LCD displays each require one or more driver modules (s) to control them. These ICs are either placed directly on a circuit board (as COB or SMD) or as COG (Chip-On-Glass) directly on the LC glass.
In chip on board technology, the semiconductor chip (driver) is glued directly onto a circuit board material and contacted there via bond wires. For protection, the IC and the bonding wires are sealed with a drop of potting compound using chip-on-board technology.
Chip-on-board displays are widespread and cheaper than LCD modules with SMD components.