Industrial TFT Display

Industrial TFT display, or LCD modules for short, consists of an LCD cell, back light unit, PCB, driving IC chips, and plastic frames. An LCD cell is the key component of an LCD module. It consists of a TFT glass, a color filter glass, and liquid crystal filled in between the TFT glass and color filter (CF) glass.
LCD module manufacturers now mainly distribute in China, Korea, and Japan. Often an LCD factory is composed of these four parts:
(1) A TFT fab, where thin film transistors are formed on raw glasses.
(2) A CF fab ,where color filters are formed on raw glasses.
(3) An LC assembled fab, where TFT and CF glasses are assembled and liquid crystal is filled in between, and cut into panel-sizes.
(4) A Module line where final assembly operations are performed mostly by human operators.
TFT display process time and step numbers are the important factors to manufacturers.Usually, fabrication of a typical industrial TFTrequires 30~40 steps and its turn-around time is about 48 hours. And the CF fabrication process often consist of 15~20 steps,with a fab turn-around time of about 24 hours. The LC assembled fab produces LCD cells from industrial TFT glasses and CF glasses,with a turn-around time of 10~12 hours and about 15 steps. For example,in a 7th generation LCD Fab,eight LCD cells of 40 inches panel size are produced from a pair of TFT and CF glasses. The produced LCD cells are graded into 3~6 levels depending on their quality level.In the Module line,industrial LCD displays cell is assembled with external parts such as back light unit,polarizer,and PCB. For a given product type of LCD cell,10~30 options of LCD module are obtained depending on the specifications of the external parts. Since there are more than a dozen product (LCD cell) types, the total number of options (of industrial flat panel display) is quite large.Thus,careful synchronization of external parts supply with internal production schedule of LCD cells is very critical.