Determination of PLCC socket contact normal force and reliability

The authors present a method of analyzing and measuring sockets for plastic leaded chip carrier (PLCC) devices in order to predict the contact failure potential. Data are presented to show the magnitude of the failure risk for typical sockets and devices. From this analysis it is shown that the statistical nature of the PLCC socket contact position and PLCC device geometry tolerances dominate the failure predictions. The data show that the potential reliability range for commercial PLCC sockets is wide and that the predicted failure rates can be unacceptable for common telecommunications applications if not extra controls are implemented. The techniques presented have been used to select acceptable PLCC socket designs to ensure high levels of product reliability