A high-brightness LED with a small light-emitting angle and a manufacturing method thereof

Abstract

The application relates to a high-brightness LED with a small light-emitting angle, which comprises a support, a chip, bonding wires, white glue and packaging glue, the support is provided with a bowl cup, the bottom of the bowl cup is provided with a functional area, the electrodes of the chip arranged in the center of the bowl cup are electrically connected with the functional area through the bonding wires; the white glue is spot-coated on the bottom end of the bowl cup and covers the functional area, and the top surface of the white glue is at the same horizontal plane as the top surface of the chip; the packaging glue is spot-coated above the white glue, the packaging glue fills the bowl cup of the support and has a height higher than the top of the bowl cup of the support, and the packaging glue forms a convex lens structure with a narrow top and a wide bottom after solidification; the lens with a water-drop-like structure is formed through overturning and solidification, the light-emitting angle is smaller than that of a conventional SMD LED, and the white glue is spot-coated on the functional area, so that the light emitted from the bottom and the side of the chip is effectively reflected to the front surface, thereby increasing the overall brightness of the device.

Description

Technical Field

[0001] This invention relates to the field of LED technology, and in particular to a high-brightness LED with a small emission angle and its preparation method. Background Technology

[0002] Surface mount LEDs (SMD LEDs) are light-emitting diode devices packaged using surface mount technology. They are widely used in consumer electronics, automotive electronics, industrial control, and outdoor lighting due to their small size, suitability for automated production lines, excellent luminous efficacy, good heat dissipation, and low-voltage DC power supply. Among them, small-angle, high-brightness SMD LEDs possess the core characteristics of strong light directionality, outstanding light-focusing effect, and concentrated light output, enabling directional light emission and localized high-brightness output. They are commonly used as dedicated indicator lights, automotive backlights, industrial sensor lights, and small focused light sources, making them indispensable core optoelectronic devices in precision electronics and special lighting scenarios.

[0003] Currently, small-angle surface-mount LEDs in the industry generally use a mold-top process to form lenses. This process requires dedicated mold-top production equipment and customized molds that match each product model. This not only results in high equipment investment costs and long product development cycles, but also requires new molds for products of different sizes and optical angles, leading to poor production versatility and low changeover efficiency. In addition, conventional surface-mount LEDs rely solely on the silver plating layer of the bracket functional area for light reflection, with a reflectivity typically only 85% to 95%. Light emitted from the bottom and sides of the chip cannot be efficiently recovered and utilized, resulting in significant light loss. This directly leads to low overall light output efficiency and insufficient brightness to meet the demands of high-end applications. Summary of the Invention

[0004] To address the aforementioned problems, this invention discloses a high-brightness LED with a small emission angle. It employs a flip-cured, teardrop-shaped encapsulating adhesive combined with a high-reflectivity white glue, thus solving the issues of high cost, poor versatility, low light utilization, and excessively large emission angle associated with small-angle LEDs.

[0005] The specific technical solution is as follows: A high-brightness LED with a small emission angle includes a bracket, a chip, bonding wires, white glue, and encapsulating adhesive. The bracket has a cup, and the bottom of the cup has a functional area. The electrodes of the chip are located in the center of the cup and are electrically connected to the functional area through bonding wires. The white glue is applied to the bottom of the cup and covers the functional area, and the top surface of the white glue is at the same level as the top surface of the chip. The encapsulating adhesive is applied above the white glue, fills the cup of the bracket, and is higher than the top of the cup. After curing, the encapsulating adhesive forms a convex lens structure that is narrow at the top and wide at the bottom.

[0006] Furthermore, the functional area includes a conductive part and an insulating part, the insulating part being disposed in the middle of the conductive part and insulatingly dividing the conductive part into two conductive parts, and the surface of each conductive part being provided with a silver plating layer.

[0007] Furthermore, the bottom of the bracket is provided with two metal electrodes for surface mounting, and the surfaces of the metal electrodes are plated with nickel.

[0008] Furthermore, the chip is a purple LED chip, which is fixed to the center of the bottom of the bowl / cup with die bond adhesive, and the positive and negative electrodes of the chip are electrically connected to two conductive parts respectively through bonding wires.

[0009] Furthermore, the white adhesive is a high-reflectivity white silicone with a reflectivity ≥98%.

[0010] Furthermore, the bottom of the encapsulating adhesive fills the inner cavity of the support cup, and the upper part of the encapsulating adhesive extends upward from the edge of the cup into a continuous arc-shaped convex surface that is high in the middle and low around the edges, making the encapsulating adhesive appear as a teardrop shape.

[0011] Furthermore, the encapsulating adhesive is a high-transmittance transparent silicone with a transmittance ≥98% and a viscosity coefficient of 3500-4500 mPa·s.

[0012] A method for fabricating a high-brightness LED with a small emission angle includes the following steps: S1. Chip Placement: Take the entire support frame, apply die bonding adhesive to the bottom of several cups on the support frame, and place the LED chip on the die bonding adhesive in each cup. S2, die bonding and curing: Place the above-mentioned chip-bearing bracket into a constant temperature chamber and heat and cure the die bonding adhesive to fix the chip to the bottom of the cup. S3. Wire bonding: The chip electrodes are electrically connected to the functional area at the bottom of the cup using bonding wires; S4. One-time dispensing: Use a dispensing machine to apply white glue inside the cup, so that the white glue covers the functional area and the top surface is flush with the top surface of the chip. S5. Curing treatment: Place the bracket with the white glue applied above into a constant temperature chamber and heat and cure the white glue in sections. S6. Secondary dispensing: Apply encapsulating adhesive to the cured white adhesive. The encapsulating adhesive is a transparent silicone with a light transmittance of ≥98% and a viscosity of 3500-4500 mPa・s. Make sure the height of the encapsulating adhesive is higher than the mouth of the cup of the support without overflowing. After all the adhesive is dispensed, let it stand for 1 minute to stabilize the outline of the encapsulating adhesive. S7. Flipping and molding: After the entire bracket is conveyed to a fixed position through the flow channel, it is picked up by the flipping mechanism and slowly flipped 180°, so that the encapsulating adhesive forms a raised teardrop-shaped structure under the action of gravity.

[0013] S8. Finished product curing: Place the above bracket into a constant temperature chamber and heat and cure the water droplet-shaped encapsulating adhesive to finally obtain a high-brightness LED with a small light-emitting angle.

[0014] Furthermore, in S2, the curing conditions for the die bond adhesive are 150°C for 120 minutes.

[0015] Furthermore, in S5, the white glue is cured in stages under the following conditions: heat preservation at 80°C for 60 minutes, followed by heating to 150°C and heat preservation for 10 minutes.

[0016] Furthermore, in S8, the curing conditions for the encapsulating adhesive are 150°C for 120 minutes.

[0017] The beneficial effects of this invention are reflected in: This invention uses a dispensing and flipping gravity molding process to prepare lenses, eliminating the need for traditional mold-top processes, saving on investment in special equipment and customized molds, reducing production costs, shortening development cycles, enabling LED light emission at small angles, and improving production versatility and efficiency.

[0018] This invention uses a high-reflectivity white glue applied to the functional area of ​​the bowl / cup to reflect light emitted from the side and bottom of the chip to the front, thereby improving light utilization and effectively enhancing the overall brightness and luminous efficacy of the LED. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the present invention.

[0020] Figure 2 This is a top view of the present invention.

[0021] Figure 3 This is a frontal view of the entire support piece after adhesive application in this invention.

[0022] Figure 4 This is a schematic diagram of the entire support piece being flipped after being glued in this invention.

[0023] Figure labeling: 1-Bracket, 2-Chip, 3-Bonding wire, 4-White glue, 5-Encapsulating glue. Detailed Implementation

[0024] To make the technical solution of the present invention clearer and more explicit, the present invention will be further described below with reference to the accompanying drawings. Any solution derived by equivalent substitution and conventional reasoning of the technical features of the present invention falls within the protection scope of the present invention.

[0025] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0026] This embodiment provides a high-brightness LED with a small emission angle. By using a moldless flip-gravity forming process combined with a high-reflectivity packaging structure, it replaces the traditional mold-top production method, solving the problems of poor versatility and low luminous efficiency in the production of small-angle LEDs, and can be adapted to automated mass production.

[0027] Please see the appendix Figure 1-4 This high-brightness LED with a narrow beam angle comprises a support, a chip, bonding wires, white glue, and encapsulating adhesive. A cup-shaped structure is mounted on the support to hold the chip, white glue, and encapsulating adhesive, while also initially focusing the light and optimizing the initial light path. A functional area is located at the bottom of the cup, including a conductive section and an insulating section. The insulating section is located in the middle of the conductive section, dividing it into two independent conductive sections to achieve electrical isolation between the positive and negative electrodes of the chip and prevent short circuits. A silver-plated layer is applied to the surface of the conductive section, working in conjunction with the white glue to improve overall light utilization. Two nickel-plated metal electrodes are located at the bottom of the support for surface mounting, enhancing soldering reliability and conductivity stability to meet the needs of automated assembly line mounting production.

[0028] The chip uses a violet LED chip, which is fixed to the center of the bottom of the cup using die-bonding adhesive. This centrally positioned chip ensures uniform light emission and prevents light deflection. The positive and negative electrodes of the chip are electrically connected to two conductive parts via bonding wires.

[0029] The white adhesive is made of high-reflectivity white silicone with a reflectivity of ≥98%. It is applied to the bottom of the cup and covers the functional area. The top surface of the white adhesive is at the same level as the top surface of the chip. This arrangement avoids blocking light emitted from the front of the chip while reflecting scattered light from the sides and bottom of the chip from all directions, structurally reducing light loss. In this embodiment, the white silicone used is KMT-1872 from Commet, which is existing technology and will not be described in detail here.

[0030] The encapsulating adhesive uses high-transmittance transparent silicone with a transmittance ≥98% and a viscosity coefficient of 3500-4500 mPa·s. This viscosity range ensures that the adhesive does not flow or overflow during the flipping and molding process, guaranteeing the stability of the lens profile. In this embodiment, Shin-Etsu KER-2500 transparent silicone is used, which is existing technology and will not be described in detail here. The encapsulating adhesive is dotted on top of the white adhesive, filling the inner cavity of the support cup at the bottom, completely encapsulating the chip and bonding wires, providing mechanical protection, dustproofing, and moisture protection. The height of the encapsulating adhesive is higher than the top of the support cup, and after curing, it forms a convex lens structure that is narrow at the top and wide at the bottom. The upper part extends upward from the edge of the cup into a continuous arc-shaped convex surface that is high in the middle and low around the edges, giving it an overall teardrop shape. This curved surface structure can directionally converge light, significantly reducing the emission angle and achieving a high-brightness light emission effect at a small angle.

[0031] This embodiment also discloses a method for preparing a high-brightness LED with a small emission angle, specifically including the following steps: S1. Chip Placement: Take the entire support frame, apply die-bonding adhesive to the bottom of multiple cups on the support frame, and place the LED chip on the die-bonding adhesive in each cup.

[0032] S2. Die Bonding and Curing: Place the chip-bearing bracket into a constant temperature chamber and heat the die bond adhesive to cure it. The curing conditions are 150℃ for 120 minutes to fix the chip at the bottom of the cup and prevent the chip from shifting during subsequent processing.

[0033] S3. Wire bonding: Bonding wires are used to electrically connect the chip electrodes to the functional area at the bottom of the bowl, achieving a stable electrical path and ensuring that the LED can light up normally after being powered on.

[0034] S4. First application of adhesive: Apply white adhesive to the inside of the bowl, so that the white adhesive covers the functional area and the top surface is flush with the top surface of the chip.

[0035] S5. Curing treatment: Place the bracket with white glue applied into a constant temperature chamber and heat and cure the white glue in sections. The curing conditions are 80℃ for 60 minutes, then raise the temperature to 150℃ and keep it for 10 minutes. Sectional curing can completely cure and shape the white glue, prevent the glue from cracking and falling off, and improve the structural stability.

[0036] S6. Secondary dispensing: Apply encapsulating adhesive to the cured white glue. The encapsulating adhesive is a transparent silicone with a light transmittance of ≥98% and a viscosity of 3500-4500 mPa·s. Ensure that the height of the encapsulating adhesive is higher than the mouth of the bracket cup without overflowing. After all the adhesive is dispensed, let it stand for 1 minute to stabilize the outline of the encapsulating adhesive and remove the tiny air bubbles generated during the dispensing process to ensure the quality of lens forming.

[0037] S7. Flip molding: After the entire bracket is conveyed to a fixed position through the flow channel, it is slowly flipped 180°, so that the encapsulating glue forms a raised teardrop-shaped structure under the action of gravity. The lens is naturally formed by gravity, without the need for molds, which simplifies the production process.

[0038] S8. Finished product curing: Place the bracket in a constant temperature chamber and heat and cure the teardrop-shaped encapsulating adhesive. The curing conditions are 150℃ for 120 minutes to allow the encapsulating adhesive to fully set and form a stable teardrop-shaped focusing lens, ultimately producing a high-brightness LED with a small light emission angle.

[0039] This embodiment replaces the traditional mold-top process with a flip-gravity forming method, eliminating the need for customized molds and special equipment. This reduces production costs and shortens the development cycle. The lens with a teardrop-shaped structure formed by flip-curing has a smaller light-emitting angle than conventional SMD LEDs. At the same time, the combination with high-reflectivity white glue can fully recover scattered light, improving the device's luminous efficiency and brightness, and is suitable for the efficient production of various specifications of small-angle LEDs.

[0040] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A high-brightness LED with a small emission angle, comprising a bracket, a chip, bonding wires, white glue, and encapsulating glue, wherein a cup is provided on the bracket, a functional area is provided at the bottom of the cup, and electrodes of the chip are disposed in the center of the cup and electrically connected to the functional area through bonding wires; characterized in that, The white adhesive is applied to the bottom of the cup and covers the functional area, and the top surface of the white adhesive is at the same level as the top surface of the chip; the encapsulating adhesive is applied above the white adhesive, fills the cup of the support and is higher than the top of the cup of the support, and the encapsulating adhesive is cured to form a convex lens structure that is narrow at the top and wide at the bottom.

2. The high-brightness LED with a small emission angle as described in claim 1, characterized in that, The functional area includes a conductive part and an insulating part. The insulating part is disposed in the middle of the conductive part and insulatingly divides the conductive part into two conductive parts. The surface of each conductive part is provided with a silver plating layer.

3. A high-brightness LED with a small emission angle as described in claim 1, characterized in that, The chip is a purple LED chip, which is fixed to the middle of the bottom of the bowl with die bond adhesive. The positive and negative electrodes of the chip are electrically connected to two conductive parts respectively through bonding wires.

4. A high-brightness LED with a small emission angle as described in claim 1, characterized in that, The white adhesive is a high-reflectivity white silicone with a reflectivity of ≥98%.

5. A high-brightness LED with a small emission angle as described in claim 1, characterized in that, The bottom of the encapsulating adhesive fills the inner cavity of the cup of the support, and the upper part of the encapsulating adhesive extends upward from the edge of the cup into a continuous arc-shaped convex surface that is high in the middle and low around the edges, making the encapsulating adhesive appear as a teardrop shape.

6. A high-brightness LED with a small emission angle as described in claim 1, characterized in that, The encapsulating adhesive is a high-transmittance transparent silicone with a transmittance of ≥98% and a viscosity coefficient of 3500-4500 mPa·s.

7. A method for preparing a high-brightness LED with a small emission angle, used to prepare the high-brightness LED with a small emission angle as described in any one of claims 1-6, characterized in that, Includes the following steps: S1. Chip Placement: Take the entire support frame, apply die bonding adhesive to the bottom of several cups on the support frame, and place the LED chip on the die bonding adhesive in each cup. S2, die bonding and curing: Place the above-mentioned chip-bearing bracket into a constant temperature chamber and heat and cure the die bonding adhesive to fix the chip to the bottom of the cup. S3. Wire bonding: The chip electrodes are electrically connected to the functional area at the bottom of the cup using bonding wires; S4. First application of adhesive: Apply white adhesive to the inside of the bowl, so that the white adhesive covers the functional area and the top surface is flush with the top surface of the chip. S5. Curing treatment: Place the bracket with the white glue applied above into a constant temperature chamber and heat and cure the white glue in sections. S6. Secondary dispensing: Apply encapsulating adhesive to the cured white adhesive. The encapsulating adhesive is a transparent silicone with a light transmittance of ≥98% and a viscosity of 3500-4500 mPa・s. Make sure the height of the encapsulating adhesive is higher than the mouth of the cup of the support without overflowing. After all the adhesive is dispensed, let it stand for 1 minute to stabilize the outline of the encapsulating adhesive. S7. Flipping and molding: Slowly flip the entire bracket that has been dispensed 180° so that the encapsulating adhesive forms a raised teardrop-shaped structure under the action of gravity. S8. Finished product curing: Place the above bracket into a constant temperature chamber and heat and cure the water droplet-shaped encapsulating adhesive to finally obtain a high-brightness LED with a small light-emitting angle.

8. In the method for preparing a high-brightness LED with a small emission angle as claimed in claim S2, the die-attach adhesive is cured at 150°C for 120 minutes.

9. Further, in S5, the white glue is cured in stages under the following conditions: heat preservation at 80°C for 60 minutes, followed by heating to 150°C and heat preservation for 10 minutes.

10. Further, in S8, the curing conditions for the encapsulating adhesive are 150°C for 120 minutes.

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