The reason why the light-emitting diode lamp beads are discharged
I firmly believe that everyone has basically encountered the situation where the LED beads are powered off, but the factors for power off are different. Some LED bead strings lose electricity due to the inspection after the LED bead strings are packaged, some are caused by long-term placement, some are caused by embrittlement, and some are caused by spot welding. So what is the main reason for the LED string to lose electricity? Today, professional and technical personnel will tell people his personal opinions:
The LED lamp beads are discharged due to ground stress.
The ground stress is caused by the thermal deformation of the material. The raw materials in LED bulbs are different, and the coefficient of linear expansion is also different. In the link where the temperature is constantly changing, the chemical substances cannot recover to the conditions when they first came into contact with each other and maintain a certain degree of ground stress.
But it is not necessarily harmful. Only when the thermal expansion coefficient is very different and the processing technology standard is not suitable, can there be considerable ground stress. This kind of ground stress will seriously crush the integrated ic, cause the integrated ic to be destroyed, cause power failure, and part of the area will be cracked and not lit, or completely lead the way. When the local stress is not very large, it sometimes causes serious harm.
At the beginning, there is a suspension button on the side of the LED lamp bead. The ground stress causes the surface molecules to shift slightly. The electrostatic field of the suspension bond is in an unbalanced state, which causes the electronic energy level at the PN junction of the inner hole to change and discharge electricity.
Wrong operation will cause the LED lamp bead to lose electricity.
This type of situation is very rare. When the LED lamp bead manufacturer increases the higher working voltage to the LED lamp bead, it is likely to destroy the PN junction and cause power failure.
The processing technology is unreasonable, causing cracks in the processor.
The colloidal solution at the bottom of the integrated IC of the light-emitting diode lamp is uneven, or there are cracks under the solder layer, the integrated IC will be destroyed when wiring, resulting in a short circuit or common failures. The unreasonable adjustment of the HMD destroys the integrated IC, resulting in short circuits or common failures.
Fourth, the problem of electrostatic induction.
The problem of electrostatic induction cannot be ignored. Electrostatic induction charging and discharging requires a conductive power supply circuit, which does not mean that electrostatic induction will destroy it. When the light-emitting diode lamp bead has only a small amount of electricity, it can be considered that the electrostatic induction is inadvertently destroyed. If a lot of them are produced, it is more likely to be a problem of integrated IC environmental pollution or ground stress.
If the silver glue is too high, it will cause power failure and partial welding.
In the field of LED lamp bead packaging, it is a common problem that the silver glue is too high and the wire is biased to lead to power loss, which is omitted here.
The integrated ic is destroyed and the power goes out.
It is a very critical phenomenon that the integrated IC is powered off by environmental pollution: the integrated IC of the light-emitting diode is very small, and the dust is easily covered. What is important is that dust, water vapor and various residual positive ions will adhere to the surface of the integrated IC. This will not only harm the surface layer of the LED bead integrated IC, but will continue to spread to the inside of the LED bead integrated IC. For example, iodide ions and potassium ions are very easy to spread into semiconductor devices, and a very small number can severely malign the characteristics of the semiconductor industry.
There is a power-off condition. The LED lamp beads are encapsulated in the casing, and the LED lamp beads are filled with soft glue to prevent moisture. However, it is found that there is a power failure from the wire of the LED lamp bead. After removing the potting glue around the LED lamp beads, the power supply disappeared. That also shows that in fact, it is not that the LED lamp bead is out of electricity, but that there is something wrong with the potting glue.