Highly reliable PCB package structure

Abstract

The utility model relates to LED display technical field discloses a high reliability's PCB package structure, including PCB board, even distribution is provided with a plurality of ink hole in the PCB board, is provided with the PCB pad in the bottom four -quarter of ink hole, the ink hole is filled with ink, the bottom of ink hole is covered with ink cover, ink cover is connected with the ink in the ink hole, and its edge is connected with the PCB pad, the utility model avoids that the glue pollutes the pad.

Description

Technical Field

[0001] This utility model relates to the field of LED display technology, and in particular to a highly reliable PCB packaging structure. Background Technology

[0002] In traditional LED packaging structures, the PCB board is a crucial component, consisting of a circuit board substrate and LED chips mounted on it via soldering. Each pixel has four solder pads, which play a key role in circuit connection. Individual LEDs are interconnected through vias filled with ink to ensure electrical insulation and maintain structural stability. After via filling, the entire assembly is separated into individual LED devices through a dicing process. With the front and back circuitry completed through the ink-filling process, the basic fabrication of the PCB board is finished.

[0003] However, problems arise during the reflow soldering process. Reflow soldering uses a specific heating environment to remelt the pre-applied solder paste on the PCB pads, thus establishing a mechanical and electrical connection between surface mount components and the PCB pads. During reflow soldering, due to the principle of thermal expansion and contraction, gaps appear between the ink and the hole walls. When subsequent potting operations are performed, some adhesive seeps through these gaps and into the back of the PCB through the vias. Since the back of the PCB has four pads, if adhesive contaminates these pads, it severely affects their electrical performance, causing the LEDs to malfunction and ultimately leading to LED failure. Utility Model Content

[0004] In view of this, the purpose of this utility model is to provide a highly reliable PCB packaging structure to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, this utility model adopts the following technical solution:

[0006] A high-reliability PCB packaging structure includes a PCB board with a plurality of ink plug holes evenly distributed on the PCB board. PCB pads are arranged around the bottom of the ink plug holes. The ink plug holes are filled with ink. The bottom of the ink plug holes is covered with an ink cap. The ink cap is connected to the ink in the ink plug hole, and its edge is connected to the PCB pads.

[0007] Furthermore, the ink plugging hole includes an upper plugging hole and a lower plugging hole that are interconnected and coaxial, wherein the diameter of the upper plugging hole is smaller than the diameter of the lower plugging hole.

[0008] Furthermore, a dike is provided on the top of the PCB board around the ink plug holes.

[0009] Furthermore, the cofferdam is made using solder resist ink.

[0010] Furthermore, the cofferdam is composed of a bottom layer and a surface layer set on top of the bottom layer. The bottom layer uses solder resist ink with added glass microspheres, and the surface layer uses solder resist ink with added nano-Al2O3.

[0011] Furthermore, the top of the lower plug hole is provided with one or more annular connecting grooves at intervals, and the ink filling the lower plug hole fills into the connecting grooves.

[0012] Furthermore, the longitudinal cross-section of the connecting groove has a trapezoidal structure that is smaller at the top and larger at the bottom.

[0013] Beneficial effects

[0014] Compared to existing technologies, this invention offers at least the following advantages: The ink-filled vial features a stepped structure formed by connecting an upper and lower plug hole, resulting in a stepped adhesion between the ink and the via wall, structurally reducing the probability of gaps between the ink and the via wall. The connecting groove design enhances the bonding strength between the ink and the via wall, further preventing adhesive from seeping through the via wall. The dam design adds a barrier to the adhesive at the top of the ink-filled vial, while the ink cap covers the bottom of the vial, its edge connecting to the PCB pads. This prevents adhesive from contacting the pads through any gaps at the bottom of the vial. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the bottom structure of this utility model.

[0016] Figure 2 This is a schematic diagram of the top structure of this utility model.

[0017] Figure 3 This is a cross-sectional structural diagram of one embodiment of the present invention.

[0018] Figure 4 This is a cross-sectional structural diagram of another embodiment of the present invention.

[0019] Figure 5 This is a partial cross-sectional structural diagram of another embodiment of the present invention.

[0020] The diagram is labeled as follows: 1-PCB board; 2-PCB pad; 3-Ink plug hole; 30-Upper plug hole; 31-Lower plug hole; 4-Ink cap; 5-Dyke; 6-Connecting groove. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this utility model clearer, a detailed description is provided below in conjunction with the accompanying drawings and specific embodiments. Many specific details are set forth in the following description to provide a full understanding of this utility model. However, this utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed below.

[0022] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly on the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0024] See Figures 1-5 This embodiment provides a highly reliable PCB packaging structure, including a PCB board 1. A plurality of ink plug holes 3 are uniformly arranged on the PCB board 1. PCB pads 2 are arranged around the bottom of the ink plug holes 3 on the back side of the PCB board 1. The ink plug holes 3 are filled with ink. The bottom of the ink plug holes 3 is covered with an ink cap 4. The ink cap 4 is connected to the ink in the ink plug holes 3, and its edge is connected to the PCB pads 2.

[0025] In this embodiment, the ink plugging hole 3 includes an upper plugging hole 30 and a lower plugging hole 31 that are interconnected and coaxial. The diameter of the upper plugging hole 30 is smaller than that of the lower plugging hole 31, resulting in a stepped structure within the ink plugging hole 3. By connecting the upper plugging hole 30 and the lower plugging hole 31 to form a stepped structure, the ink adheres to the hole wall on a stepped surface, structurally reducing the probability of gaps between the ink and the hole wall.

[0026] The top of the PCB board 1 has a surrounding dam 5 around the ink plug holes 3. The surrounding dam 5 is made of solder resist ink. Preferably, the surrounding dam 5 consists of a bottom layer and a surface layer on top of the bottom layer. The bottom layer uses solder resist ink with added glass microspheres, and the surface layer uses solder resist ink with added nano-Al2O3 to improve hardness and prevent scratches.

[0027] In this embodiment, the top edge of the lower plug hole 31 is provided with one or more annular connecting grooves 6 at intervals. The longitudinal cross-section of the connecting groove 6 is a trapezoidal structure with a smaller upper opening and a larger lower opening. The ink filling the lower plug hole 31 fills into the connecting groove 6. The structural design of the connecting groove 6 improves the bonding strength between the ink and the hole wall, further preventing adhesive from seeping through the gaps in the hole wall.

[0028] In the technical solution of this embodiment, preferably, the ink filling the ink plug 3 is mixed with a small amount of thermally expanding microspheres. At low temperature, the microspheres shrink and do not affect the initial bonding; at high temperature, the microspheres expand and actively fill the gap caused by the shrinkage of the ink and PCB, and offset the loosening between the ink and the hole wall caused by thermal stress.

[0029] The above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. A high-reliability PCB packaging structure, characterized in that, The invention includes a PCB board, on which multiple ink plug holes are evenly distributed. PCB pads are arranged around the bottom of the ink plug holes. The ink plug holes are filled with ink. The bottom of the ink plug holes is covered with an ink cap. The ink cap is connected to the ink in the ink plug hole, and its edge is connected to the PCB pad.

2. The high-reliability PCB packaging structure according to claim 1, characterized in that, The ink plugging hole includes an upper plugging hole and a lower plugging hole that are interconnected and coaxial, wherein the diameter of the upper plugging hole is smaller than the diameter of the lower plugging hole.

3. A high-reliability PCB packaging structure according to claim 1 or 2, characterized in that, The top of the PCB board has a dike around the ink plug holes.

4. The high-reliability PCB packaging structure according to claim 3, characterized in that, The cofferdam was made of solder resist ink.

5. A high-reliability PCB packaging structure according to claim 2, characterized in that, The top of the lower plug hole is provided with one or more annular connecting grooves at intervals, and the ink filling the lower plug hole fills into the connecting grooves.

6. A high-reliability PCB packaging structure according to claim 5, characterized in that, The longitudinal cross-section of the connecting groove has a trapezoidal structure that is smaller at the top and larger at the bottom.

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