A COB light source and a manufacturing method thereof

Abstract

The application discloses a COB light source and a manufacturing method thereof, and relates to the technical field of light source manufacturing. The method comprises the following steps: sequentially stacking a first insulating carrier provided with a first light outlet hole and a second insulating carrier provided with a second light outlet hole and a component mounting hole on a base material, the orthographic projection of the second light outlet hole completely covers the first light outlet hole, and the component mounting hole is isolated from the second light outlet hole. The electronic component is fixed to the first insulating carrier and corresponds to the component mounting hole; the LED chip is fixed to the base material and corresponds to the first light outlet hole; the LED chip and the electronic component are connected through a bonding wire; and the second light outlet hole is filled with fluorescent glue and is baked and solidified. The electronic component is built-in between the double-layer carriers, does not occupy the light-emitting area, and guarantees the integrity of the light-emitting surface, the flatness of the surface, and better heat dissipation and adaptability while the integrated circuit is integrated.

Description

Technical Field

[0001] This invention relates to the field of light source technology, and in particular to a COB light source and its manufacturing method. Background Technology

[0002] COB (Chip On Board) is a packaging technology that directly mounts multiple bare chips onto a substrate and wire bonds them to form an integrated light source. A typical COB substrate structure usually consists of a substrate as a support and reflective layer, an insulating carrier disposed on the substrate, and a circuit layer formed on the surface of the insulating carrier.

[0003] In practical products, to meet functional requirements such as driving, protection, or dimming, electronic components such as constant current diodes, Zener diodes, and resistors are often integrated onto a COB substrate. However, placing these components on the substrate surface or within the dammed area often results in protrusions on the light source surface, affecting the overall flatness and aesthetics. Furthermore, the presence of these components may encroach on the effective light-emitting area or alter the external contour of the light source, thereby weakening its compatibility with general luminaire structures. Moreover, confining the components to the dammed area restricts the optimization design space for circuitry and heat dissipation paths, ultimately adversely affecting the overall photoelectric performance of the light source. Summary of the Invention

[0004] The technical problem to be solved by the embodiments of the present invention is how to provide a solution that can maintain the good appearance and excellent performance of COB light source while integrating necessary electronic components.

[0005] To address the aforementioned problems, this invention provides a method for fabricating a COB light source, comprising: A substrate, a first insulating carrier, and a second insulating carrier are provided. The first insulating carrier and the second insulating carrier are sequentially stacked on the substrate. The first insulating carrier is provided with a first light-emitting hole. The second insulating carrier is provided with a second light-emitting hole and a component mounting hole. The orthogonal projection of the second light-emitting hole on the substrate completely covers the orthogonal projection of the first light-emitting hole on the substrate. The component mounting hole is isolated from the second light-emitting hole. At least one electronic component is fixed to the first insulating carrier, and the electronic component is positioned corresponding to the component mounting hole. At least one LED chip is fixed to the substrate, and the LED chip is positioned corresponding to the first light-emitting hole. The LED chip is electrically connected to the electronic components via bonding wires; Fill the second light-emitting hole with fluorescent adhesive; The filled fluorescent adhesive is then baked and cured.

[0006] Optionally, the thickness of the second insulating carrier is greater than the height of the electronic component in the direction perpendicular to the substrate.

[0007] Optionally, the electronic components are fixed to the first insulating carrier by conductive adhesive or solder.

[0008] Optionally, the first insulating carrier and the second insulating carrier are fixed to the substrate by adhesive bonding or mechanical clamping.

[0009] Optionally, the step of baking and curing the filled fluorescent adhesive includes: First, perform preliminary curing at a temperature lower than the first preset temperature, and then perform complete curing at a higher temperature than the first preset temperature.

[0010] Secondly, embodiments of the present invention provide a COB light source, comprising: Substrate; A first insulating carrier is disposed on the substrate, and the first insulating carrier is provided with a first light-emitting hole; A second insulating carrier is disposed on the first insulating carrier. The second insulating carrier is provided with a second light-emitting hole and a component mounting hole. The orthographic projection of the second light-emitting hole on the substrate completely covers the orthographic projection of the first light-emitting hole on the substrate. The component mounting hole is isolated from the second light-emitting hole. At least one electronic component is fixed to the first insulating carrier and located within the component mounting hole; At least one LED chip is fixed on the substrate and is positioned corresponding to the first light-emitting hole; Fluorescent adhesive is filled and cured into the second light-emitting hole; The LED chip and the electronic components are electrically connected via bonding wires.

[0011] Optionally, the thickness of the second insulating carrier is greater than the height of the electronic component in the direction perpendicular to the substrate.

[0012] Optionally, the electronic components are fixed to the first insulating carrier by conductive adhesive or solder.

[0013] Optionally, the first insulating carrier and the second insulating carrier are fixed to the substrate by an adhesive layer or a mechanical structure.

[0014] Optionally, the LED chip is a blue light chip.

[0015] Compared with the prior art, the technical effects achieved by the embodiments of the present invention include: This invention utilizes a first insulating carrier with a first light-emitting aperture and a second insulating carrier with a larger second light-emitting aperture and isolated component mounting holes, stacked on a substrate. Electronic components are fixed to the first insulating carrier and housed within the component mounting holes, while LED chips are fixed to the substrate corresponding to the first light-emitting aperture. This design allows the electronic components to be internally concealed between the two carrier layers, completely avoiding occupying the effective light-emitting area defined by the second light-emitting aperture. This ensures the integrity and maximization of the light-emitting surface while integrating necessary circuit components. Consequently, the light source surface remains flat and consistent, significantly improving product aesthetics; exposed and protruding components are eliminated, enhancing compatibility and versatility with various lighting kits; and the layout of electronic components is no longer limited by traditional enclosure areas, providing more design space for optimizing electrical connections and heat dissipation paths, thereby improving the overall photoelectric performance and reliability of the light source. Attached Figure Description

[0016] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0019] Figure 1 This is a schematic flowchart illustrating a method for fabricating a COB light source according to an embodiment of the present invention. Figure 2 This is a schematic diagram of the structure of a COB light source proposed in an embodiment of the present invention.

[0020] Figure Labels Substrate 10, first insulating carrier 20, second insulating carrier 30, first light-emitting hole 40, second light-emitting hole 50, component mounting hole 60, electronic component 70, fluorescent adhesive 80. Detailed Implementation

[0021] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Similar component reference numerals in the drawings represent similar components. Obviously, the embodiments described below are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0022] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0023] It should also be understood that the terminology used in this specification of embodiments of the invention is for the purpose of describing particular embodiments only and is not intended to limit the embodiments of the invention. As used in this specification of embodiments of the invention and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0024] See Figure 1 This invention provides a method for manufacturing a COB light source, comprising the following steps: S1, a substrate, a first insulating carrier, and a second insulating carrier are provided. The first insulating carrier and the second insulating carrier are stacked sequentially on the substrate. The first insulating carrier is provided with a first light-emitting hole. The second insulating carrier is provided with a second light-emitting hole and a component mounting hole. The orthographic projection of the second light-emitting hole on the substrate completely covers the orthographic projection of the first light-emitting hole on the substrate. The component mounting hole and the second light-emitting hole are isolated from each other.

[0025] In specific implementations, the substrate can be selected from mirrored aluminum plates, ceramic plates, ordinary aluminum plates, copper plates, etc., and this invention is not specifically limited to any particular type. For example, a mirrored aluminum plate can be selected because its surface has high reflectivity.

[0026] The first insulating carrier is, for example, an FR4 or BT substrate, with a circular first light-emitting hole in its central region. The second insulating carrier is, for example, another FR4 or BT substrate, with a circular second light-emitting hole in its central region, and one or more rectangular component mounting holes are formed around the second light-emitting hole.

[0027] The diameter of the second light-emitting aperture is larger than that of the first light-emitting aperture. When the second insulating carrier is stacked on the first insulating carrier, the orthographic projection of the second light-emitting aperture on the substrate can completely cover the orthographic projection of the first light-emitting aperture, forming a stepped reflection structure. At the same time, the component mounting holes and the second light-emitting aperture are spatially isolated from each other and have no direct connection.

[0028] In some preferred embodiments, the first insulating carrier and the second insulating carrier are fixed to the substrate by adhesive bonding or mechanical snap-fitting.

[0029] In one implementation of this embodiment, the first and second insulating carriers are fixed to the substrate by adhesive bonding. Specifically, a layer of high-temperature resistant epoxy resin adhesive is coated onto the substrate surface. Then, the first and second insulating carriers, with pre-drilled holes, are sequentially pressed onto the adhesive. The adhesive is then cured by heating or allowing it to stand at room temperature, thereby firmly bonding the two carrier layers to the substrate. In another optional implementation, a mechanical snap-fit ​​method can also be used. For example, the first and second insulating carriers can be snap-fitted and fixed to the substrate using the housing of the light source; this is not specifically limited by the present invention.

[0030] S2, at least one electronic component is fixed on the first insulating carrier, and the electronic component is positioned corresponding to the component mounting hole.

[0031] In practice, solder paste is used to solder and fix electronic components, such as a constant current diode, to a predetermined position on the upper surface of the first insulating carrier corresponding to the component mounting hole.

[0032] In some preferred embodiments, the thickness of the second insulating carrier is greater than the height of the electronic component in the direction perpendicular to the substrate.

[0033] In practice, the thickness of the second insulating carrier is greater than the height of the electronic component. This design ensures that after the electronic component is installed, its top does not protrude from the upper surface of the second insulating carrier, thus being completely contained and hidden within the component mounting hole, guaranteeing the overall flatness of the outer area of ​​the light-emitting surface.

[0034] In some preferred embodiments, the electronic components are fixed to the first insulating carrier by conductive adhesive or solder.

[0035] In a specific implementation, in one embodiment of this invention, the step of fixing the electronic components onto the first insulating carrier is achieved through soldering. During operation, solder paste is first printed onto the pads corresponding to the component mounting holes on the first insulating carrier. Then, a surface mount device is used to precisely place the electronic components onto the solder paste. Finally, the carrier fixture is passed through a reflow oven, where the high temperature melts the solder paste, wetting the component leads and the pads on the first insulating carrier. Subsequent cooling forms a stable mechanical and electrical connection. In another optional implementation, conductive silver paste can also be used for fixing. That is, conductive silver paste is applied to the pads, the electronic components are mounted, and then the silver paste is cured by heating to achieve fixing and conductivity.

[0036] S3, at least one LED chip is fixed on the substrate, and the LED chip is positioned corresponding to the first light-emitting hole.

[0037] In a specific implementation, at least one LED chip is die-bonded to the surface of the substrate, and the position of the LED chip corresponds to the position of the first light-emitting hole.

[0038] In this field, the process of fixing LED chips onto a substrate is often referred to as "die bonding," which is achieved, for example, by eutectic bonding or conductive adhesive bonding.

[0039] S4, the LED chip is electrically connected to the electronic component via bonding wires.

[0040] In practice, a gold wire bonding machine is used to electrically connect the electrodes of the LED chip to the corresponding pins of the electronic components through bonding wires, forming a reliable electrical connection.

[0041] S5, fill the second light-emitting hole with fluorescent adhesive.

[0042] In practice, the prepared fluorescent silicone is injected into the second light-emitting hole through a dispensing device to cover the LED chip.

[0043] S6, Bake and cure the filled fluorescent adhesive.

[0044] In practice, the semi-finished product with the adhesive applied is placed in an oven and heated according to a preset temperature rise curve to fully cross-link and cure the fluorescent adhesive, forming a stable fluorescent adhesive layer, thereby completing the light source fabrication.

[0045] This embodiment constructs a sandwich structure with embedded electronic components by sequentially stacking and perforating a first insulating carrier and a second insulating carrier. Specifically, the components are fixed on the first insulating carrier and housed within component mounting holes in the second insulating carrier, while the LED chip is die-bonded to the substrate and located in the area corresponding to the first light-emitting hole. This structural design effectively hides the electronic components between the two carrier layers, without occupying the effective light-emitting area defined by the second light-emitting hole. Therefore, the light-emitting surface of the light source remains intact and clean, avoiding light loss and appearance defects caused by component protrusion. Simultaneously, the isolation design between the component mounting holes and the light-emitting hole ensures that adhesive does not flow into the component area when filling with phosphor adhesive, guaranteeing electrical reliability. This method, through structural optimization, improves the light extraction efficiency and appearance quality of the COB light source while integrating necessary driving or protective components.

[0046] In some preferred embodiments, the baking and curing of the filled fluorescent adhesive includes: first performing preliminary curing at a temperature lower than a first preset temperature, and then performing complete curing at a higher temperature than the first preset temperature.

[0047] In a specific implementation, one method of this embodiment involves baking and curing the filled fluorescent adhesive using a two-step baking method. First, preliminary curing is performed: the workpiece after dispensing is placed in an oven at approximately 80 degrees Celsius and baked for 30 minutes. This stage is low-temperature baking, designed to allow the solvent in the fluorescent adhesive to slowly evaporate, the adhesive to initially gel, and to gain some initial strength to maintain its shape, but it is not yet fully cured. Subsequently, complete curing is performed: the pre-cured workpiece is transferred to an oven at approximately 150 degrees Celsius and baked for another 60 minutes. This stage is high-temperature baking, designed to promote the complete cross-linking reaction of the main resin in the fluorescent adhesive, enabling it to achieve its final mechanical strength, thermal stability, and optical stability.

[0048] This invention provides a COB light source, prepared by the above method, comprising: Substrate 10; A first insulating carrier 20 is disposed on the substrate 10, and the first insulating carrier 20 is provided with a first light-emitting hole 40; The second insulating carrier 30 is disposed on the first insulating carrier 20. The second insulating carrier 30 is provided with a second light-emitting hole 50 and a component mounting hole 60. The orthogonal projection of the second light-emitting hole 50 on the substrate 10 completely covers the orthogonal projection of the first light-emitting hole 40 on the substrate 10. The component mounting hole 60 is isolated from the second light-emitting hole 50. At least one electronic component 70 is fixed on the first insulating carrier 20 and located within the component mounting hole 60; At least one LED chip is fixed on the substrate 10 and is disposed corresponding to the first light-emitting hole 40; Fluorescent adhesive 80 is filled and cured into the second light-emitting hole 50; The LED chip and the electronic component 70 are electrically connected via bonding wires.

[0049] In this specific implementation, an embodiment provides a COB light source. The light source includes a substrate 10, which can be made of mirrored aluminum plate, ceramic plate, ordinary aluminum plate, or copper plate, etc., and is not specifically limited in this invention. A first insulating carrier 20 is fixed on the substrate 10. The first insulating carrier 20 is, for example, an FR4 board or a BT board, with a circular first light-emitting hole 40 in its center. A second insulating carrier 30, also made of the same material (FR4 board or BT board), is stacked and fixed on top of the first insulating carrier 20. A larger-diameter circular second light-emitting hole 50 is formed in the center of the second insulating carrier 30, and component mounting holes 60 are formed around the second light-emitting hole 50. The orthographic projection of the second light-emitting hole 50 completely covers the first light-emitting hole 40 below. Electronic components 70 are die-bonded to the upper surface of the first insulating carrier 20 and located within the component mounting holes 60. An LED chip is die-bonded to the surface of the substrate 10, and its position is directly opposite the first light-emitting hole 40. The electrodes of the LED chip and the electronic components 70 are connected to form the required circuit via multiple gold bonding wires. The second light-emitting hole 50 is filled with cured phosphor adhesive 80, completely covering the LED chip. The component mounting hole 60 is not connected to the area filled with phosphor adhesive 80 (i.e., the second light-emitting hole 50).

[0050] Furthermore, in some preferred embodiments, the thickness of the second insulating carrier 30 is greater than the height of the electronic component 70 in the direction perpendicular to the substrate 10.

[0051] In practice, the thickness of the second insulating carrier 30 is greater than the height of the electronic component 70. After the electronic component 70 is installed, it will not protrude from the upper surface of the second insulating carrier 30 and will be completely contained within the component mounting hole 60.

[0052] In some preferred embodiments, the electronic component 70 is fixed to the first insulating carrier 20 by conductive adhesive or solder.

[0053] In specific implementation, electronic components 70 are fixed by conductive adhesive or solder, but this invention is not specifically limited to this.

[0054] In some preferred embodiments, the first insulating carrier 20 and the second insulating carrier 30 are fixed to the substrate 10 by an adhesive layer or mechanical structure.

[0055] In specific implementation, this embodiment provides two typical fixing methods between the insulating carrier and the substrate 10. The main advantage of the mechanical snap-fit ​​fixing method is that it enables rapid, pollution-free assembly and potential modular design. It eliminates the need for gluing and curing, improving production efficiency, and facilitates non-destructive disassembly and replacement during maintenance, which conforms to the maintainability design concept.

[0056] Furthermore, the main effect of the adhesive layer fixing method is to achieve uniform stress distribution and good sealing performance across the entire surface. The adhesive can fill all microscopic unevenness on the contact surfaces, forming a continuous bonding interface, effectively preventing moisture or contaminants from penetrating between layers, thus improving the product's environmental sealing rating and long-term weather resistance.

[0057] In some preferred embodiments, the LED chip is a blue light chip.

[0058] In specific implementation, the LED chip is a blue light chip, but this invention is not specifically limited to that. The scheme of combining a blue light chip with yellow phosphor to achieve white light is one of the most mature and photoelectric conversion efficiency technologies in the field of solid-state lighting.

[0059] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0060] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," 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.

[0061] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0062] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0063] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0064] In the description of this specification, the 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. The illustrative expressions of the above terms in this specification should not be construed as necessarily referring 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. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0065] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Since these modifications and variations fall within the scope of the claims and their equivalents, this invention also intends to include these modifications and variations.

[0066] The above description describes specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered 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 method for manufacturing a COB light source, characterized in that, include: A substrate, a first insulating carrier, and a second insulating carrier are provided. The first insulating carrier and the second insulating carrier are sequentially stacked on the substrate. The first insulating carrier is provided with a first light-emitting hole. The second insulating carrier is provided with a second light-emitting hole and a component mounting hole. The orthogonal projection of the second light-emitting hole on the substrate completely covers the orthogonal projection of the first light-emitting hole on the substrate. The component mounting hole is isolated from the second light-emitting hole. At least one electronic component is fixed to the first insulating carrier, and the electronic component is positioned corresponding to the component mounting hole. At least one LED chip is fixed to the substrate, and the LED chip is positioned corresponding to the first light-emitting hole. The LED chip is electrically connected to the electronic components via bonding wires; Fill the second light-emitting hole with fluorescent adhesive; The filled fluorescent adhesive is then baked and cured.

2. The method for manufacturing a COB light source according to claim 1, characterized in that, The thickness of the second insulating carrier is greater than the height of the electronic component in the direction perpendicular to the substrate.

3. The method for manufacturing a COB light source according to claim 1, characterized in that, The electronic components are fixed to the first insulating carrier by conductive adhesive or solder.

4. The method for manufacturing a COB light source according to claim 1, characterized in that, The first insulating carrier and the second insulating carrier are fixed to the substrate by adhesive bonding or mechanical snap-fitting.

5. The method for manufacturing a COB light source according to any one of claims 1 to 4, characterized in that, The step of baking and curing the filled fluorescent adhesive includes: First, perform preliminary curing at a temperature lower than the first preset temperature, and then perform complete curing at a higher temperature than the first preset temperature.

6. A COB light source, characterized in that, include: Substrate; A first insulating carrier is disposed on the substrate, and the first insulating carrier is provided with a first light-emitting hole; A second insulating carrier is disposed on the first insulating carrier. The second insulating carrier is provided with a second light-emitting hole and a component mounting hole. The orthographic projection of the second light-emitting hole on the substrate completely covers the orthographic projection of the first light-emitting hole on the substrate. The component mounting hole is isolated from the second light-emitting hole. At least one electronic component is fixed to the first insulating carrier and located within the component mounting hole; At least one LED chip is fixed on the substrate and is positioned corresponding to the first light-emitting hole; Fluorescent adhesive is filled and cured into the second light-emitting hole; The LED chip and the electronic components are electrically connected via bonding wires.

7. The COB light source according to claim 6, characterized in that, The thickness of the second insulating carrier is greater than the height of the electronic component in the direction perpendicular to the substrate.

8. The COB light source according to claim 6, characterized in that, The electronic components are fixed to the first insulating carrier by conductive adhesive or solder.

9. The COB light source according to claim 6, characterized in that, The first insulating carrier and the second insulating carrier are fixed to the substrate by an adhesive layer or a mechanical structure.

10. The COB light source according to any one of claims 6 to 9, characterized in that, The LED chip is a blue light chip.

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