LCD module Process Capability

Fully automatic equipment is used from cleaning to output of complete modules to ensure the stability and quality of the produced products

What is the main production process of LCD?

The main process of LCD manufacture: LCD cutting, cleaning and drying, attaching polarizer and vacuum defoaming, first test, COG process, FOG process and second test, backlight assembly and third test, and finally packaging

COG and FOG are the most important processes, which will affect the electrical performance of the display

What does COG mean?

COG (chip on glass) encapsulates the IC on the LCD screen through the anisotropic conductive adhesive (ACF) to realize the interconnection and encapsulation of the IC electrode and the electrode on the glass. character LCD and segment LCD as well as most TFT LCDS adopt this method. There is another method, COF (chip on film), which is similar to COG technology. IC chip is directly packaged on FPC, reducing the size and allowing free bending.

What does FOG mean?

FOG module refers to a key process in the LCD manufacturing industry. The full name of FOG is film on glass, which uses ACF to fix the FPC on the LCD panel. This process, like COG process, requires temperature and pressure control to ensure accuracy and stability

Key material of COG and FOG process

driver IC

The driver IC is the key component of the LCD display. Usually, each resolution corresponds to a driver IC. The driver IC is a very precise semiconductor device that can analyze the signals transmitted by the MIPI interface, RGB interface, and SPI interface into the control signals of the LCD panel. 

driver IC



ACF is the abbreviation of Anisotropic Conductive Adhesive, which is mainly used in the lcd display industry to connect the driver IC, display FPC and the lcd panel, which can not only play the role of bonding, but also conduct the circuit. ACF needs to be stored at low temperature and heated and pressurized when used. Once cured, it cannot be reversed.

ACF structure

ACF bonding process

First attach the ACF to the lcd panel, and then fix the driver IC or display FPC on the lcd panel under pressure and heat. During this process, the ACF will solidify, and the driver IC and lcd panel will create a circuit higher than other areas at the position that needs to be turned on, which is called bump. These bumps will crush the conductive particles, thus conducting up and down.

ACF bonding process 1

After bonding, it can be seen that the metal lines on the LCD panel will have traces, which indicates that the conduction is good, and the conductive particles corresponding to each clear indentation are called effective conductive particles. Different ACF manufacturers have different requirements for the number of effective conductive particles on each bump: SONY’s ACF requires more than 5 effective conductive particles; HITACHI’s ACF requires more than 3 effective conductive particles.

COG and FOG bonding state

COG and FOG process

Process of COG and FOG

Attach ACF (Anisotropic Conductive Adhesive) to the LCD panel

cog process-acf attached

Attach the driver IC to the lcd panel through a certain temperature and pressure

cog process-ic bonding

Use ACF to bond the display FPC to the lcd panel

cog process-fpc bonding

Use special glue to fix the driver IC and FPC after bonding to prevent the entry of moisture and impurities and ensure stability

cog process-glue

Key equipment capacity


ACF Attachment accuracy

Attachment accuracy


X: ±0.15mm, Y: ±0.1mm

Preloading accuracy: ±10umLocal pressure accuracy: ±15um (including pre-pressure accuracy


X: ±0.15mm, Y: ±0.1mm

Preloading accuracy: ±10umLocal pressure accuracy: ±15um (including pre-pressure accuracy

Backlight assembly machine


Assembly accuracy: ±0.05mm

Our critical equipment

Automatic FPC Feeder

Fully automatic LCD feeding to ensure smooth and accurate

Automatic FOG machine

Using CCD alignment, high-precision attachment

Automatic AOI Inspection Machine

CCD detects defective products and confirms the stability of yield

Automatic LCD Feeder

Fully automatic LCD feeding to ensure smooth and accurate

Automatic plasma cleaning machine

Quickly clean LCD at high temperature to ensure ACF adhesion

Automatic COG machine

Using CCD alignment, high-precision attachment

Quality Assurance Equipment

Vibration Tester

Vibration Tester

Provide a bright inspection environment to detect defects in polarizers


large microscope

High-precision dimensional measuring instruments for monitoring product dimensions.

Mechanical Tester

Mechanical testing machine

Environmental testing equipment is used to test the state of polarizers under high temperature and high humidity or alternating hot and cold conditions

Recent TFT LCD Products

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