 20% or 1% to 10% of the entire thickness of the third transparent body 125. In this embodiment, a junction between the first portion 1251 and the second portion 1252 is an arc. The first part 1251 has a side surface 1251S, which is slightly inclined upward (face-up), and is farther from the light emitting body 121 than the side surface 1241 of the second transparent body 124, and can guide light to both sides of the light emitting unit 12.

In one embodiment, the light-emitting unit 12A is a light-emitting structure that emits light to five faces (upper, left-right, front-back, front-back) and has a beam angle of about 140 degrees. Alternatively, a diffusing powder may be added to the first transparent body 122, or / and the second transparent body 124, or / and the third transparent body 125. In another embodiment, the light emitting unit 12A does not include the third transparent body 125.

FIG. 3B is a schematic cross-sectional view of a light-emitting unit 12B according to another embodiment of the present invention. Figure 3C is a top view of Figure 3B. The light-emitting unit in FIG. 3B is similar to the light-emitting device in FIG. 3A. The same symbols or symbols correspond to the elements or devices, and they have similar or identical elements or devices. As shown in FIG. 3B, the third transparent body 125 ′ has a frustum shape and has a flat surface 1253 and an inclined surface 1254. The design of the inclined surface 1254 can increase the light extraction amount of the light emitting body 121 and change the light field of the light emitting unit 12. The plane 1253 and the inclined surface 1254 can be at an angle (Φ) between 120 ° and 150 °, and the depth (H ₁ ) of the inclined surface 1254 is 30% to 70% of the overall thickness (H ₂ ) of the third transparent body 125 'or 40% ~ 60%. As shown in FIG. 3C, the area (Al; triangle) of the plane 1253 may be 40% to 95% or 40% to 60% of the total projected area (A; diagonal line) of the third transparent body 125 ′.

FIG. 3D is a schematic cross-sectional view of a light-emitting unit 12D according to another embodiment of the present invention. The light-emitting unit in FIG. 3D is similar to the light-emitting device in FIG. 3A. The same symbols or symbols correspond to the elements or devices, and they have similar or identical elements or devices. The light emitting unit 12D further includes a reflective structure 129 formed between the first transparent body 124 and the second transparent body 125. The reflective structure 129 has a reflectance of greater than 85% when the light incident on the reflective structure 129 has a wavelength range between 450nm and 475nm; or it has a reflectance greater than 80% when the wavelength of the incident light is between 400nm and 600nm. Reflectivity. The light that is not reflected by the reflective structure 129 can enter the third transparent body 125 and leave the light emitting unit 12D or the third transparent body 125 from above or from the side of the third transparent body 125. If the reflective structure 129 can reflect most light, such as a reflectance greater than 95%, the third transparent body 125 in the light emitting unit 12D may be omitted. The reflective structure 129 may be a single-layer structure or a multi-layer structure. The single-layer structure is, for example, a metal layer containing, for example, silver or aluminum, or an oxide layer containing, for example, titanium dioxide. The multilayer structure can be a stack of metal and metal oxide or a distributed Bragg reflector (DBR) to achieve the reflection effect. A stack of a metal and a metal oxide is, for example, a stack of aluminum and alumina. The decentralized Bragg mirror can be a non-semiconductor stack or a semiconductor stack. The material of the non-semiconductor stack can be selected from one of the following groups: aluminum oxide (Al ₂ O ₃ ), silicon oxide (SiO ₂ ), titanium dioxide (TiO ₂ ), niobium pentoxide (Nb ₂ O ₅ ), nitride Silicon (SiN _x ). The material of the semiconductor stack can be selected from one of the following groups: gallium nitride (GaN), aluminum gallium nitride (AlGaN), aluminum indium gallium nitride (AlInGaN), aluminum arsenide (AlAs), aluminum gallium arsenide ( AlGaAs), gallium arsenide (GaAs). In this embodiment, no matter whether it is a single-layer structure or a multi-layer structure, light will not be completely reflected, so at least part of the light will directly pass through the reflective structure 129.

In another embodiment, the light emitting unit 12 in FIG. 1A may have a structure similar to the light emitting units 12A, 12B, and 12D in FIG. 3A, 3B, or 3D, but the structure does not include the phosphor layer 123. That is, the light emitting unit 12 emits only the original light from the light emitting body 121, such as red light, green light, or blue light. A plurality of phosphor particles (wavelength conversion substances) may be added to the optical structure 10 to absorb the first light emitted by the light emitting body 121 and convert it into a second light having a different frequency spectrum from the first light, the first light and the second light Light mixing produces white light. Therefore, the light-emitting device 100 may have a white light color temperature of 2200K ~ 6500K (for example, 2200K, 2400K, 2700K, 3000K, 5700K, 6500K) in a thermally stable state. The point value (CIE x, y) will fall within the range of seven MacAdam ellipse and have a color rendering (CRI) greater than 80 or greater than 90.

The light-emitting unit of this embodiment is formed on a carrier board in a flip-chip manner. In other embodiments, a plurality of horizontal or vertical light emitting units (not shown) may be fixed on the carrier board with silver glue or conductive transparent glue first; then, the light emitting units are electrically connected to each other by wire bonding; finally An optical structure is provided to cover the light emitting unit to form a light emitting device.

FIG. 4 is a perspective view of a light bulb 30 according to an embodiment of the present invention. The light bulb 30 includes a lamp housing 301, a circuit board 302, a support post 303, a plurality of light emitting devices 100, a heat sink 304, and an electrical connector 305. The plurality of light emitting devices 100 are fixed and electrically connected to the support post 303. In detail, an electrode member 307 is formed on the support post 303 and is electrically connected to the circuit board 302. The third electrode pad 134 of each light-emitting device 100 is connected to the circuit board 302 through a metal wire 308. Since the first electrode pad 131 is electrically connected to the third electrode pad 134, the first electrode pad 131 is also electrically connected to the circuit board 302. The second electrode pad 132 of each light-emitting device 100 is connected to the electrode member 307 through a metal wire 309. In this embodiment, the light-emitting devices 100 are connected in parallel with each other by the above-mentioned electrical connection method. In other embodiments, the light emitting devices 100 may be connected in series or in series.

FIG. 5A shows a manufacturing flow chart of the light-emitting device of the present invention. As shown in FIGS. 5A and 5B, step 501: provide a bracket 21. The bracket 21 includes two frames 211 and a plurality of carrier boards 11 connected between the two frames 211. The carrier board 11 has a circuit structure 13. The circuit structure 13 may be formed before or after the bracket 21 and the carrier board 11 are formed. For example, if the bracket 21 and the carrier plate 11 are formed on a single plate using a stamping technique, the circuit structure 13 may be pre-formed on the single plate or formed on the carrier plate 11 after the stamping step. As shown in FIGS. 5A and 5C, step 502: Fix the light-emitting units 12 on the carrier board 11 by using surface bonding technology (SMT), and the light-emitting units 12 are electrically connected to each other through the circuit structure 13. As shown in Figures 5A and 5D, Step 503: Use a casting method, such as injection molding or transfer molding, to form an optical structure 10 that covers the light-emitting unit 12 and the carrier plate 11 and exposes only the electrode pads 131 and 132. . As shown in FIGS. 5A and 5E, step 504: a punch or laser cutting process is performed to separate the carrier plate 11 and the two frames 211, so that a plurality of independent light-emitting devices 100 can be formed simultaneously or at a time.

It should be understood that the above-mentioned embodiments of the present invention can be combined or replaced with each other where appropriate, instead of being limited to the specific embodiments described. The embodiments listed in the present invention are only used to illustrate the present invention and are not intended to limit the scope of the present invention. Any obvious modifications or changes made by anyone to the present invention can be made without departing from the spirit and scope of the present invention.

Claims (10)

A light emitting device includes:
A first carrier board having a first portion and a second portion extending from the first portion;
A plurality of light emitting units are disposed on the second part;
A first electrode pad is disposed on the first part;
A conductive line is electrically connected to at least one of the plurality of light-emitting units and the first electrode pad;
A first reflective layer is located on the conductive circuit; and an optical structure includes a wavelength conversion substance disposed on the second portion and exposing the first portion,
Wherein, in a top view, the first portion is wider than the second portion. The light-emitting device according to item 1 of the scope of patent application, wherein the first carrier board has an upper surface and a lower surface opposite to the upper surface, the plurality of light-emitting units are disposed on the upper surface, and the light-emitting device A first brightness can be measured above the upper surface, and a second brightness can be measured below the lower surface. The ratio of the first brightness to the second brightness is between 2 and 9. The light-emitting device according to item 1 of the scope of patent application, wherein the first electrode pad is not covered by the optical structure. The light-emitting device according to item 1 of the patent application scope further includes a second electrode pad and the first electrode pad located on the same side of the first carrier plate. The light-emitting device described in item 1 of the scope of the patent application, further includes a second reflective layer on an opposite side of the first carrier plate relative to the plurality of light-emitting units. The light-emitting device according to item 1 of the scope of patent application, wherein each of the plurality of light-emitting units has a light-emitting body, and a reflective structure is located on the light-emitting body. A light bulb includes a light-emitting device and a lamp housing, and the light-emitting device is located in the lamp housing. The light bulb described in item 7 of the scope of patent application further includes a second carrier board, and the second carrier board is not parallel to the first carrier board. The light bulb described in item 8 of the scope of patent application, wherein each of the first carrier board and the second carrier board has a lower surface without a light emitting unit. As described in item 9 of the scope of patent application, wherein each of the lower surfaces faces the central axis of the bulb.