TW201705549A - Light-emitting device - Google Patents

Abstract

A light-emitting device includes a carrier with a first surface and a second surface opposite to the first surface; and a light-emitting unit disposed on the first surface and emitting a light toward the first surface without passing therethrough. A first light intensity of the light-emitting device is measured at a first side of the first surface, a second light intensity of the light-emitting device is measured at a second side of the second surface, and a ratio of the first light intensity to the second light intensity is in a range of 2~9.

Description

Illuminating device

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

Light-Emitting Diode (LED) for solid-state lighting devices has the characteristics of low energy consumption, long life, small size, fast response, and stable optical output. Therefore, the light-emitting diodes slowly replace the traditional ones. Lighting products are also used in general household 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 the LED filament still need to be improved. Furthermore, it is still a development goal to cause the light-emitting diode filament to emit an omnidirectional light field and to deal with heat dissipation problems.

The above and other objects, features, and advantages of the present invention will become more apparent and understood.

A light-emitting device includes a carrier plate having a first surface and a second surface opposite to the first surface, and a light-emitting unit disposed on the first surface to emit light toward but not through the first surface. The illuminating device can measure a first brightness above the first surface, and a second brightness can be measured under the second surface, and the ratio of the first brightness to the second brightness is 2-9.

The present invention will be described with reference to the drawings, in which the same or the same reference numerals are used in the drawings or the description, and in the drawings, the shape or thickness of the elements may be enlarged or reduced. It is to be noted that elements not shown or described in the figures may be in a form known to those skilled in the art.

FIG. 1A is a perspective view showing a light emitting device 100 according to an embodiment of the present invention. Fig. 1B only shows a schematic plan view of the carrier 11 in Fig. 1A. Fig. 1C only shows a bottom view of the carrier 11 in Fig. 1A. Fig. 1D is a cross-sectional view showing the 1A diagram and taken along line I-I of Fig. 1B. Fig. 1E is a schematic cross-sectional view showing the YZ direction of Fig. 1A. Referring to FIGS. 1A-1E, the light-emitting device 100 includes an optical structure 10, a carrier 11, and a plurality of light-emitting units 12. The carrier 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 of the upper surface 111 and connected to each other in series by the conductive lines 133. In other embodiments, the light-emitting units 12 may be connected in parallel, in series, or in a bridge structure by other conductive lines 133. In this embodiment, the carrier 11 is not penetrated (opaque) by the light emitted from the light-emitting unit 12, and therefore, even if the light-emitting unit 12 emits light toward the upper surface 111, it does not pass through the upper surface 111. The carrier board 11 can be a circuit board. The core layer of the circuit board comprises a metal, a thermoplastic material, a thermosetting material, or a ceramic material. The metal comprises an alloy of aluminum, copper, gold, silver or the like, a laminate, or a single layer. The thermosetting material comprises a phenolic resin (Phonetic), an epoxy resin (Epoxy), a Bismaleimide Triazine resin, or a combination thereof. The thermoplastic material comprises a polyimide resin, a polytetrafluorethylene or the like. The ceramic material includes aluminum oxide, aluminum nitride, tantalum 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 traces 1331, 1332 and the electrode pads 131, 132 to be electrically connected to the light-emitting unit 12 are exposed. The conductive line 1331 and the conductive line 1332 are physically separated from each other. In this embodiment, the conductive line 1332A and the electrode pad 131 are physically separated from each other and the conductive line 1331B and the electrode pad 132 are physically separated from each other. Each of the light-emitting units 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 the present embodiment, the exposed conductive lines 1331, 1332 are rectangular and have long sides parallel to the long sides of the carrier 11. In another embodiment, the long sides of the exposed conductive lines 1331, 1332 are parallel to the short sides of the carrier 11, or are at an angle of 0 to 90 与 with the long sides. Alternatively, the exposed conductive lines 1331, 1332 can be circular, elliptical, or polygonal. Further, the arrangement of the reflective layer 14 can help reflect the light emitted by the light emitting unit 12 toward the carrier 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 11 . The third electrode pad 134 and the fourth electrode pad 135 respectively correspond to the positions of the first electrode pad 131 and the second electrode pad 132. A first through hole 151 penetrates the carrier 11 and has a conductive material completely or partially formed therein to electrically connect the first electrode pad 131 and the third electrode pad 134. A second through hole 152 extends through the carrier 11 and has a conductive material completely or partially formed therein to electrically connect the second electrode pad 132 and the fourth electrode pad 135. In an implementation, an external power supply is connected to the first electrode pad 131 and the second electrode pad 132 respectively to enable the plurality of light emitting units 12 to 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 are electrically connected to the external power source by means of electric welding, the electrode pads 134, 135 are arranged to facilitate the clamping of the light-emitting device 100 during the process. Robustness and providing a conductive path. In one embodiment, when the electrode pads 131, 132 are electrically connected to an external power source by 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 11, and the side walls 113 on both sides of the long side of the carrier 11, but exposes the electrode pads 131, 132, 134, 135. . The optical structure 10 has a rectangular-like cross section. Fig. 1F is an enlarged view of Fig. 1E. The optical structure 10 has an arcuate top surface 101; two substantially linear and mutually parallel side surfaces 102; two side bottom surfaces 103; and a substantially planar bottom surface 104 connecting the two side bottom surfaces 103. The top surface 101 is located above the upper surface 111 of the carrier 11 and the bottom surface 104 is located below the lower surface 112 of the carrier 11. The side surface 102 extends from the top surface 101 along the Z direction toward the lower surface 112 of the carrier plate 11. Each of the bottom surfaces 103 includes a first portion 1031 extending from the side surface 102 toward the bottom surface 104 at an oblique angle; and a second portion 1302. The second portions 1302 on the left and right sides of the drawing 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 11 is spaced from the bottom surface 104 of the optical structure 10 by a first distance (D1) of 0.3 mm to 0.7 mm; the upper surface 111 of the carrier 11 is spaced from the top surface 101 of the optical structure 10 by 0.8. The second distance (D2) of mm~0.13 mm. The second distance (D2) is greater than the first distance (D1). The curved surface of the top surface 101 has a radius of curvature of 0.4 mm to 0.7 mm and has an arc angle θ1 (the center angle corresponding to the arc) is between 40 ∘ and 60 ∘ or an arc of 2 π / 9 ~π/3. The arc of the second portion of the side bottom surface 103 has a radius of curvature of 0.2 to 0.4 mm and has an arc angle θ2 (the center angle corresponding to the arc) between 5 ∘ 20 ∘ or one radians π/36~π/9. A diffusion powder (e.g., titanium dioxide, zirconium oxide, 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 percent concentration (w/w) of the diffusion 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 percent of the diffusion powder in the colloid can be measured by a thermogravimetric analyzer (TGA). Briefly, during the heating process, the colloid will be removed due to the gradual increase in temperature and after reaching a certain temperature (evaporation or thermal cracking), and the diffusion powder will remain. At this time, the change in weight can be known, so that it can be obtained. The respective weights of the colloid and the diffusion powder are used to derive the weight percent concentration of the diffusion powder in the colloid. Alternatively, the total weight of the colloid and the diffusion powder can be measured first, and then the solvent is used to remove the colloid, and finally the weight of the diffusion powder is measured, thereby obtaining the weight concentration of the diffusion powder in the colloid. In Fig. 1A, the light-emitting unit 12 is visible. However, when the diffusion powder is filled into the optical structure 10 and reaches a certain concentration, the optical structure 10 is rendered white and the internal light-emitting unit 12 is not visible.

The optical structure 10 is transparent to sunlight or light emitted by the illumination unit 12. The optical structure 10 comprises Silicone, Epoxy, Polyimine (PI), benzocyclobutene (BCB), Perfluorocyclobutane (PFCB), SU8, Acrylic Resin , polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), polycarbonate (PC), polyetherimide (Polyetherimide), fluorocarbon polymer (Fluorocarbon Polymer), alumina (Al ₂ O ₃ ), SINR, or spin-on glass (SOG).

FIG. 2A shows a schematic diagram of the path of light emitted by the illumination unit 12 in the optical structure 10. It should be noted that the path in the schema is only one of many possible paths, non-unique path, the same below. For example, the light (L) from the light-emitting unit 12 is incident on the curved top surface 101, and the light (L) generates a first refracted ray (L11) and a first reflected ray (L12) on the top surface 101. The first reflected light (L12) is incident on the side surface 102, and the second refracted ray (L21) and the second reflected light (L22) are generated on the side surface 102. The second reflected light (L22) is incident on the bottom surface 104, and a third refracted ray (L31) and a third reflected ray (L32) are generated at the bottom surface 104. Alternatively, as shown in FIG. 2B, for example, the light (M) from the light-emitting unit 12 is incident on the curved top surface 101, and the light (M) generates the first refracted light (M11) and the 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 the second refracted ray (M21) and the 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 ray (M31) and a third reflected ray (M32) are generated at the bottom surface 104. The 2C and 2D diagrams show a schematic representation of other possible travel paths of light in the optical structure 10. The shape of the optical structure 10 of the present invention is designed to increase the probability of light exiting from the lower surface 112 of the carrier 10 and the probability of light exiting from the bottom surface 104. The illuminating device 100 can measure a first brightness above the upper surface 111 (the first side), and a second brightness (the second side) below the lower surface 112, the ratio of the first brightness to the second brightness Between 2 and 9. The definitions of the first brightness and the second brightness can be referred to the subsequent description. It should be noted that the path in the schema is only one of many possible paths, not a unique path. Further, in the above description, the light is simultaneously refracted and reflected on the surface. However, the light may also be only refracted or reflected on the surface, depending on the refractive index difference of the material interface, the angle of incidence, the wavelength of the light, and the like.

FIG. 2E shows a light distribution graph obtained by the light-emitting device 100 under a current of 10 mA and in a thermal steady state. In detail, when the light-emitting device 100 emits light, the light-emitting luminance of an imaginary circle (such as the P1 circle in FIG. 1A) can be measured by using a light distribution curve meter. Further, a light distribution curve can be obtained by plotting the brightness of the light and the angle. At the time of measurement, the geometric center of the illuminating device 100 is substantially at the center of the P1 circle. In the present embodiment, the weight percent concentration of the diffusion powder in the optical structure 10 is 0.3%. As shown, the maximum brightness of the illumination device 100 is about 4.53 candelas (cd), and the brightness from 0 degrees to 180 degrees is roughly a lambertian distribution. Specifically, the brightness of -90 degrees is the smallest and is about 0.5 candle light (cd), the brightness of -90 degrees to -80 degrees is about the same, and the brightness of -80 degrees to 90 degrees is 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 relative to the distribution of light intensity at 90~180~-90 degrees. It is axisymmetric at a linear line of 90 to 90 degrees. In addition, the total brightness of 0~90~180 degrees in the light distribution graph is defined as the first brightness, and the total brightness of 0~-90~-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 illumination angle of the light-emitting device 100 is about 160 degrees.

The illuminating angle is defined as the illuminating angle when the brightness is 50% of the maximum brightness. For example, first convert the light distribution curve (polar coordinates) measured on the P1 circle in the 2E image into a rectangular coordinate map to obtain a brightness curve; wherein the X axis is the brightness and the Y axis is the angle (the figure is not shown) ). Next, draw a line parallel to the X-axis at about 2.265 candlelight (50% of maximum brightness) and intersect the brightness curve at two points; calculate the angular range between the two points, which is defined as the illumination angle.

Fig. 3A is a cross-sectional view showing a light emitting unit 12A in an embodiment of the present invention. The light emitting unit 12A includes a light emitting body 121, a first transparent body 122, a phosphor powder 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 shown above), and two electrodes 1211. When the illuminating body 121 is a heterostructure, the first type semiconductor layer and the second type semiconductor layer are, for example, a cladding layer and/or a confinement layer, respectively, and can respectively provide electrons, 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 comprise a III-V semiconductor material such as Al _x In _y Ga _(1-xy) N or Al _x In _y Ga _(1-xy) P, wherein 0≦x, y≦1; (x+y)≦1. According to the material of the active layer, the illuminating body 121 can emit a red peak with a peak wavelength or a dominant wavelength between 610 nm and 650 nm, and the peak or dominant wavelength is between 530 nm and 570 nm. Green light, or blue light with a peak or dominant wavelength between 450 nm and 490 nm. The phosphor structure 123 comprises a plurality of phosphor particles. The phosphor particles have a particle size (diameter) of about 5 um to 100 um and may contain one or more types of phosphor materials. Fluorescent powder materials include, but are not limited to, yellow-green phosphor powder and red phosphor powder. The components of the yellow-green phosphor are, for example, aluminum oxide (YAG or TAG), citrate, vanadate, alkaline earth metal selenide, or metal nitride. The components of the red phosphor are, for example, fluoride (K ₂ TiF ₆ : Mn ⁴⁺ , K ₂ SiF ₆ : Mn ⁴⁺ ), citrate, vanadate, alkaline earth metal sulfide, metal oxynitride, or tungsten. a mixture of molybdate groups. The phosphor structure 123 can absorb the first light emitted by the light-emitting body 121 and be converted into a second light of a different 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 in 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 is mixed with the second light to produce violet, yellow, or other non-white light.

The light emitting unit 12 further includes an insulating layer 126 formed on the first transparent body 122, a phosphor layer 123 and the second transparent body 124 and not covering the two electrodes 1211 of the light emitting body 121; and the two extending electrodes 127 are respectively formed on The two electrodes 1211 are electrically connected to the two electrodes 1211. The two extension electrodes 127 are respectively formed as the first connection pad 120A and the second connection pad 102B (as shown in FIG. 1D). The insulating layer 126 is a mixture comprising a matrix and a high reflectivity material. The matrix can be either a silicone matrix or an epoxy matrix. The high reflectivity material may comprise titanium dioxide, cerium oxide or aluminum oxide. Further, the insulating layer 126 may have a function of reflecting light or diffusing light. The extension electrode 127 contains a metal such as copper, titanium, gold, nickel, silver, an alloy thereof, or a laminate thereof. The first transparent body 122, the second transparent body 124, and the third transparent body 125 are transparent to sunlight or the light emitted by the light emitting unit 12. The first transparent body 122 or the second transparent body 124 may comprise Silicone, Epoxy, Polyimidine (PI), benzocyclobutene (BCB), Perfluorocyclobutane (PFCB) , SU8, Acrylic Resin, Polymethyl Methacrylate (PMMA), Polyethylene terephthalate (PET), Polycarbonate (PC), Polyetherimide, Fluorocarbon Fluorocarbon Polymer, alumina (Al ₂ O ₃ ), SINR, or spin-on glass (SOG). A third transparent body 125 may include sapphire (Sapphire), diamond (Diamond), glass (Glass), an epoxy resin (Epoxy), quartz (quartz), acrylic resin (Acrylic Resin), silicon oxide (SiO _X), alumina (Al ₂ O ₃ ), zinc oxide (ZnO), or silicone (Silicone).

As shown in Fig. 3A, the third transparent body 125 has a shape that is wide and narrow. In detail, the third transparent body 125 has a first portion 1251 and a second portion 1252. The second portion 1252 is closer to the second transparent body 124 and has a width smaller than the width of the first portion 1251. The thickness of the first portion 1251 is about 1% to 20% or 1% to 10% of the entire thickness of the third transparent body 125. In this embodiment, the junction of the first portion 1251 and the second portion 1252 is an arc. The first portion 1251 has a side surface 1251S which is slightly inclined upward (face up) and is away from the light emitting body 121 than the side surface 1241 of the second transparent body 124 to 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 toward five faces (up and down, left and right) and has a beam angle of about 140 degrees. Alternatively, a diffusion 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 cross-sectional view showing a light emitting unit 12B in another embodiment of the present invention. Figure 3C is a top view of Figure 3B. The illuminating unit of Fig. 3B is similar to the illuminating device of Fig. 3A, and the same symbols or elements or devices corresponding to the symbols 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 a slope 1254. The design of the slope 1254 can increase the amount of light extraction 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 sandwiched at an angle of 120 ∘ to 150 Ф (Ф) 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 (A1; triangle) of the plane 1253 may be 40% to 95% or 40% to 60% of the total projected area (A; oblique line) of the third transparent body 125'.

Fig. 3D is a cross-sectional view showing a light emitting unit 12D in another embodiment of the present invention. The illumination unit of Fig. 3D is similar to the illumination device of Fig. 3A, and the same symbols or elements or devices corresponding to the symbols 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 greater than 85% for light incident on the reflective structure 129 between 450 nm and 475 nm, or between 400 nm and 600 nm for incident light. Has a reflectivity greater than 80%. Light that is not reflected by the reflective structure 129 can enter the third transparent body 125 and exit 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 a plurality of rays, for example, a reflectance greater than 95%, the third transparent body 125 in the light emitting unit 12D can be omitted. The reflective structure 129 can be a single layer structure or a multilayer structure. The single layer structure is, for example, a metal layer comprising, for example, silver or aluminum, or an oxide layer comprising, for example, titanium dioxide. The multilayer structure may be a laminate of metal and metal oxide or a distributed Bragg reflector (DBR) to achieve reflection. A laminate of a metal and a metal oxide such as a laminate of aluminum and aluminum oxide. The decentralized Bragg mirrors can be non-semiconductor laminates or semiconductor stacks. The material of the non-semiconductor laminate may be selected from one of the group consisting of alumina (Al ₂ O ₃ ), cerium oxide (SiO ₂ ), titanium dioxide (TiO ₂ ), niobium pentoxide (Nb ₂ O ₅ ), nitriding.矽 (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, the light is not completely reflected, whether it is a single layer structure or a multilayer structure, so that at least part of the light passes directly through the reflection structure 129.

In another embodiment, the light-emitting unit 12 in FIG. 1A may have a structure similar to that of the light-emitting units 12A, 12B, and 12D in the 3A, 3B, or 3D drawings, but the phosphor layer 123 is not included in the structure. 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 converting substances) may be added to the optical structure 10 to absorb the first light emitted by the light emitting body 121 and converted into a second light having a different spectrum from the first light, the first light and the second light. Light mixing produces white light. Therefore, the light-emitting device 100 can have a white color temperature of 2200K~6500K (for example, 2200K, 2400K, 2700K, 3000K, 5700K, 6500K) under thermal steady state, and its color point value (CIE x, y) will fall under seven. The range of MacAdam ellipse and has a color rendering (CRI) greater than 80 or greater than 90.

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

Figure 4 is a perspective view of a bulb 30 in accordance with one 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. A 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 electrically connected to the circuit board 302. The third electrode pad 134 of each of the light emitting devices 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 of the light-emitting devices 100 is connected to the electrode member 307 through a metal wire 309. In the present embodiment, the light-emitting devices 100 are connected in parallel to each other by the above-described electrical connection. In other embodiments, the light emitting devices 100 can be connected to each other in series or in series and connected.

Fig. 5A is a flow chart showing the fabrication of the light-emitting device of the present invention. As shown in Figures 5A and 5B, step 501: providing a bracket 21. The bracket 21 has two frames 211 and a plurality of carrier plates 11 connected between the two frames 211. The carrier board 11 has a circuit structure 13 which can be formed before or after the carrier 21 and the carrier board 11 are formed. For example, if the bracket 21 and the carrier 11 are formed on a single plate by a press forming technique, the circuit structure 13 may be pre-formed on the single plate or formed on the carrier 11 after the press forming step. As shown in FIGS. 5A and 5C, step 502: the light-emitting unit 12 is fixed to the carrier 11 by surface bonding technology (SMT), and the light-emitting units 12 are electrically connected to each other by the circuit structure 13. As shown in FIGS. 5A and 5D, step 503: forming an optical structure 10 by a molding method, for example, injection molding or transfer molding, so as to cover the light-emitting unit 12 and the carrier. 11 and only the electrode pads 131, 132 are exposed. Step 504 as shown in Figures 5A and 5E: a punch or laser cutting process is performed to separate the carrier 11 from the two frames 211, whereby a plurality of mutually independent illumination devices 100 can be formed simultaneously or at one time.

It is to be understood that the above-described embodiments of the present invention may be combined or substituted with each other as appropriate, and are not limited to the specific embodiments described. The examples of the invention are intended to be illustrative only and not to limit the scope of the invention. Any obvious modifications or variations of the present invention are possible without departing from the spirit and scope of the invention.

100‧‧‧Lighting device
10‧‧‧Optical structure
101‧‧‧ top surface
102‧‧‧ side surface
103‧‧‧ side bottom surface
1031‧‧‧Part 1
1032‧‧‧Part II
104‧‧‧ bottom surface
11‧‧‧ Carrier Board
111‧‧‧Upper surface
112‧‧‧ lower surface
12, 12A, 12B, 12D‧‧‧ lighting units
120A‧‧‧First connection pad
120B‧‧‧Second connection pad
121‧‧‧Lighting subject
1211‧‧‧electrode
122‧‧‧ first transparent body
123‧‧‧Fluorescent powder layer
124‧‧‧Second transparent body
125, 125'‧‧‧ third transparent body
1251‧‧‧Part 1
1251S‧‧‧ side surface
1252‧‧‧Part II
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 lines
134‧‧‧ third electrode pad
135‧‧‧fourth electrode pad
151‧‧‧ first through hole
152‧‧‧second through hole
21‧‧‧ bracket
211‧‧‧Frame
30‧‧‧Light bulb
301‧‧‧ lamp shell
302‧‧‧ boards
303‧‧‧Support column
304‧‧‧ Heat sink
305‧‧‧Electrical connectors
307‧‧‧Electrode parts
308, 309‧‧‧ metal wire

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

Fig. 1B is a top plan view showing the carrier in Fig. 1A.

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

Fig. 1D is a cross-sectional view showing the 1A diagram and taken along line I-I of Fig. 1B.

Fig. 1E is a schematic cross-sectional view showing Fig. 1A.

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

Figures 2A-2D show schematic diagrams of different paths of travel of the light emitted by the illumination unit in the optical structure, respectively.

Fig. 2E is a view showing a light distribution curve of the light-emitting device in an embodiment of the present invention.

Fig. 3A is a cross-sectional view showing a light emitting unit in an embodiment of the present invention.

Figure 3B is a cross-sectional view showing one of the light emitting units in another embodiment of the present invention.

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

Figure 3D is a cross-sectional view showing one of the light-emitting units in another embodiment of the present invention.

Fig. 4 is a perspective view showing a light bulb in an embodiment of the present invention.

Fig. 5A is a flow chart showing the fabrication of a light-emitting device according to an embodiment of the present invention.

5B-5E are schematic perspective views showing a manufacturing process of a light-emitting device according to an embodiment of the present invention.

no

no

100‧‧‧Lighting device

10‧‧‧Optical structure

11‧‧‧ Carrier Board

12‧‧‧Lighting unit

131‧‧‧First electrode pad

132‧‧‧Second electrode pad

Claims (10)

A light emitting device comprising: a carrier having a first surface and a second surface opposite to the first surface; and a light emitting unit disposed on the first surface to emit light toward but not through the a first surface; wherein the illuminating device can measure a first brightness above the first surface, and a second brightness under the second surface, the ratio of the first brightness to the second brightness It is 2~9. The illuminating device of claim 1, further comprising an optical structure penetrated by the light and having a top surface above the first surface and a bottom surface below the second surface . The illuminating device of claim 2, wherein the optical structure further has a side surface extending from the top surface toward the bottom surface. The illuminating device of claim 3, wherein the side surface has an arcuate region having an arc of between π/36 and π/9. The illuminating device of claim 2, wherein the optical structure further has a side bottom surface having a portion having an arc shape and having an arc of between 2π/9 and π/3. The illuminating device of claim 2, wherein the ray is traversable through the bottom surface. The illuminating device of claim 2, wherein the optical structure further comprises a wavelength converting substance dispersed therein. The illuminating device of claim 2, wherein the optical structure further comprises a diffusion powder having a concentration by weight of 0.1 to 0.5% of the optical structure. The illuminating device of claim 1, wherein the illuminating unit has a illuminating body, a first transparent structure covers the illuminating body, and a second transparent structure is formed on the first transparent structure. The illuminating device of claim 9, wherein the illuminating unit further comprises a reflective structure formed between the first transparent structure and the second transparent structure.