Reliability Analysis of Solderless Press-Fit Interconnections

This paper treats typical mechanical problems met in a solderless press-fit assembly. First, the elastic-plastic properties of a pin and the friction coefficient of the pin in thin plated through hole (TH) are determined by the experiments and the three-dimensional finite element (FE) analysis. The elastic-plastic properties of the press-fit pin are determined by the small scale three-point bending. The friction coefficient of the pin in the TH is successfully determined from the load-displacement relationship of the pin during press-fit assembly. The validity of the determined parameters is to be clarified by conducting the press-fit assemblies into the holes with different diameters. By comparing the damaged area of the printed circuit boards after assembly and the stress distributions obtained numerically, the failure stress of the board is determined. Finally, both the retention force of the pin and the damage of the printed circuit board after assembly become possible to be predicted by the numerical analysis.