In today's increasingly widespread application of LED display screen, in order to make the use of display screen more efficient, application enterprises should have the basic knowledge of maintenance of LED display screen. Whether it is indoor or outdoor LED display, heat will be generated in the process of operation, which will lead to the increase of the temperature of the LED display. But what's the effect of the display screen on the working condition at high temperature, do you know? Let's analyze it.

     Usually, the indoor LED display can naturally dissipate heat because of its low brightness, but the outdoor LED display needs air conditioning or axial flow fan to dissipate heat because of its high brightness and high heat. Because the LED display is an electronic product, the rise of temperature will affect the light decay of the LED display lamp beads, the working efficiency of driving IC, the service life of the LED display, and so on.

     Opening and Failure of LED Display Screen

     When the working temperature of the LED display exceeds the load-bearing temperature of the chip, the luminous efficiency of the LED display will decrease rapidly, resulting in obvious light decay and damage. Most of the LED display screens are encapsulated with transparent epoxy resin. If the junction temperature exceeds the solid phase transition temperature (usually 125 C), the encapsulation material will change to rubber shape and the thermal expansion coefficient will be abrupt. Lift, resulting in open circuit and failure of LED display. High temperature will affect the light decay of display LED screen

     The lifetime of the LED display is shown by its light decay, that is, the brightness becomes lower and lower as time goes on until * goes out. Usually, the lifetime of LED display is defined as the time when the luminous flux decreases by 30. High temperature is the main cause of LED display light decay and shorten the life of LED display. Different brands of LED display have different light fading. Usually the manufacturers of LED display will give a set of standard light fading curve. The luminous flux attenuation caused by high temperature is irreversible. The luminous flux before the irreversible luminous attenuation does not occur in the LED display screen, which is called the "initial luminous flux" of the LED display screen.

     Increased temperature will reduce the luminous efficiency of the LED screen

     With the increase of temperature, the concentration of electrons and holes increases, the bandgap width decreases and the electron mobility decreases; with the increase of temperature, the radiation recombination probability of electrons and holes in potential well decreases, resulting in non-radiation recombination (heat generation), which reduces the internal quantum efficiency of LED display screen; with the increase of temperature, the blue wave peak of the chip moves towards long wave. Direction offset, which makes the emission wavelength of the chip mismatch with the excitation wavelength of phosphor, will also result in the decrease of the external light extraction efficiency of white LED display; with the increase of temperature, the quantum efficiency of phosphor decreases, the light output decreases, and the external light extraction efficiency of LED display decreases; the performance of silica gel is greatly affected by environmental temperature. With the increase of temperature, the thermal stress inside the silica gel increases, which leads to the decrease of the refractive index of the silica gel, thus affecting the light efficiency of the LED display screen.

Source: Shangxian World