Panel of the driver IC encapsulation type can be divided into TCP (Tape Carrier Package), COF Package (Chip on Film) and COG (Chip on Glass), and other three categories, the mainstream packaging technology for TCP in the past, however, with the panel toward the development of high quality and high resolution, and wafer thin and short of demand, the driver IC circuit center to center distance (pitch), spacing (spacing), such as more and more ultra-micronization model.the, packaging substrate design also must cooperate with the Chip circuits spacing ultra-micronization model.the provide corresponding packaging substrate, direct packaging substrates toward high density packaging technology development. So COF package to flip chip Bonding way instead of TCP TAB (Tape Automated Bonding), makes chips and soft substrate can be extremely high density phase conjugation, particles due to the wafer testing technology for miniature Fine spacing (Fine Pitch) process and development trend, TCP pin spacing within the limit of 40 microns, COF package has production, the minimum distance of 25 microns, therefore COF package replaced the TCP packaging.

       Currently the world's major COF package factory for South Korea's LG Innotek (LGIT) and Stemco, Japanese Flexceed, and at domestic bond with huadian etc. Five. As for COF package process technology is mainly divided into lithography (also called subtraction method) (Subtractive) and half addition method (Semi - i.e. the). In control, because of the principle using chemical etching method is relatively stable, easy to cause a horizontal cabling be dissolved at the same time. Half bonus law is through the copper foil after pressing, conduction drill hole, add in a specific range of corrosion inhibitor for exposure required wiring, width is not only comply with the design requirements, and lines can be repeated high-density wiring, relatively high yield.