IC Mounting Technologies
SMT ― Surface Mounting Technology
SMT using quad flat packages on printed circuit boards was the most popular at the early years of liquid crystal display industry, and is still available for mass production. The components have small metal tabs (or caps) that are soldered directly to the surface of the printed circuit board on tin-lead, silver, or gold plated copper pads, called solder pads.
COB ― Chip-on-Board
COB is a popular IC mounting method that provides wire bonding as the direct attachment of bare die to laminated printed circuit boards. The LCD driver is formatted into an area on the PCB. Electrical connections are made by micro diameter gold wires. The entire area is then covered with epoxy. All of DLC standard Character LCD modules are of the Chip-On-Board design.
COG ― Chip-on-Glass
COG is one of the high-tech mounting methods that uses Gold Bump or Flip Chip IC, and implemented in most compact applications. Chip-On-Glass integrated circuits were first introduced by Epson. In flip-chip mounting, the IC chip is not packaged but is mounted directly onto the PCB as a bare chip. Because there is no package, the mounted footprint of the IC can be minimized, along with the required size of the PCB. This technology reduces a mounting area and is better suited to handling high-speed or high-frequency signals.
TAB ― Tape Automated Bonding
TAB LCD driver or controller electronics are encapsulated in a thin, hard bubble package, of which the drive leads extend from the bubble package on a thin plastic substrate. The adhesive along the edges is used to attach the TAB to the LCD glass and/or PCB.
Tape Automated Bonding IC mounting method uses the same type of integrated circuits as Chip-On-Glass technology - Gold Bumped or Flip Chips. After this type IC chip has been produced, a gold bump is placed on the IC chip and then sealed onto the polymide board. (This procedure is called ILB or Inner Lead Bonding) and is how the TCP IC is produced. TAB LCD modules are always custom made from DLC.