Eight LED quality assurance technologies and daily maintenance methods

From the display technology, LCD is a display screen composed of liquid crystals, while LED is a display screen composed of light-emitting diodes. Each pixel unit in the LED digital display is a light-emitting diode. If it is monochrome, it is generally a red light-emitting diode. Let's take a look at the eight major technologies of LED quality assurance and daily maintenance methods.

Eight major technologies of LED quality assurance

To produce a good quality LED display screen, it is necessary to do a good job of technical control in the following aspects:

1. Anti-static LED display assembly factory should have good anti-static measures. Special anti-static ground, anti-static floor, anti-static soldering iron, anti-static mat, anti-static ring, anti-static clothing, humidity control, equipment grounding (especially foot cutting machine) are all basic requirements, and they must be regularly tested with an electrostatic meter.

2. Drive circuit design The arrangement of the driver IC on the driver circuit board of the LED display module will also affect the brightness of the LED. Because the output current of the driver IC is transmitted over a long distance on the PCB board, the voltage drop of the transmission path will be too large, affecting the normal working voltage of the LED and causing its brightness to decrease. We often find that the brightness of the LEDs around the LED display module is lower than that in the middle, which is the reason. Therefore, to ensure the consistency of the brightness of the display screen, it is necessary to design a good drive circuit distribution diagram.

3. Design current value The nominal current of the LED is 20mA. It is generally recommended that its maximum current should not exceed 80% of the nominal value. Especially for display screens with very small dot spacing, the current value should be reduced due to poor heat dissipation conditions. According to experience, due to the inconsistency of the attenuation speed of red, green and blue LEDs, the current values ​​of blue and green LEDs are targeted to maintain the consistency of the white balance of the display screen after long-term use.

4. Mixed lights LEDs of the same color but different brightness levels need to be mixed, or plugged in according to the plug-in diagram designed according to discrete rules to ensure the consistency of the brightness of each color of the entire screen. If there is a problem with this process, the brightness of the local display screen will be inconsistent, which will directly affect the display effect of the LED display screen.

5. Control the verticality of the lamp For direct-plug LEDs, there must be sufficient process technology to ensure that the LED is perpendicular to the PCB board when passing through the furnace. Any deviation will affect the brightness consistency of the already set LEDs, resulting in color blocks with inconsistent brightness.

6. The temperature and time of wave soldering must be strictly controlled. The recommended temperature is: preheating temperature 100℃±5℃, the maximum temperature should not exceed 120℃, and the preheating temperature should rise steadily. The welding temperature is 245℃±5℃. The welding time is recommended not to exceed 3 seconds. After the furnace, do not vibrate or impact the LED until it returns to normal temperature. The temperature parameters of the wave soldering machine should be checked regularly, which is determined by the characteristics of the LED. Overheating or fluctuating temperature will directly damage the LED or cause quality risks for the LED, especially for small-sized circular and oval LEDs such as 3mm.

7. Control of cold soldering When the LED display screen does not light up, there is often a probability of more than 50% that it is caused by various types of cold soldering, such as cold soldering of LED pins, cold soldering of IC pins, cold soldering of pin headers and motherboards. The improvement of these problems requires strict improvement of the process and strengthening of quality inspection. Vibration test before leaving the factory is also a good inspection method.

8. Heat dissipation design LED will generate heat when working. Excessive temperature will affect the attenuation speed and stability of LED. Therefore, the heat dissipation design of PCB board and the ventilation and heat dissipation design of the box will affect the performance of LED.

Collection of daily maintenance methods for LED

With the full launch of LED backlight LCD monitors in the market, many consumers often ignore the daily maintenance and care of LED backlight LCD monitors. Such long-term use will not only affect the user's visual experience, but also greatly reduce the life of the monitor.

The increase in the use of LED LCD monitors is due to the fact that major manufacturers have reduced the workmanship and materials of the products in order to control production costs, resulting in the premature aging of a few accessories of some products; on the other hand, it is caused by improper user habits. In particular, the latter situation is more common, and most users do not know how to properly use and maintain LED LCD monitors. Next, we will give you a brief introduction to the application and maintenance of LED backlight LCD monitors.
Broken screen problem

To avoid possible problems, we can choose passive protection and active protection. Passive protection means that users in some public places such as Internet cafes and dormitories can choose to buy monitors with tempered glass, which can make your display screen "invulnerable to swords and guns, water and fire", but it will affect the color of the display and there will be reflections; while active protection means that you should be extra careful in normal use, try to keep objects that may cause damage to the screen away from the screen, and wipe the screen as gently as possible when cleaning it to minimize the possibility of damage.

Maintain the humidity of the environment

All users who have damaged their keyboards by spilling drinks on them know this common sense. Don't let anything with moisture enter your LED display. If you find fog, wipe it gently with a soft cloth before turning on the power. If moisture has entered the inside of the display, you must place the display in a warmer and drier place to allow the moisture and organic compounds in it to evaporate. Powering on a humid LCD display can cause corrosion of the liquid crystal electrodes, which in turn causes permanent damage.

Daily maintenance

LCD monitors have the closest relationship with our users, so it is very necessary to do a good job of cleaning and sanitation. In fact, LCD monitors are also very easy to get dirty. The white appearance is indeed beautiful, but if you don't pay attention to maintenance, it will soon turn slightly yellow; the piano paint is indeed very good, but after a week of use, the shell must be covered with fingerprints; even if it is an ordinary black matte material, after a period of time, the screen must be dusty. Many users know that they need to clean LED monitors regularly, but do you know how to clean LCDs correctly?

You should first consider buying a cleaning kit with better quality. The cost of cleaning fluid generally includes electrolyte, high-purity distilled water, antistatic fluid, etc., which can effectively clean the dust, fingerprints and other stains on the screen. You can buy some well-known brands of products. And a good cleaning cloth is also very particular. It must be a product made of ultra-fine fibers. Generally, the glasses cloth given by high-end glasses can also be used as a cleaning cloth.

Some people think that clean water is also OK, and it will not damage the LCD screen. However, the cleaning effect of clean water is relatively poor, and the dust will adhere again after cleaning. Of course, if you want to save money, you can use clean water, which is better than those cleaning fluids of unknown origin. At the same time, it should be noted that you must not spray water on the screen, but spray a small amount of cleaning fluid on the cleaning cloth, and then gently wipe it in the same direction. Before cleaning, you need to unplug the power cord.

For most LED backlight monitors, their most vulnerable part is the screen. The hardness of the general screen is below 3H (the hardness of the pencil lead). If you don't pay attention to it during normal use, it is easy to be "accidentally injured" by other devices, and once the screen is damaged, it means that this LED monitor is basically scrapped.