Advantages of LED small pitch

Position: Home> News Center Advantages of LED Small Pitch

Compared with other display technologies, LED display screens have the advantages of self-illumination, excellent color restoration, high refresh rate, power saving, and easy maintenance. The two characteristics of high brightness and super large size can be completed by splicing, which are the decisive factors for the rapid growth of LED displays in the past two decades. In the field of ultra-large screen outdoor display, so far no other technology can compete with LED display technology.

However, in the past, LED display screens also have their shortcomings. For example, the distance between packaged lamp beads is large, resulting in lower resolution, which is not suitable for indoor and close-space viewing. In order to improve the resolution, it is necessary to reduce the distance between the lamp beads, but the reduction in the size of the lamp beads can certainly improve the overall screen resolution, and the cost will also rise rapidly. The excessive cost affects the large-scale commercial application of small-pitch LED displays. .

In recent years, with the efforts of chip manufacturers and packaging manufacturers, IC circuit manufacturers and screen manufacturers, the cost of single-package devices is getting lower and lower, LED package devices are getting smaller and smaller, and the pixel pitch of display screens is getting smaller. The higher and higher resolution makes the advantages of small-pitch LED displays in large-screen displays indoors more and more obvious.

At present, small-pitch LEDs are mainly used in the fields of advertising media, stadiums, stage backgrounds, municipal engineering, etc., and open up markets from time to time in areas such as transportation, broadcasting, and the military. It is estimated that by 2018, the market range will be close to 10 billion. It can be predicted that in the next few years, small-pitch LED displays will expand market share from time to time and squeeze the market space of DLP rear projection. According to the prediction of Everbright Securities Research Institute, by 2020,

First, the demand for LED chips from small-pitch LED displays

As the LED chip at the center of the LED display, it plays a vital role in the development of small-pitch LEDs. The current achievements and future development of small-pitch LED displays rely on the unremitting efforts of the chip side.

On the one hand, the pitch of indoor display screens has gradually decreased from P4 in the early period to P1.5, P1.0, and P0.8 in development. Correspondingly, the size of the lamp beads has been reduced from 3535 and 2121 to 1010. Some manufacturers have developed 0808 and 0606 sizes, and some manufacturers are developing 0404 sizes.

As is known to all, the reduction in the size of packaged lamp beads necessarily requires a reduction in chip size. At present, the appearance area of ​​blue-green chips for small-pitch display screens in the market is about 30mil2, and local chip factories have been mass-producing 25mil2 to 20mil2 chips.

On the other hand, the surface area of ​​the chip becomes smaller, the brightness of the single core decreases, and a series of problems affecting the display quality also become prominent.

The first is a request for grayscale. Unlike outdoor screens, the difficulty in indoor screen demand is not in brightness but in grayscale. At present, the brightness requirements of indoor large-pitch screens are about 1500cd / m2-2000cd / m2, and the brightness of small-pitch LED displays is generally about 600cd / m2-800cd / m2, and the best brightness for long-term attention is 100cd / m2-300cd / m2.

One of the problems with current small-pitch LED screens is "low brightness and low gray." That is, the gray level at low brightness is not enough. To complete the "low-brightness and high-gray", the current plan for the package end is a black bracket. Since the black bracket has a weak reflection of the chip, the chip is requested to have sufficient brightness.

The second problem is the display of averaging. Compared with the conventional screen, the smaller the pitch, the problems such as afterglow, darker first sweep, reddish low brightness, and low gray unevenness appear. At present, for the problems of afterglow, first-scanning darkness and low grayish redness, both the packaging end and the IC control end have made efforts to effectively alleviate these problems. The brightness average problem in low grayscale has also been corrected point by point Technology has eased. However, as one of the source of the problem, the chip side needs more effort. In detail, it is better that the brightness is uniform under a small current, and the divergence of the parasitic capacitance is better.