On the road to highly integrated LED display packaging, who can take the lead in the five packaging technologies?

China's LED display screen started from packaging. After decades of development, five major types of packaging technologies have been derived: DIP, SMD, IMD, COB, and mass transfer, which are suitable for chip packaging with different pixel pitches. The five major packaging technologies co-exist, each with its own characteristics and application markets. Why is the packaging industry beginning to be integrated? Analyzing from the perspective of the characteristics of the five major technology applications, you can know something.
Technical interpretation
With DIP technology, the lamp beads are directly inserted into the PCB board, and then the display module is made by welding, which is a direct plug-in package.
SMD technology is to glue single or multiple LED chips to a metal bracket with a plastic “cup-shaped” frame through a machine, and then fill the plastic frame with liquid encapsulating glue. It is baked and molded at high temperature. It belongs to automated surface mount package.
 
The IMD all-in-one packaging technology combines two or more pixel structures in one packaging unit. At present, the four-in-one technology is the most mature and belongs to integrated packaging technology.
 
COB packaging technology integrates multiple LED bare chips with conductive or non-conductive glue directly attached to the PCB board, eliminating the need for brackets, and encapsulating the entire module completely. It is a highly integrated packaging technology. In addition, COB packaging reduces the process of lamp beads and reflow soldering patch, integrates upstream, middle and downstream technologies, merges lamp beads and PCB panel packaging, from LED chip packaging to LED display unit module or display production. To be completed by one company, it requires close cooperation between upstream, midstream, and downstream companies. This is the integration of the production process.
 
Mini/Micro LED display technology highly integrates millions of wafers together, that is, massive transfer technology, so it is also a highly integrated packaging technology. Combining the above and the development history of packaging technology, it can be seen that LED display packaging technology is moving towards integration.

 
Application prospect analysis
As the oldest packaging technology, DIP has been in the field of packaging for decades. With its simple process and low cost advantages, it has a relatively high market share. However, this technology is inefficient, and is only suitable for outdoor displays above P10. With the overall display trending below 10 and the replacement trend caused by the aging of early LED screens, the DIP technology market has shrunk severely and withdrawn from the main historical stage of the packaging industry.
SMD is suitable for packaging with pixel pitch between P2-P10 and is also the current mainstream packaging technology in the packaging industry. It has the advantages of mature technology, high machine surface mount efficiency, and performance in brightness, consistency, reliability, viewing angle, appearance, etc.is good. However, due to the existence of congenital bracket problems, there are problems such as poor air tightness, poor heat dissipation, uneven luminescence, and reduced luminous efficiency. Although many companies have researched and discussed, they have not been able to completely solve this problem. In addition, in the past two years, there has been a serious overcapacity of conventional SMD packaging chips, spreading to Taiwan, Japan, South Korea and other regions, prices have fallen, and profits have fallen sharply. At the same time, the LED conventional display market has also become saturated. The chip packaging industry has entered a development bottleneck period. Shipment is difficult, inventory is large, the industry is in a sluggish state, and companies are under attack from three sides. New development momentum is urgently needed to get rid of the development dilemma.
 
At this time, due to the increase in personalized demand, various market segments began to exert force. Among them, the fine pitch LED display has risen strongly due to the expansion of the security market and has become a profit point for major companies. Therefore, the major packaging manufacturers’ Enterprise deployment is also focusing on fine pitch lamp beads, and the fine pitch plan is carried out in an orderly manner. Although SMD is the most common packaging technology in the industry, when the package size is less than 2.0, it is limited by factors such as die bonding, wire bonding, dicing (punching), and wire bonding equipment accuracy, which will lead to a sharp increase in process difficulty. The yield rate decreases and the terminal cost increases. Therefore, it is difficult for SMD packaging to enter the most profitable fine pitch packaging market. SMD technology is not suitable for fine pitch packaging, prompting the birth of another packaging technology with the same root, the IMD all-in-one integrated packaging technology.
 
COB packaging and IMD technology have several common features. First, both can break through the limitations of SMD technology and reduce the pixel pitch to less than 2.0mm; secondly, the two technologies are also derived from the fine pitch LED display technology. Development, and are mainly used in the field of fine pitch LED display. By analogy, since COB and IMD technologies can be applied to fine pitch LED display products, they can also be applied to large-pitch LED displays. It is undeniable that due to its inherent defects, COB technology will have cost problems when applied to large-screen products. However, IMD technology originated from SMD and inherited the experience, technology, equipment and production line of SMD. The application cost is relatively low, and it can be extended to a pitch of 2.0 or more. In addition, COB packaging and IMD technology are the most discussed topics in the packaging industry in the past two years. The feasibility, reliability, production yield, and scope of application of the two technologies have been explored as the industry continues to deepen and promote Both are moving towards a more stable and mature application stage. Therefore, it is not impossible that SMD will be replaced by IMD technology in the future.
Mini/Micro LED shows that the technology is relatively advanced, and there are many technical difficulties that need to be overcome. The biggest difficulty has been the massive transfer of technology and a better solution has not been developed. In addition, Mini/Micro LED displays have not yet formed a corresponding industry chain. Even if the trend of Mini/Micro LED displays is hot in the future, it still has a long way to go.
From the perspective of application scenarios, conventional screens have entered the platform stage. Although market segments are also in the expansion stage, the development momentum and application range of fine pitch are even better. Moreover, with the further implementation of the smart city policy, the security surveillance market will continue to expand; in addition, with the popularization of 5G networks, conference visualization has also begun to enter the conference rooms of major companies; not only that, but companies in major segments are also Begin to explore the possibility of displaying its products in fine pitch, and relatively mature products have appeared on the market. The development of several major trends will continue to drive the development of fine pitch LED displays. Therefore, the expected fine pitch display field in the future will become the first choice for most LED packaging companies and even LED screen companies in the future strategic layout. It can be seen that LED display packaging is also quietly moving towards integration.
From a technical point of view, SMD, COB and IMD are the first to break through. From the perspective of development prospects, COB, IMD and Mini/Micro LED are promising in the future, but Mini/Micro LED has not yet formed a certain development, so COB and IMD stand out. From this comprehensive analysis, it is concluded that the five major packaging technologies, COB and IMD will take the lead.