News

Detailed Explanation of LED Display And LED Packaging Method

　With the rapid development of LED display technology, its dot pitch is getting smaller and smaller. LED packages have continued from 3528, 2020, 1515, 1010, 0505 to smaller sizes to meet high-density needs, and become a hot product in the LED industry. High-density LEDs have four development trends: high pixel density, high scan ratio, high refresh rate, and high gray level. High-density LEDs can be used to combine concepts such as touch, naked-eye 3D, smart applications, cloud broadcast control, etc., and Meihong Electronics has also expanded the application fields of LED displays.

　　 At present, the small-pitch LED display market has great potential. The small-pitch LED display has the characteristics of seamless, low energy consumption, long life, and excellent display effect. With the continuous improvement of light efficiency and the continuous maturity of integrated control technology, the small-pitch LED display will gradually replace the original DLP and LCD. The spatial scale of the market is also expanding.

　　 But the three major bottlenecks of small-pitch LED display, large-resolution loading, and splicing gap restrict the development of LED display. At the same time, the spacing of high-density LED display screens is getting smaller and smaller, and the heat dissipation problem is also highlighted, which seriously affects its color uniformity and display life. In order to solve the heat dissipation problem of high-density LED display, we propose a new packaging method in this article, which can effectively solve the problems of heat dissipation and mounting difficulties.

　　1. Traditional packaging method

　　The traditional display is to mount the driver integrated circuit (IC) on one side of the printed circuit board (PCB), and mount the lamp body on the other side, and drive the lamp body to emit light through a constant current chip. Whether the layout of the constant current chip is reasonable or not directly affects the display effect of the display screen, and the generated heat affects the normal light-emitting characteristics of the LED; and then affects the color uniformity of the entire display screen. In addition, the miniaturization of the LED lamp body size will cause difficulties in the mounting process and rework of the surface mount packaging technology. In addition to the smaller and smaller pixel pitch of high-density displays, the output pins of constant current chips have also increased. The heat dissipation problem has become an urgent problem that needs to be solved. Poor heat dissipation will cause uneven heat of the screen, which will affect the uniformity and life of the display. .

　　 LED package 1515, 2020, 3528 lamp body, the pin shape adopts J or L package. NationStar’s 1010 and Jingtai’s 0505 are both in a quad flat no-lead package (QFN). QFN is a new type of surface mount packaging technology with small pad size, small volume, and plastic as the sealing material. The heat of the chip in the package is released through the exposed lead frame and the pad with direct heat dissipation channel, which has excellent heat dissipation performance. At the same time, since the conductive path between the internal pin and the pad is short, the self-inductance and the wiring resistance in the package are very low, so it can provide good electrical performance, and the overall electromagnetic interference is small. However, the solder joints are completely at the bottom, and the entire device needs to be removed for repair, which is difficult for high-density LED displays.

　　2. New packaging method

In order to solve the two difficulties of heat dissipation and repair difficulties in traditional packaging methods, this paper proposes a new packaging method that can effectively solve these problems and greatly improve the reliability of the product, making it possible to arrange extremely high-density pixel LEDs. . In summary, the law of LED technology development is that it can withstand greater current drive on a smaller LED chip area, and obtain better luminous flux and thinner characteristics, so as to obtain better performance.