Chip On Glass(COG)

▎Glass Encapsulation (COG) Introduction:

COG packaging technology is called chip on glass in English, that is, chip technology on glass. It directly through the anisotropic conductive adhesive (ACF) to package the driver IC on the liquid crystal glass, to realize the driver IC conductive bump and the ITO transparent conductive pad on the liquid crystal glass interconnection and packaging together, so as to realize the lighting screen, the process is mainly used in the liquid crystal display driver IC packaging.

        For reliable operation, the rail resistivity of the connector connected to the driver IC must be lower than that of the ITO connection used within the liquid crystal unit. To realize ACF binding technology, the driver IC has gold bumps on the connection pads. The connection between the driver IC and the glass substrate is also formed by ITO, and ACF consists of epoxy resin (similar to UV-curable glue) containing conductive particles. The conductive particles ensure contact between the gold bumps that drive the IC and the ITO conductors on the glass. The fixation of ACF glue establishes the necessary pressure between the chip and the liquid crystal glass to ensure a good electrical connection between the bump and the track on the liquid crystal glass. Due to the surface tension of the glue on the conductor beads, there is no horizontal contact between the conductive particles, thus avoiding a short circuit between the adjacent gold bumps that drive the IC.

        The packaging process used by COG is wafer, which divides the wafer into a state of dies, using process technologies including grinding, cutting, picking, etc. Among them, the grinding process is to use physical means to cut the thickness of thin wafers, and if the polishing process is added to the process, the wafer stress can be dispersed and the grain strength after cutting can be enhanced; Cutting is mainly a process of dividing wafers into single dies according to the cutting lane; Guangxi Huaxin Zhenbang has rich production experience and high-end technology for ultra-thin product grinding process, laser grooving process, tool cutting process and picking process, providing better quality and diversified choices.

▎Glass laminated packaging features：

       • Ultra-thin wafer grinding and dry polishing processes meet customer quality requirements for large Die Strength and small Die TTV.

       • The Laser + Blade process with high aspect ratio ICs (greater than 60:1) meets customer quality requirements for the smallest die chipping

       • With laser Low-k low chip process capability, improve the quality perfect to meet customer requirements

       • Internationally certified driver ICs for automotive panels

▎Product Application：

Main applications:

   • Driver ICs for displays used in wristbands, mobile phones, tablets, notebook computers, and automotive panels

   • Touch panel driver IC

   • Under-screen fingerprint reader, etc

   • Components for medical equipment (hearing aids, blood glucose meters...)

Application Industry:

   • Displays, medical, industrial control, mobile phones, Internet of Things (AioT), automotive, etc