Mechanical engineers are mainly responsible for the selection of wire to wire connectors, because they need to consider the layout of the whole circuit board or subsystem, and the selection of connectors is more about size and space. The electrical performance usually only considers the rated current of the terminal. In the design, it is necessary to determine how many terminals transmit the signal, the size and shape of the connector body and the firmness of the connector, especially in military projects. In avionics or portable systems, the size of each device is very important, which is a great challenge to the selection of connectors.

The design of line-to-line connector has been completely changed, and a special signal integration engineer is required to be responsible for the selection. The new connector design must also meet the electrical performance requirements, rather than measuring the electrical performance parameters after the completion of the whole connector design as in the past. Especially for high-speed signals above 10GHz, electrical performance is very critical. When designing high-performance connectors, whether expensive backplane connectors or common standard PC connectors, the first thing to consider is the electrical performance requirements. The selection of connectors has also changed from packaging engineers to electrical engineers who design circuits.