COG is an advanced technology to adhere IC chips onto glass (LCD). By Flip Chip technology, a gold bumped IC chip is connected to the ITO of LCD panels with ACF as a media. When this technology is applied to LCD panels due to the circuit board being glass, it is so-called Chip on Glass (COG), and bonding of the flexible printed circuit (FPC) and glass (LCD) is called FOG (Film On Glass). COG would be produced by means of wafer to tray. After LCD panel module factory acquires IC, the gold bump of the IC is bonded to the circuit board of LCD panels with ACF, then use ACF bonding with FPC, this production is called FOG process.