Light emitting device and method of manufacturing the same

Abstract

This disclosure provides a light-emitting device and a method for manufacturing the same. The light-emitting device includes a substrate, a light source, and an optical lens. The substrate has a main surface. The light source is disposed on the main surface and has a light-emitting surface away from the main surface. The optical lens is disposed on the main surface and covers the light source, wherein the optical lens has an outer surface away from the light source and a recess located on the outer surface and above the light-emitting surface. This recess can reflect and / or refract light emitted from the light source, thereby effectively weakening the light intensity at the center and thus enhancing the light uniformity of the light-emitting device.

Description

Technical Field

[0001] This disclosure relates to a light-emitting device and its manufacturing method. Background Technology

[0002] With advancements in semiconductor technology, today's light-emitting diodes (LEDs) can provide high brightness output. Due to their advantages such as energy saving, small size, low-voltage driving, and mercury-free operation, LEDs are widely used in displays and lighting.

[0003] LEDs typically exhibit strong directional light emission. Therefore, when LEDs are used in backlights, the backlight may suffer from uneven light distribution. Furthermore, when using diffusers to scatter the light from LEDs, it is not easy to simultaneously achieve both uniform light emission and reduced structural thickness.

[0004] Therefore, how to propose a light-emitting device that can solve the above problems is one of the problems that the industry urgently wants to solve. Summary of the Invention

[0005] This disclosure provides a light-emitting device including a substrate, a light source, and an optical lens. The substrate has a main surface. The light source is disposed on the main surface and has a light-emitting surface away from the main surface. The optical lens is disposed on the main surface and covers the light source, wherein the optical lens has an outer surface away from the light source and a recess located on the outer surface and above the light-emitting surface.

[0006] In some embodiments, the outer surface has a convex curved surface, and the recess has a concave curved surface.

[0007] In some implementations, the distance between the bottom of the recess and the light-emitting surface is 0 mm to 19.9 mm.

[0008] In some embodiments, the optical lens has a first diameter and the recessed opening has a second diameter, the ratio of the first diameter to the second diameter being 1.3:1 to 2:1.

[0009] In some embodiments, the optical lens comprises silicone, epoxy resin, polymethyl methacrylate, thixotropic gel, or a combination thereof.

[0010] In some implementations, the depth of the recess is from 0.05 mm to 19.9 mm.

[0011] In some embodiments, in the cross-section of the light-emitting device, the light-emitting surface has a first endpoint and a second endpoint, the first endpoint and the edge of the recessed first opening define a first virtual line, the second endpoint and the edge of the recessed second opening define a second virtual line, and the angle between the first virtual line and the second virtual line is greater than 0 degrees and less than or equal to 160 degrees.

[0012] In some embodiments, the light-emitting device further includes at least one light-shielding wall disposed on the main surface and close to the optical lens, wherein the optical lens has a first height, the light-shielding wall has a second height, and the second height is less than or equal to twice the first height.

[0013] In some embodiments, the light-emitting device further includes a light-shielding material in the recess.

[0014] In some implementations, the light-shielding material has a transmittance of less than 80% for light with wavelengths from 360 nm to 1000 nm.

[0015] In some implementations, the light-shielding material fills the recess and protrudes from it.

[0016] In some embodiments, the light-shielding material includes an encapsulant and pigment powder dispersed in the encapsulant.

[0017] This disclosure provides a method for manufacturing a light-emitting device, the method comprising the following operations: placing a light source on a substrate; placing a dispensing machine above the light source, wherein the dispensing machine includes a dispensing nozzle and a striking pin disposed in a channel of the dispensing nozzle; pushing the striking pin with dispensing pressure to strike the inner surface of the channel, extruding encapsulant from the channel and dispensing an encapsulation layer onto the light source, wherein the encapsulation layer has a recess facing the dispensing nozzle; and curing the encapsulation layer to form an optical lens.

[0018] In some embodiments, the viscosity of the encapsulant is from 0.2 mPa·s to 100,000 mPa·s.

[0019] In some implementations, the time for the ejector pin to strike the inner surface is from 0.01 milliseconds to 500 milliseconds, and the dispensing pressure is from 1 bar to 10 bar.

[0020] In some embodiments, curing the encapsulation layer includes the following operations: heating the encapsulation layer at a first temperature of 40°C to 60°C; heating the encapsulation layer at a second temperature of 80°C to 100°C; and heating the encapsulation layer at a third temperature of 110°C to 130°C.

[0021] In some embodiments, the encapsulant includes silicone, epoxy resin, polymethyl methacrylate, thixotropic adhesive, or a combination thereof.

[0022] In some embodiments, the method further includes forming a light-shielding material in the recess.

[0023] In some implementations, the light-shielding material fills the recess and protrudes from it.

[0024] In some embodiments, forming a light-shielding material in a recess includes the following operations: dispensing an encapsulating material and pigment powder into the recess, wherein the pigment powder is dispersed in the encapsulating material; heating the encapsulating material and pigment powder at a first temperature of 40°C to 60°C; heating the encapsulating material and pigment powder at a second temperature of 80°C to 100°C; and heating the encapsulating material and pigment powder at a third temperature of 110°C to 130°C. Attached Figure Description

[0025] This disclosure can be more fully understood by reading the following detailed description of the embodiments and referring to the accompanying drawings.

[0026] Figure 1 The light intensity distribution curves of a light-emitting diode embedded in a conventional optical lens according to a comparative example of the present disclosure are shown at emission angles from -90 degrees to 90 degrees.

[0027] Figure 2 This is a flowchart illustrating various methods for manufacturing a light-emitting device according to the present disclosure.

[0028] Figure 3A A schematic diagram illustrating an intermediate stage in the manufacture of a light-emitting device according to various embodiments of this disclosure.

[0029] Figure 3B This diagram shows a cross-sectional view of an intermediate stage in the formation of an encapsulation layer on a light source using a dispensing machine, according to various embodiments of this disclosure.

[0030] Figure 4A , Figure 4B and Figure 5 These are cross-sectional schematic diagrams of various embodiments of the light-emitting device according to this disclosure.

[0031] Figure 6 Show Figure 4A The light intensity distribution curve of the light-emitting device at a light emission angle from -90 degrees to 90 degrees.

[0032] Figure 7 Show Figure 5 The light intensity distribution curve of the light-emitting device at a light emission angle from -90 degrees to 90 degrees.

[0033] Figure 8 , Figure 9 , Figure 10 , Figure 11 , Figure 12 and Figure 13 These are cross-sectional schematic diagrams of various embodiments of the light-emitting device according to this disclosure.

[0034] Figure 14The light-emitting devices of Examples 1 to 3 are the light intensity variation curves generated at a light-emitting angle from -90 degrees to 90 degrees in the 0-degree longitudinal plane.

[0035] Figure 15 The light-emitting devices of Examples 1 to 3 are the light intensity variation curves generated at a 90-degree longitudinal plane and at a light emission angle from -90 degrees to 90 degrees.

[0036] The reference numerals in the attached figures are explained as follows:

[0037] 100, 100', 100A, 100B, 100C, 100D, 100E, 100F, 100G: Light-emitting devices

[0038] 110: Substrate

[0039] 111: Main Surface

[0040] 120: Light source

[0041] 121: Luminous Surface

[0042] 130, 130': Optical lens

[0043] 131: Outer surface

[0044] 132: Depression

[0045] 133: Inner surface

[0046] 140: Shading material

[0047] 141: Curved upper surface

[0048] 142: Curved upper surface

[0049] 143: Upper surface

[0050] 150: Blackout wall

[0051] 200: Method

[0052] 300: Dispensing machine

[0053] 310: Dispensing nozzle

[0054] 320: Firing Pin

[0055] 330: Flow channel

[0056] 340: Storage slot

[0057] 350: Driver

[0058] S1, S2, S3, S4, S5: Operations

[0059] A: Direction

[0060] C1, C2, C3: Light intensity distribution curves

[0061] CI: Smooth Curved Interface

[0062] D1: First diameter

[0063] D2: Second diameter

[0064] DB: Distance

[0065] Dp: Depth

[0066] e1: First endpoint

[0067] e2: Second endpoint

[0068] E1: Encapsulant

[0069] E2: Encapsulation layer

[0070] h1, h2: Heating operation

[0071] H1, H2: Height

[0072] L1: First virtual line

[0073] L2: Second virtual line

[0074] oe1: First opening edge

[0075] oe2: Second opening edge

[0076] RO: Reflow oven

[0077] S1: Inner surface

[0078] W1: Width

[0079] W2: Maximum width

[0080] φ: Angle Detailed Implementation

[0081] Embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. Where possible, the same reference numerals are used in the drawings and description to refer to the same or similar parts.

[0082] The following multiple embodiments are described in detail with reference to the accompanying drawings. For clarity, many practical details will be set forth in the following description. However, it should be understood that these practical details are not intended to limit the scope of this disclosure. That is, these practical details are not essential in some embodiments of this disclosure. Furthermore, for the sake of simplicity, some known structures and elements are illustrated schematically in the drawings.

[0083] LEDs typically exhibit strong luminous directivity. Therefore, when LEDs are used in displays and lighting applications, this strong directivity can cause uneven light distribution. For example, Figure 1 The diagram shows the light intensity distribution curve C1 of a light-emitting diode embedded in a conventional optical lens according to a comparative example of this disclosure, at emission angles from -90 degrees to 90 degrees, where the conventional optical lens is a plano-convex lens. The radial coordinate represents the luminous intensity, and the angular coordinate represents the emission angle. Luminous intensity can also be referred to as light intensity. Figure 1 As shown, the luminous intensity distribution curve C1 is relatively narrow, indicating that most of the light is emitted from the central part of the convex surface of a conventional optical lens. When this light-emitting diode is used in a display device, the display device may exhibit uneven light emission.

[0084] This disclosure provides a light-emitting device and its manufacturing method to solve the problem of uneven light distribution. In the light-emitting device, an optical lens with a recessed outer surface is disposed on the light source. The light source can be an LED, an LED chip, or other light-emitting element. The optical lens can change the intensity distribution (light pattern) of the light emitted by the light source to achieve uniform light output. More specifically, the recess of the optical lens can reflect and / or refract light emitted from the light source, thereby effectively weakening the light intensity at the center. Furthermore, a light-shielding material can be disposed at the recess to further weaken the light intensity at the center, thereby further enhancing light uniformity. When the light-emitting device of this disclosure is applied to a backlight module, it can simultaneously meet the requirements of providing uniform light and reducing module thickness. Since the light source can be encapsulated by the optical lens, the light-emitting device of this disclosure can be applied to micro-LED packages and mini-LED packages. Furthermore, the manufacturing method of this light-emitting device is simple, which helps to reduce manufacturing costs. Next, this disclosure will describe methods for manufacturing light-emitting devices according to various embodiments of this disclosure, followed by descriptions of light-emitting devices according to various embodiments of this disclosure.

[0085] Please refer to Figure 2 and Figure 3A . Figure 2 This is a flowchart of a method 200 for manufacturing a light-emitting device according to various embodiments of the present disclosure. Method 200 includes operations S1, S2, S3, S4, and S5. Figure 3AThis diagram illustrates intermediate stages in the manufacture of a light-emitting device according to various embodiments of this disclosure. The method 200 of this disclosure has a simple process, thus reducing manufacturing costs. Although the method disclosed herein is described below using a series of operations or steps, the order in which these operations or steps are shown should not be construed as a limitation of this disclosure. For example, some operations or steps may be performed in a different order and / or simultaneously with other steps. Furthermore, it is not necessary to perform all illustrated operations, steps, and / or features to achieve the embodiments of this disclosure. Additionally, each operation or step described herein may comprise several sub-steps or actions.

[0086] refer to Figure 2 and Figure 3A . Figure 3A The process of manufacturing a light-emitting device is shown. The number of light-emitting devices is not limited. Figure 3A The design can be adjusted arbitrarily according to design requirements. For clarity, the manufacturing method of a single light-emitting device will be described below. In operation S1, the light source 120 is placed on the substrate 110. In some embodiments, the substrate 110 is a printed circuit board (PCB), but is not limited thereto. In some embodiments, the light source 120 is a micro-LED, a micro-LED chip, a mini-LED, a mini-LED chip, an LED (larger than micro-LEDs and mini-LEDs), an LED chip, or a combination thereof, but is not limited thereto. For example, the light source 120 is a chip-scale package (CSP) LED. In some embodiments, such as Figure 3A As shown, setting the light source 120 on the substrate 110 includes: printing solder paste (not shown) onto the main surface 111 of the substrate 110; mounting the light source 120 onto the solder paste using surface-mount technology (SMT); soldering the light source 120 and the solder paste using reflow soldering in a reflow oven (RO); and removing the substrate 110 with the light source 120 attached from the RO. In some embodiments, after removing the substrate 110 with the light source 120 attached from the RO, a reflector is directly attached to the upper surface of the light source 120.

[0087] Please note now. Figure 2 , Figure 3A and Figure 3B . Figure 3BThis diagram shows a cross-sectional view of an intermediate stage in the formation of an encapsulation layer E2 on a light source 120 using a dispensing machine 300 according to various embodiments of this disclosure. The dispensing machine 300 may also be referred to as a dispenser. In operation S2, the dispensing machine 300 is placed above the light source 120, wherein the dispensing machine 300 includes a dispensing nozzle 310 and a firing pin 320 disposed in a flow channel 330 of the dispensing nozzle 310. The dispensing machine 300 further includes a reservoir 340 for supplying encapsulant to the flow channel 330, and a driver 350 for driving the firing pin 320. In some embodiments, the dispensing machine 300 is an automated robot dispenser equipped with a firing pin.

[0088] Please refer to Figure 2 , Figure 3A and Figure 3B In operation S3, such as Figure 3B As shown, the dispensing pressure pushes the ejector pin 320 to strike the inner surface S1 of the flow channel 330, extruding encapsulant E1 from the flow channel 330 and dispensing an encapsulation layer E2 onto the light source 120, wherein the encapsulation layer E2 has a recess 132 facing the dispensing nozzle 310. Figure 3A and Figure 3B As shown, the encapsulation layer E2 covers the light source 120. The recess 132 is formed naturally during the dispensing process, meaning that the formation of the encapsulation layer E2 and the formation of the recess 132 can be completed simultaneously. The shape of the recess 132 can be adjusted using dispensing parameters. The recess 132 can also be referred to as a concave part or a dent.

[0089] like Figure 3BAs shown, the striking pin 320 is driven by the driver 350. More specifically, the striking pin 320 can be pushed downward by the driver 350 to strike the inner surface S1 of the flow channel 330, and then pulled upward. In some embodiments, the viscosity of the encapsulant E1 is from 0.2 mPa·s to 100,000 mPa·s, for example, 0.2, 0.5, 1, 5, 10, 50, 100, 500, 1000, 2000, 3000, 4000, 5000, 6000, 7000, 8000, 9000, 10000, 20000, 30000, 40000, 50000, 60000, 70000, 80000, 90000, or 100000 mPa·s. When the viscosity of the encapsulant E1 falls within the aforementioned range, the encapsulant E1 can easily flow from the dispensing nozzle 310 to form an encapsulation layer E2 with recesses 132. In some embodiments, the encapsulant E1 comprises silicone, epoxy resin, polymethyl methacrylate, thixotropic adhesive, or combinations thereof. In some embodiments, the impact time of the ejector pin 320 on the inner surface S1 is from 0.01 milliseconds to 500 milliseconds, and the dispensing pressure is from 1 bar to 10 bar. For example, the time is 0.01, 0.05, 0.1, 0.5, 1, 5, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 200, 300, 400, or 500 milliseconds. For example, the dispensing pressure is 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 bar. When the impact time and / or dispensing pressure fall within the above-mentioned range, the encapsulant E1 can easily flow from the dispensing nozzle 310 to form an encapsulation layer E2 with a recess 132. The height and diameter of the encapsulation layer E2, as well as the depth and diameter of the recess 132, can be adjusted by the above-mentioned dispensing parameters (encapsulant viscosity, impact time, and / or dispensing pressure).

[0090] like Figure 2 and Figure 3A As shown, in operation S4, the encapsulation layer E2 is cured to form an optical lens 130, thereby forming a light-emitting device 100. Figure 3AAs shown, the light-emitting device 100 includes a portion of a substrate 110, a light source 120, and an optical lens 130 covering the light source 120. In some embodiments, the encapsulation layer E2 is cured by a heating operation h1. For example, the temperature of the heating operation h1 can be from 40°C to 130°C, such as 40, 50, 60, 70, 80, 90, 100, 110, 120, or 130°C. In some embodiments, curing the encapsulation layer E2 includes the following operations: heating the encapsulation layer E2 at a first temperature of 40°C to 60°C, such as 40, 45, 50, 55, or 60°C, thereby preheating the encapsulation layer E2. Next, heating the encapsulation layer E2 at a second temperature of 80°C to 100°C, such as 80°C, 85°C, 90°C, 95°C, or 100°C, thereby curing the encapsulation layer E2. Subsequently, the encapsulation layer E2 is heated at a third temperature between 110°C and 130°C, for example, 110, 115, 120, 125, or 130°C, thereby hardening the encapsulation layer E2. This heating operation effectively cures the encapsulation layer E2 and makes it less prone to deformation during the curing process. Figure 3A The simple process shown can easily form an integrated structure including an optical lens 130 and a light source 120.

[0091] Please refer to the following: Figure 2 and Figure 3A In operating S5, such as Figure 3A As shown, a light-shielding material 140 is formed in a recess 132 to form a light-emitting device 100A. The light-emitting device 100A includes a portion of a substrate 110, a light source 120, an optical lens 130 covering the light source 120, and the light-shielding material 140 in the recess 132. In some embodiments, operation S5 is omitted. In some embodiments, forming the light-shielding material 140 in the recess 132 includes the following operation: Encapsulating material and pigment powder (light-shielding material 140) are dispensed into the recess 132 using, for example, a dispensing machine, wherein the pigment powder is dispersed in the encapsulating material. In some embodiments, the refractive index of the encapsulating material is 1.41 to 1.6. The pigment powder can have any color and includes, for example, white powder, black powder, gray powder, red powder, orange powder, yellow powder, green powder, blue powder, purple powder, pink powder, brown powder, or combinations thereof. For example, the pigment powder includes TiO2 powder, SiO2 powder, or combinations thereof. White powder, due to its better light reflectivity, can have a better effect of reducing central light. For example, the central light intensity of the light-emitting device 100A may be less than 80%.

[0092] The encapsulation material and pigment powder can be cured by heating operation h2. For example, the temperature of heating operation h2 can be from 40°C to 130°C, such as 40, 50, 60, 70, 80, 90, 100, 110, 120, or 130°C. In some embodiments, curing the encapsulation material and pigment powder includes the following operations: Preheating the encapsulation material and pigment powder by heating them at a first temperature of 40°C to 60°C, such as 40, 45, 50, 55, or 60°C. Next, curing the encapsulation material and pigment powder by heating them at a second temperature of 80°C to 100°C, such as 80°C, 85°C, 90°C, 95°C, or 100°C. Subsequently, curing the encapsulation material and pigment powder by heating them at a third temperature of 110°C to 130°C, such as 110, 115, 120, 125, or 130°C. The above heating operation can effectively solidify the encapsulation material and pigment powder, and prevent them from deforming during the solidification process.

[0093] Figure 4A and Figure 5 Further description of light-emitting device 100 and light-emitting device 100A. Figure 4B Another light-emitting device similar to light-emitting device 100 is shown. Figure 4A , Figure 4B and Figure 5 These are cross-sectional schematic diagrams of various embodiments of the light-emitting device according to this disclosure.

[0094] like Figure 4A As shown, the light-emitting device 100 includes a substrate 110, a light source 120, and an optical lens 130. The substrate 110 has a main surface 111, i.e. Figure 4A The top surface of the substrate 110 is shown. A light source 120 is disposed on the main surface 111 and has a light-emitting surface 121 away from the main surface 111. An optical lens 130 is disposed on the main surface 111 and covers the light source 120, wherein the optical lens 130 has an outer surface 131 away from the light source 120 and a recess 132 located on the outer surface 131 and above the light-emitting surface 121. In some embodiments, the optical lens 130 comprises silicone, epoxy resin, polymethyl methacrylate, thixotropic adhesive, or a combination thereof. Along direction A perpendicular to the main surface 111 of the substrate 110, the recess 132 is correspondingly disposed to the light-emitting surface 121, so that the vertical projection of the recess 132 on the main surface 111 overlaps with the vertical projection of the light source 120 on the main surface 111. Figure 4A As shown, in some embodiments, the outer surface 131 has a convex curved surface and the recess 132 has a concave curved surface.

[0095] Please refer to the following: Figure 4A In some embodiments, the distance D between the bottom of the recess 132 and the light-emitting surface 121 is...B The depth Dp of the recess 132 is from 0 mm to 19.9 mm, for example, 0, 0.05, 0.1, 0.5, 1, 2, 4, 6, 8, 10, 12, 14, 16, 18, or 19.9 mm. In some embodiments, the depth Dp of the recess 132 is from 0.05 mm to 19.9 mm, for example, 0.05, 0.1, 0.5, 1, 2, 4, 6, 8, 10, 12, 14, 16, 18, or 19.9 mm. When the distance D... B When the depth Dp falls within the above range, light emitted from the central portion of the optical lens 130 can be effectively reduced. In some embodiments, the height H1 of the optical lens 130 is from 0.1 mm to 20 mm, for example 0.1, 0.5, 1, 2, 4, 6, 8, 10, 12, 14, 16, 18 or 20 mm.

[0096] like Figure 4A As shown, in some embodiments, in the cross-section of the light-emitting device 100, the light-emitting surface 121 has a first endpoint e1 and a second endpoint e2. The first endpoint e1 and the first opening edge oe1 of the recess 132 define a first virtual line L1, and the second endpoint e2 and the second opening edge oe2 of the recess 132 define a second virtual line L2. The first opening edge oe1 and the second opening edge oe2 are located at the highest point of the optical lens 130. The angle φ between the first virtual line L1 and the second virtual line L2 is greater than 0 degrees and less than or equal to 160 degrees, for example, 0, 20, 40, 60, 80, 100, 120, 140, or 160 degrees. When the angle φ falls within the above range, the light emitted from the central portion of the optical lens 130 can be effectively reduced.

[0097] Please refer to the following: Figure 4A The optical lens 130 has a first diameter D1, and the opening of the recess 132 has a second diameter D2. In some embodiments, the ratio of the first diameter D1 to the second diameter D2 is 1.3:1 to 2:1, for example, 1.3:1, 1.4:1, 1.5:1, 1.6:1, 1.7:1, 1.8:1, 1.9:1, or 2:1. When the ratio falls within the above range, light emitted from the central portion of the optical lens 130 can be effectively reduced. For example, the central light intensity of the light-emitting device 100 can be less than 80%. In some embodiments, the first diameter D1 is 0.5 mm to 10 mm, for example, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 mm. In some embodiments, the second diameter D2 is 0.1 mm to 8 mm, for example, 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, or 8 mm.

[0098] Please refer to the following: Figure 4AThe light source 120 has a width W1. In some embodiments, the second diameter D2 of the opening of the recess 132 is greater than or equal to the width W1 of the light source 120. In some embodiments, the second diameter D2 of the opening of the recess 132 is less than the width W1 of the light source 120. All of the above embodiments can increase the uniformity of light distribution. When the second diameter D2 is greater than or equal to the width W1, the uniformity of light distribution is better.

[0099] Although Figure 4A The optical lens 130 shown has two distinct transition points between its outer surface 131 and the inner surface 133 of the recess 132, but this disclosure is not limited thereto. Furthermore, the shape of the recess 132 is not affected by… Figure 4A Due to limitations, any shape of recess 132 can reduce the intensity of the central light. Now please note... Figure 4B . Figure 4B The light-emitting device 100' and Figure 4A The difference in the light-emitting device 100 is that the outer surface 131 of the optical lens 130' is smoothly connected to the inner surface 133 of the recess 132, without any obvious turning point. In other words, the outer surface 131 of the optical lens 130' and the inner surface 133 of the recess 132 form a smooth curved interface CI. Through the aforementioned dispensing parameters, Figure 2 , Figure 3A and Figure 3B The process shown can also form Figure 4B The optical lens 130' is shown. In practical applications, both the light-emitting device 100' and the light-emitting device 100 can provide uniform light output. It is worth noting that the following... Figure 5 , Figure 8 , Figure 9 , Figure 10 , Figure 11 , Figure 12 and Figure 13 The optical lens 130 shown can also be modified to have Figure 4B The smooth curved interface CI is shown.

[0100] Please refer to the following: Figure 5 . Figure 5 The light-emitting device 100A and Figure 1 The difference between the light-emitting devices 100 is that the light-emitting device 100A further includes a light-shielding material 140 located in the recess 132. In some embodiments, the distance D between the light-shielding material 140 and the light-emitting surface 121 is... BThe depth Dp of the recess 132 is from 0 mm to 19.9 mm, for example, 0, 0.05, 0.1, 0.5, 1, 2, 4, 6, 8, 10, 12, 14, 16, 18, or 19.9 mm. In some embodiments, the depth Dp of the recess 132 is from 0.05 mm to 19.9 mm, for example, 0.05, 0.1, 0.5, 1, 2, 4, 6, 8, 10, 12, 14, 16, 18, or 19.9 mm. When the distance D... B When the depth Dp falls within the aforementioned range, light emitted from the central portion of the optical lens 130 can be effectively reduced. In some embodiments, such as Figure 5 As shown, the light-shielding material 140 fills and protrudes from the recess 132. In some embodiments, the light-shielding material 140 has a convex, curved upper surface 141, but this disclosure is not limited thereto. In some embodiments, the light-shielding material 140 has a transmittance of less than 80% for light with wavelengths from 360 nm to 1000 nm (e.g., 360, 400, 500, 600, 700, 800, 900, or 1000 nm). The transmittance may be less than or equal to 75, 70, 65, 60, 55, 50, 45, 40, 35, 30, 25, or 20%. In some embodiments, the light-shielding material 140 includes an encapsulant and pigment powder dispersed in the encapsulant. In some embodiments, the encapsulant of the light-shielding material 140 includes silicone, epoxy resin, polymethyl methacrylate, thixotropic adhesive, or combinations thereof.

[0101] Please refer to Figure 4A and Figure 5 In the light-emitting device 100, the optical lens 130 can change the intensity distribution (light pattern) of the light emitted from the light source 120 to achieve uniform light output. The recess 132 of the optical lens 130 can reflect and / or refract the light emitted by the light source 120, thereby effectively reducing the light intensity at the center. Furthermore, in the light-emitting device 100A, both the recess 132 of the optical lens 130 and the light-shielding material 140 can reflect and / or refract the light emitted by the light source 120, thereby effectively reducing the light intensity at the center. Figure 4B The advantages of the light-emitting device 100' are similar to those of the light-emitting device 100.

[0102] Please refer to the following: Figure 5 The light-shielding material 140 has a maximum width W2. In some embodiments, the maximum width W2 of the light-shielding material 140 is greater than or equal to the width W1 of the light source 120. In some embodiments, the maximum width W2 of the light-shielding material 140 is less than the width W1 of the light source 120. All of the above embodiments can increase the uniformity of light distribution. When the maximum width W2 is greater than or equal to the width W1, the uniformity of light distribution is better.

[0103] Next, Figure 6 Show Figure 4AThe light intensity distribution curve C2 generated by the light-emitting device 100 at a light emission angle of -90 degrees to 90 degrees. Figure 7 Show Figure 5 The light intensity distribution curve C3 generated by the light-emitting device 100A at a light emission angle of -90 degrees to 90 degrees.

[0104] It should be noted that, Figure 6 and Figure 7 The light intensity distribution curves were obtained using the same light source 120 and the same optical lens 130. The light source 120 is a blue flip-chip (FC) LED chip (6V) with green and red phosphors and a size of 18mil × 18mil. The first diameter D1 of the optical lens 130 is 5.5 mm, and the height H1 of the optical lens 130 is 1.2 mm. Figure 6 It can be seen that the luminous intensity (central light intensity) at a 0-degree emission angle is approximately 50%, and the luminous intensity at a 90-degree emission angle is approximately 93%. The viewing angle along the X-axis is 156 degrees, and the viewing angle along the Y-axis is also 156 degrees. From Figure 7 It can be seen that the luminous intensity (central light intensity) at a 0-degree emission angle is approximately 35%, and the luminous intensity at a 90-degree emission angle is approximately 44%. The viewing angle along the X-axis is 171 degrees, and the viewing angle along the Y-axis is 165 degrees. Therefore, it can be concluded that both light-emitting device 100 and light-emitting device 100A can reduce the central light intensity. Light-emitting device 100A can have a larger viewing angle and / or beam angle. Since light-emitting device 100A includes light-shielding material 140, it can further effectively reduce the central light intensity.

[0105] In some embodiments, the light-emitting device 100 has a viewing angle greater than or equal to 150 degrees. In some embodiments, the light-emitting device 100A has a viewing angle greater than or equal to 150 degrees. When N1 light-emitting devices are arranged in the backlight module, and the lenses of these light-emitting devices are not recessed, more light-emitting devices need to be arranged to meet the requirements of the backlight module. When N2 light-emitting devices 100 or N2 light-emitting devices 100A are provided in the backlight module, since the lenses of the light-emitting devices 100 or 100A have a recess 132, they have a larger viewing angle, so fewer light-emitting devices 100 or fewer light-emitting devices 100A can be arranged to meet the requirements of the backlight module. This means that the number N2 is less than the number N1. Therefore, the light-emitting devices 100 and 100A of this disclosure can reduce the manufacturing cost of the backlight module.

[0106] Furthermore, one hundred known light-emitting devices and Figure 5One hundred light-emitting devices 100A are shown, each mounted on a PCB with dimensions of 100 mm × 100 mm. The known light-emitting devices and light-emitting devices 100A each comprise a blue flip-chip LED chip (6V) with green and red phosphors and dimensions of 18 mil × 18 mil. Diffuser sheets are disposed above the known light-emitting devices and light-emitting devices 100A. In these known light-emitting devices, each blue flip-chip LED chip is covered by a plano-convex lens with a diameter of 5.5 mm and a height of 1.2 mm. In these light-emitting devices 100A, each blue flip-chip LED chip is covered by an optical lens 130 with a recess 132 (second diameter D2 is 5.5 mm, height H1 is 1.2 mm). Furthermore, each light-emitting device 100A has a white light-shielding material 140. The known light-emitting devices have a spacing of 7.5 mm × 7.5 mm, and the light-emitting devices 100A also have a spacing of 7.5 mm × 7.5 mm. The distance between the top surface of the PCB and the bottom surface of the diffuser sheet is the vertical distance (H), and the distance between adjacent light-emitting devices is the horizontal distance (P). In structures including known light-emitting devices, the optical distance (OD) is approximately 7.0 mm to approximately 8.0 mm (H / P ratio is approximately 1.0). In structures including light-emitting device 100A, the OD is approximately 3.5 mm to approximately 4.0 mm (H / P ratio is approximately 0.5). Therefore, it can be seen that when light-emitting device 100A is applied to a backlight module, the OD can be reduced, thereby reducing the thickness of the backlight module.

[0107] Figure 8 , Figure 9 , Figure 10 , Figure 11 and Figure 12 These are cross-sectional schematic diagrams of various embodiments of the light-emitting device according to this disclosure.

[0108] Figure 8 The light-emitting device 100B is shown, and the light-emitting device 100B is... Figure 5 The difference between the light-emitting device 100A and the light-emitting device 100B is that the light-shielding material 140 of the light-emitting device 100B has a concave curved upper surface 142, and a portion of the recess 132 is not filled by the light-shielding material 140, and the light-shielding material 140 does not protrude from the recess 132. In other embodiments, a portion of the recess 132 is not filled by the light-shielding material 140, and the light-shielding material 140 protrudes from the recess 132 (not shown).

[0109] Figure 9 The light-emitting device 100C is shown, and the light-emitting device 100C and Figure 5 The difference between the light-emitting device 100A and the light-emitting device 100C is that the light-shielding material 140 of the light-emitting device 100C has a substantially flat upper surface 143. In some embodiments, such as Figure 9As shown, the recess 132 is filled with light-shielding material 140. In some other embodiments, the light-shielding material 140 is below the highest position of the optical lens 130 (not shown).

[0110] The shapes of the optical lens 130 and the recess 132 are not limited to Figure 4A , Figure 4B , Figure 5 , Figure 6 , Figure 7 , Figure 8 and Figure 9 . Figure 10 The light-emitting device 100D is shown, wherein Figure 10 The second diameter D2 of the depression 132 is less than Figure 5 The second diameter D2 of the depression 132, therefore Figure 10 140 ratio of light-blocking material Figure 5 The light-blocking material is 140mm narrow. Figure 11 The light-emitting device 100E is shown, wherein Figure 11 The second diameter D2 of the depression 132 is less than Figure 10 The second diameter D2 of the depression 132. Therefore Figure 11 140 ratio of light-blocking material Figure 10 The light-shielding material 140 is narrow. The second diameter D2 and the width of the light-shielding material 140 can be adjusted according to different light distribution uniformity requirements.

[0111] Figure 12 The light-emitting device 100F is shown. The light-shielding material 140 is in direct contact with the light-emitting surface 121 of the light source 120. In other words, the distance between the light-shielding material 140 and the light-emitting surface 121 is 0 μm. Furthermore, the distance between the bottom of the recess 132 and the light-emitting surface 121 of the light source 120 is 0 μm.

[0112] Figure 13 This is a cross-sectional schematic diagram of a light-emitting device 100G according to various embodiments of the present disclosure. The light-emitting device 100G includes a substrate 110, a light source 120, an optical lens 130, and at least one light-shielding wall 150. The substrate 110 has a main surface 111. Each light source 120 is disposed on the main surface 111 and has a light-emitting surface 121 away from the main surface 111. Each optical lens 130 is disposed on the main surface 111 and covers the light source 120, and has an outer surface 131 away from the light source 120 and a recess 132 located on the outer surface 131 and above the light-emitting surface 121. Figure 13A light-shielding wall 150 is shown. Each light-shielding wall 150 is disposed on the main surface 111 and close to the optical lens 130. The light-shielding walls 150 can separate the light sources 120 from each other to avoid light interference or light overflow. In some embodiments, the optical lens 130 has a height H1 (first height), and the light-shielding wall 150 has a height H2 (second height), wherein the height H2 is less than or equal to twice the height H1, thereby achieving a better effect in avoiding light interference or light overflow. In some embodiments, the light-shielding wall 150 is white. The light-shielding wall 150 can have any color, such as white, black, gray, red, orange, yellow, green, blue, purple, pink, brown, or combinations thereof. When the light-shielding wall 150 is white, it can have a better effect in preventing light interference.

[0113] The characteristics of this disclosure will be described more clearly below with reference to Experimental Examples 1 and 2. Although the following experimental examples are described, the materials, their quantities and proportions, processing details, and processing procedures may be appropriately modified without departing from the scope of this disclosure. Therefore, this disclosure should not be interpreted restrictively based on the experimental examples described below.

[0114] Experiment Example 1: Measurement of a Light-Emitting Device

[0115] In Example 1, multiple such Figure 5 The light-emitting devices 100A shown are respectively mounted on the PCB. The light source 120 uses a CSP LED, and the light-shielding material 140 is white. A diffuser is placed above the light-emitting device 100A. The distance between the top surface of the PCB and the bottom surface of the diffuser is the vertical distance (H), and the distance between adjacent light-emitting devices 100A is the horizontal distance (P). The structural parameters, other structural parameters, and measurement results of the optical lens 130 are listed in Table 1 below. Embodiments 2 and 3 are similar to Embodiment 1, and the parameters of Embodiments 2 and 3 are listed in Table 1 below.

[0116] Table 1

[0117]

[0118]

[0119] Figure 14 The light-emitting device 100A of Examples 1 to 3 produces a light intensity variation curve at a 0-degree longitudinal plane and at a light emission angle from -90 degrees to 90 degrees. Figure 15 The table shows the luminous intensity variation curves of the light-emitting device 100A in Examples 1 to 3 at a 90-degree longitudinal plane and at a luminous angle from -90 degrees to 90 degrees. (See Table 1 for details.) Figure 14 and Figure 15It can be seen that, since the light-emitting device 100A of Embodiment 1 has a larger first diameter D1 and a larger second diameter D2, it has a larger central light intensity. Therefore, Embodiments 2 and 3 are more advantageous in reducing the central light intensity. Furthermore, since the first diameter D1 and the second diameter D2 of Embodiment 3 are smaller, the H / P ratio is greater than that of Embodiments 1 and 2. Therefore, Embodiment 2 can simultaneously achieve a good effect of reducing the central light intensity and a smaller H / P ratio.

[0120] Experiment Example 2: Manufacturing of a Light-Emitting Device

[0121] In Examples 4 to 9, multiple methods were used respectively. Figure 5 The light-emitting device 100A shown uses a CSP LED as the light source 120, and the light-shielding material 140 is white. The structural parameters and measurement results of the optical lens 130 are listed in Table 2 below. When the ratio of the first diameter D1 to the second diameter D2 falls between 1.3 and 2, the light emitted from the central part of the optical lens 130 can be effectively reduced.

[0122] Table 2

[0123]

[0124] In summary, this disclosure provides a light-emitting device and a method for manufacturing the same. The light-emitting device includes an optical lens with a recess, which can change the intensity distribution (light pattern) of light emitted from a light source to achieve uniform light output. The recess can reflect and / or refract light emitted from the light source, thereby effectively reducing the light intensity at the center to reduce the light emission directionality. A light-shielding material can be disposed in the recess to further reduce the light intensity at the center, thereby further enhancing the light uniformity. When this light-emitting device is disposed in a backlight module, the optical distance (OD) of the backlight module can be shortened, thereby reducing the overall thickness of the module and enabling the backlight module to have a uniform light intensity distribution.

[0125] Although this disclosure has been described in considerable detail with reference to certain embodiments, other embodiments may also be possible. Therefore, the spirit and scope of the appended claims should not be limited to the description of the embodiments included herein.

[0126] It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of this disclosure without departing from its scope or spirit. In view of the foregoing, this disclosure is intended to cover any modifications and variations falling within the scope of the appended claims.

Claims

1. A light-emitting device, characterized in that, include: A substrate having a main surface; A light source is disposed on the main surface and has a light-emitting surface that is away from the main surface; as well as An optical lens is disposed on the main surface and covers the light source, wherein the optical lens has an outer surface away from the light source and a recess located on the outer surface and above the light-emitting surface.

2. The light-emitting device as claimed in claim 1, wherein the outer surface has a convex curved surface and the recess has a concave curved surface.

3. The light-emitting device as claimed in claim 1, wherein the distance between a bottom of the recess and the light-emitting surface is 0 mm to 19.9 mm.

4. The light-emitting device as claimed in claim 1, wherein the optical lens has a first diameter, the recessed opening has a second diameter, and the ratio of the first diameter to the second diameter is 1.3:1 to 2:

1.

5. The light-emitting device of claim 1, wherein the optical lens comprises silicone, epoxy resin, polymethyl methacrylate, thixotropic adhesive, or a combination thereof.

6. The light-emitting device as claimed in claim 1, wherein the depth of the recess is from 0.05 mm to 19.9 mm.

7. The light-emitting device as claimed in claim 1, wherein in a cross-section of the light-emitting device, the light-emitting mask has a first end point and a second end point, the first end point and the edge of the recessed first opening define a first virtual line, the second end point and the edge of the recessed second opening define a second virtual line, and an angle between the first virtual line and the second virtual line is greater than 0 degrees and less than or equal to 160 degrees.

8. The light-emitting device of claim 1 further includes at least one light-shielding wall disposed on the main surface and close to the optical lens, wherein the optical lens has a first height, the light-shielding wall has a second height, and the second height is less than or equal to twice the first height.

9. The light-emitting device as claimed in claim 1 further includes a light-shielding material in the recess.

10. The light-emitting device of claim 9, wherein the light-shielding material has a transmittance of less than 80% for light with wavelengths from 360 nm to 1000 nm.

11. The light-emitting device of claim 9, wherein the light-shielding material fills the recess and protrudes from the recess.

12. The light-emitting device of claim 9, wherein the light-shielding material comprises an encapsulant and a pigment powder dispersed in the encapsulant.

13. A method for manufacturing a light-emitting device, characterized in that, The method includes: A light source is placed on a substrate; A dispensing machine is placed above the light source, wherein the dispensing machine includes a dispensing nozzle and a striking pin disposed in a flow channel of the dispensing nozzle; By applying pressure to push the ejector pin against an inner surface of the flow channel, an encapsulant is extruded from the flow channel and applied as an encapsulation layer to the light source, wherein the encapsulation layer has a recess facing the dispensing nozzle; and The encapsulation layer is cured to form an optical lens.

14. The method of claim 13, wherein the viscosity of the encapsulant is from 0.2 mPa·s to 100,000 mPa·s.

15. The method of claim 13, wherein the time for the ejector pin to strike the inner surface is from 0.01 milliseconds to 500 milliseconds, and the dispensing pressure is from 1 bar to 10 bar.

16. The method of claim 13, wherein curing the encapsulation layer comprises: The encapsulation layer is heated at a first temperature of 40°C to 60°C; The encapsulation layer is heated at a second temperature of 80°C to 100°C; as well as The encapsulation layer is heated at a third temperature of 110°C to 130°C.

17. The method of claim 13, wherein the encapsulant comprises silicone, epoxy resin, polymethyl methacrylate, thixotropic adhesive, or a combination thereof.

18. The method of claim 13, further comprising forming a light-shielding material in the recess.

19. The method of claim 18, wherein the light-shielding material fills the recess and protrudes the recess.

20. The method of claim 18, wherein forming the light-shielding material in the recess comprises: An encapsulation material and a pigment powder are dispensed into the recess, wherein the pigment powder is dispersed in the encapsulation material; The encapsulation material and the pigment powder are heated at a first temperature of 40°C to 60°C. The encapsulation material and the pigment powder are heated at a second temperature of 80°C to 100°C; and The encapsulation material and the pigment powder are heated at a third temperature of 110°C to 130°C.

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