TWI757315B - Light-emitting device and manufacturing method thereof - Google Patents

Abstract

A light-emitting device includes a light-emitting element, a wavelength conversion layer and a reflective wall. The light-emitting element has a first top surface, a bottom surface and a lateral surface arranged between the first top surface and the bottom surface. The wavelength conversion layer has a wavelength conversion material and includes a second top surface covering the first top surface. The reflective wall surrounds the lateral surface of the light-emitting element, and directly contacts the wavelength conversion layer. A step is formed between the reflective wall and the second top surface. The light-emitting device has a light angle of 110° to 118°.

Description

Light-emitting device and method of manufacturing the same

The present invention relates to a light-emitting device and a manufacturing method thereof, and more particularly, to a light-emitting device including a wavelength conversion layer and a reflective fence and a manufacturing method thereof.

Light-Emitting Diode (LED) has the characteristics of low power consumption, low calorific value, long operating life, impact resistance, small size and fast response speed, so it is widely used in various fields that require the use of light-emitting elements. For example, vehicles, home appliances, and lighting fixtures.

LED is a monochromatic light, which needs to be mixed with other colors of light if it is to be used as a white light emitting device. There are several ways to mix other colors of light, for example, a wavelength conversion layer, such as a phosphor layer, can be covered on the LED to achieve this purpose. Phosphor powder is a kind of photoluminescent material, which can absorb the first light emitted by LED and emit second light of different spectrum. In the case where the first light is not completely consumed, after the unconsumed first light and the second light are mixed with each other, mixed light of another color, such as white light, can be formed.

The LED white light emitting device has different requirements for the luminous angle in different applications, but the luminous angle of the general LED white light emitting device may not necessarily meet the required application.

The invention discloses a light-emitting device comprising a light-emitting element, a wavelength conversion layer and a reflection fence. The light-emitting element includes an upper surface, a lower surface, and a side surface between the upper surface and the lower surface. The wavelength conversion layer includes a wavelength conversion material, and includes a second upper surface covering the first upper surface. The reflective fence surrounds the side surface of the light-emitting element, directly contacts the wavelength conversion layer, and has a distance from the second upper surface. The light-emitting angle of the light-emitting device is between 110 degrees and 118 degrees.

The present invention discloses a method for forming a light-emitting device. A plurality of light-emitting elements are formed on a carrier board. A wavelength conversion film is covered on these light-emitting elements. Part of the wavelength conversion film is removed to form a plurality of wavelength conversion layers. A reflective layer is covered on the wavelength conversion layers. Part of the reflective layer is removed to form a reflective frame and the wavelength conversion layers are exposed, wherein at least one wavelength conversion layer and the reflective frame form a gap. Parts of the reflective frame are separated to form a plurality of reflective fences.

FIG. 1A is a cross-sectional view of a light-emitting device 100 disclosed according to an embodiment of the present invention. The light-emitting device 100 includes a light-emitting element 120 , a wavelength conversion layer 140 and a reflection fence 160 . In this embodiment, the light emitting device 100 further includes a reflective layer 150 (a first reflective layer) and a conductive portion 180 . In another embodiment, the light emitting device 100 does not include the reflective layer 150 and the conductive portion 180 . The wavelength conversion layer 140 covers a part of the surface of the light emitting element 120 . In addition, the reflective fence 160 surrounds the wavelength conversion layer 140 . Specifically, referring to FIG. 1B , the reflective fence 160 surrounds the light-emitting element 120 and the wavelength conversion layer 140 at the same time. Referring to FIG. 1A , the light emitting device 100 includes a top surface 102 , a bottom surface 104 and a plurality of side surfaces 106 , and the side surfaces 106 are located between the top surface 102 and the bottom surface 104 .

In one embodiment, the light-emitting element 120 includes a carrier substrate 122 , a light-emitting layer 124 and a contact electrode 126 . One side of the light-emitting layer 124 faces the carrier substrate 122 , and the other side faces the contact electrode 126 . In addition, the light-emitting element 120 includes an upper surface 121 , a lower surface 123 and a plurality of side surfaces 125 , and the side surfaces 125 are located between the top surface 121 and the bottom surface 123 . The carrier substrate 122 may be used to carry or support the light emitting layer 124 . In addition, the light emitted by the light emitting layer 124 may pass through the carrier substrate 122 . To further illustrate, the side of the carrier substrate 122 away from the light-emitting layer 124 is also the upper surface 121 of the light-emitting element 120 , that is, the light-emitting surface of the light-emitting element 120 . In one embodiment, the carrier substrate 122 is a growth substrate, such as a sapphire substrate, which is used as a substrate for epitaxial growth of the light-emitting layer 124 . In another embodiment, the carrier substrate 122 is not a growth substrate, and the growth substrate is removed or replaced with other substrates (eg, substrates of different materials, structures, or shapes) during the manufacturing process of the light emitting device 100 .

In one embodiment, the light emitting layer 124 includes a first semiconductor layer, an active layer, and a second semiconductor layer (not shown). The first semiconductor layer may be an n-type semiconductor layer, and the second semiconductor layer may be a p-type semiconductor layer. In one embodiment, the contact electrode 126 includes two contact electrodes 126a and 126b located on the same side of the light emitting element 120 as an interface for the electrical connection between the light emitting element 120 and the outside world. The lower surface 123 includes the surfaces of the two contact electrodes 126a and 126b. Therefore, in FIG. 1A, the lower surface 123 refers to a part of the bottom surface of the light emitting layer 124 and the surfaces of the contact electrodes 126a and 126b. The contact electrodes 126a and 126b are electrically connected to the first semiconductor layer and the second semiconductor layer, respectively. In addition, the contact electrodes 126a and 126b may protrude (below) the bottom surface of the wavelength conversion layer 140 (as shown), or be approximately flush with the bottom surface (not shown), or only one of them may protrude from the bottom surface (not shown). ). The side surface 125 includes the side surface of the carrier substrate 122 and the light emitting layer 124 . The side surface 125 can also be the light-emitting surface of the light-emitting element 120 . In one embodiment, the light emitting element 120 has four side surfaces 125, and the opposite side surfaces 125 are substantially parallel to each other, that is, the light emitting element 120 is square, rectangular or parallelogram in the top view. Parts of the upper surface 121 and the lower surface 123 are also substantially parallel to each other. In one embodiment, the light emitting element 120 is a flip chip LED die.

The light emitting element 120 can be a light emitting diode die (LED die), such as but not limited to a blue light emitting diode die or an ultraviolet (UV) light emitting diode die. In one embodiment, the light-emitting element 120 is a blue light-emitting diode die, which can provide a power through a power source to emit a first light, and the dominant wavelength or peak wavelength of the first light is between 430 between nm and 490 nm. In another embodiment, the light-emitting element 120 is a violet light-emitting diode die, and the dominant wavelength or peak wavelength of the first light is between 400 nm and 430 nm. In another embodiment, the light-emitting element 120 is an ultraviolet light-emitting diode die, and the peak wavelength of the first light is between 315 nm and 400 nm or between 280 nm and 315 nm. .

The wavelength conversion layer 140 may include an adhesive 142 and a plurality of wavelength conversion particles 144 dispersed in the adhesive 142, wherein the wavelength conversion particles 144 can absorb the first light emitted by the light emitting element 120 and convert part or all of it into The second light with different wavelengths or spectrums of the first light. The color emitted by the second light is, for example, green light, yellow-green light, yellow light, amber light, orange-red light or red light. In one embodiment, the second light emitted by the wavelength conversion particles 144 after absorbing the first light (eg, blue light or UV light) is yellow light, and its dominant wavelength or peak wavelength is between 530 nm and 590 nm. In another embodiment, the second light emitted by the wavelength conversion particles 144 after absorbing the first light (eg, blue light or UV light) is green light, and its dominant wavelength or peak wavelength is between 515 nm and 575 nm. In other embodiments, the second light emitted by the wavelength conversion particles 144 after absorbing the first light (eg, blue light or UV light) is red light, and its dominant wavelength or peak wavelength is between 600 nm and 660 nm.

The wavelength converting layer 140 may contain a single type or multiple types of wavelength converting particles 144 . In one embodiment, the wavelength converting layer 140 includes a single type or multiple wavelength converting particles that can emit yellow light. In another embodiment, the wavelength conversion layer 140 includes various wavelength conversion particles that can emit green and red light. In this way, in addition to the second light emitting green light, the third light emitting red light is also included, and a mixed light can be generated with the unabsorbed first light ray. In another embodiment, the first light rays are completely or almost completely absorbed by the wavelength converting particles in the wavelength converting layer 140 . As used herein, "almost completely" means that the light intensity at the peak wavelength of the first light in the mixed light is less than or equal to 3% of the light intensity at the peak wavelength of the second light and/or the third light. The wavelength conversion layer 140 may also be composed of a multi-layer structure (not shown). In one embodiment, the wavelength conversion layer 140 includes a layer containing the wavelength conversion particles 144 and another light diffusion layer (not shown). The wavelength conversion layer 140 containing various wavelength conversion particles may have a single-layer structure or a multi-layer structure. The monolayer structure means that a plurality of wavelength converting particles are uniformly or non-uniformly distributed in a single layer. The multi-layer structure means that a single type of wavelength conversion particles is generally only distributed in a single layer, and different types of wavelength conversion particles have relatively distinct and distinguishable interfaces. In one embodiment, the wavelength conversion layer 140 includes a short wavelength wavelength conversion layer and a long wavelength wavelength conversion layer. The short-wavelength wavelength conversion layer mentioned herein refers to wavelength conversion particles containing relatively short emission peaks, for example, the peaks are between 510 nm and 590 nm. Long-wavelength wavelength-converting layers refer to wavelength-converting particles containing relatively long emission peaks, for example, between 600 nm and 660 nm. In one embodiment, the long wavelength wavelength conversion layer is closer to the light emitting element 120 than the short wavelength wavelength conversion layer.

The binder 142 can disperse the wavelength conversion particles 144 in space, and can fix the relative positions of the wavelength conversion particles 144 to each other. Generally speaking, the higher the concentration (or weight percentage) of the wavelength converting particles 144, the more light from the light-emitting element 100 can be converted into another light (the higher the conversion ratio). However, if the concentration of the wavelength conversion particles 144 is too high, it means that the content of the binder 142 is too small, and the wavelength conversion particles 144 may not be effectively fixed. In one embodiment, the weight percentage of the wavelength conversion particles 144 in the wavelength conversion layer 140 is below 70%. In another embodiment, the weight percentage of the wavelength conversion particles 144 in the wavelength conversion layer 140 is 20%-60%. The wavelength conversion particles 144 can obtain better conversion ratio and scattering effect in the above-mentioned weight percentage range, and can be effectively fixed in the position in space. In one embodiment, the light emitted by the light-emitting element 100 is mixed with another light converted by the wavelength conversion particles 144 to produce white light, and the color temperature of the white light in the light-emitting device 100 can be transmitted through the light emitted by the light-emitting element 100 and the wavelength conversion particles. 144 Scale adjustment of another ray emitted. In one embodiment, the color temperature of the light emitting device 100 is between 1900K and 6000K. In addition, in order to enable the first light ray that excites the wavelength conversion particles 144 and the second light rays emitted by the wavelength conversion particles 144 to have high light extraction efficiency, the adhesive 142 has a high penetration rate for the first light and the second light. The rate is better, for example, the penetration rate is greater than 80%, 90%, 95% or 99%.

The material of the adhesive 142 can be thermosetting resin, and the thermosetting resin can be epoxy resin or silicone resin. In one embodiment, the adhesive 142 is silicone resin, and the composition of the silicone resin can be adjusted according to the requirements of required physical properties or optical properties. In one embodiment, the adhesive 142 contains an aliphatic silicone resin, such as a methyl siloxane compound, which has greater ductility and is better able to withstand the thermal stress generated by the light-emitting element 110 . In another embodiment, the adhesive 142 contains an aromatic silicone resin, such as a phenylsiloxane compound, which has a larger refractive index than a methylsiloxane compound, which can improve the light extraction efficiency of the light-emitting element 110 . The smaller the difference between the refractive index of the adhesive 142 and the refractive index of the material of the light emitting surface of the light emitting element 120 is, the larger the angle of light exit is, and the efficiency of light extraction can be further improved. In one embodiment, the material of the light-emitting surface of the light-emitting element 120 is sapphire, and its refractive index is about 1.77, and the material of the adhesive 142 is an aromatic silicone resin, and its refractive index is greater than 1.50.

The material of the wavelength conversion particles 144 may include inorganic phosphor, organic fluorescent colorant, semiconductor material, or a combination of the above materials. The semiconductor material includes nano-crystalline semiconductor materials, such as quantum-dot light-emitting materials. In one embodiment, the material of the wavelength conversion particles 144 is phosphor powder, which can be selected from Y ₃ Al ₅ O ₁₂ : Ce, Gd ₃ Ga ₅ O ₁₂ : Ce, Lu ₃ Al ₅ O ₁₂ : Ce, (Lu, Y) ₃ Al ₅ O ₁₂ : Ce, Tb ₃ Al ₅ O ₁₂ : Ce, SrS: Eu, SrGa ₂ S ₄ : Eu, (Sr, Ca, Ba) (Al, Ga) ₂ S ₄ : Eu , (Ca, Sr) S: (Eu, Mn), (Ca, Sr) S: Ce, (Sr, Ba, Ca) ₂ Si ₅ N ₈ : Eu, (Sr, Ba, Ca) (Al, Ga) Si N ₃ : Eu, SrLiAl ₃ N ₄ : Eu ²⁺ , CaAlSi ON: Eu, (Ba, Sr, Ca) ₂ SiO ₄ : Eu, (Ca, Sr, Ba) ₈ MgSi ₄ O ₁₆ (F, Cl, Br) ₂ : the group consisting of Eu, (Ca, Sr, Ba)Si ₂ O ₂ N ₂ : Eu, K ₂ SiF ₆ : Mn, K ₂ TiF ₆ : Mn, and K ₂ SnF ₆ : Mn. The semiconductor material may comprise II-VI semiconductor compounds, III-V semiconductor compounds, IV-VI semiconductor compounds, or combinations thereof. The quantum dot light-emitting material can include a core region (core) that mainly emits light and a shell (shell) that coats the core region, and the material of the core region can be selected from zinc sulfide (ZnS), zinc selenide (ZnSe), zinc telluride (ZnTe), zinc oxide (ZnO), cadmium sulfide (CdS), cadmium selenide (CdSe), cadmium telluride (CdTe), cesium lead chloride (CsPbCl ₃ ), cesium lead bromide (CsPbBr ₃ ), iodide Cesium lead (CsPbI ₃ ), gallium nitride (GaN), gallium phosphide (GaP), gallium selenide (GaSe), gallium antimonide (GaSb), gallium arsenide (GaAs), aluminum nitride (AlN), phosphorus Aluminum (AlP), Aluminum Arsenide (AlAs), Indium Phosphide (InP), Indium Arsenide (InAs), Tellurium (Te), Lead Sulfide (PbS), Indium Antimonide (InSb), Lead Telluride (PbTe) ), lead selenide (PbSe), antimony telluride (SbTe), zinc cadmium selenide (ZnCdSe), zinc cadmium selenium sulfide (ZnCdSeS), and copper indium sulfide (CuInS).

The wavelength conversion layer 140 may cover one or more light-emitting surfaces of the light-emitting element 120 . In one embodiment, the light-emitting surface of the light-emitting element 120 includes an upper surface 121 and a side surface 125 , and the wavelength conversion layer 140 covers the upper surface 121 and the side surface 125 of the light-emitting element 120 at the same time. In addition, in one embodiment, the wavelength conversion layer 140 is in direct contact with the upper surface 121 and several side surfaces 125 of the light-emitting element 120 . In another embodiment, the wavelength conversion layer 140 only covers the upper surface 121 (not shown) of the light emitting element 120 .

The reflective fence 160 surrounds the light emitting element 120 and the wavelength conversion layer 140 , so that the reflective fence 160 can reflect the first light emitted by the light emitting element 120 and the second light converted by the wavelength conversion layer 140 to emit light from the top surface 102 of the light emitting device 100 . In one embodiment, the reflective fence 160 surrounds the side surface 125 of the light emitting element 120 and the side surface of the wavelength conversion layer 140 and exposes the upper surface 121 of the light emitting element 120 and the upper surface 141 of the wavelength conversion layer 140 . In one embodiment, there is a gap between the reflection fence 160 and the wavelength conversion layer 140 , and the reflection fence 160 is higher than the wavelength conversion layer 140 . In this way, part of the light emitted from the upper surface 141 of the wavelength conversion layer 140 can be reflected by the reflection fence 160 , which can improve the light extraction rate when the light-emitting device 100 is connected to the optical element. For specific description, referring to FIG. 2 , the light emitting device 220 is used as a light source to emit a light L1 , which passes through an optical element 240 and then emits light L2 . When all the light rays L1 are within the angle θ ₁ , it means that all the light rays L1 can be utilized by the optical element 240 . In other words, the etendue of the light source is less than the etendue of the system. If the light ray L1 is within the larger angle θ ₂ , there will be some light sources that cannot be utilized by the optical element 240 . Through the design of the reflection fence 160 higher than the wavelength conversion layer 140 in the present invention, more light rays L1 can fall within the angle θ ₁ , thereby improving the light extraction rate. Referring to FIG. 1A , in one embodiment, the top surface 162 of the reflective fence 160 is higher than the upper surface 141 of the wavelength conversion layer 140 (ie, the height h of the step difference) is between 5 micrometers (μm) and 100 micrometers, the light emitting device 100 The light-emitting angle is between 110 degrees and 118 degrees. The light emission angle refers to the angle corresponding to half of the maximum light intensity. In another embodiment, the level difference h is between 5 micrometers (μm) and 50 micrometers. When the level difference h is less than 5 microns, the light emission angle is about 120〬. Therefore, the light emitting angle difference between the light emitting device 100 with the height difference between 5 μm and 100 μm relative to the light emitting device 100 with the height difference less than 5 μm (comparative example) is between 2 degrees and 10 degrees. When the level difference h is greater than 100 μm, when the light emitting device 100 is matched with the optical element (see FIG. 5 ), the reflection fence 160 and the optical element are very close, so the reflection fence 160 may interfere with the optical element. In one embodiment, the height h of the step difference, the height of the wavelength conversion layer 140 and the thickness of the reflective layer 150 are added together to be about the overall thickness H of the light emitting device 100 , wherein the ratio of h to H (h/H) is 0.01 to 0.4. In another embodiment, the ratio of h to H (h/H) is between 0.015 and 0.2. Within the range of the above h/H ratio, on the one hand, the reflection effect of the reflective fence 160 can be improved, and on the other hand, the required height of the wavelength conversion layer 140 in the light emitting device 100 can be satisfied.

In one embodiment, the reflective fence 160 includes resin and reflective particles dispersed in the resin, such as titanium oxide, zinc oxide, aluminum oxide, barium sulfate or calcium carbonate. In one embodiment, the reflective particles are titanium oxide, and the weight percentage of titanium oxide relative to the reflection fence 160 is not less than 60%. In another embodiment, the weight percentage of titanium oxide relative to the reflection fence 160 is 20% to 60%. between. In one embodiment, the thickness T of the reflective fence 160 is between 20 micrometers (μm) and 200 micrometers.

The reflection layer 150 is formed on the bottom surface of the light emitting element 120 , the wavelength conversion layer 140 and the reflection fence 160 . In one embodiment, the reflective layer 150 directly contacts the light emitting element 120 (as shown). In another implementation, the reflective layer 150 does not directly contact the light-emitting element 120 (not shown). The reflective layer 150 forms a plurality of through holes to expose the contact electrodes 126a and 126b. In one embodiment, the reflective layer 150 can reflect the light emitted by the light emitting device 100 , so the light emitting efficiency of the light emitting device 100 can be improved. In one embodiment, the reflective layer 150 includes an adhesive (not shown) and reflective particles (not shown) dispersed in the adhesive. The material of the adhesive can be silicone resin or epoxy resin. The material of the reflective particles contains titanium oxide, aluminum oxide or zinc oxide. In addition, the reflective layer 150 surrounding the conductive parts 180 can also reduce the risk of short circuits between the conductive parts 182 and 184 .

The conductive parts 180 are respectively filled in the through holes and surrounded by the reflective layer 150 . The conductive portion 180 can be used for physical and electrical connection between the contact electrodes 126a and 126b of the light-emitting element 120 and the circuit board (not shown). The higher the bonding strength between the conductive portion 180 and the conductive pads 126a and 126b, the less likely the problem of peeling occurs. The material of the conductive portion 180 can be a conductive metal material with a lower melting point. In one embodiment, the temperature of the melting point (or liquefaction point) of the material of the conductive portion 180 is preferably not higher than 280°C. In another embodiment, the material of the conductive portion 180 includes pure tin or tin alloy. Types of tin alloys such as: tin-silver alloy (Sn/Ag alloy), tin-silver-copper alloy (Sn/Ag/Cu alloy), tin-copper alloy (Sn/Cu alloy), tin-lead alloy (Sn/Pb alloy) or tin Antimony alloy (Sn/Sb alloy). The conductive part 180 may be a single-layer or multi-layer structure. In one embodiment, the conductive portion 180 is a single-layer structure, and the material is tin alloy. In yet another embodiment, the conductive portion 180 is a multi-layer structure, and the metal close to or in direct contact with the contact electrodes 126a and 126b has a higher melting point; the metal away from or not in direct contact with the contact electrodes 126a and 126b has a lower melting point. In one embodiment, the high melting point metal is a tin-antimony alloy (the first tin alloy), and the low melting point metal is a tin-silver-copper alloy (the second tin alloy). In another embodiment, the metal with high melting point is copper, and the metal with low melting point is tin alloy (including but not limited to tin-antimony alloy, tin-silver-copper alloy).

FIGS. 3A to 3F and FIGS. 3H to 3K show a manufacturing flow chart of a light emitting device according to an embodiment of the present invention. Referring to FIG. 3A, a temporary substrate 312 is provided, an adhesive layer 314 is formed on the temporary substrate 312, and the light-emitting elements 120a, 120b, 120c are located on the adhesive layer 314, wherein the number of light-emitting elements is only By way of example, it is not limited to three, and there may be more or less than three. In one embodiment, the temporary substrate 312 is a glass, a sapphire substrate, a metal or a plastic material, which can be used as a support. The adhesive layer 314 can be used for temporarily fixing the light-emitting elements 120a, 120b, and 120c. In one embodiment, the adhesive layer 314 is a thermal curing adhesive. In this step, the adhesive layer 314 has not been fully cured and still has adhesive properties. In another embodiment, the adhesive layer 314 may be a photo curing adhesive.

Referring to FIG. 3B, a wavelength conversion film 140' is formed on the adhesive layer 314 and covers the light-emitting elements 120a, 120b, and 120c at the same time. The wavelength conversion film 140' is formed on the light emitting elements 120a, 120b, 120c and the temporary substrate 312 after mixing a plurality of wavelength conversion particles with a binder. Forming methods include: direct coating, mold forming or pre-forming sheet-like structures. The way of direct coating can be dispensing or spraying. The size of the sheet-like structure can be adjusted according to requirements. For example, the sheet-like structure includes several wavelength conversion sheets separated from each other, and the several wavelength conversion sheets separated from each other can cover several light-emitting elements in batches or sequentially, that is, one The wavelength conversion film 140 ′ covers only one or part of the light-emitting elements (eg, 1/50, 1/100, or 1/200 or less of the total number of light-emitting elements on the temporary substrate 312 ). For another example, the sheet-like structure is a tape, which can cover several light-emitting elements continuously and at one time, that is, one wavelength conversion sheet simultaneously covers many or all light-emitting elements on the temporary substrate (for example, temporary light-emitting elements). 1/50, 1/100, 1/200 or more of the total number of light-emitting elements on the substrate).

Referring to FIG. 3C, the wavelength conversion film 140' is divided into a plurality of wavelength conversion layers 140a, 140b, and 140c through a separation process. This separation process may be the first separation. The wavelength conversion film 140' may be cured prior to the separate process. In one embodiment, the wavelength conversion film 140' is cured by heating. In another embodiment, the wavelength converting film 140' can be cured using other types of energy, such as radiation. The separate process includes cutting the wavelength conversion film 140' and part or all of the adhesive layer 314 with the cutting tool 331 and forming a cutting line.

Referring to FIG. 3D, a reflective layer 160' (second reflective layer) is formed on the plurality of wavelength conversion layers 140a, 140b, 140c and the temporary substrate 312. In one embodiment, the reflective layer 160' covers all the upper surfaces and sidewalls of the wavelength conversion layers 140a, 140b, and 140c. In addition, the reflective layer 160' is in direct contact with the surface of the adhesive layer 314. The reflective layer 160' can be formed by laminating or molding. In one embodiment, the reflective particles are pre-mixed with the adhesive and then pre-shaped into a sheet-like structure, and the sheet-like structure is heated and pressure is applied to make the reflective layer 160' coat the upper surfaces of the wavelength conversion layers 140a, 140b, 140c and filling the recesses or cutting lines between the light-emitting elements 120a, 120b, and 120c. The reflective layer 160' at this stage is still in a semi-cured state, or a glue material called B-stage. In one embodiment, the reflective layer 160' can be cured by heating. The heated reflective layer 160' is transformed into a fully cured state, or a so-called C-staged reflective layer 160'. In other embodiments, the reflective layer 160' is formed by coating or laminating a film material. In one embodiment, the reflective particles can be directly coated on the wavelength conversion layers 140a, 140b, and 140c after being mixed with the bonding agent to form the reflective layer 160'. In another embodiment, the reflective layer 160' may be cured using other types of energy, such as UV light.

Referring to FIGS. 3E and 3F, a portion of the reflective layer 160' over the wavelength conversion layers 140a, 140b, 140c is removed to form a reflective frame 160''. The wavelength conversion layers 140a, 140b, and 140c are exposed from the reflective layer 160', and the reflective frame 160'' and the wavelength conversion layers 140a, 140b, and 140c have a level difference structure. In one embodiment, referring to FIG. 1A , the level difference h is between 5 micrometers (μm) and 50 micrometers. In one embodiment, the way to remove the reflective layer 160' is to pass through a roller 370, and adhere the part of the reflective layer 160' on the upper surfaces of the wavelength conversion layers 140a, 140b, 140c and around the reflective layer 160' to the roller 370. Specifically, since the adhesive force between the reflective layer 160' and the wavelength conversion layers 140a, 140b, 140c is smaller than the breaking strength of the reflective layer 160' itself, and the breaking strength of the reflective layer 160' itself is smaller than the adhesion of the roller 370 to the reflective layer 160' force. Therefore, the required height of the reflective frame 160 ″ is defined by a frame 390 . The height of the frame 390 is slightly higher than the height of the wavelength conversion layers 140 a , 140 b and 140 c . When the roller 370 rolls over the reflective layer 160 ′, the wavelength conversion is taken away. The layers 140a, 140b, 140c are partially reflective layers 160' on the upper surfaces, so a structure of level difference will be generated between the reflective frame 160'' and the wavelength conversion layers 140a, 140b, 140c.

Referring to FIG. 3H, the temporary substrate 312 and the adhesive layer 314 are removed and transferred to another temporary substrate 352 and another adhesive layer 354 before the temporary substrate 312 and the adhesive layer 314 are removed. The materials of the temporary substrate 352 and the temporary substrate 312 may be the same or similar. The materials of the adhesive layer 354 and the adhesive layer 314 can also be the same or similar, such as thermal release adhesive or thermal curing adhesive.

Referring to FIG. 3I, a plurality of conductive portions 180a, 180b, and 180c are formed on the contact electrodes 126a, 126b, and 126c, respectively. In one embodiment, the conductive parts 180a, 180b, and 180c are made of solder, which can be formed on the contact electrodes 126a, 126b, and 126c by means of reflow. In one embodiment, the reflow temperature is between 160°C and 260°C.

Referring to FIG. 3J, reflective layers 150' and 150'' (first reflective layers) are formed on the surface of the light-emitting layer 124 (the upper surface in the figure) and the surface of the reflective frame 160'' (the upper surface in the figure) and covering Contact electrodes 126a, 126b, 126c and conductive parts 180a, 180b, 180c. After that, the reflective layer 150'' is removed to expose the conductive parts 180a, 180b, 180c.

Referring to FIG. 3K, the reflective frame 160'' is divided into a plurality of reflective fences 160a, 160b, 160c and the reflective layer 150' is divided into a plurality of reflective layers 150 through a separation process. This separation process can be the second separation. The separate process includes cutting the reflective frame 160'', the reflective layer 150' and part or all of the adhesive layer 354 with the cutting tool 333 and forming a dicing line. After this step, the light emitting devices 100a, 100b, 100c can be formed.

FIG. 3A to FIG. 3G show a manufacturing flow chart of a light-emitting device according to another embodiment of the present invention. The difference from the above-mentioned embodiment is that the present embodiment does not have the reflective layer 150 and the conductive parts 180a, 180b, and 180c.

After the partial reflective layer 160' on the upper surfaces of the wavelength conversion layers 140a, 140b, and 140c is removed to form the reflective frame 160'' (FIG. 3E and FIG. 3F), referring to FIG. 3G, through a separate process, the reflective frame is 160" is divided into a plurality of reflection fences 160a, 160b, 160c. This separation process can be the second separation. The separate process includes cutting the reflective frame 160'' and part or all of the adhesive layer 314 with the cutting tool 332 and forming a cutting line.

FIGS. 3A to 3B and FIGS. 4A to 4F show a manufacturing flow chart of a light emitting device according to another embodiment of the present invention. After forming a wavelength conversion layer 140' on the adhesive layer 314 and covering the light-emitting elements 120a, 120b, and 120c at the same time (FIG. 3B). In one embodiment, referring to FIG. 4A, a temporary layer 430' is overlaid on the wavelength converting layer 140'. One of the purposes of the temporary layer 430' is to subsequently form the level difference between the reflection frame 160'' and the wavelength conversion layers 140a, 140b, and 140c. The material of the temporary layer 430' may be a photo-curable resin or a heat-curable resin. In one embodiment, the temporary layer 430' is a film layer formed of a photocurable resin, which is formed by irradiating light with a specific wavelength, such as ultraviolet light.

4B, the wavelength conversion layer 140' is divided into a plurality of wavelength conversion layers 140a, 140b, 140c, and the temporary layer 430' is divided into a plurality of temporary layers 430a, 430b, 430c through a separation process. This separation process may be the first separation. The plurality of temporary layers 430a, 430b, 430c each correspond to over the plurality of wavelength converting layers 140a, 140b, 140c.

Referring to FIG. 4C, a reflective layer 460' (first reflective layer) is formed on a plurality of wavelength conversion layers (140a, 140b, 140c), a plurality of temporary layers (430a, 430b, 430c), the temporary substrate 312 and the adhesive above layer 314 . For the function and formation method of the reflective layer 460', please refer to FIG. 3D and related paragraphs.

Referring to Figure 4D, a portion of the reflective layer 460' on the temporary layers 430a, 430b, 430c is removed to form a reflective frame 460''. In one embodiment, the upper surface of the reflective frame 460 ″ can be mechanically smoothed, wet stripped, or a combination of the two, so that the upper surface of the reflective frame 460 ″ and the temporary layers 430a , 430b , 430c can be removed. of.

Referring to FIG. 4E, the temporary layers 430a, 430b, 430c are removed to expose the wavelength converting layers 140a, 140b, 140c. This step may form a step structure between the wavelength conversion layers 140a, 140b, 140c and the reflection frame 460''.

Referring to FIG. 4F, the reflective frame 460'' is divided into a plurality of reflective fences 460a, 460b, 460c through a separate process. This separation process can be the second separation. The separate process includes cutting the reflective frame 460" and part or all of the adhesive layer 354 with a cutting tool and forming a cutting line. After this step, the light emitting devices 400a, 400b, 400c can be formed.

FIG. 5 shows a light emitting module 500 according to an embodiment of the present invention. The light emitting module 500 includes a first light emitting device 520 a , a second light emitting device 520 b , a carrier board 540 and an optical element 560 . The first light emitting device 520a and the second light emitting device 520b are respectively formed on the carrier board 540, and the optical element 560 covers the first light emitting device 520a and the second light emitting device 520b. In one embodiment, the first light-emitting device 520a includes a first light-emitting element 522a, a first wavelength conversion layer 524a, and a first reflective fence 526a. The second light emitting device 520b includes a second light emitting element 522b, a second wavelength conversion layer 524b, and a second reflection fence 526a. In this embodiment, the first light emitting device 520a and the second light emitting device 520b can emit light with different color temperatures. In one embodiment, the first wavelength conversion layer 524a and the second wavelength conversion layer 524b respectively have different wavelength conversion layers, so the color temperature of the first light emitting device 520a and the second light emitting device 520b are different. Different wavelength conversion layers may refer to different wavelength conversion materials, the same wavelength conversion material but with different concentrations, or the same wavelength conversion material but with different ratios. In one embodiment, the color temperature of the first light-emitting device 520a is between 1800K and 3000K, and the color temperature of the second light-emitting device 520b is between 4000K and 7000K. In one embodiment, the color temperature difference between the first light emitting device 520a and the second light emitting device 520b is greater than 2000K, so that the light emitting module 500 can more clearly emit light with two different color temperatures. The light-emitting module 500 can be applied to flashlights in electronic products. Through the design of light sources with different color temperatures, it can provide more detailed white balance processing in different environments, so it can be closer to the real image.

In one embodiment, the carrier board 540 is a circuit board with circuit layers 542a and 542b electrically connected to the first light-emitting device 520a and the second light-emitting device 520b, respectively. In one embodiment, the optical element 560 is a Fresnel lens. There are two groups of concentric circles in the Fresnel lens facing the first light emitting device 520a and the second light emitting device 520b respectively. In this way, the first light-emitting device 520a and the second light-emitting device 520b can emit light in an approximate or equivalent parallel light manner through the Fresnel lens.

6A and 6B are respectively a cross-sectional view and a top view of a light emitting device 600 according to another embodiment of the present invention. The light-emitting device 600 includes a light-emitting element 620 , a wavelength conversion layer 640 , a reflection fence 660 , a reflection layer 650 and a conductive portion 680 . The difference from FIG. 1 is that the reflective fence 660 has a sloped surface. In one embodiment, the inclined surface is located on the inner surface of the reflective fence 660 , that is, the surface facing the light-emitting element 620 . Specifically, the inner surface of the reflective fence 660 , the upper surface of a wavelength conversion layer 640 , the bottom surface of the light-emitting element 620 and the top surface of the reflective layer 650 may enclose an inverted trapezoidal structure. The reflective fence 660 has the light-emitting device 600 with an inclined surface, which can change the traveling direction of the light in the light-emitting device 600 and reduce the light-emitting angle. The specific structures, functions and formation methods of the light emitting element 620 , the wavelength conversion layer 640 , the reflective fence 660 , the reflective layer 650 and the conductive portion 680 can be referred to FIG. 1 and the corresponding paragraphs.

The above-mentioned embodiments are only to illustrate the technical ideas and characteristics of the present invention, and the purpose is to enable those who are familiar with the art to understand the content of the present invention and implement it accordingly. It should not be used to limit the patent scope of the present invention. That is, all equivalent changes or modifications made according to the spirit disclosed in the present invention should still be covered within the patent scope of the present invention.

100, 100a, 100b, 100c, 220, 520a, 520b, 600‧‧‧Light-emitting device 102‧‧‧Top surface 104‧‧‧Bottom surface 106‧‧‧Side surface 120, 120a, 120b, 120c, 522a, 522b, 620 ‧‧‧Light emitting element 121‧‧‧Top surface 122‧‧‧Support substrate 123‧‧‧Lower surface 124‧‧‧Light emitting layer 125‧‧‧Side surfaces 126, 126a, 126b, 126c‧‧‧contact electrodes 140, 140a, 140b, 140c, 524a, 524b, 640‧‧‧Wavelength converting layer 140'‧‧‧Wavelength converting film 141‧‧‧Top surface 142‧‧‧Binder 144‧‧‧Wavelength converting particles 150, 160', 460', 526a, 526b, 650‧‧‧reflective layer 160, 160a, 160b, 160c, 460a, 460b, 460c, 526a, 526b, 660‧‧‧reflective fence 160'', 460''‧‧‧reflective frame 162‧‧‧ Top surface 180, 180a, 180b, 180c, 182, 184, 680‧‧‧conductive part 240, 560‧‧‧optical element 312, 352‧‧‧Temporary substrate 314, 354‧‧‧adhesive layer 331, 332, 332, 534‧‧‧Cutting tool 370‧‧‧Roller 390‧‧‧Frame 430', 430a, 430b, 430c‧‧‧Temporary layer 500‧‧‧Light-emitting module 540‧‧‧Carrier board 542a, 542b‧‧‧ Circuit layer h‧‧‧step height H‧‧‧overall thickness T‧‧‧thickness

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

Fig. 1B is a top view showing the light emitting device of Fig. 1A.

FIG. 2 shows the light-emitting angle of the light-emitting device according to an embodiment of the present invention.

FIGS. 3A to 3F and FIGS. 3H to 3K show a manufacturing flow chart of a light emitting device according to an embodiment of the present invention.

FIG. 3A to FIG. 3G show a manufacturing flow chart of a light-emitting device according to another embodiment of the present invention.

FIGS. 3A to 3B and FIGS. 4A to 4F show a manufacturing flow chart of a light emitting device according to another embodiment of the present invention.

FIG. 5 shows a light emitting module according to an embodiment of the present invention.

FIG. 6A is a cross-sectional view of a light-emitting device according to another embodiment of the present invention.

Fig. 6B is a top view showing the light emitting device of Fig. 6A.

without

without

100‧‧‧Light-emitting device

102‧‧‧Top surface

104‧‧‧Bottom surface

106‧‧‧Side

120‧‧‧Light-emitting element

121‧‧‧Top surface

122‧‧‧Growth substrate

123‧‧‧Lower surface

124‧‧‧Light Emitting Layer

125‧‧‧Side

126, 126a, 126b‧‧‧contact electrodes

140‧‧‧Wavelength Conversion Layer

142‧‧‧Binders

144‧‧‧Wavelength Conversion Materials

150‧‧‧Reflector

160‧‧‧Reflection Fence

180, 182, 184‧‧‧Conductive part

h‧‧‧step height

H‧‧‧Overall thickness

T‧‧‧Thickness

Claims (10)

A light-emitting device, comprising: a light-emitting element, comprising a first upper surface, a lower surface, and a plurality of first side surfaces located between the first upper surface and the first lower surface, and the plurality of first side surfaces are parallel to each other ; a wavelength conversion layer, including a plurality of wavelength conversion particles, and including a second upper surface located directly above the first upper surface; and a reflective fence surrounding the plurality of first side surfaces, including a top surface and a plurality of Inner side, wherein, the plurality of inner sides and the plurality of first sides are parallel to each other, wherein, the top surface is h higher than the second upper surface, the height of the light-emitting device is H, and the ratio of h to H ( h/H) is between 0.01 and 0.4, wherein the light-emitting device has a light-emitting angle, and the light-emitting angle is between 110 degrees and 118 degrees. The light-emitting device of claim 1, wherein the top surface is higher than the second upper surface by h, the height of the light-emitting device is H, and the ratio of h to H (h/H) is between 0.015 and 0.2 between. The light-emitting device of claim 1, wherein there is a difference between the top surface and the second top surface, and the top surface is higher than the second top surface by between 5 microns and 100 microns. The light-emitting device of claim 1 of the claimed scope, wherein the light-emitting device has a color temperature, and the color temperature is between 1800K and 7000K. The light-emitting device of claim 1, wherein the reflective fence has a thickness, and the thickness is between 20 microns and 200 microns. The light-emitting device of claim 1 of the claimed scope further comprises a reflective layer formed on the lower surface. The light-emitting device of claim 6 of the claimed scope further comprises a conductive portion surrounded by the reflective layer. The light-emitting device of claim 1, wherein the reflection fence includes an inner surface, and the inner surface has an inclined surface. A light-emitting module, comprising: a carrier board with a circuit layer; the light-emitting device as claimed in item 1 of the patent application scope, capable of emitting a light and being formed on the carrier board to be electrically connected with the circuit layer; and an optical element , covering the light-emitting device. The light-emitting module of claim 9, wherein the optical element comprises a Fresnel lens.

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