High-performance flip RGB lamp bead structure and preparation method

Abstract

This invention provides a high-performance flip-chip RGB LED structure and its fabrication method, comprising a double-layer substrate, an RGB chip at least partially embedded in the top of the double-layer substrate, and a double-layer encapsulation layer encapsulating the top of the double-layer substrate and covering the RGB chip. The double-layer substrate includes a first substrate layer and a second substrate layer stacked vertically. The top of the second substrate layer has a cup-like structure recessed therein. The RGB chip is disposed in the center of the cup cavity of the second substrate layer. An ink protective layer is provided on the side of the first substrate layer. The double-layer encapsulation layer includes a first encapsulation layer covering the RGB chip and a second encapsulation layer disposed above the first encapsulation layer. Through differentiated formulation of the double-layer encapsulation layer, the upper first encapsulation layer is doped with large-particle-size diffusing powder to improve brightness and widen the light emission angle, while the lower second encapsulation layer is doped with trace amounts of black agent to optimize ink color. Combined with the cup cavity extending the water vapor path to improve airtightness, the LED achieves high brightness, high ink color uniformity, excellent heat dissipation, and long service life.

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, and in particular to a high-performance flip-chip RGB LED structure and its fabrication method. Background Technology

[0002] With the rapid iteration of Mini LED and small-pitch high-definition display technology, flip-chip RGB LEDs have become core components of high-end commercial displays and virtual shooting screens due to their advantages of leadless packaging and miniaturization. The industry is simultaneously demanding improvements in both the color consistency and brightness of the LEDs.

[0003] Current conventional flip-chip RGB LEDs generally use a single-layer flat substrate combined with an integrated single-layer encapsulant design. Due to structural limitations, it is difficult to balance optical performance indicators and is gradually becoming unsuitable for current high-definition display standards. The single-layer encapsulant cannot simultaneously achieve high ink color consistency and high luminous brightness. If black additives are added to the encapsulant to optimize ink color and suppress reflection, they will absorb the light emitted by the chip, causing brightness reduction. If the amount of black additives is reduced to maintain brightness, problems such as uneven ink color of the LEDs, white black areas, and low contrast will occur. At the same time, the lack of cup-shaped positioning and vertical copper pillars for heat conduction further exacerbates the industry pain point of the incompatibility between brightness and ink color. Summary of the Invention

[0004] Based on this, the purpose of this invention is to provide a high-performance flip-chip RGB LED structure for display, so as to fundamentally solve the problem that current single-layer encapsulation colloids cannot simultaneously achieve high ink color consistency and high luminous brightness.

[0005] According to an embodiment of the present invention, a high-performance flip-chip RGB LED structure includes a double-layer substrate, an RGB chip at least partially embedded in the top of the double-layer substrate, and a double-layer encapsulant that encapsulates the top of the double-layer substrate and covers the RGB chip. The dual-layer substrate includes a first substrate layer and a second substrate layer stacked on top of each other. The top of the second substrate layer has a cup-like structure recessed. The RGB chip is disposed in the center of the cup cavity of the second substrate layer. The first substrate layer has an ink protective layer on its side. The bottom of the RGB chip is connected to multiple electroplated copper pillars that penetrate the second substrate layer. The side of the electroplated copper pillars away from the RGB chip is connected to the front circuit of the first substrate layer. The double-layer encapsulation includes a first encapsulation layer covering the RGB chip and a second encapsulation layer disposed above the first encapsulation layer. The second encapsulation layer fills the cup cavity of the second substrate layer and covers the top of the first encapsulation layer.

[0006] Furthermore, large-particle-size diffusing powder is mixed inside the first encapsulating adhesive layer to optimize the light emission angle and improve the overall luminous brightness of the LED.

[0007] Furthermore, a black pigment and a diffusion powder are added to the second encapsulating adhesive layer to absorb stray light and improve ink color consistency. At the same time, in conjunction with the cup cavity of the second substrate layer, the moisture penetration path is extended to improve the encapsulation airtightness.

[0008] Furthermore, the inner wall of the cup of the second substrate layer is an inclined slope that converges inward from top to bottom, and a limiting step is formed at the cup opening position to limit the second encapsulating adhesive layer and assist the first encapsulating adhesive layer in shaping into a hemispherical shape.

[0009] Furthermore, the electroplated copper pillar is formed by electroplating copper filling through the through holes of the second substrate layer, simultaneously achieving conductive connection and vertical heat conduction and heat dissipation between the RGB chip and the first substrate layer.

[0010] Furthermore, the first substrate layer is a double-sided circuit substrate with conductive vias inside. The leads are connected to the electroplated leads on the front side through the conductive vias, and ink plugs are provided at the holes of the conductive vias.

[0011] Furthermore, the first substrate layer and the second substrate layer are hot-pressed together with PP adhesive film to form an integrated double-layer substrate.

[0012] Furthermore, the RGB chip includes a red light chip, a green light chip, and a blue light chip. Each chip is fixed to the die bond end by soldering with solder paste. The die bond end is disposed on the upper surface of the second substrate layer and located on the upper end face of the electroplated copper pillar.

[0013] The method for preparing a high-performance flip-chip RGB LED bead according to an embodiment of the present invention is used to operate the high-performance flip-chip RGB LED bead structure described in the present invention, the method comprising: The first substrate layer and the second substrate layer with a cup-like cavity are respectively processed and shaped. Copper is electroplated in the reserved through hole of the second substrate layer to form an electroplated copper pillar. Ink is printed on the side of the first substrate layer to form an ink protective layer. Electroplated leads are etched on the front side of the first substrate layer and pins are made on the bottom side. The first substrate layer and the second substrate layer are hot-pressed together using PP adhesive to make the lower end of the electroplated copper pillar and the electroplated lead wire connected and conductive. Solder paste is printed on the die bond surface, and RGB chips are positioned and mounted. The die bonding of the chips is completed by reflow soldering. A second encapsulating adhesive layer is formed by injecting and curing adhesive into the cavity of the second substrate layer, and then a hemispherical first encapsulating adhesive layer is formed above the RGB chip.

[0014] Compared with existing technologies, the high-performance flip-chip RGB LED structure in the above embodiments of the present invention adopts a double-layer substrate and double-layer encapsulation structure design. The first substrate layer is hot-pressed and composited with a second substrate layer with a cup-like structure. The inclined inner wall of the second substrate layer and the cup-shaped step limit and shape the encapsulation. The die-bonding end and the bottom electroplated lead are connected by an electroplated copper pillar that penetrates the substrate, which takes into account both conductivity and vertical heat dissipation. The double-layer encapsulation has a differentiated formula. The upper first encapsulation layer contains large-particle diffuser powder to improve brightness and widen the light emission angle, while the lower second encapsulation layer contains a trace amount of black agent to optimize the ink color. Combined with the cup cavity to extend the water vapor path and improve air tightness, the LED achieves high brightness, high ink color uniformity, excellent heat dissipation and long service life. This solves the problem that the current single-layer encapsulation can not simultaneously achieve high ink color uniformity and high light emission brightness. Attached Figure Description

[0015] Figure 1 This is a schematic cross-sectional view of the high-performance flip-chip RGB LED structure in Embodiment 1 of the present invention; Figure 2 This is a partial structural diagram of the double-layer substrate in the high-performance flip-chip RGB LED bead structure of Embodiment 1 of the present invention; Figure 3 This is a partial front view of the second substrate layer in the high-performance flip-chip RGB LED bead structure of Embodiment 1 of the present invention; Figure 4 This is a partial front view of the second substrate layer in the high-performance flip-chip RGB LED bead structure of Embodiment 1 of the present invention; Figure 5 This is a partial front view of the first substrate layer in the high-performance flip-chip RGB LED bead structure of Embodiment 1 of the present invention; Figure 6 This is a partial rear view of the first substrate layer in the high-performance flip-chip RGB LED bead structure of Embodiment 1 of the present invention.

[0016]

[0017] The following detailed description of the embodiments will further illustrate the present invention in conjunction with the above-described accompanying drawings. Detailed Implementation

[0018] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Several embodiments of the invention are illustrated in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

[0019] It should be noted that when a component is said to be "fixed to" another component, it can be directly on the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0020] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0021] Example 1 Please see Figures 1 to 6 The image shows a high-performance flip-chip RGB LED structure in the first embodiment of the present invention, including a double-layer substrate, an RGB chip 4 at least partially embedded in the top of the double-layer substrate, and a double-layer encapsulation layer encapsulated on the top of the double-layer substrate and covering the RGB chip 4. The double-layer substrate includes a first substrate layer 6 and a second substrate layer 3 stacked vertically. The top of the second substrate layer 3 has a cup-like structure recessed. The RGB chip 4 is disposed in the center of the cup cavity of the second substrate layer 3. The side of the first substrate layer 6 is provided with an ink protective layer 7. The bottom of the RGB chip 4 is connected to multiple electroplated copper pillars 5 penetrating the second substrate layer 3. The side of the electroplated copper pillars 5 away from the RGB chip 4 is connected to the front circuit of the first substrate layer 6. The double-layer encapsulation layer includes a first encapsulation layer 1 covering the RGB chip 4 and a second encapsulation layer 2 disposed above the first encapsulation layer 1. The second encapsulation layer 2 fills the cup cavity of the second substrate layer 3 and covers the top of the first encapsulation layer 1.

[0022] Furthermore, the first encapsulating layer 1 contains large-particle-size diffusing powder to optimize the light emission angle and improve the overall brightness of the LED. The second encapsulating layer 2 contains black pigment and diffusing powder to absorb stray light and improve ink color consistency. Simultaneously, it works in conjunction with the cup cavity of the second substrate layer 3 to extend the moisture penetration path and improve encapsulation airtightness. The inner wall of the cup of the second substrate layer 3 is an inclined slope that converges inward from top to bottom, and a limiting step is formed at the cup opening to limit the second encapsulating layer 2 and assist in shaping the first encapsulating layer 1 into a hemispherical shape. The electroplated copper pillar 5 is electroplated through the through-holes of the second substrate layer 3. Copper filling molding simultaneously achieves conductive connection and vertical heat conduction between RGB chip 4 and first substrate layer 6. The first substrate layer 6 is a double-sided circuit substrate with conductive vias inside. The pins 8 are connected to the front electroplated leads 10 through the conductive vias. Ink plug holes are provided at the conductive vias. The first substrate layer 6 and the second substrate layer 3 are hot-pressed together with PP adhesive film to form an integrated double-layer substrate. The RGB chip 4 includes a red light chip, a green light chip, and a blue light chip. Each chip is fixed to the die bond end 9 by solder paste. The die bond end 9 is located on the upper surface of the second substrate layer 3 and is located on the upper end face of the electroplated copper pillar 5.

[0023] It should be noted that this application is mainly applied to high-end display fields such as MiniLED small-pitch displays, commercial high-definition display screens, film and television virtual shooting screens, and command center control screens. It effectively solves the industry pain points of traditional single-layer substrate and single-layer encapsulated LED beads, which cannot achieve both high brightness and high color consistency, poor heat dissipation, and insufficient air tightness. The main body of this LED bead consists of three core components: a double-layer substrate, an RGB chip 4, and a double-layer encapsulation. The RGB chip 4 is at least partially embedded in the top area of ​​the double-layer substrate, and the double-layer encapsulation is completely encapsulated on the upper surface of the double-layer substrate, achieving all-round coverage, protection, and optical calibration of the RGB chip.

[0024] In practical implementation, a double-layer substrate is used, with the first substrate layer 6 and the second substrate layer 3 bonded together by high-temperature hot pressing using PP adhesive film. The two substrate layers are tightly bonded to form an integrated structure. The PP adhesive not only achieves bonding and fixation between the two substrate layers but also fills the gaps in the substrate composite, preventing moisture from penetrating inward through the interlayer gaps, thus improving the overall airtightness from a structural perspective. In addition, the first substrate layer 6 is made of conventional BT resin board. It should be noted that BT resin substrate has the advantages of low coefficient of thermal expansion, excellent insulation performance, resistance to high temperatures during reflow soldering, and good dimensional stability. It can adapt to the entire high-temperature processing process, including etching, electroplating, ink printing, hot pressing, and die bonding reflow soldering, meeting the requirements of fine production of small-pitch LED beads. Furthermore, the first substrate layer 6 adopts a double-sided wiring structure. The front side of the substrate is formed by chemical etching to create electroplated leads 10, and the surface of the electroplated leads 10 is treated with nickel-gold electroplating to improve the oxidation resistance of the pads. In terms of solder paste wetting performance, multiple sets of conductive vias are arranged through the first substrate layer 6. Exposed leads 8 are formed on the bottom surface of the substrate. The leads 8 are electrically connected to the electroplated leads 10 on the front side through the conductive vias. The conductive vias are sealed with ink plugging treatment. The ink fills the gaps in the vias, isolating leakage and short circuits between adjacent lines. At the same time, the gaps in the vias are sealed to prevent moisture from entering the substrate. Black ink is printed around the entire edge of the first substrate layer 6 to form an ink protective layer 7. The ink protective layer 7 completely covers the exposed metal lines on the side of the substrate. On the one hand, it isolates the PCB pads, metal auxiliary materials and side lines from accidental contact during assembly, which may cause short circuits. On the other hand, it unifies the appearance color of the side of the substrate and optimizes the uniformity of ink color of the entire board of LEDs. In some optional embodiments of the present invention, the overall thickness of the first substrate layer can be controlled between 0.28mm and 0.31mm, and the line width is uniformly set to 0.1mm, taking into account the line layout space and the mechanical strength of the substrate.

[0025] Furthermore, the second substrate layer 3, stacked above the first substrate layer 6, is also made of BT resin. The upper end of the second substrate layer 3 has an inwardly recessed, integrally molded, cup-like structure. The cup body has a circular outline, and the inner wall of the cup is provided with an inclined slope that converges from top to bottom. The slope angle is preferably 45°~50°. An integrally molded annular limiting step is formed at the cup mouth. The inclined inner wall and the limiting step form a double limiting structure. In the subsequent dispensing process, the limiting step can prevent the second encapsulating adhesive layer 2 from overflowing from the cup mouth. The inclined inner wall relies on the cohesive force of the adhesive itself to help retain the adhesive, which facilitates the first encapsulating adhesive layer 1 to naturally form a regular hemispherical shape based on the adhesive inside the cup cavity. This avoids the defects such as adhesive overflow, irregular molding, and scattered light emission caused by the lack of limit in traditional flat substrates. In addition, the hollow cavity space of the cup cavity provides a space for the double-layer encapsulation. The closed cavity structure can significantly extend the path length for external moisture to penetrate towards the chip. Moisture needs to pass through two layers of encapsulating adhesive and multiple barriers of the cup side wall. This allows for contact with the chip, significantly improving the overall moisture-proof and airtight performance of the LED bead and extending its lifespan. Furthermore, a vertical through-hole is formed in the center of the cup cavity of the second substrate layer 3. Inside the through-hole, an electroplated copper pillar 5 is created using an electroplating copper-filling process. The electroplated copper pillar 5 vertically penetrates the entire second substrate layer 3. After the substrate is hot-pressed together, the lower end of the electroplated copper pillar 5 precisely connects with the electroplated lead wire 10 on the surface of the first substrate layer 6. A die-bonding end 9 is fixedly mounted on the upper end of the electroplated copper pillar 5. The die-bonding end 9 has a metal pad structure. Copper has a much higher thermal conductivity than BT resin and epoxy encapsulation colloid. Therefore, multiple electroplated copper pillars 5, while achieving electrical conductivity, form a vertically efficient heat-conducting channel extending from the chip to the bottom substrate. Most of the heat generated during the operation of the RGB chip 4 can be quickly conducted to the electroplated copper pillar 5 via the die-bonding end 9, and then transferred downwards to the first substrate layer 6. Relying on the large-area substrate for outward heat dissipation, this completely improves the problems of traditional LED beads relying solely on resin for slow horizontal heat conduction, heat accumulation, and rapid chip photoaging.

[0026] Next, a modified flip-chip three-primary-color light-emitting chip is selected for RGB chip 4, specifically including independent red, green, and blue light chips. The three chips are arranged independently and can emit light when powered on individually. Full-color display is achieved by mixing the three colors. RGB chip 4 is fixed to the die bond 9 by soldering with solder paste. In the specific assembly, solder paste is first precisely applied to the surface of die bond 9 using a stencil printing process. The thickness of the solder paste is controlled according to the chip size. Then, a high-precision die bonder is used to complete the chip alignment and mounting by using positioning marks. After mounting, it is sent to a reflow oven. After the solder paste is heated, melted, and cooled, it achieves mechanical fixation and electrical connection between the chip and die bond 9. After assembly, the bottom of RGB chip 4 is completely inside the cup cavity, and the top surface of the chip is higher than the bottom plane of the cup and extends into the encapsulation area. This achieves the structural feature that at least part of the chip is embedded on the top of the double-layer substrate. Moreover, the flip-chip eliminates the need for traditional bonding wires, which not only reduces the overall size of the LED to adapt to MiniLED micro-pitch applications, but also eliminates the light loss caused by the gold wire blocking the light output, further improving the light output efficiency of the LED.

[0027] Next, the double-layer encapsulation on the top of the LED bead consists of a first encapsulation layer 1 and a second encapsulation layer 2. The two layers of encapsulants use different formulations and work together to balance the brightness and color consistency of the LED bead, overcoming the technical shortcomings of traditional single-layer encapsulants that are inconsistent in some aspects. The second encapsulation layer 2 fills the entire cavity of the second substrate layer 3, surrounding and wrapping the sidewall of the first encapsulation layer 1. The raw material for the second encapsulation layer 2 is transparent epoxy resin. Diffusion powder and a trace amount of black pigment are added to the inside of the colloid according to the formula. The raw material ratio is as follows: transparent epoxy resin: diffusion powder: black pigment = 1:0.02:0.00025. The black pigment can effectively absorb ambient stray light, reduce disordered light reflection inside the colloid, and improve the color uniformity and image contrast of the LED bead when it is not lit. A small amount of diffusion powder optimizes the internal light path, softens the light emission, and avoids local bright spots. In conjunction with the closed cavity structure of the cup, the second encapsulation layer 2 fills the gaps in the cup, blocks the water vapor penetration channel, and strengthens the airtight protection effect.

[0028] Finally, the first encapsulating layer 1 is in the form of a complete hemispherical shape, tightly covering the top of the RGB chip 4. The formula of the first encapsulating layer 1 is epoxy resin A: epoxy resin B: large particle size diffusing powder: black agent = 1:0.5:1 (particle size 100μm):0.08. The large particle size diffusing powder in this colloid is the key to improving the brightness and light emission angle of the LED. The large particle size powder can scatter the direct light from the chip over a wide range, broadening the light emission angle of the LED. At the same time, the appropriate ratio of black agent added to the colloid is also important. With extremely low absorption and almost no effective light output, the chip's light output brightness is maximized while ensuring the basic ink color. The first encapsulation layer 1 is naturally shaped into a hemisphere by relying on the cup-shaped step and the limiting support of the second encapsulation layer 2. The regular spherical structure optimizes the light output surface, improves the central light intensity and light utilization, and achieves high brightness output. At the same time, the double-layer encapsulation design focuses on increasing brightness and expanding the angle, while the lower layer focuses on controlling ink color and locking airtightness. This achieves both high brightness and high contrast performance indicators from the perspectives of materials and structure.

[0029] In summary, the high-performance flip-chip RGB LED structure in the above embodiments of the present invention employs a double-layer substrate and a double-layer encapsulation structure design. The first substrate layer 6 is hot-pressed together with the second substrate layer 3, which has a cup-like structure. The inclined inner wall of the second substrate layer 3 and the cup-shaped step limit and shape the encapsulation. The die-bonding end 9 and the bottom electroplated lead 10 are connected by the electroplated copper pillar 5 that penetrates the substrate, which takes into account both conductivity and vertical heat dissipation. The double-layer encapsulation has a differentiated formula. The upper first encapsulation layer 1 is mixed with large-particle diffuser powder to improve brightness and widen the light emission angle, while the lower second encapsulation layer 2 is mixed with trace amounts of black agent to optimize the ink color. Combined with the cup cavity to extend the water vapor path and improve air tightness, the LED achieves high brightness, high ink color uniformity, excellent heat dissipation, and long service life. This solves the problem that current single-layer encapsulation materials cannot simultaneously achieve high ink color uniformity and high luminous brightness.

[0030] Example 2 The method for preparing a high-performance flip-chip RGB LED bead according to the second embodiment of the present invention is used in a high-performance flip-chip RGB LED bead structure. The method specifically includes steps S01-S04: Step S01: The first substrate layer and the second substrate layer with a cup-like cavity are respectively processed and shaped. Copper is electroplated in the reserved through holes of the second substrate layer to form electroplated copper pillars. Ink is printed on the side of the first substrate layer to form an ink protective layer. Electroplated leads are etched on the front side of the first substrate layer and pins are formed on the bottom side.

[0031] In practice, the substrate is processed in separate parts, and BT plates are cut to make the first substrate layer blank and the second substrate layer blank respectively. The first substrate layer is drilled, etched, electroplated with leads on the front side, formed with bottom leads, drilled with conductive through holes and filled with ink. After completion, black ink is printed and cured on the entire side of the substrate to form an ink protective layer. The second substrate layer is stamped or etched to form a round cup-like cavity with inclined inner walls and limiting steps. Through holes are drilled in the center of the cup cavity, and then the through holes are electroplated with copper to fill them. The copper fills the through holes to form an integrated electroplated copper pillar. A die bonding pad area is reserved at the top of the copper pillar.

[0032] In step S02, the first substrate layer and the second substrate layer are hot-pressed together using PP adhesive to make the lower end of the electroplated copper pillar and the electroplated lead wire connected.

[0033] In practice, the substrate is laminated and pressed together. A PP adhesive film is placed between the first substrate layer and the second substrate layer. Pressure and temperature are applied by a high-temperature hot pressing device to melt and bond the two substrate layers together. This ensures that the lower end of the electroplated copper pillar is precisely attached to and connected to the electroplated leads on the surface of the first substrate layer. After the pressing is completed, the substrate is cooled and shaped to obtain an integrated double-layer substrate semi-finished product.

[0034] Step S03: Print solder paste on the die bond surface, position and mount the RGB chip, and complete the die bond by reflow soldering.

[0035] In practice, during the die bonding process, solder paste is printed at specific points on the surface of each die bond using printing equipment. The vision positioning system of the die bond equipment is used to pick up the red, green, and blue RGB chips and accurately place them into the corresponding die bond positions. After all the chips are placed, they are sent to the reflow soldering equipment and heated according to the standard temperature range curve of the solder paste. The solder paste melts when heated and then cools and solidifies, achieving a reliable electrical and mechanical connection between the RGB chips and the die bond. After die bonding, an initial electrical inspection is performed to remove defective products with poor solder joints or misalignment.

[0036] Step S04: Inject adhesive into the cup cavity of the second substrate layer and cure it to form a second encapsulating adhesive layer, and then form a hemispherical first encapsulating adhesive layer on top of the RGB chip.

[0037] In practice, the double-layer encapsulation dispensing molding process involves using a dispensing machine to quantitatively inject the prepared second encapsulation adhesive material into the cup cavity of the second substrate layer. After curing at room temperature or with heating, the second encapsulation adhesive layer is formed. Subsequently, the first encapsulation adhesive material is dripped onto the RGB chip at a fixed point. The adhesive material naturally flows and forms a hemisphere under the constraint of the limiting structure due to its own surface tension. After curing, the first encapsulation adhesive layer is formed.

[0038] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0039] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A high-performance flip-chip RGB LED structure, characterized in that, It includes a double-layer substrate, an RGB chip at least partially embedded on the top of the double-layer substrate, and a double-layer encapsulant that is encapsulated on the top of the double-layer substrate and covers the RGB chip. The dual-layer substrate includes a first substrate layer and a second substrate layer stacked on top of each other. The top of the second substrate layer has a cup-like structure recessed. The RGB chip is disposed in the center of the cup cavity of the second substrate layer. The first substrate layer has an ink protective layer on its side. The bottom of the RGB chip is connected to multiple electroplated copper pillars that penetrate the second substrate layer. The side of the electroplated copper pillars away from the RGB chip is connected to the front circuit of the first substrate layer. The double-layer encapsulation includes a first encapsulation layer covering the RGB chip and a second encapsulation layer disposed above the first encapsulation layer. The second encapsulation layer fills the cup cavity of the second substrate layer and covers the top of the first encapsulation layer.

2. The high-performance flip-chip RGB LED structure according to claim 1, characterized in that, The first encapsulating adhesive layer contains large-particle-size diffusing powder to optimize the light emission angle and improve the overall luminous brightness of the LED.

3. The high-performance flip-chip RGB LED structure according to claim 1, characterized in that, The second encapsulating adhesive layer contains a black colorant and a diffusion powder to absorb stray light and improve ink color consistency. It also works in conjunction with the cup cavity of the second substrate layer to extend the moisture penetration path and improve the airtightness of the encapsulation.

4. The high-performance flip-chip RGB LED structure according to claim 1, characterized in that, The inner wall of the cup of the second substrate layer is an inclined slope that converges inward from top to bottom, and a limiting step is formed at the cup opening to limit the second encapsulating adhesive layer and assist the first encapsulating adhesive layer in shaping into a hemispherical shape.

5. The high-performance flip-chip RGB LED structure according to claim 1, characterized in that, The electroplated copper pillar is formed by electroplating copper into the through-holes of the second substrate layer, simultaneously achieving conductive connection and vertical heat conduction between the RGB chip and the first substrate layer.

6. The high-performance flip-chip RGB LED structure according to claim 1, characterized in that, The first substrate layer is a double-sided circuit substrate with conductive vias inside. The leads are connected to the electroplated leads on the front side through the conductive vias, and ink plugs are provided at the holes of the conductive vias.

7. The high-performance flip-chip RGB LED structure according to claim 1, characterized in that, The first substrate layer and the second substrate layer are integrally bonded together by hot pressing with PP adhesive film to form the double-layer substrate.

8. The high-performance flip-chip RGB LED structure according to claim 1, characterized in that, The RGB chip includes a red light chip, a green light chip, and a blue light chip. Each chip is fixed to the die bond end by soldering with solder paste. The die bond end is disposed on the upper surface of the second substrate layer and located on the upper end face of the electroplated copper pillar.

9. A method for manufacturing high-performance flip-chip RGB LEDs, characterized in that, The method for operating the high-performance flip-chip RGB LED structure as described in any one of claims 1 to 8, the method comprising: The first substrate layer and the second substrate layer with a cup-like cavity are respectively processed and formed. Copper is electroplated in the reserved through hole of the second substrate layer to form an electroplated copper pillar. Ink is printed on the side of the first substrate layer to form an ink protective layer. Electroplated leads are etched on the front of the first substrate layer and pins are made on the bottom. The first substrate layer and the second substrate layer are hot-pressed together using PP adhesive to make the lower end of the electroplated copper pillar and the electroplated lead wire connected and conductive. Solder paste is printed on the die bond surface, and RGB chips are positioned and mounted. The die bonding of the chips is completed by reflow soldering. A second encapsulating adhesive layer is formed by injecting and curing adhesive into the cavity of the second substrate layer, and then a hemispherical first encapsulating adhesive layer is formed above the RGB chip.

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