Inverted SMD (Surface Mount Device) lamp bead

Abstract

The utility model provides a flip SMD lamp bead which comprises a substrate and at least three light-emitting chips arranged on the front face of the substrate, the two ends of each light-emitting chip are connected with the substrate through first bonding pads respectively, at least two second bonding pads are arranged on the back face of the substrate at intervals, and the second bonding pads are connected with the light-emitting chips through second bonding pads respectively. The side, away from the substrate, of the second bonding pad is connected with a PCB through solder paste, the side, away from the substrate, of the second bonding pad is provided with a groove, and the groove is filled with the solder paste. According to the utility model, the probe can be effectively contacted with the part of the second bonding pad in the groove during light splitting of the lamp bead, the misjudgment rate is reduced, the tinning area of the second bonding pad is increased during surface mounting of the lamp bead, the combinability of the lamp bead and the PCB is improved, the firmness of the lamp bead after surface mounting is improved, and the overall display effect is ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of semiconductors, in particular to a flip-chip lamp bead. Background Art

[0002] With the popularization of the display application market, the market has increasingly higher requirements for the performance parameters of lamp beads.

[0003] In the existing CHIP lamp bead structure, the bottom pad is generally a smooth planar structure. However, since the bottom pad of the lamp bead is always exposed to the outside, it is easy to be contaminated and scratched, which leads to the misjudgment of the lamp bead as failure due to poor probe contact during light separation. In addition, when the lamp bead is mounted, the bottom pad of the flat structure has a limited tinning area, and the lamp bead is less firm after mounting. It is easy to fall off during subsequent use, resulting in the lack of brightness of a single pixel in the LED module, seriously affecting the overall display effect. Utility Model Content

[0004] Based on this, the purpose of the present utility model is to provide a flip-chip lamp bead, which aims to solve the technical problems in the prior art that the bottom solder pad in the lamp bead is a smooth plane structure, the solder pad is easily contaminated and damaged, resulting in the lamp bead being easily misjudged as failure due to poor probe contact during spectrometry, and the bottom solder pad has a limited tinning area during patching, the lamp bead has low firmness after patching, and is easy to fall off.

[0005] The purpose of the present utility model is to provide a flip-chip lamp bead, comprising a substrate and at least three light-emitting chips arranged on the front side of the substrate, wherein the two ends of the light-emitting chips are respectively connected to the substrate through a first soldering pad, and at least two second soldering pads are provided at intervals on the back side of the substrate, and the side of the second soldering pad facing away from the substrate is connected to a PCB board through solder paste, and the side of the second soldering pad facing away from the substrate is provided with a groove, and the groove is filled with the solder paste.

[0006] Compared with the prior art, the beneficial effect of the flip-chip lamp bead of the present invention is that: by setting a groove on the side of the second pad facing away from the substrate, when the second pad is exposed to the outside for a long time, the part of the second pad located inside the groove is not easily contaminated and scratched. When the lamp bead performs light splitting, the probe can effectively contact the part of the second pad located inside the groove, thereby reducing the misjudgment rate; at the same time, when the lamp bead is mounted, the setting of the groove can increase the tin-eating area of the second pad, thereby increasing the bonding between the lamp bead and the PCB board, and improving the firmness of the lamp bead after mounting, so that the lamp bead is not easy to fall off during subsequent use, and can effectively ensure the overall display effect.

[0007] In addition, the flip-chip lamp beads according to the present invention may also have the following additional technical features:

[0008] Furthermore, the solder paste wraps the opposite side surfaces of the two second solder pads.

[0009] Furthermore, the cross section of the groove is arc-shaped, and the depth of the groove is smaller than the thickness of the second pad.

[0010] Furthermore, a back ink layer is provided between the two second pads, and one side of the back ink layer is connected to the back surface of the substrate.

[0011] Furthermore, a front ink layer is provided on the front surface of the substrate, and the front ink layer covers the surface of the first pad at one end away from the light-emitting chip.

[0012] Furthermore, an epoxy layer is provided on the front surface of the substrate, and the epoxy layer covers the surface of the front ink layer, a portion of the surface of the first pad, and the surface of the light-emitting chip, and the top of the epoxy layer is a planar structure.

[0013] Furthermore, the gap between the two first pads at both ends of the light-emitting chip is filled with the epoxy adhesive layer.

[0014] Furthermore, the substrate is made of resin.

[0015] Furthermore, three light-emitting chips are provided on the front surface of the substrate, and the three light-emitting chips are arranged side by side on the substrate at equal intervals. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a cross-sectional structural diagram of the flip-chip lamp bead of the present invention.

[0017] Among them, the above drawings include the following figure marks: 10-substrate; 20-light-emitting chip; 30-first soldering pad; 40-second soldering pad; 41-groove; 50-solder paste; 60-PCB board; 70-front ink layer; 80-back ink layer; 90-epoxy adhesive layer.

[0018] The following specific embodiments will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0019] To facilitate understanding of the present invention, a more comprehensive description of the present invention will be provided below with reference to the accompanying drawings. The drawings illustrate several embodiments of the present invention. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and comprehensive understanding of the present invention.

[0020] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be an intermediate element. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only.

[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains. The terms used herein in the specification of this invention are intended only to describe specific embodiments and are not intended to limit the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0022] See also Figure 1 The utility model provides a flip-chip lamp bead, comprising a substrate 10 and at least three light-emitting chips 20 arranged on the front side of the substrate 10, wherein the two ends of the light-emitting chip 20 are connected to the substrate 10 through a first soldering pad 30 respectively, and at least two second soldering pads 40 are provided at intervals on the back side of the substrate 10. The side of the second soldering pad 40 facing away from the substrate 10 is connected to the PCB board 60 through solder paste 50, and a groove 41 is provided on the side of the second soldering pad 40 facing away from the substrate 10, and the groove 41 is filled with a part of the solder paste 50, and the solder paste 50 wraps the opposite side of the two second soldering pads 40. It can be understood that after the solder paste 50 located in the groove 41 is cured, it can form a rivet structure shape, thereby effectively increasing the bonding between the lamp bead and the PCB board 60, making it less likely for the lamp bead to be dimmed due to falling during subsequent use.

[0023] Specifically, in this embodiment, three light-emitting chips 20 are provided on the front of the substrate 10. The three light-emitting chips 20 are arranged side by side on the substrate 10 at equal intervals. The two ends of each light-emitting chip 20 are connected to the front of the substrate 10 via a first soldering pad 30. Four second soldering pads 40 are provided on the back of the substrate 10. The four second soldering pads 40 are evenly spaced and arranged on both sides of the back of the substrate 10. Each second soldering pad 40 has a groove 41 on the side facing away from the substrate 10. The groove 41 is a circular groove 41 with an arc-shaped cross-section. The groove depth of the groove 41 is less than the thickness of the second soldering pad 40. In actual use, the groove 41 can be formed by punching the second soldering pad 40 on the side facing away from the substrate 10 using an impact technique.

[0024] Furthermore, a back ink layer 80 is provided between the two second solder pads 40. One side of the back ink layer 80 is connected to the back side of the substrate 10. A front ink layer 70 is also provided on the front side of the substrate 10. The front ink layer 70 covers the surface of the first solder pad 30 at the end away from the light-emitting chip 20. The back ink layer 80 and the front ink layer 70 are provided to cover the wiring on the substrate 10, thereby reducing the exposed area of the wiring and effectively improving the contrast of the packaged lamp bead.

[0025] Furthermore, an epoxy layer 90 is provided on the front surface of the substrate 10, which covers the surface of the front ink layer 70, part of the surface of the first pad 30, and the surface of the light-emitting chip 20. The top of the epoxy layer 90 is a planar structure.

[0026] Furthermore, the gap between the two first pads 30 at both ends of the light-emitting chip 20 is filled with an epoxy layer 90. It can be understood that by filling the gap with epoxy, the contact area between the epoxy layer 90 and the substrate 10 can be enhanced, making the bonding between the two stronger.

[0027] Furthermore, the substrate 10 is made of resin, which can make the substrate 10 more flexible, thereby better preventing the light-emitting chip 20 from burning due to a short circuit, thereby increasing the service life of the lamp bead.

[0028] In summary, the beneficial effect of the flip-chip lamp bead of the present invention is that: by setting a groove on the side of the second pad facing away from the substrate, when the second pad is exposed to the outside for a long time, the part of the second pad located inside the groove is not easily contaminated and scratched, and when the lamp bead performs light splitting, the probe can effectively contact the part of the second pad located inside the groove, thereby reducing the misjudgment rate; at the same time, when the lamp bead is patched, the setting of the groove can increase the tin-eating area of the second pad, thereby increasing the bonding between the lamp bead and the PCB board, and improving the firmness of the lamp bead after patching, so that the lamp bead is not easy to fall off during subsequent use, and can effectively ensure the overall display effect.

[0029] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0030] The above-described embodiments merely represent several implementation methods of the present invention. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make various modifications and improvements without departing from the spirit of the present invention, and these modifications and improvements fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A flip chip lamp bead, characterized in that: The invention comprises a substrate and at least three light-emitting chips arranged on the front side of the substrate, wherein the two ends of the light-emitting chip are connected to the substrate through a first soldering pad respectively, and at least two second soldering pads are provided on the back side of the substrate at intervals, and the side of the second soldering pad facing away from the substrate is connected to a PCB board through solder paste, and the side of the second soldering pad facing away from the substrate is provided with a groove, and the groove is filled with the solder paste.

2. The flip chip lamp bead according to claim 1, characterized in that: The solder paste wraps the opposite side surfaces of the two second solder pads.

3. The flip chip lamp bead according to claim 1, characterized in that: The cross section of the groove is arc-shaped, and the depth of the groove is smaller than the thickness of the second pad.

4. The flip chip lamp bead according to claim 1, characterized in that: A back ink layer is provided between the two second pads, and one side of the back ink layer is connected to the back surface of the substrate.

5. The flip chip lamp bead according to claim 1, characterized in that: A front ink layer is further provided on the front surface of the substrate, and the front ink layer covers the surface of the first pad at one end away from the light-emitting chip.

6. The flip chip lamp bead according to claim 5, characterized in that: An epoxy adhesive layer is further provided on the front surface of the substrate, and the epoxy adhesive layer covers the surface of the front ink layer, a portion of the surface of the first solder pad, and the surface of the light-emitting chip. The top of the epoxy adhesive layer is a planar structure.

7. The flip chip lamp bead according to claim 6, characterized in that: The gap between the two first pads at both ends of the light emitting chip is filled with the epoxy adhesive layer.

8. The flip chip lamp bead according to claim 1, characterized in that: The substrate is made of resin.

9. The flip chip lamp bead according to claim 1, characterized in that: Three light-emitting chips are arranged on the front of the substrate, and the three light-emitting chips are arranged side by side on the substrate at equal intervals.

Images