From a technical point of view, the outdoor LED display was originally in-line type, the lamp beads of the three colors of RGB are independent. Surface mount (SMD) LED display can only be widely used indoors. With the development of the lamp beads packaging technology and also to solve the shortcomings of in-line lamps as full-color outdoor LED displays, outdoor surface mount lamp beads have gradually replaced in-line lamps. The development of packaging technology has made surface mount displays not limited to indoors that nowadays most outdoor LED displays adopt the surface mount type, and the technological development is also changing with each passing day.
The process of potting is to inject liquid epoxy resin into the LED molding cavity first, then insert the pressure-welded LED bracket, put it in an oven to cure the epoxy resin, and then release the LED from the mold cavity. Due to the relatively simple manufacturing process and low cost, it has a high market share in the early stage of development. The in-line type is larger in size and can be operated by manual plug-ins or AI machines. Due to the high brightness of in-line LEDs, it is easy to do waterproof treatment. The glue is poured through a glue filling machine,it is generally used for the light source of outdoor LED displays; such outdoor full color LED displays are widely adopted in projects such as LED mesh displays, traffic information screens and outdoor full-color information screens in service areas.
Application of in-line LED outdoor display (Image source: SANSI)
The surface mount LED is attached to the surface of the circuit board, suitable for SMT processing, reflow soldering, and it tackles the problems of brightness, viewing angle flatness, reliability and consistency, etc., using lighter PCB board and reflective layered materials; The display reflective layer needs to be filled with less epoxy resin and is lighter in weight. Surface mount LEDs are generally used as light sources for large indoor LED screens, but with technological breakthroughs, the brightness of surface mount LEDs has been greatly improved, and the waterproof treatment can also be well resolved. It is widely applied in indoor conference activities, stadiums, outdoor media advertising, large screen display in buildings and other scenarios.
Outdoor LED display, as one of the important communication medium, is still full of vitality in modern cities. According to market demands, outdoor displays with intelligent high-definition and brightness control will be very popular. Therefore, we need to have a unique vision and use different packaging technologies according to different application scenarios.
In-line and surface mount as two packaging technologies, there is no much distinction between the two. What is suitable is good, and the appropriate packaging technology should be selected according to the actual needs and application scenarios of the project. Only by making good use of the technical characteristics of the two packaging technologies, can it better serve the customers.