Full-color LED display research based on chip on board(COB) package

Abstract

LED display industry has entered an integrated period with the characteristics of more mature technology of every aspect and higher demand for the quality of LED display. LED display are developing in the direction of the high resolution, high density, small pixel pitch, intelligent. So the demand for the LED display screen manufacturing technology, especially the LED display module package is higher and higher, the pixel pitch of current LED display are below 2.5 mm(P2.5), some can reach P2, P1.5, P1.0 and even less. However, the current LED display with high definition and small pixel pitch used reflow soldering to mount surface mounted device three-in-one onto the printed circuit board. It's mature and widely used to manufacture LED display by this way, but there are many problems by using these discrete LED components to manufacture the LED display of high density, such as the poor reliability, the bad yield and the heat dissipation problem. Described in this paper, a new integrated packaging method called COB package-mounting the LED chips directly to the module substrate, and then doing the whole molding, will reduce the process and manufacturing cost greatly, improve the reliability and show better picture quality. COB packaging method will be a trend of LED display package in the future.