In the process of use, it is often encountered that the LED light does not light up, which is commonly referred to as the dead light phenomenon. There are two reasons: First, the leakage current of the LED is too large, causing the PN junction to fail, so that the LED light does not light up, which generally does not affect the work of other LED lights; second, the internal connection of the LED lights The lead is disconnected, causing no current to pass through the LED, resulting in a dead lamp. This situation will affect the normal operation of other LED lamps. The reason is that the working voltage of the LED lamp is low. Generally, series and parallel are used to adapt to different working voltages. The more LED lights in series, the greater the impact. As long as one of the LED lights has an open circuit, the entire string of LED lights in the series circuit will not light up. It can be seen that this situation is more serious than the first situation.

  LED dead lights are the key to affecting product quality and reliability. How to reduce and eliminate dead lights is a key problem that packaging and application companies need to solve. The following is an analysis of the causes of dead lights.

  1. Static electricity causes damage to LED chips. Static electricity is extremely harmful and has caused huge economic losses. Therefore, preventing static electricity from damaging electronic components is a very important job in the electronics industry. In the LED packaging production line, all kinds of equipment must be grounded, and the grounding resistance must meet the requirements. Generally, the grounding resistance is required to be 4Q. In some cases with high requirements, the grounding resistance must be equal to or equal to 2Qo. If the packaging company does not strictly follow the grounding regulations , it will cause the product qualification rate to drop and reduce the economic benefits of the enterprise. Similarly, if the equipment and personnel are poorly grounded in companies that apply LEDs, the LEDs will also be damaged. According to the requirements of the LED standard manual, the lead of the LED should be bent or welded at a distance of not less than 3-5mm from the gel, but most application companies have not done this, which will also cause damage or damage to the LED, because it is too high. The soldering temperature will affect the chip, make the chip characteristics worse, reduce the luminous efficiency, and even damage the LED. Some small companies use manual soldering, using a 40W ordinary soldering iron, and the soldering temperature cannot be controlled, and the soldering iron temperature is generally 300 --- 400 Above ℃, too high soldering temperature will also cause dead lamp oLED leads to have a higher expansion coefficient at high temperature than that at about 150℃, and the internal gold wire solder joints will be welded due to excessive thermal expansion and contraction. Click to open, resulting in a dead light phenomenon.