Design of a Compliant Press-Fit Pin Connection

A design method for a compliant press-fit pin connection in a plated through hole (PTH) is presented. In this connection, both compliant press-fit pin and PTH cause elastic-plastic deformation. Considering this feature, three fundamental design concepts for this connection are discussed. First, three design conditions are set: 1) the upper limit of pin insertion force to protect the copper plate of the inner PTH, 2) the lower limit of pin retention force to accomplish reliable wire wrapping connection, and 3) acceptable PTH diameter tolerance. Second, the deformation and radial force characteristics were studied for both pin and PTH. These characteristics were numerically analyzed by using the elastic-plastic finite element method (FEM). According to actual connection states, the pin edge indentation effect into the plated copper is taken into consideration for the PTH deformation characteristics. Finally, the design point was determined, where the pin and PTH radial forces balance. This design point should satisfy the above-mentioned three conditions. An example of a compliant press-fit pin with N-shaped cross section was studied. Results from the numerical analysis are compared with those obtained from experiments. The two results compare favor- ably.