Under the new situation, the development direction of China's LED display package
About of LED packaging, this is the beginning of the rise of China's LED industry, Chinese companies cut into the LED industry, the main breakthrough. China's LED industry started late. Under the circumstance that the LED core technology is firmly controlled by the international giants, the upstream chip end is difficult to intervene. Chinese enterprises have to choose the technical difficulty is not very high, the entry barrier is relatively low, and then the Upstream and downstream extensions. Today, China's LED packaging has reached a world-class level. LED packaging is no longer a simple assembly link, but a test of the production process and technical level.
For LED displays, the LED device package accounts for 30%-70% of the total cost, and the quality of the package directly closes the quality of the LED display. For a long time, the advancement of LED display device packaging technology has promoted the development of LED display screens; and with the development of LED display screens towards high-definition displays, the requirements for the technology and processes of LED display device packaging have also become higher and higher. The current LED display industry is mainly based on surface-mount packages. Simultaneously, in-line packages and COB packages coexist, but since last year, COB technology has gradually received attention from display manufacturers, while Mini LED and Micro LED technologies have also been widely used. and. Faced with this new trend, how will our LED packaging companies cope with, and where tomorrow's LED display device packaging will eventually go? These have become the current concerns of the enterprise.
LED display device packaging technology development process
To understand the current status of LED packaging industry development and future trends, we must first review the history of China's packaging industry development. China's LED industry probably emerged in the 1980s. The development of LED display packaging devices mainly went through several stages: dot matrix module, in-line (lamp), sub-surface, and surface-mount (SMD). Today, dot matrix modules and sub-surface-mount packages have been eliminated from the market. In-line packages are still used in large-pitch outdoor markets above P10, while others are superseded by surface mount devices. With the continuous development of the small-pitch LED display market, more display companies are turning their attention to the COB package. At the same time, with the emergence of a new generation of display technology, Micro LED, which is seen as potentially disrupting the industry, Micro LED packaging technology has also been widely discussed in the industry. Let us take a look at the respective technical characteristics of these types of packaging.
1, DIP package
As the in-line package following the dot matrix module, the technical principle is to use a lead frame as a pin of various package shapes. Usually, one end of the bracket has a “cup-shaped” structure to stick and fix the LED chip in the “ In the cup-shaped structure, the liquid epoxy resin is injected into the cavity of the LED mold, then the pressure-welded lead-type LED bracket is inserted, the epoxy resin is cured by high-temperature grilling, and finally the mold is released. forming.
The DIP type can be said to be the first LED product that has been successfully developed and put on the market in a large number, with various types and mature technologies. The manufacturing process is simple and the cost is low. Therefore, the inline package has a very high market share before SMD appears. In-line LED package products are mainly used for outdoor large screens, with advantages of high brightness, high reliability, and strong environmental adaptability.
At present, due to the fact that the distance between outdoor spots is also increasing towards the high density, in-line insertion is limited by the insertion of three components of red, green, and blue, which cannot achieve high density. Therefore, outdoor spot pitch P10 is gradually replaced by surface-mounted LED devices. It is generally believed that the outdoor in-line LED display screen uses P10 as the boundary line, but there are also LED display products in the industry that will be used in the P9 display.
2. Surface Mount (SMD) Package
Surface Mount (SMD) package is to solder single or multiple LED chips on a metal bracket with a plastic “cup shape” frame (the external pins of the bracket connect the P and N poles of the LED chip respectively), and then to the plastic frame. The liquid epoxy or silicone is encapsulated and then baked at high temperatures. The final cut is then separated into individual surface mount packages. Due to the surface mount technology (SMT), it is highly automated. The use of surface mount packaging device display screen, in the color reproduction, color consistency, uniformity, viewing angle, the overall picture, especially in terms of volume, all have the advantages of in-line display can not be compared. However, SMDLEDs are also congenitally deficient, with high failure rate and decay rate, and relatively poor adaptability to harsh environments.
At present, SMD LEDs are mainly divided into TOP LED and Chip LED. The former often uses a PLCC (Plastic Leaded Chip Carrier) bracket, which uses a PCB circuit board as a carrier for LED chips. The cost of the PLCC support is low, but there are problems such as poor air tightness, poor heat dissipation, uneven light emission, and decreased luminous efficiency in applications. Although there are also PCT and EMC material holders with better performance and light efficiency, they are not widely used in the industry because they are expensive and costly.
3, COB package
A COB (chip on board) package is a method for attaching a bare chip to an interconnect substantially with conductive or non-conductive adhesive, and then performing wire bonding to achieve its electrical connection. The COB package is a stand-less technology without the stand's solder PIN pin. Each lamp bead and solder wire is tightly encapsulated in epoxy by colloidal epoxy without any exposed elements.
Compared to SMD-packaged displays, the COB display uses integrated packaging technology. This eliminates the need for a single LED device package and then the SMT packaging process, which can effectively solve the SMD packaging display, due to the ever-decreasing point spacing. The difficulty of the process is increased, the yield is low, and the cost increases. However, COB packaging has not been widely used in the display industry since COB packaging integrates upstream chip technology, midstream packaging technology and downstream display technology. To realize the large-scale application of the COB package, it needs the close cooperation of the upper, middle, and downstream enterprises.
4, Micro LED package
The English name of the Micro LED is "Micro Light Emitting Diode," and Chinese is also called a micro light emitting diode. It can also be written as "μLED."
Micro LED's thinning, miniaturization and arraying of its LED structure make its volume about 1% of the size of mainstream LED. Each pixel can be addressed and driven independently to reduce the pixel pitch from millimeter to micrometer. Thus the theory reaches 1500 ppi and even 2000 ppi ultra high resolution.
Micro LED inherits the advantages of low power consumption, high brightness, ultra-high resolution, color saturation, fast response speed, ultra-power saving, long life, and high efficiency. LED's power consumption is about 10% of LCD, OLED 50%. Therefore, MicroLED is seen as a new generation of display technology that may disrupt the industry.
The future of LED display packaging industry in China
Technology and markets often determine the future of the industry.
In the LED display device packaging technology, processes continue to make progress, the global packaging production accelerated the transfer to China under the background, the development of China's LED display packaging industry has a bright future.
Of course, no matter how the international situation changes in 2018, it is impossible to reverse the fundamentals of the continuous development and expansion of China's LED packaging industry. Moreover, based on the LED display device package leader, we not only lead in the production capacity, but also in the world leading position in the field of small-pitch LED display device packaging, this dominant position, not a temporary change of the current situation can easily shake.
In the future, China's LED packaging industry will maintain its momentum of sustained development in the turmoil, and the market size of LED packaging companies in China will further expand. With the development of MINI LED and Micro LED technology, the future LED display will present a variety of technologies to coexist and co-prosperity.