COB packaging technology - the future king

2016 small spacing LED industry once again get a bumper harvest. From the LED show the whole industry growth perspective, small spacing LED TV has won almost 9 increments. In the small pitch LED display products at the same time, small spacing LED display technology is also in progress. This year COB packaging products become a new favorite, and has become the trend of the future king.

COB came, small spacing LED TV into a new stage

What is the COB (Chip On Board) small distance display technology? That is directly to the LED light emitting wafer encapsulation in PCB circuit board, and the CELL unit into display technology. At present, SONY and other industry giants, Wei Chong has given strong support for the technology.

The domestic high-end large screen display leading brand that the development of small spacing Vtron, LED display can be divided into two stages: the first stage is to solve the problem, can be used for me, the core technology breakthrough is reflected in the pixel spacing is reduced to below 2 mm, P1.5 and P1.2 mass production products; small pitch LED display second development stages it is mainly to provide the reliability and effect of visual experience higher product, the COB package is one of the most important technical direction.

The spring of 2016, Wei Chong officially launched the COB P1.5 standard package products. Industry experts believe that, with the 2016 COB packaging small spacing LED TV products built early exploits, the type of product in the year of 2017 or gradually into the supply side of the outbreak of growth".

Simplify, COB packaging small spacing LED why so magical

For small spacing LED screen applications, dead lights are the biggest problem. The P1.6 product as an example, more than 390 thousand beads, nearly 1 million 600 thousand per square meter with lead. These components constitute a very complex process system problem: that is, such a complex system, we need to use a process known as "reflow" connection. The reflow process itself means "artificial high temperature" (240 degrees, far more than the normal operating temperature of the LED display).

In high temperature operation, due to the different material SMD SMD package LED lamp in, such as copper stent, epoxy resin materials, crystal beads of different thermal expansion coefficient, its thermal stress stress change will inevitably occur. This has become a small spacing LED screen bad lights, dead lights of the core culprit".

The use of COB packaging technology, in the chip after the packaging process, LED crystal once the smallest CELL display unit, not in the last two "table" welding. The engineering process, by reducing a high precision and high temperature operation, the maximum degree of protection of the electric and semiconductor structure stability of LED crystals, can make the lamp display bad rate dropped by more than an order of magnitude.

In other words, the characteristics of the COB package is, after the LED package, no longer need the traditional table paste process. Due to the omission of one step high temperature and high precision, the reliability of the whole engineering system is enhanced. This is the COB package is a small pitch LED industry optimistic about the core reasons.

The overall package, COB technology benefits

Small spacing between the LED screen and the stability of the lamp point of view, in addition to reflow welding high temperature damage process, there are several aspects need to attach great importance to:

First, the collision process of the display unit. SMD surface mount products beads is not seamless connection with PCB plate, which makes the collision process easy to cause the stress concentration at the single lamp. The large screen system of transport, installation, etc., there is inevitably shock and collision. This has resulted in an increase in the "Engineering" rate of small spacing LED displays. COB packaging technology, through the epoxy resin, wafer, PCB board of highly integrated bond molding, can effectively protect the wafer and wafer electrical connection stability.

Second, the temperature uniformity in the working process of the system. The smaller the distance between the smaller SMD packaging products, the more the use of high power small particle LED crystal. At the same time, the gap between the lamp and the display panel is to work in the process of heat conduction ability of wafer disorder. Due to the adoption of a more integrated whole process, the COB can be used to select the wafer with lower power density and larger crystal size in the crystal selection, and then reduce the working intensity of the core luminous point. At the same time, COB package to achieve a full package of epoxy resin under the full solid heat sink, so that the working state of the LED crystal heat set in a moderate decline, is conducive to the extension of product life, improve system stability.

Third, the overall packaging process, COB do seal five". That is, COB can do a good job of crystal, crystal electrical connection parts of the waterproof, moisture-proof, dust-proof, anti-static, anti oxidation". In contrast to the SMD package, in the process, especially after the shock and collision, the electrical connection of the long-term chemical and electrical stability damage occurs - this is the long-term application, one of the culprits continue to bad lights.

So, as a whole, COB packaging is more SMD products can provide more reliable process.

From the visual effect, COB change is not a little

What are the benefits of the LED display system?. However, in the system with a single chip as the basic parts of defective pixel granulation, viewing angle, the soft screen and its display effect.

The traditional LED display system is used for outdoor display, remote viewing and display, and the demand for visual angle and visual comfort is not obvious. However, with the popularity of small spacing LED applications, indoor display system, a large number of close viewing system, how to enhance the LED display