Technique for predicting over insertions for partial grids and defective z-pins

Abstract

In accordance with the present invention, there is provided a technique which may be used in conjunction with an automated Z-pin insertion process to automatically monitor the insertion energy applied to the Z-pins during the initial insertion phase of the automated insertion process, and compare it to an empirically derived value for good insertions, thereafter allowing the insertion process to continue to a predetermined additional insertion depth before terminating the process. The insertion energy is calculated by cumulatively summing the insertion force and multiplying it by the insertion time, thus yielding the cumulative energy. At a specified, predetermined insertion depth, the energy accumulation is stopped and the value at the initial insertion depth is stored and compared to an empirically derived value. If the value is less than the empirical value, the insertion energy is too low, thus indicating that either a partial grid insertion is being encountered or defective Z-pins are being inserted. Insertion is allowed to continue until another empirically derived second insertion depth is reached whereat the insertion is terminated. The second depth is necessary for the continued insertion of partial grids to ensure that the Z-pins are fully inserted. The second depth is a function of the laminate thickness to ensure full depth insertions.