In today's rapidly evolving society, the application of outdoor LED large screens is expanding, yet the quality varies greatly, leading to frequent accidents. So, how can we determine the quality of outdoor LED screens?
In LED display screens, the quality of the LED beads is crucial, as they significantly affect the overall quality of the screen. LED beads are a key component used in large quantities across the entire full-color screen, with thousands to tens of thousands of beads per square meter. They are the main determinant of the screen's optical display performance, directly influencing viewers' evaluations. Moreover, the proportion of beads in the total cost of the screen can range from 30% to 70%, making their importance immediately apparent.
In the LED display field, brightness is a crucial index. Under high brightness requirements, heat dissipation becomes a significant issue. Heat dissipation has long been a concern in the LED industry, affecting both lighting and display. Major manufacturers are releasing their own heat dissipation solutions, declaring their products' heat dissipation performance as a key criterion. Another reason is that with the development of close-spaced LED, the issue of junction temperature remains unresolved.
How to distinguish the quality of LED display chips?
One: Look at the brightness, which is typically referred to as how many LM (lumens) your LED beads can reach. Lumens are the unit used to measure the brightness of LED beads.
Two: Check for even light emission and consistent color. High-quality LED beads emit light evenly and have a uniform color. Poor-quality LED beads may exhibit some beads being brighter while others are dimmer, with a chaotic and inconsistent color pattern and noticeable dark spots.
Three: Observe the chip and its size; the chip is a deciding factor for the quality of the LED beads. Generally, the larger the chip, the stronger the stability, the brighter the light, and the better the heat dissipation.
Four: Examine the glue and phosphor. High-quality products generally use imported glue, with encapsulated LED chips remaining shapeless under hand pressure. Low-quality glue will deform or even crack upon gentle pressure.
Five: Regarding the bracket, typically it is made of silver-plated red copper. The advantage of silver-plated red copper is its fast heat dissipation, which better cools the light beads and has low resistance. Some merchants on the market may use ceramic brackets as a substitute for the silver-plated red copper brackets, as ceramic brackets also possess excellent heat conductivity.
Six: When examining the encapsulation process, high-quality LED beads have even color and consistent gel. This cannot be achieved without good machinery and equipment; the production of machinery and equipment is a crucial factor. Good equipment ensures stability and consistency throughout all production stages, safeguarding the yield of high-quality products.
In reality, it's all about the LED chip, as it directly determines the color rendering index, brightness, and resistance to fading.
In high junction temperatures, optical attenuation in chips becomes extremely severe. The thermal contact is the substrate, and its thermal conductivity directly determines the junction temperature. Among major well-known manufacturers, some have already started using new ceramic materials as substrate.
Ceramic substrates, currently the best heat-dissipating substrates on the market, offer superior thermal conductivity and stability compared to aluminum, silicon, and sapphire substrates. The primary types of ceramic substrates are aluminum nitride and aluminum oxide, with the thermal conductivity of aluminum nitride reaching up to 170(W/(m·K)~230(W/(m·K)), more than double that of aluminum oxide substrates. This level of thermal efficiency ensures that LED beads do not generate junction temperatures, eliminating heat dissipation issues.
