Alisen Electronic Co., Ltd quality control

AlisenLED display quality management including below processing:

• 1. White balance test of incoming material inspection process (original components, lamp boards, etc.),
• 2. Incoming inspection of cabinets,
• 3, Module aging,
• 4. Aging of finished products,
• 5. Frame screen inspection (indoor frame, outdoor frame),
• 6. Water pouring inspection,
• 7. Finished product inspection,
• 8. Warehousing inspection.

All round strict control to ensure product quality.

The mainly content for Quality Control Attention as below:

1. The assembly plant of anti-static LED display electronic screen shall have good anti-static measures. Special anti-static ground, anti-static floor, anti-static soldering iron, anti-static platform mat, anti-static ring, anti-static clothing, humidity control, equipment grounding (especially foot cutting machine) and other basic requirements, and regular detection with an electrostatic meter.

2. Driver circuit design The layout of the driver IC on the LED display module will affect the brightness of the LED. If the drive IC output current is transmitted too far on the PCB, the voltage drop in the transmission path will be too large, which will affect the normal operating voltage of the LED and cause the brightness to decrease. We often find that the LED brightness around the LED display module is lower than that in the middle, because of this. Therefore, to ensure the consistency of display brightness, it is necessary to design the driver circuit layout.

3. The nominal current of LED with design current value is 20mA. Generally, it is recommended that the maximum current should not exceed 80% of the nominal value. Especially for the display screen with small point spacing, the current value should be reduced due to poor heat dissipation conditions.

4. The LED with the same color and different brightness levels need to be mixed or plugged in according to the light insertion diagram designed according to the discrete law to ensure the consistency of the brightness of each color on the whole screen. If problems occur in this process, the local brightness of the 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 the in-line LED, there should be enough technology to ensure that the LED is perpendicular to the PCB when passing through the furnace. Any deviation will affect the brightness consistency of the LED already set, and there will be color patches with inconsistent brightness.

6. The temperature and time of wave front welding must be strictly controlled. It is recommended that the preheating temperature should be 100 ℃± 5 ℃, not more than 120 ℃, and the preheating temperature should rise steadily. The welding temperature should be 245 ℃± 5 ℃, and the welding time should not exceed 3 seconds. Do not vibrate or shock the LED after passing the furnace, until the normal temperature is restored. The temperature parameters of the wave soldering machine should be detected regularly, which is determined by the characteristics of the LED. Overheating or fluctuating temperature will directly damage the LED or cause potential quality problems, especially for small size round and oval LEDs, such as 3mm.

7. When the LED on the LED display screen is not lit, more than 50% of the probability is caused by various types of faulty soldering, such as LED pin faulty soldering, IC pin faulty soldering, and row pin and row bus faulty soldering. These problems need to be solved by strictly improving the process and strengthening the quality inspection. Vibration test before delivery is also a good inspection method.

8. Heat dissipation design LED will heat up when working, and too high temperature will affect the attenuation speed and stability of LED, so the heat dissipation design of PCB board and ventilation and heat dissipation design of box will affect the performance of LED.