SMT

It is the abbreviation of "Surface mount technology" in English, that is, surface mount technology. The SMT process is one of the manufacturing processes of LCD display driver circuit boards (PCB boards). It uses mounting equipment to attach the mounting components (chips, resistors, capacitors, etc.) to the corresponding pad positions of the PCB board printed with solder paste. And, through a reflow equipment, a processing method of soldering components on the PCB board. This is a more traditional installation method. Its advantages are high reliability, and its disadvantages are its large size and high cost, which limit the miniaturization of LCM.

The process includes five processes: screen printing, patching, reflow, cleaning and testing. The SMT process is affected by the size (package size) of the mounted components (especially the chip), the number of chip pin gaps, and the accuracy of the device. It is suitable for the processing of large PCB boards, and because its solder joints are bare , Extremely vulnerable to damage, but easy to repair.

Taking into account the cost and product volume, IC manufacturers are reducing the output of QFP (a type of SMT) packaging. Therefore, the traditional SMT method will be gradually replaced in future products.

COB

It is the abbreviation of "Chip On Board" in English, that is, the chip is bonded on the PCB.

The process is to stick the bare chip directly on the designated position of the PCB board with an adhesive sheet glue, connect the chip electrode and the corresponding pad of the PCB board with the aluminum wire through the welding machine, and then seal the chip and the aluminum wire with black glue to solidify, Thus, the electrical and mechanical connection between the chip and the electrode of the circuit board is realized. This process includes seven processes: adhesive sheet, curing, pressure welding, testing, sealing, curing and testing.

The COB process uses a small bare chip with high equipment accuracy. It is used to process PCB boards with a large number of wires, a small gap, and a small area requirement. After the chip is pressed, it is cured and sealed with black glue, so that the solder joints and welding lines are not It is damaged by the outside world and has high reliability, but it cannot be repaired after being damaged and can only be scrapped.

TAB

It is the abbreviation of "Tape Aotomated Bonding" in English, that is, the connection method of anisotropic conductive adhesive. It is an IC with a package form of TCP (Tape Carrier Package) through ACF (anisotropic conductive film) at a certain temperature A processing method that realizes the connection between the screen and the drive circuit board by hot pressing under pressure and time. It mainly includes four processes: ACF preloading, alignment inspection, main pressure and inspection.

COG

It is the abbreviation of "Chip On Glass" in English. That is, the chip is directly bonded on the glass.

The process is to stick the LSI-IC special chip for LCD on a small area with concentrated design of the external leads of the LCD, use the welding wire to weld the endpoints together as required, and then cast a drop of sealing glue on it And the input end of the IC is also designed on the LCD outer lead glass, and is also pressure-welded to the input end point of the chip. At this time, this chip-mounted LCD has constituted a complete LCD module. The interface is usually led out by FPC or conductive paper, which is convenient for customers. The process mainly includes seven processes: screen placement, ACF placement, chip placement, alignment inspection, die bonding, sealing and inspection.

This processing method can greatly reduce the volume of the entire LCD module, and is easy to mass-produce. It is suitable for LCDs for consumer electronic products, such as mobile phones, PDAs, MP3 and other portable electronic products. Driven by IC manufacturers, COG will be the main connection between IC and LCD in the future.

COF

It is the abbreviation of "Chip On Film" in English, that is, the chip is directly mounted on the flexible PCB, and then the flexible film transmission belt is connected to the outer lead of the liquid crystal display device with anisotropic conductive adhesive. . This connection is highly integrated, and peripheral components can be mounted on the flexible PCB together with the IC.