LED display is widely used in public places, the square is a large screen for the LED screen, with long life, low energy consumption and other characteristics. LED display in the design if not appropriate, will affect the use of the future, this paper summarizes the eight factors in the LED screen design should focus on:
1, Heat dissipation design
LED work will heat, the temperature is too high will affect the decay rate and stability of the LED, so the heat dissipation design of the PCB board, the design of the ventilation and heat dissipation will affect the performance of LED.
2, Mixed lights
The same color different brightness of the LED need to mix lights, or in accordance with the law of the discrete design of the plug in the light of the lamp, in order to ensure the consistency of each screen color brightness. This process if there is a problem, there will be a large screen local brightness inconsistencies, a direct impact on the large LED screen display.
3, Design current value
The nominal current of LED is 20mA, it is recommended that the maximum current is not more than 80% of the nominal value, especially for small spacing of large screen, due to poor thermal conditions, but also to reduce the current value. According to the experience, due to the red, green, blue LED decay rate of inconsistency, targeted to reduce the blue, green LED current value, in order to maintain the consistency of the white screen after a long time to use the screen.
4, Drive circuit design
The drive circuit board driver IC on the large screen module will also affect the brightness of the LED. Due to the drive IC output current in the PCB board transmission distance is too far, it will make the transmission path pressure drop is too large, the impact of the normal operating voltage of LED led to its brightness reduction. We often find that the LED brightness around the big screen module is lower than that in the middle. Therefore, to ensure the consistency of the large screen brightness, it is necessary to design a good driver circuit layout.
5, Control the verticality of the lamp
For in-line LED, there must be sufficient technology to ensure that the LED is perpendicular to the PCB plate during the furnace. Any deviation will affect the LED brightness consistency has been set up, there is a different color brightness.
Big LED screen in the LED does not shine, tend to have more than 50% probability caused by various types of weld, such as the LED pin IC pin weld, weld, weld and base pin row. These problems need to be improved by improving the process and quality inspection. The vibration test before the factory is also a good test method.
7, Wave soldering temperature and time
To strictly control the wave front welding furnace temperature and time, suggestions are: preheating temperature of 100 DEG C – 5 DEG C, the maximum not more than 120 DEG C, and preheating temperature rise for a smooth, welding temperature is 245 DEG C – 5 DEG C, the welding time that no more than 3 seconds after the furnace avoid vibration or shock LED. Until the restoration of the normal state. The temperature parameter of crest welder should be checked regularly, which is decided by the characteristics of LED, overheating or fluctuating temperatures will directly damage the LED or LED caused by quality problems, especially for small size such as round and oval LED 3mm.
Large LED screen assembly factory should have good anti-static measures. Special anti-static, anti-static flooring, anti-static, anti-static soldering pad, anti-static ring, anti-static clothing, humidity control, equipment grounding (especially cutting machine) are the basic requirements, and the use of electrostatic detection instrument regularly. For more LED display information, please continue to visit Optokingdom.com