LED support, LED lamp bead and LED device

Abstract

The utility model relates to an LED support, an LED lamp bead and an LED device. The LED support comprises a support body. The bonding pad is fixed on the bracket main body; the bonding pad comprises a first split body and a second split body which are oppositely arranged and have opposite polarities, and the bonding pad is configured to be connected with electrodes with different polarities of the LED chip through conductive adhesive; the first gap is located between the first split body and the second split body of the bonding pad; a groove is arranged in the first gap, an isolation part is arranged at the bottom of the groove, and the isolation part and the groove walls on the two sides of the groove form mutually isolated containing areas respectively. According to the utility model, the grooves are arranged to isolate the positive and negative conductive adhesives during die bonding of the flip chip, thereby avoiding short circuit caused by migration of the conductive adhesives and causing faults. The light emitting efficiency and the light emitting effect of the lamp bead are improved, and the reliability and the die bonding consistency are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of LED packaging, in particular to an LED bracket, an LED lamp bead and an LED device. Background Art

[0002] LED packaging encapsulates the light-emitting chip within a bracket or substrate to prevent failure due to exposure or mechanical damage. For TOP (Top-Emitting Light-Emitting Diode) LEDs, the conventional packaging structure is upright, with the chip facing upward. After die bonding, metal wires connect the chip to the pads. However, wire connections are prone to desoldering, lead wires are expensive, and they can easily block the light source, affecting luminous efficiency.

[0003] In a flip-chip structure, the chip's electrical surface faces downward, facing the substrate. During die bonding, conductive material is used to connect the chip, eliminating the need for wire bonding and addressing the efficiency and reliability limitations of face-up designs. However, conductive material migration on the pad surface can easily lead to short circuits between the chip's positive and negative terminals. This also creates instability in the amount of conductive adhesive and the placement of adhesive during die bonding. Utility Model Content

[0004] To this end, the technical problem to be solved by the present invention is to overcome the technical difficulty in the prior art that the conductive glue of the flip chip migrates during the solidification process, causing a short circuit between the positive and negative poles of the chip, and to provide an LED bracket, an LED lamp bead and an LED device, in which insulating grooves are set between the pads to isolate the conductive glue.

[0005] In the first aspect, in order to solve the above technical problems, the present invention provides an LED bracket, which includes:

[0006] Bracket body;

[0007] A soldering pad fixed to the bracket body; the soldering pad includes a first split body and a second split body arranged opposite to each other and having opposite polarities, and the soldering pad is configured to connect electrodes of different polarities of the LED chip through a conductive adhesive;

[0008] A first gap is located between the first and second parts of the pad; a groove is provided in the first gap, an isolation portion is provided at the bottom of the groove, and the isolation portion forms mutually isolated accommodation areas with the groove walls on both sides of the groove.

[0009] In one embodiment of the present invention, a first hydrophobic and oleophobic layer is provided on both side wall surfaces of the groove.

[0010] In one embodiment of the present invention, the groove wall is configured as an inclined surface, and the groove bottom width of the groove is smaller than the groove opening width of the groove.

[0011] In one embodiment of the present invention, the height of the isolation portion relative to the groove bottom is h1, the depth of the groove is h2, and h1 ≥ 1 / 3 h2.

[0012] In one embodiment of the present invention, both the first and second sub-bodies are provided with a crystal-fixing area, and the crystal-fixing area is used to electrically connect the electrodes of the LED chip; and a second hydrophobic and oleophobic layer is provided around the outer edge of the crystal-fixing area.

[0013] In one embodiment of the present invention, in the extension direction of the first gap, the length of the crystal fixing region is smaller than the length of the isolation portion.

[0014] In one embodiment of the present invention, there are at least two solder pads, and a second gap is provided between two adjacent solder pads.

[0015] In the second aspect, the utility model also provides an LED lamp bead, which includes an LED chip, a conductive glue and the LED bracket described in any of the above embodiments; the bracket body is formed with a reflective cup for accommodating the LED chip, and the LED chip is arranged across the first gap; the electrodes at both ends of the LED chip are respectively connected to the solid crystal area of ​​the first split body and the solid crystal area of ​​the second split body through the conductive glue.

[0016] In one embodiment of the present invention, three solder pads are provided, and the LED chip is provided as an RGB chip.

[0017] In a third aspect, the present invention further provides an LED device, which includes the LED bracket, or includes the LED lamp bead.

[0018] The above technical solution of the utility model has the following beneficial effects compared with the prior art:

[0019] The LED bracket, LED lamp bead, and LED device described in this utility model are designed to isolate the positive and negative conductive adhesive during flip-chip die bonding by providing a groove to prevent conductive adhesive migration and short circuits that could cause malfunctions. This improves light extraction efficiency and the luminous effect of the lamp bead, and enhances reliability and die bonding consistency. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to make the content of the utility model easier to understand, the utility model is further described in detail below based on the specific embodiments of the utility model in conjunction with the accompanying drawings, wherein:

[0021] Figure 1 This is a schematic cross-sectional view of the LED bracket in Example 1 of the present utility model;

[0022] Figure 2 for Figure 1A magnified schematic diagram of point A in the middle;

[0023] Figure 3 This is a schematic diagram of the cross-sectional structure of the LED lamp bead in the second embodiment of the present utility model;

[0024] Figure 4 for Figure 3 A magnified schematic diagram of point B in the middle;

[0025] Figure 5 This is a schematic diagram of the internal structure of the LED lamp bead in Example 2 of the present utility model.

[0026] Explanation of the reference numerals in the accompanying drawings in the specification: 1. Bracket body; 2. Solder pad; 21. First sub-body; 22. Second sub-body; 23. Crystal fixing area; 3. First gap; 4. Groove; 41. Groove wall; 42. Isolation portion; 43. Accommodation area; 51. First hydrophobic and oleophobic layer; 52. Second hydrophobic and oleophobic layer; 6. Second gap; 7. LED chip; 71. Electrode; 8. Conductive adhesive. DETAILED DESCRIPTION

[0027] The present invention will be further described below with reference to the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it. However, the embodiments are not intended to limit the present invention. Example 1

[0028] Reference Figure 1~Figure 2 As shown, the first embodiment of the present invention provides an LED bracket for flip-chip LED chips. Compared with upright-mounted chips, flip-mounting places the electrical surface of the chip directly opposite the bracket. While this eliminates the need for leads, preventing lead obstruction and metal wire desoldering, it does pose the problem of unstable glue dispensing during die bonding.

[0029] When securing a wafer, conductive glue 8 needs to be applied to the die-bonding position to electrically connect the chip. The conductive glue 8 at the positive and negative electrodes can attract and migrate, easily leading to a short circuit. Furthermore, offsets in the glue application position, glue volume, and size can affect chip curing, making the chip prone to shifting, tilting, or falling off. The present invention provides a gap to isolate the conductive glue 8 and stabilizes the size and shape of the glue application position through hydrophobic and oleophobic treatment.

[0030] Specifically, the LED bracket provided in the first embodiment includes a bracket body 1, a solder pad 2, a first gap 3 and a second gap 6. The bracket body 1 forms a reflective cup for accommodating the LED chip 7 and the solder pad 2, and the solder pad 2 is fixed to the bottom of the reflective cup.

[0031] Each soldering pad 2 includes a first split body 21 and a second split body 22 that are arranged opposite to each other and have opposite polarities; the surfaces of the first split body 21 and the second split body 22 are both provided with a solid crystal area 23, and the solid crystal area 23 of the first split body 21 is connected to one electrode 71 of the LED chip 7 through a conductive glue 8, and the solid crystal area 23 of the second split body 22 is connected to the other electrode 71 of the LED chip 7 with opposite polarity through a conductive glue 8.

[0032] Furthermore, the first gap 3 is located between the first split body 21 and the second split body 22 of each pad 2. That is, the pads 2 for connecting two electrodes 71 of the same chip are independently arranged in the present invention to avoid migration of the conductive glue 8 on the same pad.

[0033] Next, at least a portion of the first gap 3 is provided with a groove 4, formed by an inward depression in the surface of the support body 1 supporting the pad 2. When the conductive adhesive 8 in the die-bonding areas 23 migrates toward each other, the groove 4 is located along its migration path, isolating the conductive adhesive 8 in the die-bonding areas 23 on both sides from contacting each other.

[0034] It should be noted that, referring to Figure 2 As shown, a first hydrophobic and oleophobic layer 51 is provided on the surfaces of the groove walls 41 on both sides of the groove 4. The sides of the first and second sub-bodies 21 and 22 connecting to the groove 4 are designed as hydrophilic and oleophobic surfaces, forming a "hydrophilic-oleophilic-hydrophobic-oleophobic" surface wettability difference with the groove walls 41 of the groove 4. This prevents the conductive adhesive 8 from migrating from the pad 2 to the groove 4, reducing the risk of short circuits.

[0035] Preferably, the groove walls 41 on both sides of the groove 4 are set to be flat, so that when the conductive glue 8 overflows, it can be evenly drained into the groove 4. In addition, it is easy to process when setting the first hydrophobic and oleophobic layer 51, and the hydrophobic and oleophobic effect is more uniform.

[0036] Further, refer to Figure 2 As shown, the groove wall 41 is preferably configured as an inclined surface, so that the groove bottom width of the groove 4 is smaller than the groove opening width of the groove 4. Compared with the configuration where the groove wall 41 is perpendicular to the pad 2, the inclined surface has a better drainage effect and facilitates the processing and demolding of the bracket. In other embodiments, the groove walls 41 on both sides of the groove 4 can also be configured as flat or curved surfaces with other inclined angles according to actual needs, without limitation.

[0037] Specifically, refer to Figure 2 As shown, an isolation portion 42 is provided at the bottom of the trench 4. The isolation portion 42 and the groove walls 41 on either side of the trench 4 form mutually isolated receiving areas 43. The groove walls 41 guide overflowing conductive adhesive 8 into the receiving area 43 on one side. The isolation portion 42 physically isolates the conductive adhesive 8 in the receiving areas 43 on both sides, preventing electrical connection between the two areas within the trench 4.

[0038] Further, refer to Figure 2 As shown, the LED chip 7 and the solder pad 2 are arranged relative to each other in the height direction, and the depth direction of the groove 4 is consistent with the relative arrangement direction of the LED chip 7 and the solder pad 2. In the depth direction of the groove 4, the height of the highest point of the isolation portion 42 relative to the groove bottom is h1; in the depth direction of the groove 4, the height of the notch on the bracket body 1 relative to the groove bottom, that is, the depth of the groove 4, is h2.

[0039] When the height of the isolation part 42 is too low, it cannot effectively block the conductive glue 8. The conductive glue 8 climbs on the side of the isolation part 42 and can still contact each other after crossing the isolation part 42, causing a short circuit. Setting h1≥1 / 3h2 ensures that the isolation part 42 has a certain height to block the conductive glue 8 from climbing.

[0040] If the height of the isolation portion 42 is too high, it will not only increase the cost of the bracket, but also easily contact the electrical connection between the chip and the bracket, causing damage. Setting h1 < h2 prevents the isolation portion 42 from interfering with the electrical connection; preferably, setting h1 ≤ 1 / 2h2.

[0041] It should be noted that the isolation portion 42 is arranged in a strip shape along the extension direction of the first gap 3. In the extension direction of the first gap 3, the length of the die-bonding area 23 is shorter than the extension length of the isolation portion 42. The die-bonding area 23 determines the dispensing position of the conductive adhesive 8. By setting the extension length, any conductive adhesive 8 that overflows or migrates from the die-bonding area 23 and enters the accommodation area 43 is blocked by the isolation portion 42.

[0042] Preferably, the accommodating area 43, the die-bonding area 23, and the groove wall 41 of the groove 4 are symmetrically arranged on both sides of the isolation portion 42, and the isolation portion 42 is symmetrically arranged on both sides of the accommodating area 43. The side of the isolation portion 42 is set to a curved surface according to the type and climbing characteristics of the conductive adhesive 8.

[0043] Specifically, refer to Figure 2 As shown, in addition to the first hydrophobic and oleophobic layer 51 provided on the groove wall 41 of the groove 4, a second hydrophobic and oleophobic layer 52 is also provided around the outer edge of the crystal-bonding area 23 of the first and second sub-bodies 21 and 22. The position and shape of the crystal-bonding area 23 are determined by the position of the LED chip 7 and the electrode 71. The crystal-bonding area 23 is glued and configured to have a hydrophilic and oleophobic surface, forming another set of surface wettability differences between the crystal-bonding area 23 and the outer periphery: "hydrophilic and oleophilic - hydrophobic and oleophobic."

[0044] On the one hand, the wettability gradient inside and outside the die-bonding area 23 is used to control and correct the glue liquid position. If the glue liquid is misaligned with the die-bonding area 23, the gradient wettability surface can control the glue liquid, automatically pulling the glue liquid from the second hydrophobic and oleophobic layer 52 to the die-bonding area 23, and confining the conductive glue 8 to the target die-bonding area 23. This improves the stability of glue dispensing and the consistency of the glue point position, shape, and size.

[0045] On the other hand, the conductive glue 8 can be transferred from the hydrophobic and oleophobic treated surface to the hydrophilic and oleophobic surface, but it is difficult to transfer from the hydrophilic and oleophobic surface to the amphiphobic surface. This one-way transmission characteristic can not only improve the consistency of the glue dispensing position, but also inhibit the diffusion or overflow of the glue after correcting the glue dispensing deviation, thereby reducing the risk of short circuit.

[0046] In some embodiments, the first hydrophobic and oleophobic layer 51 can be formed by modifying the original surface to a hydrophobic and oleophobic structure through chemical modification or electron beam bombardment. Alternatively, the first hydrophobic and oleophobic layer 51 can be formed from a fluorocarbon compound, including at least one of fluorinated polyurethane, fluorinated epoxy resin, and fluorinated acrylate. The second hydrophobic and oleophobic layer 52 can be formed by laser micromachining the original surface.

[0047] Specifically, in this embodiment, there are at least two solder pads 2, and a second gap 6 is provided between two adjacent solder pads 2 to provide insulation. The second gap 6 is used to isolate different solder pads 2 connected to different LED chips 7, preventing large-scale failures and isolating conductive adhesive 8 from contacting each other.

[0048] Furthermore, a second gap 6 is formed by the placement of independently positioned solder pads 2 on the surface of the bracket body 1. This second gap 6 prevents cross-talk between different chip light sources. To prevent the effects of conductive adhesive 8 overflow and enhance bracket reliability, an isolation groove can also be provided within the second gap 6. The internal structure of the groove 4 is identical to that of the first gap 3. Example 2

[0049] Reference Figures 3 to 5 As shown, the second embodiment of the present invention provides an LED lamp bead, comprising an LED chip 7, conductive adhesive 8, and the LED bracket provided in the first embodiment. The conductive adhesive 8 is configured as silver adhesive or solder paste. The LED chip 7 is positioned across the first gap 3 to electrically interconnect with the solder pad 2. Electrodes 71 at both ends of the LED chip 7 are connected to the crystal bonding area 23 of the first and second sub-body 21 and 22 of the same solder pad 2, respectively, via the conductive adhesive 8.

[0050] The LED lamp beads provided in Example 2 adopt a flip-chip structure, which can avoid failures caused by lead shielding and desoldering, save metal wire costs, and have higher luminous efficiency and excellent thermal conductivity.

[0051] Especially for TOP type LED lamp beads, it can control and calibrate the dispensing position of the die-bonding glue, which can not only avoid the conductive glue 8 migration and short circuit affecting the display effect of the lamp beads, but also improve the reliability of the die-bonding, avoid the chip from tilting or falling off, and achieve better luminous effect.

[0052] Preferably, in the second embodiment of the present invention, three pads 2 are provided, and the LED chip 7 is provided as an RGB chip, and different colors of lamp bead luminous effects are produced by controlling the brightness and mixing ratio of the red, green, and blue light sources. Of course, the model of the LED chip 7 is not limited thereto. Example 3

[0053] A third embodiment of the present invention provides an LED device, which includes the LED bracket in the first embodiment, or the LED device includes the LED lamp bead in the second embodiment.

[0054] In some embodiments, the LED device includes an LED screen. After wire bonding, the LED beads undergo subsequent processes such as glue dispensing, light splitting, and tape mounting. After completion, the LED beads are arrayed and attached to a module board. A constant current drive circuit simultaneously energizes the polycrystalline chips, illuminating the single-color beads to form an LED display screen.

[0055] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0056] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0057] Unless otherwise specifically stated, the relative arrangement of the parts and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present application. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the drawings are not drawn according to actual proportional relationships. The techniques, methods and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the techniques, methods and equipment should be considered as part of the authorization specification. In all examples shown and discussed here, any specific values ​​should be interpreted as being merely exemplary, not as limitations. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that similar numbers and letters represent similar items in the following figures, and therefore, once an item is defined in one figure, it does not need to be further discussed in subsequent figures.

[0058] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used herein to describe the spatial positional relationship of a device or feature to other devices or features as shown in the figures. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figures. For example, if the device in the drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0059] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of this application.

[0060] The above are only preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may be subject to various modifications and variations. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application should be included in the scope of protection of the present application. The above embodiments are merely examples for clear explanation and are not limitations on the implementation methods. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the present utility model.

Claims

1. An LED bracket, characterized in that: include, Bracket body; A soldering pad fixed to the bracket body; the soldering pad includes a first split body and a second split body arranged opposite to each other and having opposite polarities, and the soldering pad is configured to connect electrodes of different polarities of the LED chip through a conductive adhesive; A first gap is located between the first and second parts of the pad; a groove is provided in the first gap, an isolation portion is provided at the bottom of the groove, and the isolation portion forms mutually isolated accommodation areas with the groove walls on both sides of the groove.

2. The LED bracket according to claim 1, characterized in that: The groove wall surfaces on both sides of the groove are both provided with a first hydrophobic and oleophobic layer.

3. The LED bracket according to claim 2, characterized in that: The groove wall is configured as an inclined surface, and the groove bottom width of the groove is smaller than the groove opening width of the groove.

4. The LED bracket according to claim 1, characterized in that: The height of the isolation portion relative to the bottom of the trench is h1, the depth of the trench is h2, and h1 ≥ 1 / 3 h2.

5. The LED bracket according to any one of claims 1 to 4, characterized in that: The first sub-body and the second sub-body are both provided with a crystal-fixing area, and the crystal-fixing area is used to electrically connect the electrodes of the LED chip; and a second hydrophobic and oleophobic layer is provided around the outer edge of the crystal-fixing area.

6. The LED bracket according to claim 5, characterized in that: In an extending direction of the first gap, a length of the crystal bonding region is smaller than a length of the isolation portion.

7. The LED bracket according to claim 1, characterized in that: There are at least two pads, and a second gap is provided between two adjacent pads.

8. An LED lamp bead, characterized in that: It comprises an LED chip, conductive glue and an LED bracket as described in any one of claims 1 to 7; the bracket body is formed with a reflective cup for accommodating the LED chip, and the LED chip is arranged across the first gap; the electrodes at both ends of the LED chip are respectively connected to the solid crystal area of ​​the first split body and the solid crystal area of ​​the second split body through the conductive glue.

9. The LED lamp bead according to claim 8, characterized in that: There are three solder pads, and the LED chip is an RGB chip.

10. An LED device, characterized in that: It comprises the LED bracket according to any one of claims 1 to 7, or comprises the LED lamp bead according to claim 8 or 9.

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