With the popularization and competition of advertising, the application of full-color LED display has become more and more extensive and has gradually become the mainstream of the development of the society. The full color LED display is not only original and unique, but also can be adjusted at will, and can play video advertising program and fixed lamp box advertising space. So what are the main technical controls of the total color LED display?
1. Anti-static full-color LED display assembly factory should have good anti-static measures. Special anti-static, anti-static floor, antistatic soldering pen, static radio pad, anti-static, anti-static clothing, humidity control, equipment grounding (especially cut foot machine) is the basic requirement, and to use the static all tested periodically.
2. LED with the same color and brightness of the same color should be mixed with lights, or the lights are inserted according to the design of discrete rules to ensure the consistency of the brightness of each color in the whole screen. If there is a problem in this process, the phenomenon of partial brightness of the display will appear, which directly affects the display effect of full color LED display.
3. The drive circuit design of full color LED display module drive IC layout will also affect the brightness of the LED. Because the drive IC output current is too far away from the PCB board, it can reduce the transmission path pressure, which can affect the normal working voltage of the LED and reduce its brightness. We often find that the LED brightness around the full color LED display module is lower than in the middle, which is the reason. Therefore, to ensure the uniformity of the brightness of the display screen, it is necessary to design the distribution diagram of the drive circuit.
4. full-color LED display, virtual welding control when the LED is not bright, often more than 50% probability for the various types of virtual welding, such as LED tube feet virtual welding, IC pin virtual welding, welding and row needle row, etc. The improvement of these problems requires strict improvement of process and quality inspection. The vibration test before the factory is also a good test method.
5. wave soldering temperature and time are required to strictly control the wave crest welding temperature and furnace time, recommended for: preheat temperature 100 ℃ + / - 5 ℃, the highest do not exceed 120 ℃, and the requirement of preheating temperature increasing is smooth, the welding temperature is 245 ℃ + 5 ℃, welding time suggest no more than 3 seconds, after furnace vibration or shock LED of avoid by all means, until the normal temperature state. Crest welder regularly test the temperature of the parameters, this is determined by the characteristics of LED, too hot or fluctuations in temperature can directly damage the LED or LED quality hidden trouble, especially for small size, such as 3 mm, round and oval LED.
6. The heat dissipation design LED will be heated, and the temperature will affect the attenuation speed and stability of the LED. Therefore, the heat dissipation design of PCB plate and the ventilation and cooling design of the box will affect the performance of the LED.
7. design result LED the nominal current of the 20 ma, general advice its maximum current for no more than 80% of the nominal value, especially for display point spacing is small, due to the poor heat dissipation condition, should also reduce the current value. According to experience, due to the inconsistency of red, green, and blue leds, the current value of blue and green leds is reduced to maintain the consistency of white balance after long time use.
8. Control the vertical degree of the lamp for the straight plug-in LED. The technology will be sufficient to ensure that the LED is perpendicular to the PCB board. Any deviation will affect the alignment of the LED brightness that has been set up and the color blocks that are inconsistent in brightness.