COB package the full name is chips on board, it is a technology to solve the problem of heat dissipation of LED. Compared with direct plug-in and SMD, it has the advantages of saving space, simplifying packaging operation and high efficiency of thermal management.
COB packaging is to bond bare chips with conductive or non-conductive adhesives on the interconnection substrate, and then wire bonding to achieve its electrical connection. If the bare chip is directly exposed to the air, it is vulnerable to pollution or man-made damage, affecting or destroying the function of the chip, so the chip and bonding wire are encapsulated with glue. It is also called soft package.
The thermal resistance of COB packaged system is much lower than that of traditional SMD packaged system, so the service life of COB packaged LED lamps is greatly improved. Traditional SMD packages use patches to attach discrete devices to PCB boards to form light source components for LED applications. This method has the problems of spot lighting, glare and ghosting. The COB package
is an integrated package and a surface light source. It has a large angle of view and can be easily adjusted to reduce the loss of light refraction.
The traditional SMD package method is to attach several different devices to the PCB board to form LED light source components. The problems of electro-optics, ghosting and glare are ubiquitous in the light source made by this packaging process. COB light source does not have the above problems. It belongs to surface light source. Its visual angle is large and easy to adjust, which reduces the loss of light caused by refraction.