Why does the LCD backlight fail? What are the reasons for the light failure of LCD backlight?

We all know that the life of the LCD lamp is limited, some industrial LCD screen its backlight life can reach 50,000 hours, and the ordinary LCD screen its backlight life can reach 15,000 hours, of course, this life refers to the LCD screen it is in a 24-hour a day non-stop work situation, know people know that the LCD screen backlight light decay is also a gradual decay process, then about LCD LED backlight light decay in fact, there are two main factors, then continue to look down.

LCD LED Light Bar Itself Quality Problems:

1. The use of LED grain quality is not good, the brightness decay faster.

2. There are certain defects in the production process.

LCD Screen Using The Conditions of The Problem:

1. LED for constant current drive, some LEDs use voltage drive reason to make LED attenuation over.

2. The drive current is greater than the rated driving conditions.

In fact, LED strip light decay for many reasons, the key or thermal problems, although many manufacturers in the secondary products do not pay special attention to the issue of heat dissipation, but these secondary LED products under long-term use, the degree of light decay will be higher than the LED products with attention to heat dissipation. LED grain itself thermal resistance, the impact of silver glue, substrate heat dissipation, as well as colloid and gold wire aspects also have a relationship with light decay.

Semiconductor materials have a very interesting characteristic, is the so-called carrier.

Carrier is divided into two categories: one for the electron, negatively charged; the other for the electric hole, with a positive charge.

LCD light-emitting principle is the use of two carriers in certain conditions can be combined, the release of energy in the form of photons released and light.

Therefore, according to the different materials, electrons and holes occupy different energy levels, that is, the relative energy level difference between electrons and holes is to determine the combination of two carriers issued by the energy level, it can produce photons with different energy, which can control the wavelength of light issued by the LED, that is, the spectrum or color. For most of the applications, LEDs are supercharged with direct current.

It has the following characteristics.

Parabolic characteristics: When the DC current has enough positive voltage, the LED current rises rapidly, and this incoming current is. This incoming current is called the "down-biased current" and the voltage across the LED is called the "down-biased voltage". If the voltage range is high and low, it means the quality is abnormal, and usually the shorter the wavelength of the LED, the higher the voltage will be.

Reverse bias characteristics: as the name implies is to give the LED negative voltage, also known as "leakage voltage", in general, different LED materials will have their own reasonable voltage value, and the cause of the reverse voltage characteristics of poor electrostatic discharge, this feature can also be used to assess the quality of this LED. LED's main material is the pn interface, and the gate fluid (Thyristor) is a common electronic power Control components, when its thickness is not uniform, there will be pn level intersection of the situation, when the voltage difference will be a big difference, which is the "gate fluid effect J, and if the voltage difference is too large, it shows that the quality of this product is not very good, so this can also be used to balance the quality of the star LED star. However, generally will not use the gate fluid effect to judge the quality of LEDs, will generally test the VFD of LEDs to determine the VFD less than 0.1V judged as qualified.