COG products generally use FPC flexible circuit boards as the connecting cables, and there are three ways to connect with the customer's end:
1. Plug in type: One side of the cable is a copper exposed gold finger (conductive contact surface), and the other side is a reinforcing plate (to strengthen the contact with the connector).

2. Welding hollow type: The pins in the cable are made of copper skin, with a hollow gap in the middle, which can be welded in both directions. Therefore, only the solder pads corresponding to the PCB board can be soldered. Generally, the PCB solder pads are first tinned or tinplate is used between soldering, and then the FPC is soldered on. After soldering, it needs to be pasted with high-temperature adhesive paper to prevent breakage or tin slag from causing short circuits.

3. Welding - Double sided board: The pins in the wiring are made of copper foil, and the gap in the middle is not hollowSimilar to the double-sided board of PCB, both sides are conductive, so the PIN pins of the wiring only need to be soldered onto the corresponding solder pads of the PCB board. Generally, tin is added to the PCB solder pads or tinplate between the solder joints, and then the FPC is soldered onto it. After soldering, it needs to be attached with high-temperature adhesive tape. This type of wiring is not easy to break, but the mold cost is high.