COB refers to chip on board packaging solution. In this solution the chip or die is directly mounted on and electrically interconnected to its final circuit board. The COB solution includes die attach, wire bonding, encapsulation of the die and wires these 3 steps. The advantages of COB technology include saving systematic space, high packing density, efficiency heat-dissipation etc. The challenge for COB technology is how to improve the reliability of the light source, and the standardization issues (the standards of package manufacturers and lighting factories are not the same). The figure below shows the LED light bulbs with COB packaging solution.