Chip-On-Board Technology brings unique assembly options to the systems designer. In this technology the silicon die is glued directly to the surface of a printed circuit board between the die and the PCB or AL2O3 to establish the electric connection; a coating of opaque epoxy resin is deposited over the die to protect it against shocks and the harmful effects of light.
High or Low Voltage Design
Multi-layer, Double-sided Boards
Functional Board Testing
High or Low Volume
Wide Temperature Ranges
Cost Competitive Solutions
A populated circuit board is shown below. It has several COBs bonded on the board. You can also see passive chip components on the board.
A detailed view of COB is shown in the following figure:
As seen from the above figure, die is attached directly to the PCB, and wires are bonded to the PCB pads directly. The entire die attachment is normally encapsulated in an adhesive. COB is useful when you want to minimize the space taken by the components. It also minimizes stray capacitance, and inductance due to smaller sizes of the wires.