A packaging structure and packaging method for an FPC-based power light-emitting diode.

Abstract

This invention relates to a packaging structure and method for an FPC-based power light-emitting diode (LED), comprising: at least two FPC substrate plastic layers, each with a negative electrode window and a positive electrode window; a light-emitting chip connected to the positive and negative terminals of a power supply via built-in copper wires; an optical lens covering the exterior of the light-emitting chip, the optical lens having a flat top, an upper arc surface above the midpoint of its side waist, and a lower arc surface below the midpoint of its side waist; and a reflective material filling the space between two adjacent optical lenses. The reflective material reflects the light emitted from the side of the light-emitting chip, and the upper arc surface of the lens refracts the light emitted from the side and top of the light-emitting chip, as well as the reflected light, and together with the light refracted by the corresponding lens from adjacent light-emitting chips, uniformly illuminates the area adjacent to the light-emitting chip, forming refracted light that fills the dark field between the light-emitting chips, reducing the brightness difference with the light emitted from the upper surface of the light-emitting chip.

Description

Technical Field

[0001] This invention relates to the field of light-emitting diodes, and more specifically to a packaging structure and packaging method for an FPC-based power light-emitting diode. Background Technology

[0002] Currently, automotive starlight headlights use light sources that transmit light to optical fibers inserted into different holes in a pre-formed panel. While the star positions can be precisely controlled, the placement and installation of the optical fibers require manual labor, which is time-consuming, difficult to mass-produce, prone to breakage, and costly. Furthermore, only simultaneous illumination and brightness / color adjustment are possible, resulting in relatively low brightness. LED light sources suffer from high power attenuation issues. Embedded glass starlight films can only be installed on transparent glass, causing glare during the day and incurring high material production costs. Other methods, such as light guide plates / films and indirect projection, are too ineffective and generally cannot meet the high-quality requirements of automobiles.

[0003] In related technologies, automotive starry sky headlights, incorporating optical lenses, light-emitting chips, and FPC substrate plastic layers, are gaining popularity. However, the high lifespan requirements of automotive-grade LEDs make it difficult to ensure that each light-emitting chip emits light as an independent star point. To meet automotive-grade requirements for continuous starlight illumination, a typical starry sky headlight panel would require thousands of stars, leading to lifespan testing requirements that are over a thousand times higher. Therefore, multiple light-emitting chips are typically used to mitigate the risk of single-unit failure and ensure continuous starlight illumination. However, the distinct brightness and darkness between multiple independently emitting chips make their outlines easily visible, necessitating new technologies to improve the aesthetics. Summary of the Invention

[0004] Based on the above description, the present invention provides a packaging structure and packaging method for an FPC-based power light-emitting diode to solve the problem in related technologies where the brightness and darkness between multiple light-emitting chips are obvious and the outline of the light-emitting chips is easily visible in appearance.

[0005] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: A packaging structure for an FPC-based power light-emitting diode, comprising: at least two FPC substrate plastic layers, the upper layer having a negative electrode opening and a positive electrode opening; an internal copper wire disposed between the two FPC substrate plastic layers; a light-emitting chip, the positive electrode passing through the positive electrode opening and connected to the internal copper wire, the negative electrode passing through the negative electrode opening and connected to the internal copper wire, the light-emitting chip being connected to the positive and negative terminals of a power supply through the internal copper wire; an optical lens covering the outside of the light-emitting chip, the top of the optical lens having a flat surface, an upper arc surface above the midpoint of the side waist, and a lower arc surface below the midpoint of the side waist; and a reflective material filling between two adjacent optical lenses and located outside the lower arc surface.

[0006] Furthermore, the FPC substrate plastic layer is provided with limiting holes, and a plurality of the limiting holes form a circular outline around the light-emitting chip. The lower end of the optical lens is located inside the circular outline, and the limiting holes are filled with adhesive.

[0007] Furthermore, the optical lens is generally chess-like in shape, with a flat top and symmetrical C-shaped arc surfaces on both sides.

[0008] Furthermore, a transparent adhesive or white adhesive is filled between two adjacent optical lenses, and the transparent adhesive or white adhesive is located on the outer side of the upper arc surface.

[0009] Furthermore, the height error between the midpoint of the waist of the optical lens and the top of the light-emitting chip is within 0.3mm.

[0010] Secondly, embodiments of the present invention also provide a packaging method for the above-mentioned FPC-based power light-emitting diode packaging structure, comprising the following steps: fabricating a negative electrode window and a positive electrode window on the plastic layer of the FPC substrate; soldering the light-emitting chip to the plastic layer of the FPC substrate, and connecting the positive electrode to the positive electrode window and the negative electrode to the negative electrode window; using a hot press plate to press a pre-shaped optical lens, so that the top is formed as a plane, the upper arc surface is formed above the midpoint of the side waist, and the lower arc surface is formed below the midpoint of the waist; and filling the space between the lower arc surfaces of two adjacent optical lenses with reflective material.

[0011] Furthermore, before the negative electrode opening and the positive electrode opening are fabricated, the process further includes: etching a circular outline around the light-emitting chip on the plastic layer of the FPC substrate to form a limiting hole; and filling the circular outline with adhesive.

[0012] Furthermore, the step of using a hot press plate to compress a pre-shaped optical lens to form a chess-like shape includes: the lower end of the optical lens is located inside the circular contour, and when compressed by the hot press plate, the optical lens presents a chess-like shape under its own tension and the restriction of the glue in the limiting hole.

[0013] Furthermore, after pressing the pre-shaped optical lens with a hot press plate to form a chess piece shape, the method further includes: injecting a reflective liquid into the optical lens and immersing it until the midpoint of its waist.

[0014] Furthermore, after filling the space between the two adjacent optical lenses with reflective material, the method further includes filling the space between the optical lenses with transparent adhesive.

[0015] Compared with the prior art, the technical solution of this application has the following beneficial technical effects: The reflective material reflects the light emitted from the side of the light-emitting chip. The upper arc surface of the lens refracts the light emitted from the side and top of the light-emitting chip, as well as the reflected light, and together with the light refracted by the corresponding lens from the adjacent light-emitting chip, they uniformly illuminate the area near the light-emitting chip, forming refracted light that fills the dark field between the light-emitting chips and reduces the brightness difference with the light emitted from the upper surface of the light-emitting chip. Attached Figure Description

[0016] Figure 1 A schematic diagram of the overall structure of the FPC-based power light-emitting diode package provided in an embodiment of the present invention; Figure 2 A light-emitting circuit diagram of the packaging structure of an FPC-based power light-emitting diode provided in an embodiment of the present invention; Figure 3 A plan view of the package structure of an FPC-based power light-emitting diode provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of the structure after dispensing in the encapsulation method provided in this embodiment of the invention; Figure 5 A schematic diagram of the hot-pressing structure of the encapsulation method provided in an embodiment of the present invention; Figure 6 A schematic diagram of the structure after adding reflective material to the encapsulation method provided in this embodiment of the invention; Figure 7 A schematic diagram of the structure after adding transparent adhesive to the encapsulation method provided in the embodiment of the present invention.

[0017] The attached diagram lists the components represented by each number as follows: 1. Optical lens; 101. Plane; 102. Upper arc surface; 103. Lower arc surface; 2. FPC substrate plastic layer; 3. Built-in copper wire; 4. Negative electrode window; 5. Positive electrode window; 6. Light-emitting chip; 7. Limiting hole; 8. Reflective material; 9. Adhesive; 10. Hot press plate; 11. Circular outline. Detailed Implementation

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

[0019] This invention provides a packaging structure for an FPC-based power light-emitting diode, which can solve the problem in related technologies where the brightness and darkness of multiple light-emitting chips are obvious when they emit light independently, and the outline of the light-emitting chips is easily visible in appearance.

[0020] See Figure 1The diagram illustrates a packaging structure for an FPC-based power light-emitting diode (LED) according to an embodiment of the present invention. The structure includes: at least two FPC substrate plastic layers 2, with a negative electrode opening 4 and a positive electrode opening 5; an internal copper wire 3 disposed between the two FPC substrate plastic layers 2, with the negative electrode opening 4 and positive electrode opening 5 exposing the internal copper wire 3; and a light-emitting chip 6, with its positive electrode passing through the positive electrode opening 5 and connected to the internal copper wire 3, and its negative electrode passing through the negative electrode opening 4 and connected to the positive and negative terminals of a power supply via the internal copper wire 3. Next, the bottom positive and negative electrodes of the chip are AuSn layers, which are melted and soldered to the corresponding built-in copper wires 3 in a reflow oven, thereby forming a good electrical and mechanical connection, ensuring that the chip remains lit and preventing it from falling off during corresponding movements; an optical lens 1 covers the outside of the light-emitting chip 6, the top of the optical lens 1 has a flat surface 101, the side has an upper arc surface 102 above the midpoint of the waist, and a lower arc surface 103 below the midpoint of the waist; a reflective material 8 fills between two adjacent optical lenses 1 and is located outside the lower arc surface 103. The reflective material 8 reflects the light emitted from the side of the light-emitting chip 6, and the upper arc surface 102 of the lens side refracts the light emitted from the side and top of the light-emitting chip 6 as well as the reflected light from the former, and together with the light refracted by the corresponding lens from the adjacent light-emitting chip, evenly illuminates the area adjacent to the light-emitting chip, forming refracted light that fills the dark field between the light-emitting chips, reducing the brightness difference with the light emitted from the upper surface of the light-emitting chip.

[0021] The FPC substrate plastic layer 2 has a negative electrode window 4 and a positive electrode window 5, and the light-emitting chip 6 is soldered onto the built-in copper wire 3.

[0022] In some embodiments, the overall structure of the FPC substrate plastic layer 2 after bonding has a limiting hole 7 for limiting the shape of the optical lens. The optical lens 1 covers the light-emitting chip 6 and does not exceed the circular outline 11 formed by the limiting hole 7. The principle is to use a high-viscosity liquid at the edge of the limiting hole 7 to increase the surface tension, thereby forming a highly convex droplet.

[0023] Preferably, the optical lens 1 is bonded to the plastic layer 2 of the FPC substrate through an encapsulation process and thermoforming.

[0024] In some embodiments, the surface of the light-emitting chip 6 may be coated with phosphor or a fluorescent film may be attached, and the top and sides of the light-emitting chip 6 may emit light.

[0025] Preferably, the material of the FPC substrate plastic layer 2 has the same or similar coefficient of thermal expansion as the material of the light-emitting chip 6.

[0026] Preferably, the optical lens 1 is made of resin material, the top of the optical lens 1 is flat, and the height of the midpoint of the waist is basically level with or slightly exceeds the height of the upper surface of the light-emitting chip 6, with a difference of less than 0.3mm.

[0027] In some embodiments, the negative electrode window 4 and the positive electrode window 5 can be blank areas cut into the shape of the window on the plastic layer 2 of the FPC substrate, or they can be deeply buried in the plastic layer 2 of the FPC substrate, or they can be copper strips higher than the plastic layer 2 of the FPC substrate. The positive and negative electrodes of the light-emitting chip 6 can be shared by the negative electrode window 4 and the positive electrode window 5, respectively.

[0028] In some embodiments, the negative electrode window 4 and the positive electrode window 5 can be enlarged to accommodate different numbers and models of chip functions.

[0029] In some embodiments, the light-emitting chip 6 may be an LED chip or other chips, the circular outline 11 may be circular, polygonal, rectangular, etc., and the limiting hole 7 may be a hole, a triangle or a combination of arcs, etc.

[0030] The packaging method includes the following steps: 1. Laser-etch limiting holes 7 around the light-emitting chip 6 in the plastic layer 2 of the FPC substrate. Use circuit board manufacturing process to etch and bond the built-in circuits that bypass the limiting holes 7, and press or directly electroplate them onto the plastic layer 2 of the FPC substrate. Make positive and negative electrodes on the plastic layer 2 of the FPC substrate.

[0031] 2. The light-emitting chip 6 is soldered onto the plastic layer 2 of the FPC substrate, coated with phosphor or attached with a fluorescent film, and then cured.

[0032] 3. Apply adhesive to the entire structure after the plastic layer 2 of the FPC substrate is bonded. The adhesive, constrained by the limiting holes 7 and its own tension, forms a high hemispherical lens, increasing its viscosity and tension. Place it in an oven for pre-forming; however, this pre-forming process can be omitted depending on the actual situation.

[0033] 4. The pre-shaped optical lens 1 is pressed by the hot press plate 10. Under its own tension and the limitation of the limiting hole 7, the optical lens 1 presents a chess-like shape. The height of the midpoint of the waist of the optical lens 1 is designed to be basically level with or slightly exceed the horizontal height of the light-emitting chip 6, and it is removed from the hot press plate 10 for heat setting.

[0034] 5. Immerse the reflective liquid until it reaches the midpoint of the waist of the optical lens 1. The light from the side of the reflective light-emitting chip 6 on the lower arc surface 103 of the lens is emitted until it is emitted directly upwards and finally refracted out from the light-transmitting inclined surface on the upper arc surface 102 of the lens, thereby increasing the brightness of the dark field between the light-emitting chips 6 and reducing the brightness difference between the light emitted from the upper surface of the light-emitting chip 6 and the light emitted from the upper surface of the light-emitting chip 6.

[0035] 6. The curved surface 102 of the lens refracts side light rays, which, together with the light refracted by the corresponding lens from adjacent light-emitting chips, evenly distribute the light in the area near the light-emitting chips, increasing the brightness of the dark field between the light-emitting chips 6 and reducing the brightness difference with the light emitted from the upper surface of the light-emitting chip 6. 7. White glue or transparent glue can be filled between the lenses as needed to adjust the refractive index by increasing or decreasing the concentration of diffuser powder. Before filling, an annular isolation chamber can be set around the FPC single light-emitting unit as a limiting dam, which can then be packaged into an FPC-based power LED.

[0036] 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 application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0037] It is understood that spatial relation terms such as "below," "under," "below," "below," "above," "above," etc., can be used here to describe the relationship between one element or feature shown in the figure and other elements or features. It should be understood that, in addition to the orientation shown in the figure, spatial relation terms also include different orientations of the device in use and operation. For example, if the device in the figure is flipped, the element or feature described as "below" or "below" of the other element or feature will be oriented "above" the other element or feature. Therefore, the exemplary terms "below" and "below" can include both upper and lower orientations. Furthermore, the device may also include other orientations (e.g., rotated 90 degrees or other orientations), and the spatial descriptive terms used herein will be interpreted accordingly.

[0038] It should be noted that when one element is considered to be "connected" to another element, it can be directly connected to the other element or connected to the other element through an intermediary element. In the following embodiments, "connection" should be understood as "electrical connection," "communication connection," etc., if the connected circuits, modules, units, etc., have the transmission of electrical signals or data between them.

[0039] When used herein, the singular forms of “a,” “an,” and “the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising,” “including,” or “having,” etc., specify the presence of the stated feature, whole, step, operation, component, part, or combination thereof, but do not preclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof.

[0040] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A packaging structure for an FPC-based power light-emitting diode, characterized in that, It includes: At least two FPC substrate plastic layers (2), with a negative electrode opening (4) and a positive electrode opening (5) on the upper layer; Built-in copper wire (3) is disposed between the two plastic layers (2) of the FPC substrate; The light-emitting chip (6) has its positive electrode passing through the positive electrode opening (5) and connected to the built-in copper wire (3), and its negative electrode passing through the negative electrode opening (4) and connected to the built-in copper wire (3). The light-emitting chip (6) is connected to the positive and negative terminals of the power supply through the built-in copper wire (3). An optical lens (1) covers the outside of the light-emitting chip (6). The top of the optical lens (1) has a flat surface (101), the side has an upper arc surface (102) above the midpoint of the waist, and a lower arc surface (103) below the midpoint of the waist. Reflective material (8) is filled between two adjacent optical lenses (1) and located on the outside of the lower arc surface (103).

2. The packaging structure of the FPC-based power light-emitting diode according to claim 1, characterized in that: The FPC substrate plastic layer (2) is provided with limiting holes (7), and a plurality of the limiting holes (7) form a circular outline (11) around the light-emitting chip (6). The lower end of the optical lens (1) is located inside the circular outline (11), and the limiting holes (7) are filled with glue.

3. The packaging structure of the FPC-based power light-emitting diode according to claim 1, characterized in that: The optical lens (1) is shaped like a chess piece, with a flat top and symmetrical C-shaped arc surfaces on both sides.

4. The packaging structure of the FPC-based power light-emitting diode according to claim 1, characterized in that: The space between two adjacent optical lenses (1) is filled with transparent glue or white glue, which is located on the outside of the upper arc surface (102).

5. The packaging structure of the FPC-based power light-emitting diode according to claim 1, characterized in that: The height error between the midpoint of the waist of the optical lens (1) and the top of the light-emitting chip (6) is within 0.3 mm.

6. A packaging method for a packaging structure of an FPC-based power light-emitting diode as described in claim 1, characterized in that, Includes the following steps: A negative electrode opening (4) and a positive electrode opening (5) are fabricated on the plastic layer (2) of the FPC substrate. The light-emitting chip (6) is soldered onto the plastic layer (2) of the FPC substrate, and the positive electrode is connected to the positive electrode opening (5) and the negative electrode is connected to the negative electrode opening (4). The pre-shaped optical lens (1) is pressed by a hot press plate (10) to form a flat surface (101) at the top, an upper arc surface (102) above the midpoint of the waist on the side, and a lower arc surface (103) below the midpoint of the waist. Reflective material (8) is filled between the lower arc surfaces (103) of two adjacent optical lenses (1).

7. The packaging method according to claim 6, characterized in that, Before the negative electrode window (4) and the positive electrode window (5) are fabricated, the following is also included: A circular outline (11) is formed by etching a limiting hole (7) around the light-emitting chip (6) on the plastic layer (2) of the FPC substrate. Fill the circular outline (11) with glue.

8. The packaging method according to claim 7, characterized in that, The method of using a hot press plate (10) to press the pre-shaped optical lens (1) includes: The lower end of the optical lens (1) is located inside the circular contour (11). When pressed by the hot press plate (10), the optical lens (1) presents a chess-like shape under its own tension and the restriction of the glue in the limiting hole (7).

9. The packaging method according to claim 6, characterized in that, After pressing the pre-shaped optical lens (1) with the hot press plate (10), the following is also included: A reflective liquid is added to the optical lens (1) and immersed until it reaches the midpoint of its waist.

10. The packaging method according to claim 6, characterized in that, After filling the space between the two adjacent optical lenses (1) with reflective material (8), the process further includes: Transparent glue or white glue is filled between the optical lenses (1), and the transparent glue or white glue may overflow the top.

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