Compliant pin interconnect challenging and reliability after RoHS exemption

The RoHS exemption for tin/lead coating on compliant pin connectors will be lifted after Jan 1, 2013. The compliant pin connector´s manufacture process in motherboard assembly becomes more and more challenging with the conversion to lead-free pin plating. Literature on the pin plating process focused mainly on matte tin finish, compliant pin connectors are not immune to the bent pin and hole wall broken defect even with relatively tin/lead plating process. In this study, a test vehicle will be designed with specific focus on different compliant pin plating characteristics, different PCB drill hole size (DHS), and different motherboards´ surface finish. Then the relevant design and materials characteristics correlate with the failure mode of compliant pin press process will be elaborated. Finally, potential solution which will be evaluated and characterized to eliminate the contact defect in compliant pin press process and interconnect reliability will be concluded.