COG bonding, which stands for Chip-On-Glass bonding, is a method used in the manufacturing of flat-panel displays, particularly LCDs (Liquid Crystal Displays). It involves directly bonding the driver IC (Integrated Circuit) onto the glass substrate of the display panel. This bonding technique offers several advantages, including space-saving, improved electrical performance, and reduced manufacturing complexity.
The COG bonding process typically involves the following steps:
Flip Chip Bonding: In COG bonding, a flip chip technique is used, where the driver IC is flipped and bonded onto the glass substrate. This bonding is achieved through thermal crimping using ACF (Anisotropic Conductive Film) .
Mainstream Method: The driver IC required to drive the flat-panel display, such as an LCD, is directly bonded onto the glass panel. This is known as COG bonding. Additionally, for narrow frame displays, driver bonding can also be done on the FPC (Flexible Printed Circuit) known as COF (Chip-On-Flex). Another approach to narrow the total frame is by pinching the pitch FOG (Film-On-Glass) .
Improved LCD Resolution: With the advancement in LCD resolution and definition, driver ICs are becoming more densely packed and have elongated shapes. COG bonding allows for efficient and compact integration of these driver ICs onto the glass substrate .
Experience and Expertise: COG bonding requires specialized knowledge and experience. Manufacturers with expertise in COG bonding can handle various bonding requirements and ensure reliable and high-quality bonding .
COG bonding offers several benefits, including reduced space requirements, improved electrical performance due to shorter interconnects, and simplified manufacturing processes. It enables the production of sleek and compact display modules, making it a preferred bonding method in the flat-panel display industry.
