Predicting bond failure after 1.5 ms of bonding, an initial study

Abstract

We employ a real-time nondestructive contact resistance method to rapidly predict the end state of ultrasonic wire bonds. We classified 64 bonds as either successful (bond attached) or failed (bond unattached) with a support vector machine method. This method predicts with 92% accuracy, 92% sensitivity, and 92% specificity as early as 1.5ms into the ultrasonic processing whether the final bond will be attached. The importance of detecting a tentative failure (on the single bond level) at an early stage is that corrective action can be taken to maximize the yield.