Double-color LED packaging structure and lamp bead

Abstract

The utility model provides a double-color LED packaging structure and a lamp bead, the double-color LED packaging structure comprises a substrate, a first light-emitting chip and a second light-emitting chip are packaged on the substrate, at least the periphery of the first light-emitting chip is provided with transparent colloid in a surrounding mode, and the height of the transparent colloid is larger than or equal to the height of the first light-emitting chip. During powder spraying operation, fluorescent powder falling from the meshes of the steel mesh only falls on the upper surface, far away from the substrate, of the first light-emitting chip and does not fall on the peripheral side face of the first light-emitting chip, so that the accuracy of the powder spraying position is improved, and the product quality is improved. When a lamp bead product is formed and used, the first light-emitting chip only excites the fluorescent powder on the upper surface, the influence on color coordinates is small, and the product quality is stable.

Description

Technical Field

[0001] The present application relates to the technical field of LED products, and in particular to a dual-color LED packaging structure and lamp beads. Background Art

[0002] The existing two-color COB (Chip on Board) manufacturing process includes CSP (Chip Scale Package), chip dispensing, and chip powder spraying. The chip powder spraying process involves spraying phosphor onto the surface of the light-emitting chip through a stencil. However, due to mismatching between the stencil and the light-emitting chip, namely the misalignment between the chip assembly position on the substrate and the mesh position on the stencil, when the chip is placed in the chip assembly position on the substrate, some phosphor can easily float through the mesh and onto the side of the chip. This can cause the phosphor to be sprayed off-center, resulting in discrete color coordinates in the finished product, and thus affecting the quality of the LED. Utility Model Content

[0003] In view of this, the present application provides a dual-color LED packaging structure and lamp beads with stable product quality and small color coordinate differences.

[0004] In order to achieve the above objectives, this application provides the following technical solutions:

[0005] A dual-color LED packaging structure includes a substrate on which a first light-emitting chip and a second light-emitting chip are packaged. A transparent colloid is provided around at least the periphery of the first light-emitting chip, and the height of the transparent colloid is greater than or equal to the height of the first light-emitting chip.

[0006] Optionally, a phosphor layer is encapsulated on the substrate, and the phosphor layer covers a side of the first light-emitting chip away from the substrate.

[0007] Optionally, the size of the phosphor layer is larger than that of the first light-emitting chip, and the phosphor layer partially covers the transparent colloid.

[0008] Optionally, a plurality of the first light-emitting chip and a plurality of the second light-emitting chip are provided, and the transparent colloid is provided around the periphery of each of the first light-emitting chips and the periphery of each of the second light-emitting chips.

[0009] Optionally, the height difference between the transparent colloid and the first light-emitting chip is set to 0.5-1.5 mm.

[0010] Optionally, the transparent colloid covers a side of the first light-emitting chip away from the substrate.

[0011] Optionally, the height of the transparent colloid increases gradually in a direction away from the first light-emitting chip, and the minimum height of the transparent colloid is equal to or greater than the height of the first light-emitting chip.

[0012] Optionally, a frame-shaped BT board is provided on the substrate, the first light-emitting chip, the second light-emitting chip and the transparent colloid are all provided inside the BT board, and the first light-emitting chip and the second light-emitting chip are electrically connected to the BT board.

[0013] Optionally, the height of the BT board is set to 0.1-0.4 mm.

[0014] Optionally, a fluorescent glue layer is encapsulated on the substrate, and the fluorescent glue layer covers the phosphor layer, the second light-emitting chip and a side of the transparent colloid away from the substrate.

[0015] A lamp bead comprises the dual-color LED packaging structure as described in any one of the above items.

[0016] The dual-color LED package structure and lamp beads provided herein feature a transparent colloid disposed around at least the periphery of the first light-emitting chip. During powder spraying, phosphor powder falling through the mesh of the steel mesh lands only on the upper surface of the first light-emitting chip, away from the substrate, and avoids the outer peripheral sides of the first light-emitting chip. This improves the accuracy of powder spraying and contributes to improved product quality. Furthermore, during the molding and use of the lamp bead product, the first light-emitting chip only excites the phosphor on the upper surface, minimizing the impact on color coordinates and maintaining stable product quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without any creative work.

[0018] Figure 1 Schematic cross-sectional view of a dual-color LED package structure according to some embodiments;

[0019] Figure 2 Schematic cross-sectional view of a dual-color LED package structure in some embodiments during a powder spraying process.

[0020] In the figure: 1. substrate; 2. BT board; 3. cofferdam; 4. first light-emitting chip; 5. second light-emitting chip; 6. transparent colloid; 7. phosphor layer; 8. fluorescent glue layer; 9. steel mesh; 10. mesh. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0022] like Figure 1-Figure 2 As shown, an embodiment of the present application provides a dual-color LED package structure, including a substrate 1, on which a first light-emitting chip 4 and a second light-emitting chip 5 are packaged. A transparent colloid 6 is also provided on the substrate 1. The transparent colloid 6 is disposed at least around the periphery of the first light-emitting chip 4, thereby wrapping the outer peripheral side of the first light-emitting chip 4 through the transparent colloid 6. Here, the transparent colloid 6 can be disposed only around the periphery of the first light-emitting chip 4, or can be disposed around the periphery of both the first light-emitting chip 4 and the periphery of the second light-emitting chip 5.

[0023] During the powder spraying operation, the phosphor powder falling from the mesh 10 of the steel mesh 9 only lands on the upper surface of the first light-emitting chip 4, away from the substrate 1, and does not land on the outer peripheral side surfaces of the first light-emitting chip 4. This improves the accuracy of the powder spraying position and helps improve product quality. Moreover, when the lamp bead product is formed and used, the first light-emitting chip 4 only excites the phosphor powder on the upper surface, which has a minimal impact on the color coordinates and maintains stable product quality.

[0024] It should be noted that if Figure 2 As shown, during the powder spraying process, the mesh 10 of the steel mesh 9 is aligned only with the first light-emitting chip 4 and does not overlap with the second light-emitting chip 5. That is, the powder spraying process only applies powder to the upper surface of the first light-emitting chip 4, thereby covering the upper surface of the first light-emitting chip 4 with a layer of phosphor powder, while the upper surface of the second light-emitting chip 5 does not need to be covered with a layer of phosphor powder. After the powder spraying process is completed, the first light-emitting chip 4 and the second light-emitting chip 5 are covered with fluorescent glue. That is, the fluorescent glue simultaneously covers the phosphor powder on the upper surface of the first light-emitting chip 4, the second light-emitting chip 5, and the transparent colloid 6.

[0025] The height of the transparent colloid 6 is greater than or equal to the height of the first light-emitting chip 4, so that the transparent colloid 6 can completely wrap the outer peripheral side of the first light-emitting chip 4, so that no phosphor is accumulated in the outer peripheral direction of the first light-emitting chip 4, thereby improving the quality and stability of the powder spraying process.

[0026] In some specific embodiments, the height difference between the transparent colloid 6 and the first light-emitting chip 4 is set to 0.5-1.5 mm, that is, the height of the transparent colloid 6 is 0.5-1.5 mm greater than the height of the first light-emitting chip 4, preferably 1 mm. The transparent colloid 6 not only provides a barrier but also conducts heat. If the thickness of the transparent colloid 6 is too large, the thermal conductivity of the transparent colloid 6 will be poor, thereby affecting the heat dissipation of the first light-emitting chip 4 and even affecting product quality. Here, the height difference between the transparent colloid 6 and the first light-emitting chip 4 is set to 1 mm, which is the optimal choice for thermal conductivity.

[0027] In this embodiment, a phosphor layer 7 is encapsulated on the substrate 1, covering the upper surface of the first light-emitting chip 4, away from the substrate 1. That is, during the powder spraying process, phosphor that passes through the meshes 10 of the steel mesh 9 and lands on the upper surface of the first light-emitting chip 4 gathers to form the phosphor layer 7. This phosphor layer 7 enables dimming of the first light-emitting chip 4, and thus also of the second light-emitting chip 5.

[0028] The size of the phosphor layer 7 is larger than that of the first light-emitting chip 4. For example, the first light-emitting chip 4 and the phosphor layer are both square, and the side length of the phosphor layer 7 is 0.15 mm larger than the side length of the first light-emitting chip 4. For another example, the first light-emitting chip and the phosphor layer are both circular, and the radius of the phosphor layer 7 is 0.15 mm larger than the radius of the first light-emitting chip 4. This allows the edge of the phosphor layer 7 to protrude from the first light-emitting chip 4, thereby allowing the edge of the phosphor layer 7 to partially cover the transparent colloid 6. In this way, during the powder spraying process, the side length of the mesh 10 of the steel mesh 9 can be made 0.15 mm larger than the side length of the first light-emitting chip 4. Even if the mesh 10 of the steel mesh 9 is not completely aligned with the first light-emitting chip 4, the phosphor layer 7 can still cover the first light-emitting chip 4, thereby improving the convenience and accuracy of the powder spraying operation and ensuring stable product quality.

[0029] In some preferred embodiments, multiple first light-emitting chips 4 and multiple second light-emitting chips 5 are provided. The multiple first light-emitting chips 4 and the multiple second light-emitting chips 5 can be staggered only in the horizontal direction, only in the vertical direction, or in both the horizontal and vertical directions, depending on specific needs. The aforementioned transparent colloid 6 is disposed around the periphery of each first light-emitting chip 4 and the periphery of each second light-emitting chip 5, so that the transparent colloid 6 covers both the peripheral side surfaces of the first light-emitting chip 4 and the peripheral side surfaces of the second light-emitting chip 5.

[0030] After fixing the first light-emitting chip 4 and the second light-emitting chip 5 on the substrate 1, a glue dispensing operation can be performed between two adjacent light-emitting chips (which can be two first light-emitting chips 4, two second light-emitting chips 5, or a first light-emitting chip 4 and a second light-emitting chip 5) to form a transparent colloid 6 between the two light-emitting chips. By controlling the position and thickness of the glue dispensing operation, the position and thickness of the formed transparent colloid 6 can be adjusted.

[0031] With such a configuration, a transparent colloid 6 can be formed on the periphery of the first light-emitting chip 4 and the periphery of the second light-emitting chip 5 by a dispensing operation, which can not only wrap the first light-emitting chip 4 and the second light-emitting chip 5, but also limit and support the positions of the first light-emitting chip 4 and the second light-emitting chip 5. The processing technology is simple and the structure is stable.

[0032] In this solution, the height of the transparent colloid 6 is uniform. Since the transparent colloid 6 is higher than the first light-emitting chip 4, a step is formed between the transparent colloid 6 and the first light-emitting chip 4. Here, in order to avoid the formation of a step between the transparent colloid 6 and the first light-emitting chip 4, the portion of the transparent colloid 6 that is higher than the first light-emitting chip 4 can be extended to the upper surface of the first light-emitting chip 4. Here, the raised portion of the transparent colloid 6 can cover the entire upper surface of the first light-emitting chip, or it can cover a portion of the upper surface of the first light-emitting chip, so that a portion of the transparent colloid 6 surrounds the outer peripheral side of the first light-emitting chip 4, and the other portion covers the upper surface of the first light-emitting chip 4. In this way, by forming a wrapping above the first light-emitting chip 4 with the transparent colloid 6, secondary reinforcement of the first light-emitting chip 4 and the second light-emitting chip 5 can also be achieved.

[0033] In other embodiments, the height of the transparent colloid 6 may also be different. For example, the height of the transparent colloid 6 increases in the direction away from the first light-emitting chip 4, and the minimum height of the transparent colloid 6 is equal to or greater than the height of the first light-emitting chip 4. In this way, the transparent colloid 6 forms a flared shape on the periphery of the first light-emitting chip 4, and during the powder spraying process, the phosphor can be guided to the upper surface of the first light-emitting chip 4.

[0034] In some embodiments, a BT board 2 is provided on the substrate 1, and the middle portion of the BT board 2 is hollowed out to form a frame-shaped structure. Here, the BT board 2 can be set in a square frame shape or a circular frame shape. In addition, positive and negative electrode pads are provided on the BT board 2, and the first light-emitting chip 4, the second light-emitting chip 5 and the transparent colloid 6 are all provided on the inner side of the BT board 2 (i.e., the position of the hollowed-out middle portion), so that the BT board 2 surrounds the overall periphery formed by the first light-emitting chip 4, the second light-emitting chip 5 and the transparent colloid 6. In this way, by electrically connecting the first light-emitting chip 4 and the second light-emitting chip 5 to the positive and negative electrode pads on the BT board 2, electrical conduction between the first light-emitting chip 4 and the second light-emitting chip 5 is achieved, thereby causing the first light-emitting chip 4 and the second light-emitting chip 5 to emit light.

[0035] The height of the BT board 2 is set to 0.1-0.4 mm, which facilitates glue dispensing between the light-emitting chips. Preferably, the height of the BT board 2 is set to 0.2-0.4 mm. When the BT board 2 is set to 0.2 mm, since the light-emitting chip is 0.15 mm high, it is easier to solder wires to the light-emitting chip. When the height is set to 0.4 mm, the height difference between the BT board 2 and the light-emitting chip is greater, and the leads on the BT board 2 are easily pressed against the BT board 2, resulting in poor soldering. In this way, by setting the height range of the BT board 2, processing convenience and product quality can be improved.

[0036] A fluorescent glue layer 8 is encapsulated on the substrate 1, and the fluorescent glue layer 8 covers the side of the phosphor layer 7, the second light-emitting chip 5 and the transparent colloid 6 away from the substrate 1. The fluorescent glue layer 8 can be excited by the first light-emitting chip 4 and the second light-emitting chip 5, thereby mixing the light of the first light-emitting chip 4 and the second light-emitting chip 5 in the fluorescent glue layer 8 to form the required light.

[0037] The packaging process of the dual-color LED packaging structure is described in detail below based on the above embodiments.

[0038] The BT board 2, the first light-emitting chip 4, and the second light-emitting chip 5 are fixed on the substrate 1. The first light-emitting chip 4 and the second light-emitting chip 5 are located on the inner side of the BT board 2. The first light-emitting chip 4 and the second light-emitting chip 5 are electrically connected to the positive and negative electrode pads on the BT board 2 through leads. The first light-emitting chip 4 and the second light-emitting chip 5 are both set as blue light chips.

[0039] A dispensing operation is performed on the substrate 1 , that is, dispensing glue to form a transparent colloid 6 in the closed area surrounded by the BT board 2 . The transparent colloid 6 is located between two adjacent light-emitting chips, and the transparent colloid 6 is wrapped around the periphery of the first light-emitting chip 4 and the peripheral side of the second light-emitting chip 5 .

[0040] Phosphor is sprayed by a powder sprayer, passing through the mesh 10 of the steel mesh 9 and sprayed onto the upper surface of the first light-emitting chip 4 and the upper surface of part of the transparent colloid 6 to form a phosphor layer 7. Here, the phosphor is set to warm white phosphor. The shape and size of the phosphor layer 7 depend on the shape and size of the mesh 10 of the steel mesh 9.

[0041] After the powder spraying process is completed, the cofferdam 3 process is carried out to form a cofferdam 3 on the upper surface of the BT board 2. Finally, a glue dispensing operation is performed within the cofferdam 3 to form a fluorescent glue layer 8, thereby forming the final product. The fluorescent glue layer 8 is formed of cool white fluorescent glue.

[0042] The present embodiment provides a lamp bead including the dual-color LED package structure described in the above embodiment. With this arrangement, during the powder spraying operation, the phosphor powder falling from the mesh 10 of the steel mesh 9 only lands on the upper surface of the first light-emitting chip 4, away from the substrate 1, and not on the peripheral side surfaces of the first light-emitting chip 4. This improves the accuracy of the powder spraying position and contributes to improved product quality. Furthermore, when the lamp bead product is formed and used, the first light-emitting chip 4 only excites the phosphor powder on the upper surface, which has a minimal impact on the color coordinates and maintains stable product quality.

[0043] The basic principles of the present application have been described above in conjunction with specific embodiments. However, it should be noted that the advantages, strengths, and effects mentioned in this application are merely illustrative and not restrictive, and it should not be assumed that these advantages, strengths, and effects are required of each embodiment of this application. In addition, the specific details disclosed above are merely illustrative and facilitating understanding, and are not restrictive. The above details do not limit this application to necessarily being implemented using the above specific details.

[0044] The block diagrams of the devices, devices, equipment, and systems involved in this application are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As will be appreciated by those skilled in the art, these devices, devices, equipment, and systems can be connected, arranged, or configured in any manner. Words such as "include," "comprise," "have," and the like are open-ended words, meaning "including but not limited to," and can be used interchangeably therewith. The words "or" and "and" used herein refer to the words "and / or" and can be used interchangeably therewith, unless the context clearly indicates otherwise. The word "such as" used herein refers to the phrase "such as but not limited to," and can be used interchangeably therewith.

[0045] It should also be noted that in the apparatus, device, and method of the present application, each component or each step can be decomposed and / or recombined, and such decomposition and / or recombination should be regarded as equivalent solutions of the present application.

[0046] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use the present application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects without departing from the scope of the present application. Therefore, the present application is not intended to be limited to the aspects shown herein, but rather to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0047] It should be understood that the qualifiers "first", "second", "third", "fourth", "fifth" and "sixth" used in the description of the embodiments of the present application are only used to more clearly illustrate the technical solutions and cannot be used to limit the scope of protection of the present application.

[0048] The above description has been provided for the purpose of illustration and description. Furthermore, this description is not intended to limit the embodiments of the present application to the forms disclosed herein. Although a number of example aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations thereof.

Claims

1. A dual-color LED packaging structure, characterized in that: The invention comprises a substrate (1), wherein a first light-emitting chip (4) and a second light-emitting chip (5) are packaged on the substrate (1), and a transparent colloid (6) is provided around at least the periphery of the first light-emitting chip (4), and the height of the transparent colloid (6) is greater than or equal to the height of the first light-emitting chip (4).

2. The dual-color LED packaging structure according to claim 1, characterized in that: A phosphor layer (7) is encapsulated on the substrate (1), and the phosphor layer (7) covers a side of the first light-emitting chip (4) away from the substrate (1).

3. The dual-color LED packaging structure according to claim 2, characterized in that: The size of the phosphor layer (7) is larger than the size of the first light-emitting chip (4), and the phosphor layer (7) partially covers the transparent colloid (6).

4. The dual-color LED packaging structure according to claim 1, wherein: A plurality of the first light-emitting chips (4) and the second light-emitting chips (5) are provided, and the outer periphery of each first light-emitting chip (4) and the outer periphery of each second light-emitting chip (5) are surrounded by the transparent colloid (6).

5. The dual-color LED packaging structure according to claim 1, wherein: The height difference between the transparent colloid (6) and the first light-emitting chip (4) is set to 0.5-1.5 mm.

6. The dual-color LED packaging structure according to claim 1, wherein: The transparent colloid (6) covers the side of the first light-emitting chip (4) away from the substrate (1).

7. The dual-color LED package structure according to claim 1, wherein: The height of the transparent colloid (6) increases gradually in a direction away from the first light-emitting chip (4), and the minimum height of the transparent colloid (6) is equal to or greater than the height of the first light-emitting chip (4).

8. The dual-color LED packaging structure according to claim 1, wherein: A frame-shaped BT board (2) is provided on the substrate (1); the first light-emitting chip (4), the second light-emitting chip (5) and the transparent colloid (6) are all provided on the inner side of the BT board (2); and the first light-emitting chip (4) and the second light-emitting chip (5) are electrically connected to the BT board (2).

9. The dual-color LED packaging structure according to claim 8, characterized in that: The height of the BT board (2) is set to 0.1-0.4 mm.

10. The dual-color LED packaging structure according to claim 2, characterized in that: A fluorescent glue layer (8) is encapsulated on the substrate (1), and the fluorescent glue layer (8) covers the fluorescent powder layer (7), the second light-emitting chip (5), and a side of the transparent colloid (6) away from the substrate (1).

11. A lamp bead, characterized in that: The invention comprises the dual-color LED packaging structure according to any one of claims 1 to 10.

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