LED full color display: attractive market prospects for the design process is soft rib

China's LED (light-emitting diode) display industry was first started in 1987, after nearly 20 years of common development, has a considerable scale. At present, more and more manufacturers of LED display screen, some of which are outstanding enterprises, they jointly prosper the emerging high-tech industries, and to promote the global LED display manufacturing center to china. Twenty-first Century is the era of flat-panel display, LED display as one of the mainstream flat-panel display products, but also will have a greater prospect.

Full color is rapidly popularization and promotion

LED display screen is a kind of electronic display which is composed of computer technology, information processing technology, electronic technology, optics and colorimetry. The LED display is divided into monochrome screen, color screen and full color. The so-called monochrome screen, as the name implies, the display is composed of a single color LED. The red and green LED as a pixel of the screen is called two-color screen or color screen. The red, green and blue three LED put together as a pixel display color or full color screen name.

With Green Chip continuously improve the brightness, decline in prices, full color is in the popularization and promotion of a hitherto unknown speed. Especially the "Green Olympics" in Beijing's call, the LED full color market prospect is more attractive.

LED full color is divided into indoor and outdoor screen screen (Indoor) (Outdoor). LED drive in general there are two, one is to change the current LED. In general, the LED working current is best set at 20mA to ensure that the LED's anti-aging. The other is the use of human visual inertia, pulse modulation to achieve gray control. The average brightness of a pixel can be determined by its decay / extinction (duty cycle), that is, periodically changing the duty cycle, as long as the cycle is short enough, the human eye can not feel its decay.

Indoor screen point spacing (Pitch) is 2mm-12mm, which is generally used in the indoor screen TOP 2mm-8mm patch or now developed a sub table manner. Outdoor screen point spacing (Pitch) is 10mm-40mm, with the current green LED brightness level, Pitch for the 20mm display is one of the most mainstream products.

The domestic display manufacturers, after ten years of development, the progress is very fast, but compared with Europe and other developed countries, there is still a certain gap, especially the main display LED package technology and design level, there are still shortcomings.

Packaging process control is very important

Full color display with LED packaging process has its own characteristics. First of all we have to do is to control the raw materials, because the outdoor full color the use of harsh environment, not long-term work at high temperatures is long-term work at low temperature, and long-term rain erosion, such as the LED trust is not very good, it is prone to blind point phenomenon, so we pay great attention to quality control material. We have a complete set of advanced equipment for material inspection, which can help us to strictly control the raw materials. Our full color LED products, is the use of high-quality copper stent has high thermal conductivity, electrical conductivity, so it can greatly reduce the thermal resistance of LED. In addition, we have made special provisions for the coating of the support to ensure our quality requirements. In order to improve the brightness of finished products, we also made a cup of the stent for the sub light treatment. In the selection of epoxy resin, we work on the characteristics of the screen, in particular, the use of a UV (UV) can be resistant to high Tg (glass transition temperature) glue. In the baking process, we use the baking process of slow cooling slow heat, the baking process by our experiments, can improve the glue point Tg, and the most critical is that it can effectively reduce the internal stress of glue, which greatly improves the reliability of the product.

The packaging factory shall strictly control and screen the chips of each batch of product. According to the specific needs of our customers, we can accurately calculate the size of the chip we need. Especially for the production of full color display with the products, we control the wafer particularly strict, not only meet customer requirements of brightness is enough, we have to stand in the customer's point of view, verily they solve the difficulties in adjusting white balance. In addition to the wavelength and brightness requirements customer requirements, details should also pay special attention, if the details do not pay attention to, display manufacturers in white balance, because the brightness and wavelength of the LED is not a normal distribution, it is especially difficult to adjust.

Pay attention to LED optical design

LED is a very sophisticated optical system, bowl cup, wafer and lens with a very good fit is a good optical design. Most of the original packaging factory did not attach great importance to this, which is our display technology can not catch up with Europe and the United States and other developed countries, a very important reason. We have a lot of analysis, found that red green and blue chip chip and double pole pad, the wafer material, each layer thickness, refractive index and their bare crystal spot has the very big difference, and their physical size is too large, in order to make the R/G/B (red green blue) LED brightness three color changes in the left and right within 90 degrees to maintain a high degree of consistency, should use different optical lens. The company has invested in the development of the two optical elliptical lens (die), a red chip dedicated, and the other for the green, blue special. In this way, we have successfully solved this difficult problem for many years.

We hope that together with each LED display Enterprises