COB packaging, namely Chip on Board packaging, is also known as chip mounting technology. It is a packaging method in which the chip is directly attached to the PCB circuit board, and the chip and the circuit board are connected through gold wires, which can make the device smaller in size, better in performance, and more reliable. The COB packaging process mainly includes the following steps:
1. Chip preparation: First, a suitable chip needs to be selected, cleaned and inspected to ensure that there are no contaminants and defects on the chip surface.
2. Chip pasting: On the prepared PCB, use conductive glue or thermal conductive glue to paste the chip to the designated position. This requires high-precision positioning and correct control of the glue.
3. Gold wire connection: Use micro wire bonding or a wire bonding machine to connect the gold wires on the chip to the pins on the PCB. These gold wires serve as signal transmission and electrical connections.
4. Encapsulation and curing: Use heat-curing or UV-curing glue to tightly connect the chip to the PCB and ensure stability and reliability.
5. Encapsulation protection: In order to protect the chip and connecting wires, epoxy resin or other protective materials are usually used for coating after encapsulation.
This packaging technology is simple and easy to implement and does not require complex equipment and processes, so the cost is low. At the same time, because the chip is directly mounted on the PCB, the package volume can be significantly reduced, integration and space utilization improved, resistance and inductance reduced, and electrical performance and signal transmission speed improved.
Please note that the specific COB packaging process may vary depending on the specific needs of the package and the type of chip. In practical applications, other factors need to be considered, such as temperature control, glue selection, process parameters, etc., to ensure packaging quality and reliability.